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Feng Y, Nitter T, Bertelsen G, Stojanovic A. Repeatability and agreement of total corneal astigmatism measured in keratoconic eyes using four current devices. Clin Exp Ophthalmol 2024. [PMID: 39034272 DOI: 10.1111/ceo.14423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/23/2024]
Abstract
BACKGROUND To evaluate repeatability and agreement in measurements of total corneal astigmatism (TCA) in keratoconic eyes, using four optical coherence tomography (OCT)-based devices: Anterion, Casia SS-1000, IOLMaster 700, and MS-39. METHODS Three consecutive measurements were taken with each device in 136 eyes. TCA values were converted into components J0 and J45. The Anterion and the IOLMaster 700 also provided axial length (AL) measurements. The repeatability was calculated using pooled within-subject standard deviation (Sw). The agreement among the four devices was assessed by pairwise comparisons and Bland-Altman plots. RESULTS For all devices, the repeatability of TCA measurements showed Sw ≤0.23 D for TCA magnitude, ≤0.14 D for J0, and ≤0.12 D for J45. There were statistically significant differences in TCA magnitude for each pair, except for IOLMaster 700 with MS-39, and Anterion with MS-39. The repeatability (Sw) of axis measurements had a statistically significant negative correlation with the TCA magnitude (p < 0.001 for all devices). Both Anterion and IOLMaster 700 had high repeatability in AL measurements (Sw: 0.007 mm for Anterion and 0.009 mm for IOLMaster 700). The difference in AL between the two was 0.015 ± 0.033 mm (p < 0.001). CONCLUSIONS All four devices showed good repeatability in TCA measurements in keratoconic eyes, the agreement for TCA measurements between the tested devices was generally low. Anterion and IOLMaster 700 showed good repeatability and agreement in AL measurements.
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Affiliation(s)
- Yue Feng
- Institute of Community Medicine, Faculty of Health Sciences, University in Tromsø, Tromsø, Norway
| | | | - Geir Bertelsen
- Institute of Community Medicine, Faculty of Health Sciences, University in Tromsø, Tromsø, Norway
- Department of Ophthalmology, University Hospital North Norway, Tromsø, Norway
| | - Aleksandar Stojanovic
- Department of Ophthalmology, University Hospital North Norway, Tromsø, Norway
- Institute of Clinical Medicine, Faculty of Health Sciences, University in Tromsø, Tromsø, Norway
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Zhang J, Liu S, Shao T, Li H, Wang H, Long K. Impact of Corneal Toricity on the Distribution of Corneal Epithelial Thickness. J Refract Surg 2023; 39:482-490. [PMID: 37449507 DOI: 10.3928/1081597x-20230609-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
PURPOSE To investigate the impact of corneal toricity on the distribution characteristics of corneal epithelial thickness (CET). METHODS A total of 330 eyes in 330 healthy participants were included in this study. They were divided into two groups based on the median of the corneal toricity value: low-toricity group (corneal toricity < 1.50 diopters) and high-toricity group (corneal toricity ≥ 1.50 diopters). The CET within a 9-mm-diameter area of the central cornea was obtained using optical coherence tomography. The difference of CET value between flat and steep meridians (F-S CET) was defined to evaluate the CET distribution. The F-S CET between the two groups was compared, and the correlations between F-S CET and the corneal toricity were analyzed. RESULTS The CET was thinner in the superior-peripheral area than in other areas. A slight intergroup difference was noted in terms of the F-S CET at the paracentral (0.11 ± 0.93 vs 0.32 ± 0.92, P = .038), midperipheral (0.45 ± 0.78 vs 0.77 ± 0.89, P = .001), and peripheral (3.11 ± 2.18 vs 4.10 ± 2.38, P < .001) zone. In each zone, the difference in F-S CET between the two groups was less than 1 μm. As the area expanded, the F-S CET continued to increase (F = 850.303, P < .001). A weak correlation was observed between F-S CET and corneal toricity (r = 0.103 to 0.240); however, this correlation was not significant in the paracentral zone. Covariance analysis demonstrated that F-S CET was slightly correlated with age, refractive state, and intraocular pressure. CONCLUSIONS The corneal toricity did not significantly affect the distribution of the corneal epithelium in normal corneas. [J Refract Surg. 2023;39(7):482-490.].
