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He SY, He T, Xu MY, Ni YJ, Hong CY, Shen T. Distribution and correlation of refractive parameters in children with different corneal curvatures in southeast China. Int J Ophthalmol 2024; 17:713-720. [PMID: 38638257 PMCID: PMC10988070 DOI: 10.18240/ijo.2024.04.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 12/05/2023] [Indexed: 04/20/2024] Open
Abstract
AIM To analyze the distribution of refractive status in school-age children with different corneal curvatures (CC) and the correlation between CC and refractive status. METHODS A total of 2214 school-aged children of grade 4 in Hangzhou who were screened for school myopia were included. Uncorrected distance visual acuity (UCDVA), non-cycloplegic refraction, axial length (AL), horizontal and vertical corneal curvature (K1, K2) were measured and spherical equivalent (SE), corneal curvature radius (CCR) and axial length/corneal radius of curvature ratio (AL/CR) were calculated. UCDVA<5.0 and SE≤-0.50 D were classified as school-screening myopia. According to the different CCRs, the patients were divided into the lower corneal curvature (LCC) group (CCR≥7.92) and the higher corneal curvature (HCC) group (CCR<7.92). Each group was further divided into the normal AL subgroup and the long AL subgroup. The refractive parameters were compared to identify any differences between the two groups. RESULTS Both SE and AL were greater in the LCC group (P=0.013, P<0.001). The prevalence of myopia was 38% in the LCC group and 44% in the HCC group (P<0.001). The proportion of children without screening myopia was higher in the LCC group (62%) than in the HCC group (56%). Among these children without screening myopia, the proportion of long AL in the LCC group (24%) was significantly higher than that in the HCC group (0.012%; P<0.001). The change of SE in the LCC group was less affected by the increase of AL than that in the HCC group. CONCLUSION School-aged children in the LCC group have a lower incidence of screening myopia and longer AL. Low CC can mask SE reduction and AL growth to some extent, and the change of AL growth change more in children with low CC than high CC. Before the onset of myopia, its growth rate is even faster than that after the onset of myopia.
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Affiliation(s)
- Si-Yuan He
- The Second Clinical College, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang Province, China
| | - Ting He
- Department of Ophthalmology, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou 310014, Zhejiang Province, China
| | - Meng-Yue Xu
- Department of Ophthalmology, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou 310014, Zhejiang Province, China
| | - Ying-Jie Ni
- The Second Clinical College, Zhejiang Chinese Medical University, Hangzhou 310053, Zhejiang Province, China
| | - Chao-Yang Hong
- Department of Ophthalmology, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou 310014, Zhejiang Province, China
| | - Ting Shen
- Eye Center, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang Province, China
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Nakakura S, Oogi S, Terao E, Nagata Y, Fujisawa Y, Dote S, Ueda K. Changes in Ocular Biometry Following PreserFlo MicroShunt Implantation and Trabeculectomy: A Prospective Observational Study. Cureus 2024; 16:e56188. [PMID: 38487650 PMCID: PMC10940033 DOI: 10.7759/cureus.56188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2024] [Indexed: 03/17/2024] Open
Abstract
Background This study aimed to evaluate postoperative changes in ocular biometry following initial PreserFlo MicroShunt implantation and trabeculectomy. Methodology This prospective, observational study analyzed 27 cases of PreserFlo MicroShunt implantation and 29 cases of trabeculectomy performed by a single surgeon. Visual acuity, intraocular pressure, corneal curvature, central corneal thickness, anterior chamber depth, and axial length were assessed at baseline and postoperatively at one day, one week, two weeks, one month, two months, three months, and six months. Patients requiring additional surgery and those with missing data were excluded. Consecutive data were compared with the baseline values using multiple comparisons. Results In both groups, intraocular pressure was significantly decreased from baseline at all postoperative time points (all p < 0.01). Visual acuity decreased in both groups at one day and one week postoperatively. Corneal curvature remained unchanged in both groups throughout the six-month follow-up. Central corneal thickness increased at one day and one week postoperatively in the PreserFlo group, but not in the trabeculectomy group. Anterior chamber depth exhibited a significant decrease at one week postoperatively in both groups. Axial length significantly decreased postoperatively until three months in the PreserFlo group and at all postoperative time points in the trabeculectomy group. Conclusions Ocular biometry following PreserFlo and trabeculectomy had a similar tendency postoperatively.
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Affiliation(s)
| | - Satomi Oogi
- Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, JPN
| | - Etsuko Terao
- Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, JPN
| | - Yuki Nagata
- Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, JPN
| | | | - Saki Dote
- Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, JPN
| | - Kanae Ueda
- Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, JPN
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Na KS, Savini G, Whang WJ, Næser K. Comparison of Automated Keratometer and Scheimpflug Tomography for Predicting Refractive Astigmatism in Pseudophakic Eyes. Diagnostics (Basel) 2023; 13:3687. [PMID: 38132271 PMCID: PMC10743115 DOI: 10.3390/diagnostics13243687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 11/17/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
PURPOSE To analyse the correspondence between refractive astigmatism and corneal astigmatism in pseudophakic eyes with non-toric intraocular lenses. SETTING Yeouido St. Mary hospital, Seoul, Republic of Korea. DESIGN Evaluation of a diagnostic test instrument. METHODS This retrospective study included 95 eyes of 95 patients. Corneal astigmatism was measured with an automated keratometer (RK-5, Canon) and Scheimpflug tomography (Pentacam HR, Oculus). Refractive astigmatism was compared to keratometric astigmatism (based on anterior corneal measurements only), equivalent K-reading, and total corneal astigmatism (both based on anterior and posterior corneal measurements). Vector analysis was carried out by Næser's polar value method. The accuracy was defined as the average magnitude of the vectorial difference in astigmatism (DA). Each corneal measurement was optimized in retrospect by a multiple linear regression equation between refractive and corneal astigmatism. RESULTS Keratometric astigmatism overestimated with-the-rule (WTR) refractive astigmatism and underestimated against-the-rule (ATR) refractive astigmatism. Several measurements based on both corneal surfaces' values did not show any statistically significant difference with respect to refractive astigmatism. The mean corneal astigmatism by total corneal refractive power (TCRP) at 4.0 mm (zone/pupil) produced the lowest mean arithmetic DA and the highest percentage of eyes with a DA ≤ 0.50 dioptre. After optimization, the accuracies of automated KA and TCRP 4.0 mm (zone/pupil) were similar. CONCLUSIONS Total corneal astigmatism measured by Scheimpflug tomography at a 4.0 mm zone centered on the pupil accurately reflects the refractive astigmatism in pseudophakic eyes. However, the accuracy of total corneal astigmatism is not different from automated KA after optimization.
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Affiliation(s)
- Kyung-Sun Na
- Department of Ophthalmology, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul 16247, Republic of Korea;
| | | | - Woong-Joo Whang
- Department of Ophthalmology, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul 16247, Republic of Korea;
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Serramito M, Privado-Aroco A, Carracedo G. Anterior, Posterior, and Thickness Cornea Differences after Scleral Lens Wear in Post-LASIK Subjects for One Year. Healthcare (Basel) 2023; 11:2922. [PMID: 37998414 PMCID: PMC10671115 DOI: 10.3390/healthcare11222922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/25/2023] Open
Abstract
The aim of this study is to analyze the anterior and posterior corneal surface shape and the corneal thickness difference outcomes between before and after scleral lens (ScCL) wear in post-LASIK ectasia subjects for one year. Twenty eyes with post-LASIK ectasia wearing scleral lenses were evaluated in a visit before contact lens and after 1, 6, and 12 months. The study variables analyzed included the apex, nasal, temporal, inferior, and superior corneal thickness; the anterior and posterior surface corneal at corneal diameters of 8, 6, 4, and 2 mm, and high-contrast visual acuity. A statistically significant increment of corneal thickness (p < 0.05) was observed in the inferior area after 6 months and in the superior area in the 12-month follow-up after wearing ScCLs. The anterior corneal curvature presented a flattening and a statistically significant steepening (p < 0.05) in the central and peripheral radii, respectively, after one year. The posterior corneal curvature showed a significant (p < 0.05) steepening, which mainly affected the central region after one year. Despite these changes, high-contrast visual acuity with ScCL correction remained at the same values. The prolonged use of scleral lenses in post-LASIK subjects showed significant changes in the corneal curvature and thickness. These outcomes recommend more detailed and periodic topographic and vision quality checks to monitor the wear in ScCL patients.
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Affiliation(s)
- Maria Serramito
- Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain; (A.P.-A.); (G.C.)
- Ocupharm Research Group, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain
| | - Ana Privado-Aroco
- Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain; (A.P.-A.); (G.C.)
- Ocupharm Research Group, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain
| | - Gonzalo Carracedo
- Department of Optometry and Vision, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain; (A.P.-A.); (G.C.)
- Ocupharm Research Group, Faculty of Optics and Optometry, Complutense University of Madrid, 28037 Madrid, Spain
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Chu Z, Ren Q, Su W, Cui W, Wu J. Effect of central corneal curvature on corneal material stiffness parameter acquired by dynamic corneal responses. Front Bioeng Biotechnol 2023; 11:1237834. [PMID: 37920247 PMCID: PMC10619688 DOI: 10.3389/fbioe.2023.1237834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 10/09/2023] [Indexed: 11/04/2023] Open
Abstract
The stress-strain index (SSI) is a measure of corneal material stiffness, which is obtained using the Corvis ST algorithm based on dynamic corneal response parameters. The reduced SSI corresponds to the longer axial length (AL). In a previous study, we found SSI increases as the corneal curvature flattens, whereas a flatter corneal curvature indicates a longer AL (emmetropia or myopia). Therefore, in this cross-sectional study, we aimed to address these contradictory findings. First, we characterized the features of SSI, curvature radius of the anterior corneal surface (CR), and AL and analyzed their correlation with advanced myopia. Next, we compared the relationship between AL and SSI after adjusting for the effect of CR. We found a significant positive correlation between SSI and CR, which contradicts the developmental law of axial myopia. Furthermore, after accounting for the effect of CR, we observed a stronger correlation between SSI and AL than that in the unadjusted model. In conclusion, CR is an independent influencing factor for SSI in addition to AL, which masked the decrease in SSI caused by prolonged AL in axial myopia.
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Affiliation(s)
- Zhe Chu
- Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao, China
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
| | - Qi Ren
- Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao, China
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
| | - Wenjie Su
- Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao, China
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
| | - Wei Cui
- Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao, China
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
| | - Jie Wu
- Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao, China
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
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Hu Y, Fan Z, Zhao X, Correa VSMC, Wu Z, Lu X, Zeng X, Chen L, Yu Z, Zheng L, He J, Zhang G. Refractive Status and Biometric Characteristics of Children With Familial Exudative Vitreoretinopathy. Invest Ophthalmol Vis Sci 2023; 64:27. [PMID: 37850946 PMCID: PMC10593135 DOI: 10.1167/iovs.64.13.27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 09/06/2023] [Indexed: 10/19/2023] Open
Abstract
Purpose To compare biometric characteristics between patients with early-stage familial exudative vitreoretinopathy (FEVR) and healthy controls. Methods This case-control study included 50 FEVR eyes in stage 1-2 and 50 control eyes matched by age, gender and spherical equivalent (SE). Biometric parameters including axial length (AL), white-to-white diameter (WTW), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), pupil diameter, vitreous chamber depth, anterior and posterior corneal surface curvature radius (ACR and PCR), anterior lens surface curvature radius (ALR) and posterior lens surface curvature radius were measured using IOLMaster 700 and compared between cases and controls using paired t-test. Correlations between SE and biometric measures were assessed using Pearson correlation coefficient (r) in cases and controls. Results Both FEVR cases and matched controls had a mean age of 7.6 years, 48% female and mean SE of -5.3 D (80% myopia). Compared to controls, FEVR eyes had smaller AL (P = 0.009), WTW (P = 0.001), ACD (P < 0.001), and ALR (P = 0.03), but larger CCT (P = 0.02) and LT (P = 0.01). In FEVR eyes, SE was negatively correlated with AL (r = -0.79, P < 0.001), positively correlated with ACR (r = 0.29, P = 0.04) and PCR (r = 0.33, P = 0.02), whereas in controls, SE was negatively correlated with AL (r = -0.82, P < 0.001) and LT (r = -0.34, P = 0.02), positively correlated with ALR (r = 0.29, P = 0.04). Conclusions Patients at early stage of FEVR exhibited a unique eye morphology resembling ocular development arrest, which may help to develop screening and early detection tools for FEVR. In FEVR patients, myopia is very prevalent and significantly associated with corneal curvature increase.
