1
|
Şimşek C, Kaya C, Karalezli A. Comparison of Central Corneal Thickness Measurements with Four Different New Devices and Ultrasound Pachymetry. Turk J Ophthalmol 2022; 52:318-323. [PMID: 36317802 PMCID: PMC9631500 DOI: 10.4274/tjo.galenos.2021.22465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Objectives: To assess the central corneal thickness (CCT) with 5 different devices, evaluate the repeatability of the devices, and determine the possible relationship between thickness values and sex. Materials and Methods: The study included 308 eyes of 154 patients (76 women, 78 men) between the ages of 18-30 who presented to the Ophthalmology Clinic of Muğla Sıtkı Koçman University Training and Research Hospital. Autorefractor (Topcon, Japan), ultrasound pachymetry (UP) (Ceniscan, USA), high-resolution Pentacam (Oculus, USA), anterior segment-optical coherence tomography (AS-OCT) (Optovue, USA), and Spectralis AS-OCT (Heidelberg, Germany) measurements were assessed. Results: The mean age of the study participants was 23.2±0.2 years and the mean CCT was 540±14.1 μm, with no statistically significant difference in CCT between sexes (p>0.05). Mean CCT values were 557.0±26.7 μm with the autorefractor, 543.6±32.9 μm with UP, 533.8±30.2 μm with the Oculus Pentacam, 519.8±30.1 μm with Optovue AS-OCT, and 547.5±31.6 μm with Heidelberg AS-OCT. Pairwise comparisons between devices showed that the Optovue AS-OCT gave significantly lower CCT measurements than the autorefractor and Heidelberg AS-OCT device (p=0.027 and p=0.033, respectively). The coefficient of repeatability for autorefractor, UP, high-resolution Pentacam, Optovue AS-OCT, and Heidelberg AS-OCT CCT measurements were 1.51%, 2.46%, 3.72%, 2.57%, and 3.34%, respectively. Conclusion: Measurements made with five different devices showed that CCT was comparable and clinically usable. However, it was determined that the Optovue AS-OCT showed lower CCT values compare to other devices. When compared in terms of repeatability, it was found to be lower in the Pentacam than other devices.
Collapse
Affiliation(s)
- Cem Şimşek
- Muğla Sıtkı Koçman University Faculty of Medicine, Department of Ophthalmology, Muğla, Turkey,* Address for Correspondence: Muğla Sıtkı Koçman University Faculty of Medicine, Department of Ophthalmology, Muğla, Turkey E-mail:
| | - Cansu Kaya
- Muğla Sıtkı Koçman University Faculty of Medicine, Department of Ophthalmology, Muğla, Turkey
| | - Aylin Karalezli
- Muğla Sıtkı Koçman University Faculty of Medicine, Department of Ophthalmology, Muğla, Turkey
| |
Collapse
|
2
|
Analysis of structural and vascular changes of the optic nerve head and macula in different stages of primary open angle glaucoma. VOJNOSANIT PREGL 2022. [DOI: 10.2298/vsp200526084p] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Background/Aim. It is possible that patients with open-angle glaucoma be asymptomatic in the early stage of the disease. The aim of this study was to determine the structural and vascular changes of the optic disc (OD) and macula in healthy and primary open-angle glaucoma (POAG) eyes, detected by optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) as well as the correlation of the OCT and OCTA measurements and their association with the presence of POAG. Methods. A total of 196 eyes were included and classified into four groups, out of them 48 were healthy eyes, 51 eyes were with mild POAG, 50 eyes with moderate POAG, and 47 eyes with advanced glaucoma. All subjects underwent standard ophthalmic examination. OCT measured the mean, superior and inferior retinal nerve fiber layer (RNFL) thickness and macular ganglion cell complex (GCC). OCTA evaluated the vessel capillary density (VCD) in OD, foveal avascular zone (FAZ) and macular vessel density (VD) in the superficial (SL) and deep (DL) retinal vascular plexus. Results. Patient characteristics were similar except for decreased visual acuity, thinner corneas, higher intraocular pressure and higher cup/disc ratio in POAG patients. OCT results showed that RNFL and GCC thickness gradually de-creased according to POAG severity. Within the assessment conducted by OCTA, VCD?s value in OD also diminished with the progression of POAG, having the lowest value in patients with advanced glaucoma. The same pattern was observed in vessel density around FAZ and VD values. Comparing the structural and vascular changes, a significant positive correlation was found between RNFL thickness and VCD inside OD, and GCC and VD SL in the macular zone. Conclusion. OCT and OCTA allow of a noninvasive quantification of the structural and vascular changes in OD and the macular zone and accurately distinguish between healthy eyes and eyes with POAG, showing an association with the presence and progression of glaucoma.