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Gurnani B, Mishra D, Kaur K, Heda A, Sahu A. Evolution of manual small-incision cataract surgery from 8 mm to 2 mm - A comprehensive review. Indian J Ophthalmol 2022; 70:3773-3778. [PMID: 36308095 PMCID: PMC9907246 DOI: 10.4103/ijo.ijo_1567_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Cataract is the most common cause of reversible blindness worldwide, accounting for approximately 50% of blindness worldwide. Cataract surgery is the most common surgical procedure performed in routine ophthalmic practice. It has undergone tremendous evolution, and the incision size has progressively reduced from 10-12 mm in extracapsular cataract surgery (ECCE) to 6-8 mm for manual small-incision cataract surgery (MSICS) and 2.2-2.8 mm in phacoemulsification. In a developing country like India, with a massive backlog of cataract, everyone cannot afford private surgery like phacoemulsification. Moreover, annual maintenance of the machine, cost of foldable IOLs, need for greater skill, learning curve, and difficulty in performing the surgery in mature and brown cataracts are other barriers. Due to these factors, MSICS is the surgery of choice in the developing world, with profound societal and economic benefits and similar visual recovery compared to phacoemulsification. During the last two decades, MSICS gained popularity in developing countries and has undergone tremendous advances. This article aims to review the various techniques of MSICS and how the surgery has evolved over the years, particularly focusing on the current technique of 2-mm MSICS.
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Affiliation(s)
- Bharat Gurnani
- Consultant Cataract, Cornea and Refractive Services, Amritsar, Punjab, India
| | - Deepak Mishra
- Associate Professor, Department of Ophthalmology, Regional Institute of Ophthalmology, Banaras Hindu University, Varanasi, Uttar Pradesh, India,Correspondence to: Dr. Deepak Mishra, Associate Professor, Regional Institute of Ophthalmology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India. E-mail:
| | - Kirandeep Kaur
- Consultant Cataract, Pediatric Ophthalmology and Strabismus Services, Dr. Om Parkash Eye Institute, Amritsar, Punjab, India
| | - Aarti Heda
- Consultant Glaucoma, National Institute of Ophthalmology, Pune, Maharashtra, India
| | - Amulya Sahu
- Department of Ophthalmology, Sahu Eye Hospital and Kamal Nethralay Pvt Ltd, Mumbai, Maharashtra, India
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Liu S, Yu L, Lu Z, Cheng C, Gu X, Liu J, Zhou X. Effect of keratometric astigmatism on visual outcomes following small incision lenticule extraction. Front Med (Lausanne) 2022; 9:982892. [PMID: 36330059 PMCID: PMC9623282 DOI: 10.3389/fmed.2022.982892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 09/29/2022] [Indexed: 11/18/2022] Open
Abstract
Purpose To investigate the influence of keratometric astigmatism on visual outcomes following small incision lenticule extraction (SMILE). Methods Eighty eyes undergoing SMILE for myopia correction were classified into two groups based on preoperative keratometric astigmatism: low keratometric astigmatism (LA) and high keratometric astigmatism (HA) groups. Refractive outcomes, vector components, and changes in higher order aberrations (HOAs) were evaluated preoperatively and 6 months postoperatively. Results At the postoperative 6-month visit, no significant difference was observed in the decentered distance between the HA and LA groups (HA: 0.17 ± 0.08 mm, LA: 0.16 ± 0.08 mm, P = 0.189). No significant differences in the correction index (P = 0.481), absolute angle of error (P = 0.104), or index of success (P = 0.147) were observed between the two groups. There was no significant difference in the induction of corneal aberrations between the two groups. Furthermore, there were no significant associations between the decentered distance and the vector components of astigmatic correction or induction of higher-order aberration in the HA group (P ≥ 0.294, P ≥ 0.112) or the LA group (P ≥ 0.323, P ≥ 0.080). Conclusions SMILE for high keratometric astigmatism could achieve comparable treatment centration and visual quality to that of low keratometric astigmatism
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Affiliation(s)
- Shengtao Liu
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Affiliated Eye Hospital of Nanchang University, Nanchang, China
| | - Lanhui Yu
- Affiliated Eye Hospital of Nanchang University, Nanchang, China
| | - Zhiyuan Lu
- Affiliated Eye Hospital of Nanchang University, Nanchang, China
| | - Chiwen Cheng
- Affiliated Eye Hospital of Nanchang University, Nanchang, China
| | - Xuejun Gu
- Affiliated Eye Hospital of Nanchang University, Nanchang, China
| | - Jingying Liu
- Affiliated Eye Hospital of Nanchang University, Nanchang, China
- *Correspondence: Jingying Liu
| | - Xingtao Zhou
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Xingtao Zhou
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Liu S, Zhang X, Zhou X. Toric Lenticule Implantation for Correction of Hyperopia and Astigmatism Following Small Incision Lenticule Intrastromal Keratoplasty With the Triple Marking Method. J Refract Surg 2022; 38:82-88. [DOI: 10.3928/1081597x-20211117-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kanclerz P, Khoramnia R, Wang X. Current Developments in Corneal Topography and Tomography. Diagnostics (Basel) 2021; 11:diagnostics11081466. [PMID: 34441401 PMCID: PMC8392046 DOI: 10.3390/diagnostics11081466] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/07/2021] [Accepted: 08/11/2021] [Indexed: 02/07/2023] Open
Abstract
Introduction: Accurate assessment of the corneal shape is important in cataract and refractive surgery, both in screening of candidates as well as for analyzing postoperative outcomes. Although corneal topography and tomography are widely used, it is common that these technologies are confused. The aim of this study was to present the current developments of these technologies and particularly distinguish between corneal topography and tomography. Methods: The PubMed, Web of Science and Embase databases were the main resources used to investigate the medical literature. The following keywords were used in various combinations: cornea, corneal, topography, tomography, Scheimpflug, Pentacam, optical coherence tomography. Results: Topography is the study of the shape of the corneal surface, while tomography allows a three-dimensional section of the cornea to be presented. Corneal topographers can be divided into large- and small-cone Placido-based devices, as well as devices with color-LEDs. For corneal tomography, scanning slit or Scheimpflug imaging and optical coherence tomography may be employed. In several devices, corneal topography and tomography have been successfully combined with tear-film analysis, aberrometry, optical biometry and anterior/posterior segment optical coherence tomography. Conclusion: There is a wide variety of imaging techniques to obtain corneal power maps. As different technologies are used, it is imperative that doctors involved in corneal surgery understand the science and clinical application of devices for corneal evaluation in depth.