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Affiliation(s)
- Yarou Hu
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Zixin Fan
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Xinyu Zhao
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Victor S. M. C. Correa
- Retina Service, Ines and Fred Yeatts Retina Research Laboratory, Angiogenesis Laboratory, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, United States
| | - Zhenquan Wu
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Xiaofeng Lu
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Xianlu Zeng
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Laijiao Chen
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Zhen Yu
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Lei Zheng
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
| | - Jicang He
- New England College of Optometry, Boston, Massachusetts, United States
| | - Guoming Zhang
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, China
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Liu W, Liu W, Wang C. Ocular biometric parameters of mild hyperopia to mild myopia children aged 6-14 years from Wenzhou optometry center: A cross-sectional study. Front Med (Lausanne) 2022; 9:992587. [PMID: 36275830 PMCID: PMC9583929 DOI: 10.3389/fmed.2022.992587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/06/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction Myopia is the most common visual disorder in school-aged children and adolescents worldwide. This study aimed to explore the ocular biometric characteristics of children aged 6–14 years from the Wenzhou optometry center and to determine the relationship between spherical equivalent refraction (SER) and macular pigment optical density (MPOD). Subjects and methods Participants underwent a full-scale ophthalmic examination anteriorly and posteriorly. Relevant parameters were documented, such as axial length (AL), anterior chamber depth (ACD), SER and lens thickness (LT), corneal curvature radius (CCR), and MPOD. Lens power (LP) was calculated using Bennett’s formula. Shapiro–Wilk tests and histograms were used to check the normality of the distribution of refractive and ocular biometric parameters. Scatter diagrams were adopted to analyze the relationships between refraction and parameters of ocular biometry. Multiple linear regression models were employed to fit the associated factors of AL, AL/CCR, and LP. Results A total of 902 mild hyperopia to mild myopia (+3.00 D ≤ SE ≤ −3.00 D) children aged 6–14 years were included. The mean age of participants was 10.03 ± 2.47 years, and the prevalence of mild hyperopia, emmetropia, and myopia was 5.65, 27.05, and 67.30%, respectively. The prevalence of mild myopia increased from 30.53% at 6 years of age to 93.62% at 14 years of age. Overall, AL, ACD, and AL/CCR increased, but LP declined from 6 to 14 years of age, whereas CCR and MPOD remained stable. An increase of 1 mm in AL was associated with −0.69 D of myopic change. A unit increase in AL/CCR was associated with −7.87 D in SER. As for the SER variance, AL explained 30.5% and AL/CCR explained 51.1%, whereas AL/CCR and LP accounted for 59.2%. Discussion In this work, we have studied the distributions of ocular biometric characteristics of mild hyperopia to mild myopia children from the perspective of an optometry center rather than a sampling survey. In addition, we found that children from the optometry center had a slower progression toward myopia than those from previous sampling surveys, which was an informative finding for future myopia prevention. In addition, we have made a correlation analysis between the macular pigment optical density and spherical equivalent refraction. Though, no correlation was found.
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Affiliation(s)
- Weiqin Liu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Weishai Liu
- Department of Ophthalmology, Ankang Hospital of Traditional Chinese Medicine, Ankang, China
| | - Chenxiao Wang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China,*Correspondence: Chenxiao Wang,
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Muacevic A, Adler JR. A Study Linking Axial Length, Corneal Curvature, and Eye Axis With Demographic Characteristics in the Emmetropic Eyes of Bangladeshi People. Cureus 2022; 14:e29925. [PMID: 36225244 PMCID: PMC9536359 DOI: 10.7759/cureus.29925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2022] [Indexed: 11/05/2022] Open
Abstract
Background Axial length (AL) and corneal curvature (CC) are one of the furthest critical parameters for optometry and oculoplastic surgery. These two variables are crucial in biometry for accurately measuring the power of the intraocular lens in cataract surgery. This research aimed to determine the association linking axial length and corneal curvature with demographic characteristics in emmetropic eyes of Bangladeshi people. Methods This descriptive cross-sectional research was carried out among 200 emmetropic eyes of Bangladeshi people attending the Department of Ophthalmology at Rajshahi Medical College, Bangladesh, with different eye conditions, between July 2017 and June 2018. Data was gathered by conducting person-to-person interviews, checking visual activity using the Snellen chart, and measuring corneal curvature using an auto-keratometer and axial eyeball length using A-scan ultrasonography. Results A total of 200 attendances were studied, 90 males and 110 females. All were emmetropic. The age range was 21-52 years, and the highest contributors were in the 21-30-year age group. The association between right axial length and right corneal curvature shows a negative relation among both sexes. It was -0.61 (β-coefficient (β-coff)), and highly significant in females at -0.89 (β-coff). Additionally, the association between left axial length and left corneal curvature shows a negative relation of -0.65 (β-coff), which was again highly significant in females at -0.87 (β-coff). Both were not significant in males. There was no significant association linking axial length and eye axis in both sexes. The multivariate regression model was used to assess the p-value, and the regression model was adjusted by age. Conclusion Optical parametric measurement is a noninvasive diagnostic and assessment tool that might help in the actual measurement of intraocular lens implantation in cataract surgery and may also provide supplementary information to the researcher domain.
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Muacevic A, Adler JR. Central Corneal Thickness of a Saudi Population in Relation to Age, Gender, Refractive Errors, and Corneal Curvature. Cureus 2022; 14:e30441. [PMID: 36407166 PMCID: PMC9671483 DOI: 10.7759/cureus.30441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2022] [Indexed: 11/27/2022] Open
Abstract
Background In this study, we aimed to investigate the relationship between central corneal thickness (CCT) and age, gender, refractive errors, and corneal curvature in a Saudi population. Methodology In this randomized, hospital-based, retrospective study, data were collected from Dr. Sulaiman Al Habib Hospital and Imam Medical Center, Riyadh. A total of 1,005 eyes were included and recruited from patients referred to the refractive surgery clinic for Lasik assessment. The study included patients aged between 17 and 57 years with no history of any ocular pathology, eye surgeries, and systemic disease, as well as all groups with stable refractions. The identifying data were the age and gender of the patients, as well as their CCT, refraction, and corneal curvature. CCT and corneal curvature were measured by ultrasound pachymeter Pentacam. Results The distribution of CCT was 543.81 ± 34.47 μm. A significant difference in the mean CCT was observed across different refractive errors (p = 0.004). Patients with astigmatism had the lowest CCT, followed by myopic and hyperopic patients. An association between the spherical equivalent of patients with myopia and CCT (p = 0.001) was noted. Conclusions In the Saudi population, we found no significant association between mean corneal curvature and CCT in all three groups. Spherical equivalent in myopic patients was significantly associated with CCT. A significant difference in the mean CCT was observed across different refractive errors. There was a significant negative and weak correlation between age in myopic and astigmatism patients and CCT. Gender was significantly associated with CCT in patients with astigmatism.
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Canestraro J, Hultcrantz M, Modi S, Hamlin PA, Shoushtari AN, Konner JA, Tew WP, Iyengar NM, Heinemann M, Abramson DH, Francis JH. Refractive Shifts and Changes in Corneal Curvature Associated With Antibody-Drug Conjugates. Cornea 2022; 41:792-801. [PMID: 34839332 PMCID: PMC9106803 DOI: 10.1097/ico.0000000000002934] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/28/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE Antibody-drug conjugates (ADCs) are a class of cancer drug wherein some are associated with corneal abnormalities, but there is a dearth of published information on refractive shifts in patients receiving ADCs. Here, we evaluated the dynamics of refractive error and keratometry readings in patients with ADC-related keratopathy and microcyst-like epithelial changes (MECs). METHODS This study is a retrospective case series including 58 eyes of 29 patients with ADC-related keratopathy from a single tertiary care cancer referral center (MSKCC). One eye (29 total) was randomly assigned for statistical analysis. In addition, a subset analysis of MEC location-refractive error correlation was performed on 20 eyes. Clinical records including slitlamp examination, indirect ophthalmoscopy, calculated spherical equivalence (SE), keratometry, and visual acuity were recorded at baseline, during, and off treatment. RESULTS A subset analysis of MEC location-refractive error correlation of 20 eyes revealed the following: Peripheral MECs were significantly associated with hyperopic shifts (P value < 0.001) and paracentral/central associated with myopic shifts (P value < 0.001). In the full cohort and on drug, the greatest change in SE from baseline was myopic (68%, as high as -4.75 D) and hyperopic (32%, as much as +3.75 D). Eighty-nine percent had a change in vision from baseline while on drug, but at the 3-month follow-up off drug, SE and vision returned to baseline in 33% and 82% of eyes. CONCLUSIONS Peripheral MECs were significantly associated with hyperopic shifts, and paracentral/central MECs were associated with myopic shifts. While on drug, most eyes had a myopic refractive shift, which corresponded with corneal steepening.
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Affiliation(s)
- Julia Canestraro
- Ophthalmic Oncology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Malin Hultcrantz
- Myeloma Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Shanu Modi
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Paul A Hamlin
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | | | - Jason A Konner
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - William P Tew
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Neil M Iyengar
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Murk Heinemann
- Ophthalmic Oncology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Weill Cornell Medical Center, New York, NY, USA
| | - David H Abramson
- Ophthalmic Oncology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Weill Cornell Medical Center, New York, NY, USA
| | - Jasmine H Francis
- Ophthalmic Oncology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA
- Weill Cornell Medical Center, New York, NY, USA
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Yuan XL, Zhang R, Zheng Y, Sun L, Wang G, Chen S, Xu Y, Chen SL, Qiu K, Ng TK. Corneal curvature-associated MTOR variant differentiates mild myopia from high myopia in Han Chinese population. Ophthalmic Genet 2021; 42:446-457. [PMID: 33979260 DOI: 10.1080/13816810.2021.1923035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/27/2021] [Accepted: 04/18/2021] [Indexed: 02/05/2023]
Abstract
BACKGROUND Myopia is the most prevalent ocular disorder in the world, and corneal parameters have been regarded as key ocular biometric parameters determining the refractive status. Here, we aimed to determine the association of genome-wide association study-identified corneal curvature (CC)-related gene variants with different severity of myopia and ocular biometric parameters in Chinese population. METHODS Total 2,101 unrelated Han Chinese subjects were recruited, including 1,649 myopia and 452 control subjects. Five previously reported CC-associated gene variants (PDGFRA, MTOR, WNT7B, CMPK1 and RBP3) were genotyped by TaqMan assay, and their association with different myopia severity and ocular biometric parameters were evaluated. RESULTS Joint additive effect analysis showed that MTOR rs74225573 paired with PDGFRA rs2114039 (P = .009, odds ratio (OR) = 4.91) or CMPK1 rs17103186 (P = .002, OR = 13.03) were significantly associated with higher risk in mild myopia. Critically, mild myopia subjects had significantly higher frequency in MTOR rs74225573 C allele than high myopia subjects (P = .003), especially in male subjects (P = .001, OR = 0.49). High myopia subjects carrying MTOR rs74225573 C allele have significant flatter CC (P = .035) and longer corneal radius (P = .044) than those carrying TT genotype. CONCLUSION This study revealed that male high myopia subjects are more prone to carry CC-related MTOR rs74225573 T allele, whereas mild myopia subjects are prone to carry the C allele. MTOR rs7422573 variant could be a genetic marker to differentiate mild from high myopia in risk assessment. ABBREVIATIONS ACD: anterior chamber depth; AL: axial length; AL/CR: axial length/corneal radius ratio; ANOVA: analysis of variance; CC: corneal curvature; CCT: central corneal thickness; C.I.: confidence interval; CMPK1: cytidine/uridine monophosphate kinase 1; CR: corneal radius; D: diopter; GWAS: genome-wide association studies; HWE: Hardy-Weinberg equilibrium; LT: lens thickness; MIPEP: mitochondrial intermediate peptidase; MTOR: mechanistic target of rapamycin kinase; OR: odds ratio; PDGFRA: platelet-derived growth factor receptor-α; RBP3: retinol-binding protein 3; SD: standard deviation; SE: spherical equivalence; SNTB1: syntrophin beta 1; VCD: vitreous chamber depth; VIPR2: vasoactive intestinal peptide receptor 2; WNT7B: wingless/integrated family member 7B.
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Affiliation(s)
- Xiang-Ling Yuan
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
- Shantou University Medical College, Shantou, Guangdong, China
| | - Riping Zhang
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Yuqian Zheng
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Lixia Sun
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Geng Wang
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Shaowan Chen
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Yanxuan Xu
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Shao-Lang Chen
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Kunliang Qiu
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Tsz Kin Ng
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
- Shantou University Medical College, Shantou, Guangdong, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
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Priji P, Jacob SC, Kalikivayi L, Kalikivayi V. Correlating Kane formula with existing intraocular lens formulae for corneal curvatures and axial lengths. Oman J Ophthalmol 2021; 14:94-99. [PMID: 34345143 PMCID: PMC8300291 DOI: 10.4103/ojo.ojo_62_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 05/19/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND: To evaluate the predictability of the Kane formula in estimating postoperative refractive outcome with various corneal curvatures and axial lengths (ALs) besides comparing with existing intraocular lens (IOL) formulae. MATERIALS AND METHODS: A prospective cross-sectional study was carried out among patients having uneventful cataract surgery at an eye hospital. A total of 50 eyes were considered for the study. The corresponding A-constant for the model of IOL implanted into the patient's eye was taken along with the actual power of IOL implanted and corresponding predicted power for the IOL power inserted were taken for all the chosen formulae and was termed as "Adjusted Predicted Refractive Power." This was compared with the actual refractive outcome and the absolute error (AE) was measured. The eyes were separated into groups in terms of corneal curvature as flat (<42D), medium (42D–46D), and steep (>46D) corneas. In terms of AL, it was grouped as short (≤22 mm), medium (>22.0–<24.0 mm), and long (>24.0 mm) eyes. RESULTS: The study included 50 eyes and the mean AE for all the selected formulae were calculated for each group. Over the entire corneal curvature range, none of the formulae showed any significance when compared with the Kane formula (P > 0.05). In short AL, SRK-T formula had a statistical significance over the Kane formula (P = 0.043), whereas no other group had any significance over the Kane formula in AL groups. CONCLUSION: The study shows, all formulae (SRK-T, Holladay1, Hoffer Q, Hill RBF, Barrett Universal II, Kane) are interchangeable to predict the IOL power for any of the corneal curvature and ALs.