Collapse
|
3
|
Anatomical and functional features of photic retinopathy: a spectral domain optical coherence tomography-based longitudinal study. Graefes Arch Clin Exp Ophthalmol 2021; 260:415-423. [PMID: 34215917 DOI: 10.1007/s00417-021-05228-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 04/22/2021] [Accepted: 04/28/2021] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND Photic retinopathy may lead to permanent foveal structural injury, leading to irreversible visual acuity loss. METHOD This prospective observational study evaluated 51 eyes of 30 patients with photic retinopathy. Optical coherence tomography (OCT) imaging was performed for all the eyes at baseline and final follow-up. All the eyes showed a focal outer retinal defect on spectral-domain OCT (SD-OCT) at the junction of the inner and outer photoreceptor segments. SD-OCT was used to measure central macular thickness, maximum horizontal dimension of the defect, maximum defect thickness, and the photic retinopathy index (PRI) through the foveal raster scan. RESULTS Although PRI improved significantly at the final follow-up from baseline with a 17% improvement in PRI after a period of 6 months in photic retinopathy eyes, visual acuity declined for 14% of the patients and was stable for 84%. There was mild correlation of visual acuity with baseline PRI. Baseline PRI was significantly higher in eyes with poorer presenting visual acuity (VA). In total, 33.3% of the eyes showed partial ellipsoid zone recovery at 6 months. The area under curve of the receiver operator characteristic curve for partial ellipsoid zone recovery with the mean baseline PRI as the independent variable was poor at 0.612. CONCLUSION OCT-based ultrastructural features in photic retinopathy seem to have poor correlation with presenting or final visual acuity. To the best of our knowledge, this is the largest study on longitudinal OCT evaluation of photic retinopathy eyes in literature.
Collapse
|
4
|
Doganay S, Tasar A, Cankaya C, Firat PG, Yologlu S. Evaluation of Pentacam‐Scheimpflug imaging of anterior segment parameters in patients with pseudoexfoliation syndrome and pseudoexfoliative glaucoma. Clin Exp Optom 2021; 95:218-22. [DOI: 10.1111/j.1444-0938.2011.00691.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
| | | | | | | | - Saim Yologlu
- Biostatistics, School of Medicine, Inonu University, Malatya, Turkey. E‐mail:
| |
Collapse
|
5
|
Chen JC, Lee LR. Solar retinopathy and associated optical coherence tomography findings. Clin Exp Optom 2021; 87:390-3. [PMID: 15575813 DOI: 10.1111/j.1444-0938.2004.tb03100.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2004] [Revised: 06/16/2004] [Accepted: 06/22/2004] [Indexed: 11/27/2022] Open
Abstract
Solar retinopathy is a rare but well-recognised clinical entity of macular damage, caused by viewing a solar eclipse or direct sun-gazing. Visual deterioration from solar retinopathy typically ranges from 6/9 to 6/60 and in most cases the visual loss is reversible. We present a case of solar retinopathy following direct sun-gazing and illustrate the damage within the retinal structure with optical coherence tomographic (OCT) findings. The visual prognosis of solar retinopathy is usually favourable but prevention remains the mainstay of treatment. The optometrist may play an important role in patient education and reassurance, as well as differentiating solar retinopathy from other likely macular abnormalities.