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Affiliation(s)
- Piotr Kanclerz
- Hygeia Clinic, Department of Ophthalmologyul, Jaśkowa Dolina 57, 80-286 Gdańsk, Poland
- Helsinki Retina Research Group, University of Helsinki, 00100 Helsinki, Finland
- Correspondence:
| | - Ramin Khoramnia
- The David J. Apple International Laboratory for Ocular Pathology, Department of Ophthalmology, University of Heidelberg, 69120 Heidelberg, Germany;
| | - Xiaogang Wang
- Department of Cataract, Shanxi Eye Hospital, Taiyuan 030002, China;
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O'Neill BP, Diakonis VF, Tsaousis KT, Weinstock RJ. Outcomes of toric IOL implantation guided by iris-registered femtosecond laser capsulotomy markings. Int Ophthalmol 2021; 41:4009-4015. [PMID: 34313930 DOI: 10.1007/s10792-021-01973-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 07/16/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE To assess the accuracy and stability of iris-registered femtosecond laser-assisted anterior capsule axis markings (compensating cyclotorsion) along with refractive and visual outcomes after toric IOL implantation. METHODS This prospective case series included eyes with visually significant cataracts and regular corneal astigmatism ranging from 1.25D to 4.0D, which received FLACS and toric IOL implantation, at The Eye Institute of West Florida, Largo, Florida, USA. Preoperative iris registration was used in conjunction with a femtosecond laser platform to create cyclotorsion corrected axis marks at the capsulotomy edge to facilitate toric IOL axial alignment. Patients were examined one, seven and thirty days after surgery to assess capsulotomy marks axis, toric IOL axis along with visual and refractive outcomes. RESULTS Eighteen eyes of 13 patients aged 74.35 ± 8.65 years were included. Mean pre-op CDVA was 0.24 ± 0.16 LogMAR, while mean post-op UDVA was 0.09 ± 0.09 LogMAR. Mean pre-op corneal astigmatism was 1.85 ± 0.41 D, decreasing to 0.24 ± 0.41 D of refractive astigmatism postoperatively (p < 0.001). The capsular toric axis markings were visible in 100% of eyes throughout the follow-up; the mean difference between intended capsulotomy mark axis and measured capsulotomy mark axis was 1.6°, 1.7° and 1.3 o at the 1, 7 and 30 day intervals (p > 0.05), respectively. No capsule-related or any other type of complications was noted. CONCLUSIONS Iris-registered femtosecond laser-assisted anterior capsule axis markings are safe and may be considered as an alternative option to the known axis marking techniques for toric IOL axial alignment at the time of cataract surgery.
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Affiliation(s)
| | | | - Konstantinos T Tsaousis
- Department of Ophthalmology, Volos General Hospital, Polymeri 134, 38222, Volos, Thessaly, Greece.