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Affiliation(s)
- P Priji
- Ahalia School of Optometry, Palakkad, Kerala, India
| | - Sajeev Cherian Jacob
- Ahalia School of Optometry, Palakkad, Kerala, India.,Ahalia Foundation Eye Hospital, Palakkad, Kerala, India
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Kawasaki M, Furujo T, Azuma K, Okamoto Y, Ito N. Keratometry in normal cats: a cross-sectional study in Japan using an automated handheld keratometer. J Vet Med Sci 2021; 83:1256-1262. [PMID: 34162774 PMCID: PMC8437713 DOI: 10.1292/jvms.21-0104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Keratometry was performed in 73 domestic cats of varied signalment in Japan using an automated handheld keratometer. The mean corneal curvature radius was significantly lower for cats younger than 1 year than for those older than 2 years (8.04 mm vs. 8.80-8.99 mm, P<0.01). The radius was significantly greater in males than in females among the cats older than 11 years (9.22 mm vs. 8.84 mm, P=0.01), while the age distributions of the males and females were similar. Corneal astigmatism did not significantly differ across the gender and age groups. The predictability of the corneal curvature and astigmatism was approximately 41-43% and less than 3%, respectively, as a function of age and bodyweight. The results highlighted some age- and sex-related keratometric variations in domestic cats in Japan.
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Affiliation(s)
- Minae Kawasaki
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8511, Japan.,Tottori University Veterinary Medical Center, 4-101 Koyama-cho Minami, Tottori 680-8553, Japan
| | - Tomoya Furujo
- Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, 4-101 Koyama-cho Minami, Tottori 680-8553, Japan
| | - Kazuo Azuma
- Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, 4-101 Koyama-cho Minami, Tottori 680-8553, Japan
| | - Yoshiharu Okamoto
- Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, 4-101 Koyama-cho Minami, Tottori 680-8553, Japan
| | - Norihiko Ito
- Tottori University Veterinary Medical Center, 4-101 Koyama-cho Minami, Tottori 680-8553, Japan.,Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, 4-101 Koyama-cho Minami, Tottori 680-8553, Japan
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14
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Zhang YL, Xu XH, Cao LJ, Liu L. Corneal curvature, asphericity, and aberrations after transepithelial photorefractive keratectomy and femtosecond laser-assisted in situ keratomileusis for myopia: A prospective comparative study. Indian J Ophthalmol 2021; 68:2945-2949. [PMID: 33229675 PMCID: PMC7856998 DOI: 10.4103/ijo.ijo_1106_20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Purpose: We aimed to compare transepithelial photorefractive keratectomy (TPRK) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for myopia treatment by analyzing corneal curvature, asphericity (Q-value), and corneal aberration. Methods: Corneal topography was measured before and 6 months after the TPRK or FS-LASIK surgery. We measured and compared corneal curvature (sagittal curvature in the 1- to 7-mm zones), change in keratometric measurements (Kmpost – Kmpre, ΔK), Q-values (from the vertex of the 6-, 7-, 8-, and 9-mm zones), higher-order aberration (HOA), vertical and horizontal trefoil (Z3-3 and Z33), vertical and horizontal coma (Z3-1 and Z31), and spherical aberration (Z40) between the two surgery groups. Results: The sagittal curvature Δ K in the 1-mm zone after TPRK was significantly higher than after FS-LASIK. The Δ K/ΔSE (ΔSE [spherical equivalent] = SEpre – SEpost) ratio in the 1- to 4-mm diameter zones was significantly higher after TPRK than after FS-LASIK. The preoperative Q-values of the 6- and 7-mm zones did not differ between the treatment groups, but postoperative values were significantly higher following FS-LASIK than following TPRK. HOA, Z40, and Z3-1 were all significantly higher after surgery in both groups. Postoperative Z3-3 was significantly higher following TPRK but not following FS-LASIK. There were no postoperative differences in aberrations in either group; however, the change in HOA and Z3-1 was significantly greater following FS-LASIK. Conclusion: TPRK changes the corneal curvature to a greater extent and the visual quality (Q-value, aberrations) to a lesser extent than FS-LASIK.
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Affiliation(s)
- Ya-Li Zhang
- Department of Ophthalmology, The Second People's Hospital of Jinan, Jinan, China
| | - Xiang-Hui Xu
- Department of Ophthalmology, The Second People's Hospital of Jinan, Jinan, China
| | - Li-Jun Cao
- Department of Ophthalmology, The Second People's Hospital of Jinan, Jinan, China
| | - Lei Liu
- Department of Ophthalmology, The Second People's Hospital of Jinan, Jinan, China
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Priji P, Jacob SC, Kalikivayi L, Kalikivayi V. Correlating Kane formula with existing intraocular lens formulae for corneal curvatures and axial lengths. Oman J Ophthalmol 2021. [PMID: 34345143 DOI: 10.4103/eye.eye_62_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023] Open
Abstract
BACKGROUND To evaluate the predictability of the Kane formula in estimating postoperative refractive outcome with various corneal curvatures and axial lengths (ALs) besides comparing with existing intraocular lens (IOL) formulae. MATERIALS AND METHODS A prospective cross-sectional study was carried out among patients having uneventful cataract surgery at an eye hospital. A total of 50 eyes were considered for the study. The corresponding A-constant for the model of IOL implanted into the patient's eye was taken along with the actual power of IOL implanted and corresponding predicted power for the IOL power inserted were taken for all the chosen formulae and was termed as "Adjusted Predicted Refractive Power." This was compared with the actual refractive outcome and the absolute error (AE) was measured. The eyes were separated into groups in terms of corneal curvature as flat (<42D), medium (42D-46D), and steep (>46D) corneas. In terms of AL, it was grouped as short (≤22 mm), medium (>22.0-<24.0 mm), and long (>24.0 mm) eyes. RESULTS The study included 50 eyes and the mean AE for all the selected formulae were calculated for each group. Over the entire corneal curvature range, none of the formulae showed any significance when compared with the Kane formula (P > 0.05). In short AL, SRK-T formula had a statistical significance over the Kane formula (P = 0.043), whereas no other group had any significance over the Kane formula in AL groups. CONCLUSION The study shows, all formulae (SRK-T, Holladay1, Hoffer Q, Hill RBF, Barrett Universal II, Kane) are interchangeable to predict the IOL power for any of the corneal curvature and ALs.
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Affiliation(s)
- P Priji
- Ahalia School of Optometry, Palakkad, Kerala, India
| | - Sajeev Cherian Jacob
- Ahalia School of Optometry, Palakkad, Kerala, India
- Ahalia Foundation Eye Hospital, Palakkad, Kerala, India
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Niruthisard D, Tulvatana W, Satitpitakul V. Time to Keratometric Stability After Pterygium Excision and the Associated Factors: A Clinical Perspective. Clin Ophthalmol 2021; 15:1277-1283. [PMID: 33790535 PMCID: PMC8006966 DOI: 10.2147/opth.s303936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/11/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To determine the percentage of eyes with corneal astigmatic power stability and mean corneal keratometric power at 6-month post-pterygium excision, and to identify the time, and the associated factors, required to achieve stability. Methods This prospective observational study enrolled patients undergoing pterygium excision. Patients were evaluated for baseline characteristics and keratometric data before and every month after pterygium excision for six months using IOL Master 500® (Carl Zeiss, Meditec). Clinically stable corneal astigmatic power and keratometric power were, respectively, defined as changes in these parameters of less than 0.25 and 0.27 diopters after two consecutive visits. Time to corneal astigmatic and keratometric power stability, as well as factors associated with the stability, were analyzed. Results Forty percent and 73.3% of eyes, respectively, demonstrated corneal astigmatic and corneal keratometric stability at six months post-operation. Within three months of reaching initial stability, the corneal astigmatic power and the mean keratometric power showed instability in 46.7% and 27.3% of patients, respectively. No patients with keratometric stability for more than three months became unstable during the study period. The extension of pterygium exceeding 3.0 mm was associated with a delay in time to corneal astigmatic stability (HRadjusted 0.41; 95% CI 0.19-0.89; P= 0.02). Conclusion According to the clinical relevance, 40% and 73% of patients, respectively, presented corneal astigmatic and keratometric stability within six months post-operation. Patients with a pterygium extension of more than 3 mm required a longer time for corneal astigmatic stability. It is recommended that keratometric stability be achieved for at least three months before commencing with additional procedures.
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Affiliation(s)
- Duangratn Niruthisard
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Wasee Tulvatana
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Vannarut Satitpitakul
- Center of Excellence for Cornea and Stem Cell Transplantation, Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
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Ding Y, Zhang Z, Min X, Xia X, Hu S. Changes of angle Kappa and corneal morphology changes in myopic patients after Sub -Bowman -Keratomileusis. Zhong Nan Da Xue Xue Bao Yi Xue Ban 2021; 46:162-168. [PMID: 33678653 PMCID: PMC10929785 DOI: 10.11817/j.issn.1672-7347.2021.190472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To investigate angle Kappa and diopter distribution in myopic patients and the changes of angle Kappa and corneal morphology after Sub-Bowman-Keratomileusis (SBK), and to analyze the effects of the surgery on corneal morphologic changes and the patients' near fixation characteristics. METHODS The clinical data of 134 myopic patients (268 eyes) undergoing SBK from August 2015 to August 2016 were retrospectively analyzed. Angle Kappa, corneal curvature in the central corneal region of 3 mm, and post-corneal Diff value were measured by Orbscan IIz Corneal Topography System before operation, 1 month and 6 months after operation. According to the values of angle Kappa before SBK, the patients were divided into 2 groups: the large K group (angle Kappa≥5°, 71 eyes) and the small K group (angle Kappa<5°, 197 eyes). Correlation analysis of the factors influencing angle Kappa at 6 months after operation was performed. RESULTS In the large K group, angle Kappa was (5.67±0.65)°, spherical equivalent was (-4.84±2.32) D, and angle Kappa was decreased after operation (both P<0.05) with the increased decreasing range over time. In the small K group, angle Kappa was (3.51±1.08)°, spherical equivalent was (-5.78±2.63) D, angle Kappa was increased after operation with decreased increasing range over time, and the difference was statistically significant between 6 months after operation and before operation (P<0.05).The post-corneal Diff value of the 2 groups was increased after operation (all P<0.001), and was decreased from 1 month to 6 months after surgery. The corneal curvature in the central corneal region of 3 mm of the 2 groups 1 month after operation was decreased significantly (both P<0.001). From 1 month to 6 months after operation, the corneal curvature of the large K group tended to be stable, while the corneal curvature of the small K group tended to increase. There was no significant correlation between the changes of angle Kappa 6 months after operation and the changes of the corneal central curvature or the post-corneal Diff value (both P>0.05), but the changes of angle Kappa 6 months after operation was positively correlated with corneal cutting thickness (rlarge K group=0.398, rsmall K group=0.218, both P<0.05) and it was negatively correlated with preoperative diopter (rlarge K group=-0.283, rsmall K group=-0.233, both P<0.05). CONCLUSIONS The angle Kappa is decreased in low-moderate myopia patients with large angle Kappa, while is increased in high myopia patients with small angle Kappa after SBK. Myopia patients after SBK will look for the new balance of the binocular accommodation and vergence function for improving the comfort in the near-work situations.
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Affiliation(s)
- Yi Ding
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008.
| | - Zhipei Zhang
- Department of Ophthalmology, First People's Hospital of Changde City, Changde Hunan 415003, China
| | - Xiaoshan Min
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008.
| | - Xiaobo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008
| | - Shengfa Hu
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008
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Wang Z, Yang W, Li D, Chen W, Zhao Q, Li Y, Cui R, Shen L, Xian J. Evaluation and comparison of a novel Scheimpflug-based optical biometer with standard partial coherence interferometry for biometry and intraocular lens power calculation. Exp Ther Med 2021; 21:326. [PMID: 33732299 PMCID: PMC7903467 DOI: 10.3892/etm.2021.9757] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 01/08/2021] [Indexed: 11/29/2022] Open
Abstract
In the present study, the axial length (AL), corneal curvature, anterior chamber depth (ACD) and white-to-white (WTW) distance were assessed using the Pentacam AXL (Oculus Optikgeraete GmbH), a novel Scheimpflug-based optical biometer with standard partial coherence interferometry (PCI). The Pentacam AXL and PCI biometer (IOLMaster 500; Carl Zeiss AG) were compared in terms of their intraocular lens (IOL) power calculations. The medical records of patients (eyes, n=190) who underwent cataract surgery were retrospectively reviewed. Biometry measurements involved the eyes of patients with cataract and were performed by the same examiner with the Pentacam AXL biometer and the IOLMaster 500 device. Following determination of the AL, mean keratometry (Km), ACD and WTW distance, the IOL power calculation was compared between the two devices using the Sanders, Retzlaff and Kraff theoretical (SRK/T) and Haigis formulas. The AL, Km and WTW values for the Pentacam AXL group were significantly lower compared with those of the IOLMaster 500 group. The difference was -0.02±0.04 mm, -0.20±0.28 D and -0.10±0.20 mm, respectively (P<0.001). The ACD for the Pentacam AXL group was higher compared with that of the IOLMaster 500 group with a difference of 0.02±0.13 mm (P=0.13). The IOL power calculated using the SRK/T and Haigis formulas exhibited significant differences between the two devices (t=11.48 and 10.97, respectively; P<0.001). In conclusion, the AL, ACD, WTW measurement and IOL power indicated optimal agreement and strong correlations between the two devices. However, constant optimization may be necessary for the novel biometer Pentacam AXL.