Collapse
Affiliation(s)
- Jennifer C Chen
- School of Optometry, Queensland University of Technology, Brisbane, Australia
| | | |
Collapse
|
6
|
Sorbara L, Maram J, Fonn D, Woods C, Simpson T. Metrics of the normal cornea: anterior segment imaging with the Visante OCT. Clin Exp Optom 2021; 93:150-6. [DOI: 10.1111/j.1444-0938.2010.00472.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
| | | | | | | | - Trefford Simpson
- School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
E‐mail:
| |
Collapse
|
7
|
Shabbir A, Rasheed A, Shehraz H, Saleem A, Zafar B, Sajid M, Ali N, Dar SH, Shehryar T. Detection of glaucoma using retinal fundus images: A comprehensive review. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2021; 18:2033-2076. [PMID: 33892536 DOI: 10.3934/mbe.2021106] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Content-based image analysis and computer vision techniques are used in various health-care systems to detect the diseases. The abnormalities in a human eye are detected through fundus images captured through a fundus camera. Among eye diseases, glaucoma is considered as the second leading case that can result in neurodegeneration illness. The inappropriate intraocular pressure within the human eye is reported as the main cause of this disease. There are no symptoms of glaucoma at earlier stages and if the disease remains unrectified then it can lead to complete blindness. The early diagnosis of glaucoma can prevent permanent loss of vision. Manual examination of human eye is a possible solution however it is dependant on human efforts. The automatic detection of glaucoma by using a combination of image processing, artificial intelligence and computer vision can help to prevent and detect this disease. In this review article, we aim to present a comprehensive review about the various types of glaucoma, causes of glaucoma, the details about the possible treatment, details about the publicly available image benchmarks, performance metrics, and various approaches based on digital image processing, computer vision, and deep learning. The review article presents a detailed study of various published research models that aim to detect glaucoma from low-level feature extraction to recent trends based on deep learning. The pros and cons of each approach are discussed in detail and tabular representations are used to summarize the results of each category. We report our findings and provide possible future research directions to detect glaucoma in conclusion.
Collapse
Affiliation(s)
- Amsa Shabbir
- Department of Software Engineering, Mirpur University of Science and Technology (MUST), Mirpur- AJK 10250, Pakistan
| | - Aqsa Rasheed
- Department of Software Engineering, Mirpur University of Science and Technology (MUST), Mirpur- AJK 10250, Pakistan
| | - Huma Shehraz
- Department of Software Engineering, Mirpur University of Science and Technology (MUST), Mirpur- AJK 10250, Pakistan
| | - Aliya Saleem
- Department of Software Engineering, Mirpur University of Science and Technology (MUST), Mirpur- AJK 10250, Pakistan
| | - Bushra Zafar
- Department of Computer Science, Government College University, Faisalabad 38000, Pakistan
| | - Muhammad Sajid
- Department of Electrical Engineering, Mirpur University of Science and Technology (MUST), Mirpur- AJK 10250, Pakistan
| | - Nouman Ali
- Department of Software Engineering, Mirpur University of Science and Technology (MUST), Mirpur- AJK 10250, Pakistan
| | - Saadat Hanif Dar
- Department of Software Engineering, Mirpur University of Science and Technology (MUST), Mirpur- AJK 10250, Pakistan
| | - Tehmina Shehryar
- Department of Software Engineering, Mirpur University of Science and Technology (MUST), Mirpur- AJK 10250, Pakistan
| |
Collapse
|
8
|
Woo SE, Lee SH. A Comparison of Central Corneal Thickness Measurements and Measurement Repeatability Using Three Imaging Modalities. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2021. [DOI: 10.3341/jkos.2021.62.2.184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
9
|
Li X, Zhou Y, Young CA, Chen A, Jin G, Zheng D. Comparison of a new anterior segment optical coherence tomography and Oculus Pentacam for measurement of anterior chamber depth and corneal thickness. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:857. [PMID: 32793701 DOI: 10.21037/atm-20-187] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background Accurate measurements of anterior chamber depth (ACD) and regional corneal thickness are especially important for the diagnosis and treatment of many ocular disease. This study aimed to evaluate the repeatability and reliability of a new swept source anterior segment optical coherence tomography (AS-OCT) and its agreement with Oculus Pentacam for measurements of ACD and corneal thickness (CT). Methods The central corneal thickness (CCT), superior corneal thickness (SCT), inferior corneal thickness (ICT), nasal corneal thickness (NCT), temporal corneal thickness (TCT) and ACD of the right eye from forty-nine adults aged 18 to 36 years (24.78±4.36 years old) were measured with Pentacam and AS-OCT (CASIA2). All subjects were measured twice with each device. The repeatability was determined using the coefficient of repeatability (COR), the relative COR and the limits of agreement (LOA). Bland-Altman plot was also used for evaluating the agreement between parameters from the two devices. Results For the repeatability of CASIA2, the COR of the two measurements of ACD, CCT, SCT, ICT, NCT and TCT was 0.31 mm, 18.58, 25.83, 28.32, 26.71 and 22.09 µm respectively. There were no statistically significant differences between the CT and ACD measurements by CASIA2 (P>0.05). For measurements with Pentacam and CASIA2, the COR of ACD, CCT, SCT, NCT, ICT and TCT was 0.294 mm, 13.10, 51.57, 48.06, 56.21 and 47.69 µm respectively. No significant differences were found between the values measured by CAISA2 and Pentacam for CT and ACD (P>0.05). The Bland-Altman analysis also suggested high consistency between measurements obtained by Pentacam and CASIA2. Conclusions Our results suggest that Pentacam and CASIA2 have good agreement in CT and ACD measurements. The two devices can be considered interchangeable for these parameters' measurements in healthy subjects when monitoring corneal conditions or planning ocular surgery. However, subtle differences between CASIA2 and Pentacam should also be kept in mind for certain specific clinical or research purposes.