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Hovanesian JA. Comparison of Preoperative Measurements with Intraoperative Aberrometry in Predicting Need for Correction in Eyes with Low Astigmatism Undergoing Cataract Surgery. Clin Ophthalmol 2021; 15:2189-2196. [PMID: 34113071 PMCID: PMC8183187 DOI: 10.2147/opth.s314618] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/03/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose To determine whether intraoperative aberrometry during cataract surgery measures higher levels of absolute astigmatism than preoperative biometry readings and which method yields a lower, final level of astigmatism if the two do not agree. Patients and Methods Retrospective record review of all patients who underwent uncomplicated cataract surgery from February 2015 to May 2019 with planned intraoperative aberrometry. Data analysis included preoperative keratometry, total astigmatism as measured by intraoperative aberrometry, intraocular lens model and power used, and postoperative manifest refraction ≥1 month after surgery. The primary outcome measure was the proportion of patients requiring astigmatism correction (≥0.5 D) when measured by preoperative keratometry vs intraoperative aberrometry. Secondary outcomes included postoperative residual astigmatism, where adjusted preoperative astigmatism fell below the 0.5 D threshold for treatment but the intraoperative measurement was ≥0.5 D or ≥1.0 D. Results A total of 451 patient records were evaluated. Intraoperative aberrometry measured statistically higher levels of mean astigmatism than keratometry (0.86 D vs 0.79 D, respectively; P < 0.0001) and significantly greater astigmatism among patients with 0.5–1.5 D of adjusted preoperative astigmatism (P < 0.0001). Significantly more patients qualified for with-the-rule astigmatism correction when measured by intraoperative aberrometry (n=339; 75%) than by preoperative keratometry alone (n=314; 70%); P < 0.03. This difference did not hold for against-the-rule or oblique astigmatism. For patients whose preoperative biometry astigmatism differed from intraoperative biometry, final postoperative astigmatism was lower when corrected if the adjusted preoperative and intraoperative measurements had a vector difference of <0.5 D, but there was no additional benefit in final astigmatism reduction when the vector difference was ≥0.5 D. Conclusion Using intraoperative biometry readings can produce lower postoperative astigmatism than using preoperative biometry readings, but caution should be used when interpreting intraoperative readings that disagree with preoperative measurements with a vector magnitude of >0.5 D.
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Molina‐martín A, Piñero DP, Caballero MT, Fez D, Camps VJ. Comparative analysis of anterior corneal curvature and astigmatism measurements obtained with three different devices. Clin Exp Optom 2021; 103:618-624. [DOI: 10.1111/cxo.13002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 09/04/2019] [Accepted: 10/09/2019] [Indexed: 11/28/2022] Open
Affiliation(s)
- Ainhoa Molina‐martín
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
- Department of Ophthalmology, Vithas Medimar International Hospital, Alicante, Spain,
| | - María T Caballero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
| | - Dolores Fez
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
| | - Vicent J Camps
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain,
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Alpins N, Ong JKY, Stamatelatos G. Assessing Total Keratometry Astigmatism, Simulated Keratometry, and Total Corneal Topographic Astigmatism Against Manifest Refractive Cylinder. J Refract Surg 2021; 37:198-201. [PMID: 34038302 DOI: 10.3928/1081597x-20210105-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate how the Total Keratometry astigmatism measure from a swept-source optical biometer compares with simulated keratometry astigmatism from the same device, and total corneal topographic astigmatism (CorT Total) derived from a Scheimpflug tomographer. METHODS For normal virgin eyes, the ocular residual astigmatism (ORA) magnitudes were determined based on Total Keratometry, simulated keratometry from the same optical biometer (SimKbiom), and CorT Total and simulated keratometry (SimKScheim) from a Scheimpflug tomographer. The ORA magnitudes for each type of measure were summarized into the standard deviations (ORAsd) and means (ORAmean). The lower the ORAsd, the less variability there is between corneal astigmatism and manifest refractive cylinder. The ORAmean indicates the amount of vectorial difference between the total corneal astigmatism and manifest refractive cylinder. RESULTS The ORAsd for Total Keratometry was not significantly different from the ORAsd for CorT Total (P = .06) or SimKbiom (P = .41). The ORAmean for Total Keratometry was not significantly different from the ORAmean for CorT Total (P = .15), but was significantly lower than the ORAmean for SimKbiom (P < .001). CONCLUSIONS Total Keratometry astigmatism correlates as well with manifest refractive cylinder as simulated keratometry astigmatism from the same device and CorT Total from a Scheimpflug tomographer. The average difference (as quantified by the ORAmean) between Total Keratometry astigmatism and manifest refractive cylinder was comparable to that of CorT Total, and less than that of simulated keratometry. Both of these results support the use of Total Keratometry over simulated keratometry in the planning of astigmatism surgery when corneal values are required. [J Refract Surg. 2021;37(3):198-201.].