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Affiliation(s)
- Ziyang Wang
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
| | - Wenli Yang
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
| | - Dongjun Li
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
| | - Wei Chen
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
| | - Qi Zhao
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
| | - Yifeng Li
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
| | - Rui Cui
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
| | - Lin Shen
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
| | - Junfang Xian
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, P.R. China
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Kumar M, Shetty R, Lalgudi VG, Vincent SJ. Scleral lens wear following penetrating keratoplasty: changes in corneal curvature and optics. Ophthalmic Physiol Opt 2020; 40:502-509. [PMID: 32436631 DOI: 10.1111/opo.12693] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 04/22/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE Visual rehabilitation following penetrating keratoplasty is the primary indication for approximately 15% of all scleral lens fittings. Since corneal biomechanics are altered following penetrating keratoplasty, the aim of this study was to quantify changes in anterior corneal optics following short-term scleral lens wear in eyes with corneal grafts. METHODS Scheimpflug images were obtained before and after a period of scleral lens wear (mean 6.3 ± 1.4 h), from eyes that had previously undergone penetrating keratoplasty (10 eyes of nine participants, mean age 31 ± 9 years). Corneal power and thickness data were examined over the central 6 mm, including regional analyses of the central (0-3 mm) and the mid-peripheral cornea (3-6 mm annulus) using customised software to deterime corneal power vectors M (best fit sphere), J0 (90/180 astigmatism) and J45 (45/135 astigmatism). Anterior corneal aberrations were extracted using corneal elevation data. RESULTS Corneal power vector J45 increased following lens wear (by 0.22 ± 0.05 D, p = 0.003) across the central 6 mm, while M displayed regional variations following lens wear indicating larger changes further from the corneal centre (p = 0.004). The change in corneal power vector M was also correlated with the magnitude of central corneal swelling (r = 0.65, p = 0.04). The anterior corneal aberration terms of oblique astigmatism, hoirzontal coma, and spherical aberration also varied following lens wear (all p ≤ 0.01). The mean change in the corneal spherocylinder derived from the elevation data following lens wear was +0.14/-0.54 × 44 for a 6 mm corneal diameter. CONCLUSIONS Clinically significant alterations in anterior corneal topography and higher order aberrations were observed following short-term scleral lens wear in eyes that had undergone penetrating keratoplasty. Spherocylindrical changes were approximately double the magnitude and more oblique in orientation compared to previous reports of healthy eyes. Changes in corneal power vector M may be related to epithelial corneal oedema.
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Affiliation(s)
- Mukesh Kumar
- Narayana Nethralaya, Bangalore, Karnataka, India
| | - Rohit Shetty
- Narayana Nethralaya, Bangalore, Karnataka, India
| | | | - Stephen J Vincent
- Contact Lens and Visual Optics Laboratory, School of Optometry & Vision Science, Queensland University of Technology, Brisbane, Australia
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Lin Y, Ding Y, Jiang D, Li C, Huang X, Liu L, Xiao H, Vasudevan B, Chen Y. Genome-Wide Association of Genetic Variants With Refraction, Axial Length, and Corneal Curvature: A Longitudinal Study of Chinese Schoolchildren. Front Genet 2020; 11:276. [PMID: 32269590 PMCID: PMC7109285 DOI: 10.3389/fgene.2020.00276] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/09/2020] [Indexed: 01/22/2023] Open
Abstract
Background Myopia is a common eye disorder that is approaching epidemic proportions worldwide. A genome-wide association study identified AREG (rs12511037), GABRR1 (rs13215566), and PDE10A (rs12206610) as being associated with refractive error in Asian populations. The present study investigated the associations between these three genetic variants and the occurrence and development of myopia, spherical equivalent refraction (SER), axial length (AL), and corneal curvature (CC) in a cohort of southeastern Chinese schoolchildren. Methods We examined and followed 550 children in grade 1 enrolled in the Wenzhou Epidemiology of Refractive Error (WERE) project. During the 4-year follow-up, non-cycloplegic refraction was evaluated twice each year, and the AL and CC were measured once every year. Age, sex, and the amounts of time spent on near work and outdoors were documented with a questionnaire. Sanger DNA sequencing was used to genotype single nucleotide polymorphisms (SNPs). SNPtest software was used to identify potential genetic variants associated with myopia, SER, AL, and CC. Ten thousand permutations were used to correct for multiple testing. Results In total, 469 children, including 249 (53.1%) boys and 220 (46.9%) girls, were included in analyses. The mean age of all the children was 6.33 ± 0.48 years. After adjusting for age, sex, time spent on near work and time spent outdoors, neither the genotypes nor the allele frequencies of the three SNPs were significantly associated with myopic shift, incident myopia or the change in SER. After adjusting for age, sex, near-work time and outdoor time with 10,000 permutations, the genotype AREG (rs12511037) was associated with an increase in AL (P′-values for the dominant, recessive, additive and general models were 0.0032, 0.0275, 0.0045, and 0.0099, respectively); the genotype PDE10A (rs12206610) was associated with a change in CC in the additive (P′ = 0.0096), dominant (P′ = 0.0096), and heterozygous models (P′ = 0.0096). Conclusion These findings preliminarily indicate that AREG SNP rs12511037 and PDE10A SNP rs12206610 are etiologically relevant for ocular traits, providing a basis for further exploration of the development of myopia and its molecular mechanism. However, elucidating the role of AREG and PDE10A in the pathogenesis of myopia requires further animal model and human genetic epidemiology studies. This trial is registered as ChiCTR1900020584 at www.Chictr.org.cn.
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Affiliation(s)
- Yaoyao Lin
- School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Yu Ding
- The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Dandan Jiang
- The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Chunchun Li
- The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xiaoqiong Huang
- The Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Linjie Liu
- School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Haishao Xiao
- School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | | | - Yanyan Chen
- The Eye Hospital, Wenzhou Medical University, Wenzhou, China
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Abstract
OBJECTIVES To review the pattern of primary pterygium-induced corneal astigmatism in patients with cataract in a southern Chinese population. DESIGN Clinic-based cross-sectional retrospective study. SETTING A secondary hospital at southern China. PARTICIPANTS A group of 1689 eyes with primary pterygium (PT group) and the other group of 4062 eyes without pterygium (NPT group) were included. MAIN OUTCOME MEASURES Corneal power was measured by an autokeratorefractometer. Corneal astigmatism was calculated as the difference in corneal power between the steepest and flattest meridians. Distribution of corneal astigmatism was compared between eyes with pterygium and eyes without pterygium. RESULTS Distribution of corneal astigmatism was different between PT group (skewness=2.548, kurtosis=8.237) and NPT group (skewness=2.778, kurtosis=15.52). Mean corneal astigmatism was significantly higher in the PT group (1.62±1.49D) compared with the NPT group (1.17±0.89D, p<0.0001). The prevalence of corneal astigmatism >1D (PT 52.3%, NPT 40.9%, p<0.0001), >2D (PT 22.4%, NPT 10.6%, p<0.0001) or >3D (PT 10.5%, NPT 3.2%, p<0.0001) was significantly higher in the PT group compared with the NPT group. Eyes in the PT group had significantly higher corneal astigmatism than the NPT group in almost every age group (all p<0.05), with the exception of patients ≥90 years. Moreover, eyes in the PT group had significantly higher with-the-rule (PT 1.72±1.59D, NPT 1.19±0.88D, p<0.0001) and against-the-rule (PT 1.63±1.46D, NPT 1.18±0.88D, p<0.0001) but similar oblique astigmatism (PT 1.11±1.00D, NPT 0.99±0.89D, p=0.065) corneal astigmatism compared with the NPT group. Power vector analysis indicated that the axis of corneal astigmatism was not significantly different between the two groups (J0, PT -0.01±0.74D, NPT 0.01±0.52D, p=0.48; J45, PT -0.03±0.82D, NPT 0.00±0.52D, p=0.54). CONCLUSIONS Pattern of corneal astigmatism in eyes with cataract and coexisting primary pterygium was different from eyes without pterygium. Pterygium is associated with higher magnitude but not different axis of corneal astigmatism.
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Affiliation(s)
- Guihua Xu
- Aier Institute of Refractive Surgery, Refractive Surgery Center, Guangzhou Aier Eye Hospital, Guangzhou, China
- Department of Ophthalmology, Huizhou Municipal Central Hospital, Huizhou, China
- Aier School of Ophthalmology, Central South University, Changsha, China
| | - Wei Qi
- Shanwei Eye Hospital, Shanwei, China
| | - Yijun Hu
- Aier Institute of Refractive Surgery, Refractive Surgery Center, Guangzhou Aier Eye Hospital, Guangzhou, China
- Aier School of Ophthalmology, Central South University, Changsha, China
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22
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Kawasaki M, Furujo T, Kuroda K, Azuma K, Okamoto Y, Ito N. Characterising keratometry in different dog breeds using an automatic handheld keratometer. Vet Rec 2020; 186:e4. [PMID: 32123011 PMCID: PMC7279203 DOI: 10.1136/vr.105393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 11/19/2019] [Accepted: 12/31/2019] [Indexed: 11/17/2022]
Abstract
Background Keratometry is clinically important and is routinely performed as part of human ophthalmic examination. In veterinary ophthalmology, little is known about keratometry in dogs, and its practical application has been limited. The present study aimed to describe keratometry in some dog breeds popular in Japan using a handheld keratometer. Methods Client-owned dogs of various signalment were enrolled prospectively in the keratometry examination. Interbreed variations in mean corneal curvatures (R1R2avg) and corneal astigmatism (Δ(R1−R2)) were evaluated statistically with respect to their bodyweight based on the data which fulfilled the predetermined inclusion criteria. P<0.05 was considered statistically significant. Results On examination of 237 dogs from 16 different breeds, R1R2avg (mean±sd) ranged from 7.54±0.30 mm in Pomeranians to 9.28±0.19 mm in golden retrievers. Δ(R1−R2) (mean±sd) ranged from 0.22±0.11 mm in miniature schnauzers to 0.57±0.30 mm in French bulldogs. Conclusion The present study successfully described keratometry in 16 dog breeds. The study revealed considerable interbreed variations in both R1R2avg and Δ(R1−R2), which did not necessarily correlate with bodyweight. These results are useful both clinically in fitting contact lenses in the management of corneal diseases and non-clinically in optometric studies in dogs.
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Affiliation(s)
- Minae Kawasaki
- Veterinary Medical Center, Tottori University, Koyama-cho Minami, Tottori, Japan.,The United Graduate School of Veterinary Science, Yamaguchi University, Yoshida, Yamaguchi, Japan
| | - Tomoya Furujo
- Joint Department of Veterinary Medicine, Tottori University, Koyama-cho Minami, Tottori, Japan
| | - Kohei Kuroda
- Department of Surgery, Keio University School of Medicine, Shinanomachi, Shinjuku, Tokyo, Japan
| | - Kazuo Azuma
- Joint Department of Veterinary Medicine, Tottori University, Koyama-cho Minami, Tottori, Japan
| | - Yoshiharu Okamoto
- Joint Department of Veterinary Medicine, Tottori University, Koyama-cho Minami, Tottori, Japan
| | - Norihiko Ito
- Veterinary Medical Center, Tottori University, Koyama-cho Minami, Tottori, Japan .,Joint Department of Veterinary Medicine, Tottori University, Koyama-cho Minami, Tottori, Japan
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Zakrzewska A, Wiącek MP, Machalińska A. Impact of corneal parameters on intraocular pressure measurements in different tonometry methods. Int J Ophthalmol 2019; 12:1853-1858. [PMID: 31850168 DOI: 10.18240/ijo.2019.12.06] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 10/29/2019] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the impact of central corneal thickness (CCT) and corneal curvature on intraocular pressure (IOP) measurements performed by three different tonometers. METHODS IOP in 132 healthy eyes of 66 participants was measured using three different tonometry techniques: Goldmann applanation tonometer (GAT), Pascal dynamic contour tonometer (DCT), and ICare rebound tonometer (RT). CCT and corneal curvature were assessed. RESULTS In healthy eyes, DCT presents significantly higher values of IOP than GAT (17.34±3.69 and 15.27±4.06 mm Hg, P<0.0001). RT measurements are significantly lower than GAT (13.56±4.33 mm Hg, P<0.0001). Compared with GAT, DCT presented on average 2.51 mm Hg higher values in eyes with CCT<600 µm and 0.99 mm Hg higher results in eyes with CCT≥600 µm. The RT results were lower on average by 1.61 and 1.95 mm Hg than those obtained by GAT, respectively. Positive correlations between CCT in eyes with CCT<600 µm were detected for all IOP measurement techniques, whereas a similar relationship was not observed in eyes with thicker corneas. A correlation between IOP values and keratometry in the group with CCT<600 µm was not detected with any of the tonometry methods. In thicker corneas, a positive correlation was found for GAT and mean keratometry values (R=0.369, P=0.005). CONCLUSION The same method should always be chosen for routine IOP control, and measurements obtained by different methods cannot be compared. All analysed tonometry methods are dependent on CCT; thus, CCT should be taken into consideration for both diagnostics and monitoring.
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Affiliation(s)
- Aleksandra Zakrzewska
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin 70-111, Poland
| | - Marta P Wiącek
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin 70-111, Poland
| | - Anna Machalińska
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin 70-111, Poland
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Zhang QW, Zhai CB, Ma DL. Comparison of corneal curvature parameters obtained from two different instruments-Pentacam and VX120. Int J Ophthalmol 2019; 12:1311-1316. [PMID: 31456922 DOI: 10.18240/ijo.2019.08.12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 07/29/2019] [Indexed: 01/02/2023] Open
Abstract
AIM To explore whether the same corneal curvature parameters and anterior chamber depth measured by Pentacam and VX120 have a good consistency and can replace each other. METHODS This study enrolled 140 eyes of 70 patients ranging in age from 19 to 53y. All eyes underwent a comprehensive ophthalmologic examination including an anterior segment analysis with the VX120 system (Visionix-Luneau Technologies, Chartres, France) and Pentacam (Oculus Optikgerate GmbH) respectively. The comparison on corneal curvature parameters was done between Pentacam and VX120 using clustered signed rank test; the interclass correlation coefficients (ICC) with 95% confidence intervals (CI) was calculated for each parameter between Pentacam and VX120; the Bland-Altman plot of each parameter was supplemented. RESULTS The anterior corneal curvature measured by VX120 was Ks: 44.00±1.78 D, KsAt: 89.45±22.18, Kf: 42.84±1.58 D, KfAt: 93.91±79.34; which measured by Pentacam was Ks: 43.80±1.82 D, KsAt: 91.17±21.40, Kf: 42.61±1.64 D, KfAt: 91.16±78.69. There was statistical difference between Pentacam and VX120 for anterior corneal curvature parameter (P<0.001). The posterior corneal curvature measured by VX120 was Ks: -6.42±1.23 D, KsAt: 91.00±23.45, Kf: -5.85±1.24 D, KfAt: 95.93±79.11; which measured by Pentacam was Ks: -6.44±0.32 D, KsAt: 92.24±11.75, Kf: -6.01±1.05 D, KfAt: 74.43±80.64. There was statistical difference between Pentacam and VX120 for posterior corneal curvature parameters (P<0.001). Anterior chamber depth (ACD) measured by Pentacam and VX120 was statistically different. Pentacam and VX120 achieved high consistency only on corneal anterior surface, including Ks and Kf. The ICCs were 0.96 (95%CI: 0.95, 0.97) and 0.95 (95%CI: 0.94, 0.97) respectively. For other corneal surface curvature parameters, all ICCs of between Pentacam and VX120 were below 0.87. Bland-Altman plots indicated of low consistency of corneal surface curvature parameters measured by Pentacam and VX120. CONCLUSION The corneal curvature parameters and anterior chamber depth measured by Pentacam and VX120 were statistically different. Data measured by Pentacam and VX120 is not suggested to replace each other, mixing data measured by Pentacam and VX120 together is not suggested either.
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Affiliation(s)
- Qing-Wei Zhang
- Beijing Institute of Ophthalmology; Beijing Tongren Eye Center; Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Chang-Bin Zhai
- Beijing Institute of Ophthalmology; Beijing Tongren Eye Center; Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Dong-Li Ma
- Beijing Institute of Ophthalmology; Beijing Tongren Eye Center; Beijing Key Laboratory of Ophthalmology and Visual Science, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
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Jin KH, Kim TG. Relationship between early structural changes at cornea incision sites and surgical outcomes after phacoemulsification. Int J Ophthalmol 2019; 12:1139-1145. [PMID: 31341805 DOI: 10.18240/ijo.2019.07.14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 09/29/2018] [Indexed: 11/23/2022] Open
Abstract
AIM To assess the early structural changes at clear corneal cataract incision sites and surgical outcomes using anterior segment optical coherence tomography (AS-OCT). METHODS We evaluated 80 eyes of 59 patients who underwent phacoemulsification with a clear corneal incision. All incisions were evaluated 1wk, 1, and 3mo postoperatively using AS-OCT and analyzed regarding angle, length of the incision, maximal corneal thickness at the incision, and if present, corneal endothelial gap length and incision gap area. The patients were divided into two groups according to whether or not an endothelial gap was present at 1wk postoperatively (endothelial gap, group 1; no endothelial gap, group 2). We analyzed the difference in patient and surgical factors between the two groups, and compared the surgical outcome and the refractive outcome. RESULTS An endothelial gap was observed in 56 (70.0%) of 80 eyes at 1wk postoperatively but not at 3mo postoperatively. The mean patient age was significantly higher in group 1 than in group 2. The longer the length of the corneal incision and the steeper the incision angle, the greater the length and area of the endothelial gap. In group 1, the mean change in mean keratometry of the anterior cornea was significantly greater than in group 2, and the spherical equivalent (SE) and mean numerical error indicated significant myopic changes at 1wk postoperatively. CONCLUSION The risk of an endothelial gap increases with patient age and a long corneal incision and steep incision angle. The presence of an endothelial gap after surgery may affect the early postoperative corneal curvature and SE.
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Affiliation(s)
- Kyung Hyun Jin
- Department of Ophthalmology, Kyung Hee University Medical Center, Kyung Hee University, Seoul 02447, Korea
| | - Tae Gi Kim
- Department of Ophthalmology, Kyung Hee University Hospital at Gangdong, Kyung Hee University, Seoul 05278, Korea
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26
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Hansen MH, Munch IC, Li XQ, Skovgaard AM, Olsen EM, Larsen M, Kessel L. Visual acuity and amblyopia prevalence in 11- to 12-year-old Danish children from the Copenhagen Child Cohort 2000. Acta Ophthalmol 2019; 97:29-35. [PMID: 30280496 DOI: 10.1111/aos.13842] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/14/2018] [Indexed: 12/17/2022]
Abstract
PURPOSE To evaluate the prevalence of amblyopia and associated biometric factors in Danish children. METHODS Determination of best-corrected visual acuity (BCVA) using ETDRS charts, non-cycloplegic subjective refractioning guided by automated refractometry, axial length and corneal curvature, fundus photography and optical coherence tomography (OCT) in 1335 children from the population-based Copenhagen Child Cohort 2000 (CCC2000) Eye Study. Birth data were obtained from the Danish Medical Birth Registry. RESULTS The mean (±SD) age of children was 11.7 (±0.4) years, and 47% were boys. Amblyopia prevalence was 1.5 (95% CL 0.8-2.2) %. Unilateral amblyopic eyes [BCVA < 80 ETDRS letters (0.8 snellen) and ≥2 lines difference between the eyes] was 0.6 (95% CL 0.3-1.0) mm shorter, 1.34 (95% CL 0.30-2.37) D more hyperopic and had 0.79 (95% CL 0.14-1.44) D more astigmatism compared with fellow eyes. Compared with the right eyes of the non-amblyopic children, unilateral amblyopic eyes were 1.0 (95% CL 0.5-1.6) mm shorter, 2.48 (95% CL 1.11-3.86) D more hyperopic, 1.09 (95% CL 0.43-1.75) D more astigmatic and had a 47 (95% CL 13-81) μm thicker subfoveal choroid. CONCLUSION Amblyopia was found in 1.5% of Danish children born 22 years after the inception of the nationwide preschool visual screening programme. Amblyopia was associated with anisometropia, astigmatism, a thicker subfoveal choroid and a history of childhood strabismus.
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Affiliation(s)
- Mathias Hvidtfelt Hansen
- Department of Ophthalmology; Rigshospitalet; Copenhagen Denmark
- Department of Clinical Medicine; University of Copenhagen; Copenhagen Denmark
| | - Inger Christine Munch
- Department of Clinical Medicine; University of Copenhagen; Copenhagen Denmark
- Department of Ophthalmology; Zealand University Hospital; Roskilde Denmark
| | - Xiao Qiang Li
- Department of Ophthalmology; Rigshospitalet; Copenhagen Denmark
| | - Anne Mette Skovgaard
- Institute of Public Health; University of Copenhagen; Copenhagen Denmark
- National Institute of Public Health; University of Southern Denmark; Odense Denmark
| | - Else Marie Olsen
- Institute of Public Health; University of Copenhagen; Copenhagen Denmark
- Centre for Clinical Research and Prevention; Capital Region, Copenhagen Denmark
| | - Michael Larsen
- Department of Ophthalmology; Rigshospitalet; Copenhagen Denmark
- Department of Clinical Medicine; University of Copenhagen; Copenhagen Denmark
| | - Line Kessel
- Department of Ophthalmology; Rigshospitalet; Copenhagen Denmark
- Department of Clinical Medicine; University of Copenhagen; Copenhagen Denmark
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27
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Muthu Krishnan V, Jayalatha K, Vijayakumar C. Correlation of Central Corneal Thickness and Keratometry with Refraction and Axial Length: A Prospective Analytic Study. Cureus 2019; 11:e3917. [PMID: 30931188 PMCID: PMC6426576 DOI: 10.7759/cureus.3917] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Introduction The correlation between corneal curvature and central corneal thickness (CCT), with ocular parameters like axial length and refraction, remains elusive. The various ocular biometric parameters are interdependent and their correlation varies with the population studied. A comprehensive study is required for a better understanding of the ocular biometric properties of Indian eyes. Methodology This is a prospective study done in 156 subjects. Subjects with clear lens and clear cornea were included in the study. Those with corneal opacity, cataract, pregnancy, and diabetes were excluded. Cycloplegic refraction, autokeratometry (Potex, ultrasonic auto keratometer), central corneal thickness (ultrasonic pachymeter), and axial length (Sonomed) were done in all subjects. Subjects were divided into two groups based on refraction, for an analysis of parameters. Group one included subjects with refraction of +3 diopters (D) to -2.99D and group two with subjects with > -3D refraction. Results With an increasing axial length and myopic refraction, the corneal curvature tends to be steeper. The average CCT of subjects in group one and group two were 530.34 microns and 542.63 microns, respectively. Subjects with refraction more than 10 diopters or axial length more than 25 mm had a mean CCT of 525.25 microns. Subjects with myopic refraction between 3 diopters and 10 diopters had a mean CCT of 551.32 microns. Conclusion Increase in corneal power is associated with increasing myopic refraction. Steeper corneal curvature is correlated with increasing axial length and thinner corneas. The mean CCT was 533.87 microns with a standard deviation (SD) of 40.02. Axial myopia is associated with an increase in corneal thickness. These ocular biometric findings have crucial implications in refractive surgeries.
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Affiliation(s)
| | | | - Chellappa Vijayakumar
- Surgery, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, IND
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28
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Sandvik GF, Vanem TT, Rand-Hendriksen S, Cholidis S, Saethre M, Drolsum L. Ten-year reinvestigation of ocular manifestations in Marfan syndrome. Clin Exp Ophthalmol 2018; 47:212-218. [PMID: 30260057 DOI: 10.1111/ceo.13408] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 09/03/2018] [Accepted: 09/20/2018] [Indexed: 11/28/2022]
Abstract
IMPORTANCE Long-term follow-up of Marfan syndrome (MFS) patients. BACKGROUND Investigate changes in ocular features in MFS patients fulfilling the Ghent-2 criteria following a period of 10 years. DESIGN Repeated cross-sectional study with two observations. PARTICIPANTS Eighty-four MFS patients were investigated in 2003-2004 (baseline). Forty-four of these patients (52%) were examined after 10 years. METHODS A comprehensive ocular examination performed at baseline and follow-up. MAIN OUTCOME MEASURES Development or progression of ectopia lentis (EL). RESULTS At follow-up, mean age was 50.1 ± 11.9 years (range: 30-80 years), 74% were female and 70% of the patients were diagnosed with EL compared to 66% at baseline. Two patients (3 eyes) had developed EL over the decade, representing a 13% risk. Furthermore, one eye had progressed from a subtle tilt of the lens to dislocation. We found no significant change in the axial length (P = 0.96), the corneal curvature (P = 0.64) or the spherical equivalent (P = 0.23). Best corrected visual acuity was improved at follow-up (P = 0.02). There were 7% and 33% risks for development of retinal detachment and cataract between baseline and follow-up, respectively. CONCLUSIONS AND RELEVANCE Our study indicates that even though EL typically occurs at an early stage in most MFS patients, there is still a risk of developing EL in adulthood. The risk of developing vision-threatening complications such as retinal detachment and cataract was much higher than in the normal population, but even so, the visual potential of the MFS patients was relatively good.
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Affiliation(s)
- Gunhild F Sandvik
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Thy T Vanem
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Svend Rand-Hendriksen
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Department of TRS National Resource Centre for Rare Disorders, Sunnaas Rehabilitation Hospital, Nesodden, Norway
| | - Symira Cholidis
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
| | - Marit Saethre
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
| | - Liv Drolsum
- Department of Ophthalmology, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
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Vergara C, Bomotti SM, Valencia C, Klein BEK, Lee KE, Klein R, Klein AP, Duggal P. Association analysis of exome variants and refraction, axial length, and corneal curvature in a European-American population. Hum Mutat 2018; 39:1973-1979. [PMID: 30157304 DOI: 10.1002/humu.23628] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 08/24/2018] [Accepted: 08/25/2018] [Indexed: 12/16/2022]
Abstract
Refractive errors, myopia, and hyperopia are common visual disorders greatly affecting older individuals. Refraction is determined by genetic factors but only a small percentage of its variation has been explained. We performed a genetic association analysis with three ocular phenotypes: spherical equivalent (a continous measure of refraction), axial length, and corneal curvature in 1,871 European-Americans from the Beaver Dam Eye Study. Individuals were genotyped on the Illumina exome array and imputed to the Haplotype Reference Consortium reference panel. After increasing the number of analyzed variants in targeted protein-coding regions 10-fold via imputation, we confirmed associations for two previously known loci with corneal curvature (chr4q12, rs2114039; g.55092626T > C, β = -0.03 (95% confidence interval [CI]): -0.06, -0.01, P value = 0.01) and spherical equivalent (chr15q14, rs634990; g.35006073T > C, β = -0.27, 95% CI: -0.45, -0.09, P value = 3.79 × 10-3 ). Despite increased single nucleotide polymorphism (SNP) density, we did not detect any novel significant variants after correction for multiple comparisons. In summary, we confirmed two previous loci associated with corneal curvature and spherical equivalent in a European-American population highlighting the potential biological role of those regions in these traits.