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Masiwa LE, Moodley V. A review of corneal imaging methods for the early diagnosis of pre-clinical Keratoconus. JOURNAL OF OPTOMETRY 2020; 13:269-275. [PMID: 31917136 PMCID: PMC7520528 DOI: 10.1016/j.optom.2019.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/22/2019] [Accepted: 11/09/2019] [Indexed: 05/15/2023]
Abstract
BACKGROUND Keratoconus (KC) is a corneal ectasia characterised by steepening corneal curvature, changes in refractive error and corneal thickness that result in visual impairment. Early signs of KC include displacement of the thinnest part of the cornea from the central position, changes in the corneal epithelial layer cell distribution, variations in the anterior corneal astigmatism/posterior corneal astigmatism relationship and a variation in corneal thickness. It is important that we review the corneal imaging methods for the diagnosis of preclinical KC. METHOD An online literature search was carried out on PubMed. Only publications detailing corneal assessment procedures were considered for this review and any publication on instruments that did not generate KC predictability indices were also excluded from the review. The 308 publications were reviewed. DISCUSSION Corneal assessment techniques, with the ability to characterise both the anterior and posterior corneal surfaces, are invaluable in the diagnosis of pre-clinical KC. Reflection based and elevation based corneal imaging systems should be used in conjunction with other assessments such as higher order aberration measuring systems to improve sensitivity and reliability in the diagnosis of pre-clinical KC. Ultra high resolution ultrasound can detect pre-clinical KC. The ability to asses both the epithelium and endothelium makes anterior surface optical coherence tomography a superior technique for pre-clinical KC diagnosis. There is a positive correlation between central corneal thickness and corneal hysteresis. Corneal biomechanics should be considered in conjunction with other corneal assessments in the diagnosis of pre-clinical KC.
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Affiliation(s)
- Lynett Erita Masiwa
- Department of Ophthalmology, University of Zimbabwe, College of Health Sciences, P. O. Box A178, Avondale, Harare, Zimbabwe.
| | - Vanessa Moodley
- School of Health Sciences, Department of Optometry, University of Kwazulu Natal, Durban, South Africa
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Kanellopoulos AJ. Scheimpflug vs Scanning-Slit Corneal Tomography: Comparison of Corneal and Anterior Chamber Tomography Indices for Repeatability and Agreement in Healthy Eyes. Clin Ophthalmol 2020; 14:2583-2592. [PMID: 32943840 PMCID: PMC7481306 DOI: 10.2147/opth.s251998] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 08/14/2020] [Indexed: 12/11/2022] Open
Abstract
Purpose To evaluate and compare the repeatability and agreement of Scheimpflug vs scanning-slit tomography of the cornea and the anterior chamber in terms of keratometric and tomographic indices in healthy eyes. Methods The 20 eyes of 10 healthy participants underwent 3 consecutive measurements using both Scheimpflug-tomography and scanning-slit tomography, diagnostic devices. Multiple corneal and anterior chamber tomographic parameters were recorded and evaluated to include corneal keratometry and its axis; corneal best-fit sphere (BFS), pachymetry mapping, angle kappa, anterior chamber depth (ACD), pupil diameter, and location. Repeatability for each device was assessed using the within each subject standard deviation of sequential exams, the coefficient variation (CV) and the intraclass correlation coefficient (ICC). Agreement between the two devices was assessed using Bland-Altman plots with 95% limits of agreement (LoA) and correlation coefficient (r). Results Both devices were found to have high repeatability (ICC>0.9) both in keratometric and other tomographic measurements. Scheimpflug tomography's repeatability though appeared superior in the average keratometry values, anterior and posterior BFS, thinnest corneal pachymetry value and location (p<0.05). Agreement: Statistically significant inter-device differences were noted in the mean values of K1, K2, BFS, ACD and thinnest corneal pachymetry (p<0.05). Despite the agreement differences noted, the two devices were well correlated (r>0.8) in respective measurements with Scheimpflug delivering consistently lower values than the scanning-slit tomography device. Conclusion Scheimpflug-tomography repeatability was found to be superior to that of scanning-slit tomography in this specific study, in most parameters evaluated. Inter-device agreement evaluation suggests that reading from the two devices may not be used interchangeably in absolute values, yet they are well correlated with Scheimpflug delivering consistently lower values in most.