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Affiliation(s)
- Candelaria Vergara
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Samantha M Bomotti
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Cristian Valencia
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Barbara E K Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Kristine E Lee
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Ronald Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Alison P Klein
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.,Department of Pathology, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Priya Duggal
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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Ruiz-Belda C, Rodrigo F, Piñero DP. Validation of keratometric measurements obtained with an intraoperative image-guided system: intra-session repeatability and interchangeability with an optical biometer. Clin Exp Optom 2017; 101:200-205. [PMID: 29090488 DOI: 10.1111/cxo.12623] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 03/29/2017] [Accepted: 06/26/2017] [Indexed: 10/18/2022] Open
Abstract
PURPOSE To evaluate the intra-session repeatability of keratometric measurements obtained in healthy eyes with the Verion image-guided system (Alcon Laboratories Inc, Fort Worth, Texas, USA) as well as the interchangeability of such measurements with those obtained with an optical biometer (Aladdin, Topcon, Tokyo, Japan). METHODS A total of 53 eyes of 53 patients (age 31-67 years) were enrolled in the study. All eyes received a comprehensive ophthalmologic examination including an analysis with the Verion image-guided and Aladdin systems. Three consecutive measurements of keratometry were obtained with the Verion system to assess the intra-session repeatability. Within-subject standard deviation (Sw ) and intraobserver precision (± 1.96 × Sw ) were calculated. Bland-Altman analysis was used for the interchangeability analysis. RESULTS Mean Sw was 0.26, 0.24 and 0.10 D for the keratometric power in the flattest meridian (K1), keratometric power in the steepest meridian (K2) and astigmatism, respectively. Mean Sw was 4.29° for the axis of the flattest corneal meridian (AX1). Statistically significant but clinically acceptable differences were found in K1, K2 and keratometric astigmatism among systems (p < 0.01). In contrast, differences among systems in AX1 were not statistically significant (p = 0.385) but clinically relevant (mean difference: 15.74°; limits of agreement: -30.93 to 62.41°). CONCLUSIONS The Verion system provides consistent measurements of keratometric parameters, with measurements of AX1 that are not interchangeable with that provided by the optical biometer Aladdin, especially in cases of low and oblique astigmatism.
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Affiliation(s)
- Clara Ruiz-Belda
- Department of Ophthalmology, Marina Baixa Hospital, Alicante, Spain.,Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Fermín Rodrigo
- Department of Ophthalmology, Marina Baixa Hospital, Alicante, Spain
| | - David P Piñero
- Department of Ophthalmology, Marina Baixa Hospital, Alicante, Spain.,Department of Ophthalmology (Oftalmar), Vithas Medimar International Hospital, Alicante, Spain
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Chen R, Mao X, Jiang J, Shen M, Lian Y, Zhang B, Lu F. The relationship between corneal biomechanics and anterior segment parameters in the early stage of orthokeratology: A pilot study. Medicine (Baltimore) 2017; 96:e6907. [PMID: 28489806 PMCID: PMC5428640 DOI: 10.1097/md.0000000000006907] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
To investigate the relationship between corneal biomechanics and anterior segment parameters in the early stage of overnight orthokeratology.Twenty-three eyes from 23 subjects were involved in the study. Corneal biomechanics, including corneal hysteresis (CH) and corneal resistance factor (CRF), and parameters of the anterior segment, including corneal curvature, central corneal thickness (CCT), and corneal sublayers' thickness, were measured at baseline and day 1 and 7 after wearing orthokeratology lens. One-way analysis of variance with repeated measures was used to compare the longitudinal changes and partial least squares linear regression was used to explore the relationship between corneal biomechanics and anterior segment parameters.At baseline, CH and CRF were positively correlated with CCT (r = 0.244, P = .008 for CH; r = 0.249, P < .001 for CRF), central stroma thickness (CST) (r = 0.241, P = .008 for CH; r = 0.244, P = .002 for CRF) and central Bowman layer thickness (CBT) (r = 0.138, P = .039 for CH; r = 0.171, P = .006 for CRF). Both CH and CRF significantly decreased from day 1 after orthokeratology. The corneal curvature and the epithelium thickness also significantly decreased, while the stromal layer thickened significantly from day 1 after orthokeratology. There was no correlation between the changes of corneal biomechanics and anterior segment parameters at day 1 and 7 after orthokeratology.While corneal biomechanics were positively correlated with CCT, CST, and CBT, the changes of CH and CRF were not correlated with the changes of corneal curvature, CCT, and corneal sublayers' thickness in the early stage of orthokeratology in our study.
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Affiliation(s)
- Renai Chen
- School of Ophthalmology and Optometry, Wenzhou Medical University
- Affiliated Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xinjie Mao
- School of Ophthalmology and Optometry, Wenzhou Medical University
- Affiliated Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jun Jiang
- School of Ophthalmology and Optometry, Wenzhou Medical University
- Affiliated Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Meixiao Shen
- School of Ophthalmology and Optometry, Wenzhou Medical University
- Affiliated Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yan Lian
- School of Ophthalmology and Optometry, Wenzhou Medical University
- Affiliated Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Bin Zhang
- College of Optometry, Nova Southeastern University, Fort Lauderdale, FL
| | - Fan Lu
- School of Ophthalmology and Optometry, Wenzhou Medical University
- Affiliated Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
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Kadhim YJ, Farhood QK. Central corneal thickness of Iraqi population in relation to age, gender, refractive errors, and corneal curvature: a hospital-based cross-sectional study. Clin Ophthalmol 2016; 10:2369-2376. [PMID: 27932859 PMCID: PMC5135410 DOI: 10.2147/opth.s116743] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Central corneal thickness (CCT) is an important indicator of corneal status. Its measurement provides valid information about corneal physiological condition and possible changes associated with diseases, traumas, and hypoxia. It is an integral part for interpretation of intraocular pressure and glaucoma patient management and in prerefractive procedure assessment. OBJECTIVE The aim of this study is to determine the mean CCT among a normal Iraqi population and to correlate between CCT and age, gender, refraction, and corneal curvature. PATIENTS AND METHODS This cross-sectional study was carried out at Ibn Al-Haitham Teaching Eye Hospital. A total of 418 eyes from 209 healthy individuals with an age range from 20 to 75 years were studied. CCT was measured by ultrasound pachymeter. Refraction was measured using an auto-refractor and confirmed by trial lenses and retinoscopy to calculate the spherical equivalent. Corneal curvature was measured using an auto-refracto-keratometer to calculate the average corneal curvature (AVK). RESULTS The mean CCT was 543.95±32.58 μm with a range from 422 to 636 μm. CCT was not affected by gender. CCT significantly negatively correlated with age and AVK. CCT significantly positively correlated with the spherical equivalence. CONCLUSION AND RECOMMENDATION Among an Iraqi population, CCT significantly decreased with age. Myopics had significantly thinner corneas. There was weak but significant negative correlation between CCT and corneal curvature. We recommend further studies about the relationship between central corneal thickness and other ocular parameters in Iraqi population such as the axial length.
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Affiliation(s)
| | - Qasim K Farhood
- Department of Ophthalmology, College of Medicine, University of Babylon, Babylon, Iraq
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Safarzadeh M, Nasiri N, Doostdar A, Kamali M. Comparative study of changes of corneal curvatures and uncorrected distance visual acuity prior to and after corneal collagen crosslinking: 1-year results. Taiwan J Ophthalmol 2016; 6:127-130. [PMID: 29018727 PMCID: PMC5525610 DOI: 10.1016/j.tjo.2016.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 06/15/2016] [Accepted: 06/16/2016] [Indexed: 11/24/2022] Open
Abstract
Background/Purpose: Keratoconus is the most common primary corneal ectatic disease and has considerable importance in public health. Corneal collagen crosslinking (CXL) is a procedure to mitigate progression of keratoconus and reduce demand for corneal transplantation. The aim of this study was to evaluate the effect of CXL on corneal topographic and uncorrected distance visual acuity (UDVA) by Oculus Pentacam in the 15–30-year-old population. Methods: In this descriptive–analytic study, we enrolled 38 eyes of 27 patients suffering from progressive keratoconus who were candidates for CXL. UDVA and the anterior and posterior corneal curvatures assessed prior to and 12 months after CXL. Data were analyzed by the paired t test and p < 0.05 was considered significant. Results: One year after the CXL, mean UDVA significantly improved 0.1 ± 0.25 logarithm of the minimal angle of resolution (p = 0.012). Changes for steep keratometry values, flat keratometry, and mean keratometry on the anterior corneal surface were statistically significant (all p < 0.005). However, the difference observed in maximum keratometry and astigmatism was not significant (p = 0.421 and p = 0.745, respectively). After 12 months, all four keratometry values on the posterior corneal surface had increased significantly (p < 0.005), while no significant change observed in astigmatism (p = 0.303). Conclusion: Corneal collagen crosslinking has been revealed as an effective and minimally invasive intervention for the treatment of progressive keratoconus that can improve UDVA.
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Affiliation(s)
- Masoud Safarzadeh
- Department of Optometry, Iran University of Medical Sciences, Tehran, Iran
| | - Nader Nasiri
- Department of Ophthalmology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Asgar Doostdar
- Department of Optometry, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Kamali
- Department of Rehabilitation Sciences, Iran University of Medical Sciences, Tehran, Iran
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Kasprzak H, Boszczyk A. Numerical analysis of corneal curvature dynamics based on Corvis tonometer images. J Biophotonics 2016; 9:436-444. [PMID: 26997615 DOI: 10.1002/jbio.201500235] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 02/11/2016] [Accepted: 03/01/2016] [Indexed: 06/05/2023]
Abstract
The paper presents numerical analysis of corneal curvature distribution, based on Corvis ST images. It was shown that a new approach to analysis of corneal curvature from tonometer images enables a better description and understanding of processes during fast corneal deformation. Ten healthy volunteers participated in nine repeated measurements on one eye. 90 sequences of images were processed with software written in Matlab, with the use of the Image Processing Toolbox. Time-spatial distribution of the local curvature distribution of the corneal profile was obtained for each and every measurement. Some new curvature parameters were proposed and analyzed. A high repeatability for individual subjects was obtained for the proposed parameters. For four of these new parameters, the ICC coefficients were higher than 0.85. The ICC value for the calculated curvature of the cornea before deformation reaches 0.989. Such high repeatability of the proposed new parameters can be useful in examination and differentiation of corneas due to their geometrical and biomechanical properties.
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Affiliation(s)
- Henryk Kasprzak
- Department of Optics and Photonics, Wroclaw University of Technology, 50 370, Wroclaw, Poland.
| | - Agnieszka Boszczyk
- Department of Optics and Photonics, Wroclaw University of Technology, 50 370, Wroclaw, Poland
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Lauschke JL, Lawless M, Sutton G, Roberts TV, Hodge C. Assessment of corneal curvature using verion optical imaging system: a comparative study. Clin Exp Ophthalmol 2016; 44:369-76. [PMID: 27381574 DOI: 10.1111/ceo.12687] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 11/03/2015] [Accepted: 11/07/2015] [Indexed: 12/27/2022]
Abstract
BACKGROUND Keratometry is a critical determinant of the postoperative refractive outcome. This study evaluates the comparability of keratometry measurements obtained using the Verion Optical Imaging System with devices used in current clinical practice. Further, it determines the interobserver reliability of the Verion Optical Imaging System. DESIGN Retrospective analysis of patient data PARTICIPANTS Keratometric data was obtained from 100 patients presenting for pre-operative evaluation. Furthermore, repeatability and reproducibility were assessed using 15 healthy volunteers. METHODS Corneal curvature values acquired by the Verion Optical Imaging System were compared with existing keratometry devices including autokeratometry, partial coherence interferometry (IOLMaster) and Scheimpflug corneal topography (Pentacam). MAIN OUTCOME MEASURES Direct comparison of corneal power, cylinder, axis of astigmatism and vector analysis were performed using correlation and Bland-Altman analyses. Reproducibility and reliability of the device were assessed using within-subject standard deviation and intraclass correlation coefficients for experienced and inexperienced technicians. RESULTS There was no statistically significant difference between Verion values and those obtained by other methods in relation to mean keratometry, corneal astigmatism, steep meridian and vector analyses (P > 0.05). Bland-Altman plots showed narrow limits of agreement for keratometry and astigmatism and wider agreement for steep meridian. Intraoperator reliability for both experienced and inexperienced operators and interoperator reproducibility showed no statistically significant differences between values. CONCLUSION Measurements show no significant difference from those obtained by the other devices. This suggests the Verion system is en par with instruments used in current clinical practice. The Verion Optical Imaging System produces repeatable data with no difference related to operator experience.
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Affiliation(s)
- Jenny L Lauschke
- Vision Eye Institute Chatswood, Sydney, New South Wales, Australia.,Department of Ophthalmology, Prince of Wales Hospital, Sydney, New South Wales, Australia
| | - Michael Lawless
- Vision Eye Institute Chatswood, Sydney, New South Wales, Australia.,Save Sight Institute, University of Sydney, Sydney, New South Wales, Australia
| | - Gerard Sutton
- Vision Eye Institute Chatswood, Sydney, New South Wales, Australia.,Save Sight Institute, University of Sydney, Sydney, New South Wales, Australia
| | - Timothy V Roberts
- Vision Eye Institute Chatswood, Sydney, New South Wales, Australia.,Save Sight Institute, University of Sydney, Sydney, New South Wales, Australia
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Liong SL, Mohidin N, Tan BW, Ali BM. Refractive error, visual acuity, and corneal-curvature changes in high and low myopes with orthokeratology treatment: A Malaysian study. Taiwan J Ophthalmol 2015; 5:164-168. [PMID: 29018692 PMCID: PMC5602134 DOI: 10.1016/j.tjo.2015.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 07/25/2015] [Accepted: 07/30/2015] [Indexed: 11/16/2022] Open
Abstract
Background/Purpose: The effect of orthokeratology (OK) on low myopia is well known, but there are a few reports on its effect on high myopia. In this study, the parametric changes in high and low myopia as results of wearing OK lenses for a period of 6 months have been analyzed. Methods: Records of schoolchildren (age 7–17 years) undergoing OK treatment from an optometry clinic were retrospectively reviewed. Data involving refractive errors, uncorrected visual acuity, and corneal curvatures at baseline and after 1 day, 1 week, 1 month, 3 months, and 6 months of OK treatment from 25 patients who fulfilled the inclusion criteria were examined. For the analysis, the participants were arbitrarily divided into two groups comprising high myopia (< −6.00 D) and low to moderate myopia (from −1.00 D to −6.00 D). Results: Significant reductions of refractive error, improvement in visual acuity, and corneal-curvature flattening were found in all participants after 6 months of OK lens wear compared to the baseline. No significant changes were found in corneal toricity in both high and low to moderate myopic groups. Almost all of these occurred after one night of lens wear in both the high- and low-myopia groups. Conclusion: The OK lens wear significantly reduced the refractive error and corneal curvature that results in the improvement in visual acuity in both high- and low-myopia groups, and the reduction seemed to occur nearly at the same time despite the difference in initial myopic power. High myopes with refractive power up to −8.25 D would benefit significantly from OK lenses.
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Affiliation(s)
- Swee Lee Liong
- Optometry and Vision Science Program, School of Healthcare Sciences, Faculty of Health, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
| | - Norhani Mohidin
- Optometry and Vision Science Program, School of Healthcare Sciences, Faculty of Health, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia.,Department of Optometry, Faculty of Health Sciences, Universiti Teknologi MARA, Puncak Alam Campus, Bandar Puncak Alam 42300, Selangor, Malaysia
| | - Bay Wah Tan
- Loyal Eye Clinic, 26, Jalan SJ17, Taman Selayang Jaya, 68100 Batu Caves, Selangor, Malaysia
| | - Bariah Mohd Ali
- Optometry and Vision Science Program, School of Healthcare Sciences, Faculty of Health, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
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Viswanathan D, Kumar NL, Males JJ, Graham SL. Comparative analysis of corneal measurements obtained from a Scheimpflug camera and an integrated Placido-optical coherence tomography device in normal and keratoconic eyes. Acta Ophthalmol 2015; 93:e488-94. [PMID: 25495530 DOI: 10.1111/aos.12622] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/31/2014] [Indexed: 01/21/2023]
Abstract
PURPOSE To assess the agreement between a Scheimpflug camera (Pentacam) and a combined Placido-optical coherence tomography device (Visante OMNI) in measuring corneal curvature, thickness and elevation values in normal and keratoconic eyes. METHODS Corneal measurements of 110 normal eyes (one eye per subject) and 70 keratoconic eyes were obtained from both devices and compared. Agreement was determined using the Bland-Altman analysis 95% limits of agreement (LoA). RESULTS The Pentacam measured significantly greater keratometry readings in the flattest (K1) and steepest meridians (K2) in normal and keratoconic eyes. The 95% LoA in normal eyes were -0.32 to 0.59 dioptres (D) (K1) and -0.41 to 0.74 D (K2). In keratoconic eyes, the 95% LoA were -1.35 to 1.92 D (K1) and -1.38 to 1.99 D (K2). The Pentacam recorded significantly higher central corneal thickness (CCT) values in both groups of eyes. The 95% LoA were -4.31 to 39.89 microns (μ) and -12.92 to 41.35 μ in normal and keratoconic eyes, respectively. Pentacam anterior and posterior corneal elevations were significantly greater in both groups of eyes. The devices demonstrated excellent repeatability and reproducibility for corneal curvature and thickness but not elevation measurements. CONCLUSIONS The Pentacam measured significantly greater corneal curvature, thickness and elevation values compared to the Visante OMNI in normal and keratoconic eyes. The devices agree moderately for anterior corneal elevations in normal eyes and do not appear to be interchangeable for corneal measurements in clinical practice.
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Affiliation(s)
- Deepa Viswanathan
- Australian School of Advanced Medicine; Macquarie University; Sydney Australia
| | - Nikhil L. Kumar
- Australian School of Advanced Medicine; Macquarie University; Sydney Australia
- Sydney Adventist Hospital Clinical School; The University of Sydney; Sydney Australia
| | - John J. Males
- Australian School of Advanced Medicine; Macquarie University; Sydney Australia
- The University of Sydney; Sydney Australia
| | - Stuart L. Graham
- Australian School of Advanced Medicine; Macquarie University; Sydney Australia
- The University of Sydney; Sydney Australia
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Zeng J, Cui Y, Li J, Xie W, Li Z, Zhang L, Meng Q. Correlation of axial length and corneal curvature with diopter in eyes of adults with anisometropia. Int J Clin Exp Med 2015; 8:13639-13643. [PMID: 26550307 PMCID: PMC4612992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 07/10/2015] [Indexed: 06/05/2023]
Abstract
PURPOSE To analyze the causes of anisometropia. METHODS Between June 2011 and November 2012 101 participants were divided into three groups. The refraction comprising the degree of refractive errors in the presence of astigmatism which was converted into the degree of spherical equivalent as well as ocular axial length (AL), corneal curvature (CR), average corneal power (ave K) and diopters were measured. RESULTS The differences of ocular AL/CR and CR between two eyes were statistically significant among the three groups (P < 0.05). Standardized regression coefficients obtained by a multiple linear regression analysis indicated that AL/CR, AL and ave K differences correlated with anisometropia in descending order. CONCLUSION The difference of AL/CR ratios between the eyes was the main cause for anisometropia, followed by AL and ave K values.
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Affiliation(s)
- Jin Zeng
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences 106 Zhongshan Er Road, Guangzhou 510080, China
| | - Ying Cui
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences 106 Zhongshan Er Road, Guangzhou 510080, China
| | - Juan Li
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences 106 Zhongshan Er Road, Guangzhou 510080, China
| | - Wenjuan Xie
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences 106 Zhongshan Er Road, Guangzhou 510080, China
| | - Zhongming Li
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences 106 Zhongshan Er Road, Guangzhou 510080, China
| | - Liang Zhang
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences 106 Zhongshan Er Road, Guangzhou 510080, China
| | - Qianli Meng
- Department of Ophthalmology, Guangdong Eye Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences 106 Zhongshan Er Road, Guangzhou 510080, China
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Özcura F, Yildirim N, Şahin A, Çolak E. Comparison of Goldmann applanation tonometry, rebound tonometry and dynamic contour tonometry in normal and glaucomatous eyes. Int J Ophthalmol 2015; 8:299-304. [PMID: 25938044 DOI: 10.3980/j.issn.2222-3959.2015.02.15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 06/11/2014] [Indexed: 11/02/2022] Open
Abstract
AIM To compare the intraocular pressure (IOP) measurements obtained with the rebound tonometry (RT), dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) in normal and glaucomatous eyes and investigate the effects of central corneal thickness (CCT) and corneal curvature (CC) on IOP measurements. METHODS One hundred and twenty-four eyes of 124 subjects were enrolled in this cross-sectional study. Fifty-six of participants were healthy individuals and 68 of them were glaucomatous patients. IOP was measured on each subject always in the same order, ICare RT-Pascal DCT-GAT, after a minimum interval of 10min between measurements. CCT and CC were measured using a rotating Scheimpflug camera before the IOP measurements in all subjects. One way repeated measures ANOVA, Pearson correlation coefficient and regression analysis, and Bland-Altman analysis was used for the statistical assessment. RESULTS Mean IOP for all enrolled eyes was 16.00±3.80 mm Hg for GAT, 16.99±4.91 mm Hg for RT, and 20.40±4.44 mm Hg for DCT. Mean differences between GAT and RT was -1.75±3.41 mm Hg in normal (P<0.001) and -0.37±3.00 mm Hg in glaucomatous eyes (P=0.563). Mean differences between GAT and DCT was -4.06±3.42 mm Hg in normal (P<0.001) and -4.67±3.12 mm Hg in glaucomatous eyes (P<0.001). GAT and RT were significantly positive correlated with CCT in normal (r=0.317, P=0.017 and r=0.576, P<0.001, respectively) and glaucomatous eyes (r=0.290, P=0.016 and r=0.351, P=0.003, respectively). DCT was also significantly positive correlated with CCT in normal eyes (r=0.424, P=0.001) but not in glaucomatous eyes (r=0.170, P=0.165). All tonometers were unaffected by CC. CONCLUSION IOP measurements by RT and DCT were significantly higher than GAT. DCT has highest IOP measurements among these tonometers. RT was most influenced tonometer from CCT although all tonometers were significantly positive correlated with CCT except DCT in glaucomatous eyes. CC did not influence IOP measurements.
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Affiliation(s)
- Fatih Özcura
- Department of Ophthalmology, Dumlupinar University School of Medicine, Kutahya 43270, Turkey
| | - Nilgün Yildirim
- Department of Ophthalmology, Eskisehir Osmangazi University School of Medicine, Eskisehir 26480, Turkey
| | - Afsun Şahin
- Department of Ophthalmology, Eskisehir Osmangazi University School of Medicine, Eskisehir 26480, Turkey
| | - Ertuğrul Çolak
- Department of Biostatistics and Medical Informatics, Eskisehir Osmangazi University School of Medicine, Eskisehir 26480, Turkey
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Drolsum L, Rand‐Hendriksen S, Paus B, Geiran OR, Semb SO. Ocular findings in 87 adults with Ghent-1 verified Marfan syndrome. Acta Ophthalmol 2015; 93:46-53. [PMID: 24853997 DOI: 10.1111/aos.12448] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 04/16/2014] [Indexed: 11/30/2022]
Abstract
PURPOSE To study ocular characteristics in 87 patients with verified Marfan syndrome (MFS) based on the Ghent criteria from 1996 (Ghent-1). METHODS The position of the lens was noted by observing the eye in different gaze directions in maximal mydriasis during slit lamp examination. Ectopia lentis (EL) was classified as subluxated (dislocation slightly backwards) or luxated (vertical or horizontal displacement). Corneal curvature, axial length (AL), corneal diameter, central corneal thickness, anterior chamber depth, lens thickness, condition of the iris, intraocular pressure, spherical equivalent and visual acuity were also investigated. RESULTS EL was found in 108 eyes (62.1%). Of the 68 phakic eyes with EL, 43 (63.2%) had subluxation. Mean AL was 24.80 ± 2.57 mm, and the AL was above 23.5 mm in 65.3%. Mean keratometry (K) in phakic eyes was 41.79 ± 1.70 diopters (D), and the K value was <41.5D in 46.8%. Iris hypoplasia was found in 3.4%. Myopia above 3D occurred in 38.4% of the phakic eyes. Mean binocular logMAR was 0.10 ± 0.32. Only five patients (5.7%) had a logMAR more than 0.5. These 5 patients had EL, and 4 of them were amblyopic. CONCLUSION In this strictly defined MFS group fulfilling the Ghent-1 criteria, the prevalence of EL was 62.1%. In many cases, the dislocation of the lens was subtle. On average, the corneas were flattened and the globe length was increased. Only a few patients were visually impaired. Children with MFS should have a thorough follow up to avoid amblyopia.
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Affiliation(s)
- Liv Drolsum
- Department of Ophthalmology Oslo University Hospital Oslo Norway
- University of Oslo Oslo Norway
| | - Svend Rand‐Hendriksen
- University of Oslo Oslo Norway
- Sunnaas Rehabilitation Hospital TRS National Resource Centre for Rare Disorders Nesodden Norway
| | - Benedicte Paus
- University of Oslo Oslo Norway
- Department of Medical Genetics Oslo University Hospital Oslo Norway
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Mahroo OA, Oomerjee M, Williams KM, O'Brart DPS, Hammond CJ. High heritability of posterior corneal tomography, as measured by Scheimpflug imaging, in a twin study. Invest Ophthalmol Vis Sci 2014; 55:8359-64. [PMID: 25425305 DOI: 10.1167/iovs.14-15043] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Anterior corneal curvature shows significant heritability. Scheimpflug imaging also permits assessment of posterior tomography. We estimated heritability of posterior and anterior tomographic parameters. METHODS Oculus Pentacam images were obtained in twins from the TwinsUK cohort. Mean anterior and posterior radii of curvature (right cornea) were compared within twin pairs, and heritability calculated (maximum likelihood structural equation modeling, using OpenMx package). Heritability estimates also were calculated for other parameters (anterior and posterior elevation at apex and thinnest point; pachymetry at apex and thinnest point; average pachymetry progression index). RESULTS Images from 138 twins were included (32 monozygotic [MZ] and 37 dizygotic [DZ] twin pairs). Mean (SD) age was 61 (11) years; 91% were female. Coefficients for intrapair correlation for MZ and DZ twins were, respectively, 0.89 and 0.42 for anterior curvature, and 0.93 and 0.46 for posterior curvature (P ≤ 0.0001 for differences between MZ and DZ correlations; Fisher r-to-z transformation). Heritability estimates (95% confidence interval [CI]) for anterior and posterior curvature were 89% (79%-93%) and 90% (83%-94%), respectively. Estimates for all other parameters were 75% or higher, except anterior apical elevation (61%). Point estimates for posterior parameters were consistently higher than anterior parameters, although CIs overlapped. Age-matching yielded similar estimates. Intereye correlations were high; correlations with age were weak (r < 0.30). CONCLUSIONS This is the first study to explore heritability of a number of different parameters of corneal tomography, including posterior curvature. Almost all parameters appeared highly heritable, with a trend toward higher heritability estimates for posterior (versus anterior) parameters.