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Affiliation(s)
- Anastasios John Kanellopoulos
- Department of Ophthalmology, The LaserVision Clinical and Research Eye Institute, Athens, Attiki, Greece.,Department of Ophthalmology, New York University Medical School, New York City, NY, USA
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Diakonis VF, Swann BF, Weinstock RJ. Femtosecond Laser-Assisted Capsulotomy Markings for the Alignment of Toric IOLs: A New Technique. J Refract Surg 2019; 34:711-712. [PMID: 30296332 DOI: 10.3928/1081597x-20180820-01] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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Piñero DP, Molina-Martín A, Camps VJ, de Fez D, Caballero MT. Validation of corneal topographic and aberrometric measurements obtained by color light-emitting diode reflection topography in healthy eyes. Graefes Arch Clin Exp Ophthalmol 2019; 257:2437-2447. [PMID: 31482276 DOI: 10.1007/s00417-019-04453-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 07/12/2019] [Accepted: 08/27/2019] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To evaluate the intrasession repeatability of anterior corneal topographic and aberrometric measurements provided by a color-LED topographer as well as their interchangeability with those provided by a Scheimpflug-based system in healthy eyes. METHODS Thirty-five healthy eyes of 35 patients (age, 16-66 years) were enrolled. A complete eye examination was performed in all cases including a complete corneal analysis with the Scheimpflug-based system Pentacam (Oculus Optikgeräte) (one measurement) and the Cassini system (i-Optics) (three consecutive measurements). Intrasession repeatability of the Cassini measurements was assessed with the within-subject standard deviation (Sw) and the intraclass correlation coefficient (ICC). The Bland-Altman analysis was used to evaluate the agreement between both devices. RESULTS Mean Sw for keratometric readings was 0.02 mm (ICC ≥ 0.992), ranging between 0.16 and 0.05 D (ICC 0.930-0.978) for anterior and total astigmatic measurements. Mean Sw for asphericity and corneal diameter were 0.06 (ICC 0.926) and 0.03 mm (IC 0.997), respectively. Aberrometric parameters showed ICCs ≥ 0.816, except for Z42 (ICC 0.741) and Z44 (ICC 0.544). When comparing devices, statistically significant differences were found for most of topographic and aberrometric data (p ≤ 0.044). Likewise, ranges of agreement between devices were clinically relevant (keratometry > 0.06 mm; total astigmatic components > 0.69 D; asphericity 0.35; second-, third-, and fourth-order Zernike terms, more than 0.20, 0.13, and 0.01 μm, respectively). CONCLUSIONS Consistent anterior corneal topographic, total corneal astigmatic, and aberrometric measurements are obtained with color-LED topography in healthy eyes, which are not interchangeable with those provided by the Scheimpflug-based topography.
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Affiliation(s)
- David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain.
- Department of Ophthalmology, Vithas Medimar International Hospital, Alicante, Spain.
| | - Ainhoa Molina-Martín
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain
| | - Vicent J Camps
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain
| | - Dolores de Fez
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain
| | - María Teresa Caballero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Crta San Vicente del Raspeig s/n, 03690, San Vicente del Raspeig, Alicante, Spain
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15
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Piñero DP, Camps VJ, de Fez D, García C, Caballero MT. Validation of posterior corneal curvature measurements with color light-emitting diode topography. Eur J Ophthalmol 2019; 30:1261-1267. [PMID: 31432704 DOI: 10.1177/1120672119870738] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To evaluate the intrasession repeatability and validity of posterior corneal curvature and astigmatism measurements provided by a color light-emitting diode reflection topography system in healthy eyes. METHODS A total of 40 healthy eyes of 40 patients (age, 16-66 years) were enrolled. A complete eye examination was performed in all cases including posterior topographic analysis with two systems: the Scheimpflug-based system (Pentacam; Oculus Optikgeräte GmbH, Wetzlar, Germany) and the Cassini system (i-Optics; Ophthec, The Hague, The Netherlands). With this last system, three consecutive measurements were taken to assess the level of intrasession repeatability (within-subject standard deviation, Sw; intraclass correlation coefficient). The Bland & Altman analysis was used to evaluate the interchangeability of both devices. RESULTS The Sw was ⩽0.06 mm for all posterior corneal radius measurements, with intraclass correlation coefficient of ⩾0.960. The Sw for the magnitude of astigmatism, J0, and J45 were 0.15, 0.04, and 0.04 D, respectively, with intraclass correlation coefficient values of 0.876, 0.897, and 0.840, respectively. Statistically significant differences between devices were found in all parameters evaluated (p ⩽ 0.025). The interchangeability analysis revealed the presence of clinically relevant limits of agreement for the flattest (0.03 to 0.50 mm) and steepest posterior corneal radii (-0.01 to 0.39 mm). In contrast, limits of agreements were not clinically relevant for the magnitude of posterior astigmatism (-0.17 to 0.27 D) and their power vector components (-0.11 to 0.15 D). CONCLUSION The Cassini system provides consistent measures of posterior corneal curvature and astigmatism in healthy eyes, but only measures of posterior astigmatism can be considered as interchangeable with those provided by the Pentacam.