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Affiliation(s)
- Omar A Mahroo
- Ophthalmology, King's College London, St. Thomas' Hospital Campus, London, United Kingdom
| | - Mohammed Oomerjee
- Ophthalmology, King's College London, St. Thomas' Hospital Campus, London, United Kingdom
| | - Katie M Williams
- Ophthalmology, King's College London, St. Thomas' Hospital Campus, London, United Kingdom
| | - David P S O'Brart
- Ophthalmology, Guy's & St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - Christopher J Hammond
- Ophthalmology, King's College London, St. Thomas' Hospital Campus, London, United Kingdom
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Abstract
PURPOSE To evaluate the relationship between corneal hysteresis (CH) and corneal resistance factor (CRF) with age, central corneal thickness (CCT), corneal curvature (KM), corneal volume (CV), and refractive error in naïve eyes. METHODS 105 healthy subjects (58 male and 47 female) were included in this study. The ages ranged from 19 to 82 years (mean 43.1 ± 15.4 years) and refraction between -11 D and +6 D (mean -0.79 ± 2.95 D). CH and CRF obtained with the Ocular Response Analyzer (ORA) were correlated with age, refractive error, Goldmann Applanation Tonometry (GAT), and with CCT, KM, CV obtained with the Pentacam, and with Corneal-Compensated Intraocular Pressure (IOPcc) and Goldmann-correlated intraocular pressure measurement (IOPg) obtained with ORA. A multivariable mixed effect model was used to evaluate associations among these parameters. RESULTS CH ranged from 6.9 to 14.6 mmHg (mean 10.26 ± 1.49 mmHg); CRF ranged from 5.8 to 17 mmHg (mean 10.38 ± 1.64 mmHg). Multivariate analysis showed a statistically significant correlation between CH with CCT (p < 0.001), and KM (p < 0.001), and between CRF with CCT (p < 0.001) and GAT (p < 0.001). CONCLUSIONS Our findings support the hypothesis that CH and CRF are related to the corneal shape and thickness, and show a decrease of CH with age.
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Affiliation(s)
- Nicola Rosa
- a Department of Medicine and Surgery , University of Salerno , Salerno , Italy
| | - Michele Lanza
- b Multidisciplinary Department of Medical , Surgical and Dental Specialities, Seconda Università di Napoli , Naples , Italy .,c Centro Grandi Apparecchiature, Seconda Università di Napoli , Naples , Italy , and
| | | | - Giuseppe Signoriello
- d Biostatistics Unit, Department of Medicine and Public Health , Seconda Università di Napoli , Naples , Italy
| | - Paolo Chiodini
- d Biostatistics Unit, Department of Medicine and Public Health , Seconda Università di Napoli , Naples , Italy
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Sorbara L, Maram J, Mueller K. Use of the Visante™ OCT to measure the sagittal depth and scleral shape of keratoconus compared to normal corneae: Pilot study. J Optom 2013; 6. [PMCID: PMC3880514 DOI: 10.1016/j.optom.2013.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Purpose The purpose of this study is to demonstrate and compare the use of optical coherence tomography (OCT) in measuring sagittal depth (SD) and in describing the corneo–scleral junctions with the use of scleral angles, in a population of keratoconics (KC) and of normals (normal). Methods Fourteen participants (one eye randomly selected) in the normal group and fourteen eyes of nine participants in the keratoconus group were enrolled in the study. Orbscan II (B&L, Rochester) topography was performed to establish eligibility, steep and flat K readings (axes) and HVID. Measurements of the sagittal depth of the cornea and the scleral angles along a particular chord diameter (their HVID and 15 mm) both flat and steep were taken with the use of the on screen measurement tools from the profile view of the cornea of the Visante™ OCT (Carl Zeiss, Dublin, CA). Results Data were taken from 14 eyes (11 Females; 3 Males) in the normal group and 14 eyes (5 females; 9 males) in the KC group where either or both eyes were measured. The study participants had a mean age of 33 ± 7yrs (normal) and 40 ± 14yrs (KC). The groups were matched according to HVID: 11.77 ± 0.41 mm (normal) and 11.75 ± 0.35 mm (KC), (p = 0.880). The steep K readings were 53.74 ± 5.98D for the keratoconus eyes as compared to 43.77 ± 1.35D for the control (p < 0.0001). The sagittal depths (±SD) of the keratoconic cornea were significantly different than the normal corneae at their HVID and at 15 mm in the steep meridian only (3.41 ± 0.88 mm versus 2.42 ± 0.09 mm, p = 0.001 and 3.93 ± 0.25 mm versus 3.70 ± 0.16 mm, p = 0.009, respectively). In addition, when the two groups were compared there was no difference in the scleral angles at the HVID's overall (p = 0.490), but there were differences by location (inferior and temporal, p = 0.003). At the 15 mm chord, there was a significant difference between the groups (p = 0.012) overall, but not by location (p = 0.130). Conclusions Measurement of the sagittal depth and the corneal-scleral junction angle in the steepest meridian at either the HVID or at 15 mm are two metrics that significantly differentiate normals from keratoconics.
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Affiliation(s)
- Luigina Sorbara
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
- Corresponding author at: School of Optometry and Vision Science, University of Waterloo, 200 University Ave. West, Waterloo, ON, Canada N3L 3G1.
| | - Jyotsna Maram
- Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine of Southern California, Los Angeles, CA, United States
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Iyamu E, Osuobeni E. Age, gender, corneal diameter, corneal curvature and central corneal thickness in Nigerians with normal intra ocular pressure. J Optom 2012; 5:87-97. [PMCID: PMC3861109 DOI: 10.1016/j.optom.2012.02.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 01/25/2012] [Indexed: 05/29/2023]
Abstract
Purpose To investigate the relationship between age, gender, corneal diameter, central corneal curvature, central corneal thickness (CCT) and intraocular pressure in Nigerians with normal intraocular pressure. Methods One hundred and thirty eyes from 130 subjects (mean age = 47.8 ± 16.8 years) including 77 males and 53 females were recruited. CCT was measured by ultrasound pachymetry, intraocular pressure was determined by non-contact tonometry, horizontal and vertical corneal diameters were measured with a ruler and central corneal curvature was measured by keratometry. Results The mean values obtained were as follows: CCT = 548.97 ± 34.28 μm, IOP = 15.61 ± 2.69 mmHg, average corneal curvature (AVK) = 42.98 ± 1.19 D, horizontal corneal diameter (HVID) = 11.39 ± 0.69 mm and vertical corneal diameter (VVID) = 10.51 ± 0.50 mm. There was a significant effect of age on CCT (r = −0.35, p < 0.001). A 10-year-increase in age was associated with a 7.0 μm decrease in CCT. Males had significantly wider HVID than females (p = 0.03). Subjects in older age groups have narrower HVID and VVID. Corneal curvature, corneal diameter and gender did not significantly affect CCT. Conclusion CCT of normotensive Nigerian adults decreases with increasing age. There was no correlation between CCT and IOP in normotensive subjects. CCT was not significantly influenced by gender, corneal curvature and corneal diameter.
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Affiliation(s)
- Eghosasere Iyamu
- Department of Optometry, Faculty of Life Sciences, University of Benin, Benin-City, Nigeria
| | - Ebi Osuobeni
- Department of Vision and Hearing Sciences, Anglia Vision Research and Vision and Eye Research Unit, Anglia Ruskin University, East Road, Cambridge, United Kingdom
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Jain R, Dilraj G, Grewal SPS. Repeatability of corneal parameters with Pentacam after laser in situ keratomileusis. Indian J Ophthalmol 2007; 55:341-7. [PMID: 17699942 PMCID: PMC2636025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIM To investigate the coefficient of repeatability (CR) for corneal parameters evaluated with Pentacam after laser in situ keratomileusis (LASIK) in myopic eyes. DESIGN AND SETTING Prospective, non-interventional, non-comparative study in an institutional setup. MATERIALS AND METHODS Forty eyes of 40 consecutive subjects who had undergone LASIK for myopia were assessed with the Scheimpflug system (Pentacam 70700: Oculus, Wetzlar Germany). The mean of five consecutive measurements of all the corneal parameters was recorded and CR was calculated as standard deviation of the difference from the mean of these repeat measurements divided by the mean response. The statistical significance of the CR was calculated for these parameters at 5% significance level. RESULTS The best CR was observed for the periphery of the anterior corneal curvature (0.18%) and the least for the horizontal meridian of the posterior corneal curvature (1.29%). Despite being significantly different ( P < 0.001), both the measurements were highly repeatable in post-LASIK eyes. The central, apical and minimal corneal thickness had a CR of 1%, 0.78% and 0.77% respectively. These were equally repeatable ( P> 0.323). The CR of the mean radius of curvature of the anterior cornea (0.29%) was significantly better ( P < 0.001) than the posterior corneal curvature (0.57%). CONCLUSION The CR for the post-LASIK cornea with Pentacam was the best for the anterior corneal curvature. Significantly, Pentacam has a high degree of repeatability for the posterior corneal curvature, which has a potential for early detection of keratectasia in these eyes. Post-LASIK pachymetry with Pentacam also showed excellent repeatability.
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Affiliation(s)
- Rajeev Jain
- Grewal Eye Institute, Sector 9-C, Madhya Marg, Chandigarh - 160 009, India
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Müller A, Craig JP, Grupcheva CN, McGhee CNJ. The effects of corneal parameters on the assessment of endothelial cell density in the elderly eye. Br J Ophthalmol 2004; 88:325-30. [PMID: 14977761 PMCID: PMC1772027 DOI: 10.1136/bjo.2003.019315] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2003] [Indexed: 11/04/2022]
Abstract
BACKGROUND The possible impact of corneal thickness, curvature, and size on the measurement of endothelial cell density (ECD) has largely been ignored in the normal eye. The aim of this study was to investigate the possible impact of the main corneal parameters on the analysis of ECD values at the central, superior, and temporal parts of the corneal surface. METHODS All 75 participants (52 females, 23 males) were assessed as part of a pre-cataract surgery investigation. The mean age was 75.7 (SD 10.9) years. Confocal microscopy was used to measure ECD and the percentage of six sided cells at the central, superior, and temporal parts of the cornea. The Orbscan II topography system was used to measure corneal thickness, topography, and horizontal corneal diameter. RESULTS The mean central ECD measured was 2488 (SD 301) cells/mm(2), compared with 2525 (SD 505) cells/mm(2) in the temporal cornea and 2639 (SD 398) cells/mm(2) in the superior cornea. The regional differences in ECD were not significant (p>0.14). The central ECD was significantly correlated to the central (mean 0.593 (SD 0.039) mm, p = 0.021) as well as the temporal (0.628 (SD 0.039) mm, p<0.001) and the superior corneal thickness (SD 0.644 (SD 0.048) mm, p = 0.018). The mean corneal curvature at the centre (7.7 (SD 0.34) mm, p = 0.002) as well as 3 and 5 mm from the apex was significantly related to ECD (p = 0.008 and p = 0.009, respectively). CONCLUSIONS The study suggests that in an older population, lower ECD values would be expected in thinner and/or steeper corneas.
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Affiliation(s)
- A Müller
- Department of Ophthalmology, The University of Auckland, Auckland, New Zealand.
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Abstract
BACKGROUND A new commercially available device (IOLMaster, Zeiss Instruments) provides high resolution non-contact measurements of axial length (using partial coherent interferometry), anterior chamber depth, and corneal radius (using image analysis). The study evaluates the validity and repeatability of these measurements and compares the findings with those obtained from instrumentation currently used in clinical practice. METHOD Measurements were taken on 52 subjects (104 eyes) aged 18-40 years with a range of mean spherical refractive error from +7.0 D to -9.50 D. IOLMaster measurements of anterior chamber depth and axial length were compared with A-scan applanation ultrasonography (Storz Omega) and those for corneal radius with a Javal-Schiötz keratometer (Topcon) and an EyeSys corneal videokeratoscope. RESULTS Axial length: the difference between IOLMaster and ultrasound measures was insignificant (0.02 (SD 0.32) mm, p = 0.47) with no bias across the range sampled (22.40-27.99 mm). Anterior chamber depth: significantly shorter depths than ultrasound were found with the IOLMaster (-0.06 (0.25) mm, p <0.02) with no bias across the range sampled (2.85-4.40 mm). Corneal radius: IOLMaster measurements matched more closely those of the keratometer than those of the videokeratoscope (mean difference -0.03 v -0.06 mm respectively), but were more variable (95% confidence 0.13 v 0.07 mm). The repeatability of all the above IOLMaster biometric measures was found to be of a high order with no significant bias across the measurement ranges sampled. CONCLUSIONS The validity and repeatability of measurements provided by the IOLMaster will augment future studies in ocular biometry.
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Affiliation(s)
- J Santodomingo-Rubido
- Neurosciences Research Institute, School of Life and Health Sciences, Aston University, Birmingham, UK
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