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Affiliation(s)
- David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain.,Department of Ophthalmology, Vithas Medimar International Hospital, Alicante, Spain
| | - Vicent J Camps
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Dolores de Fez
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - Celia García
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
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Núñez MX, Henriquez MA, Escaf LJ, Ventura BV, Srur M, Newball L, Espaillat A, Centurion VA. Consensus on the management of astigmatism in cataract surgery. Clin Ophthalmol 2019; 13:311-324. [PMID: 30809088 PMCID: PMC6376888 DOI: 10.2147/opth.s178277] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
This project was aimed at achieving consensus on the management of astigmatism during cataract surgery by ophthalmologists from Latin America using modified Delphi technique. Relevant peer-reviewed literature was identified, and 21 clinical research questions associated with the definition, classification, measurement, and treatment of astigmatism during cataract surgery were formulated. Twenty participants were divided into seven groups, and each group was assigned three questions to which they had to respond in written form, after thoroughly reviewing the literature. The assigned questions with corresponding responses by each group were discussed with other participants in round 4 – presentation of findings. The consensus was achieved if approval was obtained from at least 80% of participants. The present paper provides several agreements and recommendations for management of astigmatism during cataract surgery, which could potentially minimize the variability in practice patterns and help ophthalmologists adopt optimal practices for cataract patients with astigmatism and improve patient satisfaction.
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Affiliation(s)
- Maria X Núñez
- Unit of Cornea, Cataract and Refractive Surgery, Grupo de Investigacion Vision Sana, Clinica de Oftalmología de Cali, Universidad Javeriana, Cali, Colombia,
| | - Maria A Henriquez
- Department of Cataract, Department of Research, Oftalmosalud Instituto de Ojos, Lima, Peru
| | - Luis J Escaf
- Clinica Oftalmologica del Caribe (Cofca), Universidad Javeriana, Barranquilla, Colombia
| | - Bruna V Ventura
- Department of Cataract, Altino Ventura Foundation, HOPE Eye Hospital, Recife, Brazil
| | - Miguel Srur
- Centro de la Visión, Filial Clínica Las Condes, Universidad de Los Andes, Santiago de Chile, Chile
| | | | - Arnaldo Espaillat
- Cataract and refractive surgery service, Espaillat Cabral Institute, Santo Domingo, Dominican Republic
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17
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Kim DY, Ha M, Yi R, Kim HW, Chung SH. Comparison of Corneal Astigmatism and Higher-order Aberrations between Color Light-emitting Diode Topographer and Scheimpflug Imager. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2019. [DOI: 10.3341/jkos.2019.60.10.922] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Da Yeong Kim
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul St. Mary's Hospital, Seoul, Korea
| | - Minji Ha
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul St. Mary's Hospital, Seoul, Korea
| | - Rowoon Yi
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul St. Mary's Hospital, Seoul, Korea
| | - Hyo Won Kim
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul St. Mary's Hospital, Seoul, Korea
| | - So-Hyang Chung
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul St. Mary's Hospital, Seoul, Korea
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18
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Jin YY, Zhou Z, Yuan XY, Song H, Tang X. Effect of the posterior corneal surface on total corneal astigmatism in patients with age-related cataract. Int J Ophthalmol 2018; 11:958-965. [PMID: 29977807 DOI: 10.18240/ijo.2018.06.10] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 10/19/2017] [Indexed: 11/23/2022] Open
Abstract
AIM To explore the effect of the posterior astigmatism on total corneal astigmatism and evaluate the error caused by substituting the corneal astigmatism of the simulated keratometriy (simulated K) for the total corneal astigmatism in age-related cataract patients. METHODS A total of 211 eyes with age-related cataract from 164 patients (mean age: 66.8±9.0y, range: 45-83y) were examined using a multi-colored spot reflection topographer, and the total corneal astigmatism was measured. The power vector components J0 and J45 were analyzed. Correlations between the magnitude difference of the simulated K and total cornea astigmatism (magnitude differenceSimK-Tca), anterior J0, and absolute meridian difference (AMD) between the anterior and posterior astigmatisms were calculated. To compare the astigmatism of the simulated K and total cornea both in magnitude and axial orientation, we drew double-angle plots and calculated the vector difference between the two measures using vector analysis. A corrective regression formula was used to adjust the magnitude of the simulated K astigmatism to approach that of the total cornea. RESULTS The magnitude differenceSimK-Tca was positively correlated with the anterior corneal J0 (Spearman's rho= 0.539; P<0.001) and negatively correlated with the AMDR (Spearman's rho=-0.875, P<0.001). When the anterior J0 value was larger than 1.3 D or smaller than -0.8 D, the errors caused by determining the total corneal astigmatism with the karatometric calculation tended to be greater than 0.25 D. An underestimation by 16% was observed for against the rule (ATR) astigmatism and an overestimation by 9% was observed for with the rule (WTR) astigmatism when ignoring the posterior measurements. CONCLUSION Posterior corneal astigmatism should be valued for more precise corneal astigmatism management, especially for higher ATR astigmatism of the anterior corneal surface. We suggest a 9% reduction in the magnitude of the simulated K in eyes with WTR astigmatism, and a 16% addition of the magnitude of the simulated K in eyes with ATR astigmatism.
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Affiliation(s)
| | - Zhen Zhou
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin 300020, China
| | - Xiao-Yong Yuan
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin 300020, China
| | - Hui Song
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin 300020, China
| | - Xin Tang
- Tianjin Medical University, Tianjin 300070, China.,Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin 300020, China.,Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin 300020, China.,Tianjin Eye Institute, Tianjin 300020, China
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19
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Ferreira TB, Ribeiro FJ. Comparability and repeatability of different methods of corneal astigmatism assessment. Clin Ophthalmol 2017; 12:29-34. [PMID: 29339918 PMCID: PMC5745151 DOI: 10.2147/opth.s146730] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose To assess the comparability and repeatability of keratometric and astigmatism values measured by four techniques: Orbscan IIz® (Bausch and Lomb), Lenstar LS 900® (Haag-Streit), Cassini® (i-Optics), and Total Cassini (anterior + posterior surface), in healthy volunteers. Patients and methods Fifteen healthy volunteers (30 eyes) were assessed by the four techniques. In each eye, three consecutive measures were performed by the same operator. Keratometric and astigmatism values were recorded. The intraclass correlation coefficient (ICC) was used to assess comparability and repeatability. Agreement between measurement techniques was evaluated with Bland-Altman plots. Results Comparability was high between all measurement techniques for minimum keratometry (K1), maximum keratometry (K2), astigmatism magnitude, and astigmatism axis, with ICC >0.900, except for astigmatism magnitude measured by Cassini compared to Lenstar (ICC =0.798) and Orbscan compared to Lenstar (ICC =0.810). However, there were some differences in the median values of K1 and K2 between measurement techniques, and the Bland-Altman plots showed a wide data spread for all variables, except for astigmatism magnitude measured by Cassini and Total Cassini. For J0 and J45, comparability was only high for J0 between Cassini and Orbscan. Repeatability was also high for all measurement techniques except for K2 (ICC =0.814) and J45 (ICC =0.621) measured by Cassini. Conclusion All measurement techniques showed high comparability regarding K1, K2, and astigmatism axis. Although posterior corneal surface is known to influence these measurements, comparability was high between Cassini and Total Cassini regarding astigmatism magnitude and axis. However, the wide data spread suggests that none of these devices should be used interchangeably.
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20
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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] [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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Ferreira TB, Ribeiro FJ. A novel color-LED corneal topographer to assess astigmatism in pseudophakic eyes. Clin Ophthalmol 2016; 10:1521-9. [PMID: 27574391 PMCID: PMC4990375 DOI: 10.2147/opth.s113027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To assess the accuracy of corneal astigmatism evaluation measured by four techniques, Orbscan IIz(®), Lenstar LS900(®), Cassini(®), and Total Cassini (anterior + posterior surface), in pseudophakic eyes. PATIENTS AND METHODS A total of 30 patients (46 eyes) who had undergone cataract surgery with the implantation of a monofocal intraocular lens (AcrySof IQ) were assessed after surgery. For each eye, subjective assessment of astigmatism and its axis was performed. Minimum, maximum, and mean keratometry and astigmatism and its axis were evaluated using the four measurement techniques. All measurements were compared with the subjective measurements. Agreement between each measurement technique and subjective assessment was evaluated using Bland-Altman plots. Linear regressions were performed and compared. RESULTS Linear regression analysis of astigmatism axis showed very high R (2) for all models, with Total Cassini showing the least difference to the unit slope (0.052) and the least difference to a null constant (3.790), although not statistically different from the other models. Regarding astigmatism value, the Cassini and Total Cassini models were similar and statistically better than the Lenstar model. Cassini and Total Cassini showed better J0 compared with Orbscan. CONCLUSION On linear regression models, Cassini and Total Cassini showed the best performance regarding astigmatism value. Cassini and Total Cassini also showed the least J0 deviation from the Cartesian origin compared with Orbscan, which had the lowest performance. Total corneal measurement with the color LED topographer seems to be a better technique for astigmatism assessment.
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Emerging Technology in Refractive Cataract Surgery. J Ophthalmol 2016; 2016:7309283. [PMID: 27433353 PMCID: PMC4940542 DOI: 10.1155/2016/7309283] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 05/16/2016] [Indexed: 12/19/2022] Open
Abstract
Technology in cataract surgery is constantly evolving to meet the goals of both surgeons and patients. Recent major advances in refractive cataract surgery include innovations in preoperative and intraoperative diagnostics, femtosecond laser-assisted cataract surgery (FLACS), and a new generation of intraocular lenses (IOLs). This paper presents the latest technologies in each of these major categories and discusses how these contributions serve to improve cataract surgery outcomes in a safe, effective, and predictable manner.
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