Collapse
Affiliation(s)
- Xuepei Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yijing Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Charlotte Aimee Young
- Department of Ophthalmology, Third Affiliated Hospital, Nanchang University, Nanchang, China
| | - Aiming Chen
- The Fifth Affiliated Hospital of Sun Yat-sen University, Zhuhai, China
| | - Guangming Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Danying Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
10
|
Kamath SJ, Nayak MK. Central Corneal Thickness as Measured by Spectral-Domain Optical Coherence Tomography in Glaucomatous and Non-Glaucomatous Eyes. JOURNAL OF MEDICAL SCIENCES AND HEALTH 2020. [DOI: 10.46347/jmsh.2019.v05i03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
11
|
Abdellah MM, Mostafa EM, Anber MA, El Saman IS, Eldawla ME. Solar maculopathy: prognosis over one year follow up. BMC Ophthalmol 2019; 19:201. [PMID: 31533669 PMCID: PMC6749640 DOI: 10.1186/s12886-019-1199-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 08/13/2019] [Indexed: 11/19/2022] Open
Abstract
Background To document the visual acuity, spectral domain optical coherence tomography (SD-OCT) findings and prognosis in10 eyes of 6 patients with foveal damage from solar retinopathy in 1 year. Methods This was a prospective, observational case series of patients presented by solar maculopathy at Ophthalmology department, Sohag University. All patients underwent visual acuity (VA) testing, refraction, dilated fundus examination fluorescein angiography (FA) and SD-OCT (spectral Domain ocular coherence Tomography) imaging and follow up for 1 year. Results The mean age was 16.5 years (range 9–27 years, both eyes are affected in 4 patients. The mean spherical equivalent (SE) was – 0.25 ± 0.50 D. The visual acuity of the affected eyes ranged from 0.4 to 0.9 on presentation. At presentation Significant foveal pathology was identified on SD-OCT in 10 eyes, All eyes showed disruption of the photoreceptor ellipsoid zone and the interdigitation zone on SD-OCT, Follow up of the cases continued for 1 year.100% of cases showed improvement in VA: 20% eyes regained 1, 50% eyes with VA of 0.9; two eyes 20% 0.8 and one eyes (10%) with 0.4. The improvement began after 1 week and reached its maximum and became stationary after the 6th month of follow up, the outer retinal hole persist in OCT in 80% of cases. Conclusion Solar maculopathy has a good prognosis yet shows no improvement after 6 months. Young age might pose as a risk factor.
Collapse
|
12
|
Jiang JY, Ong K. Variability of Central Corneal Thickness Measurements-Comparing Zeiss IOL Master and Tomey Corneal Specular Microscope. Asia Pac J Ophthalmol (Phila) 2019; 8:275-279. [PMID: 31356366 PMCID: PMC6727924 DOI: 10.1097/apo.0000000000000243] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 11/30/2018] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The aim of this study was to compare the intraobserver repeatability and agreement of central corneal thickness (CCT) measurements by 2 commonly available instruments, Zeiss IOL Master 700 (SS-OCT-based optical biometry device) and Tomey corneal specular microscope EM-3000 (Noncontact specular microscopy). DESIGN Retrospective study. METHODS This is a retrospective analysis of data from routine clinical practice in which preoperative CCT measurements of 105 patients scheduled for cataract surgery were analyzed. Two consecutive CCT measurements were measured using Zeiss IOL Master 700 and Tomey corneal specular microscope EM-3000 by the same examiner. The repeatability of CCT measurements was analyzed by mean intraobserver difference, coefficient of repeatability (CR), and intraclass correlation. The agreement between the 2 methods was analyzed by mean difference and limits of agreement (LoA) using the Bland-Altman method. RESULTS The mean absolute intraobserver difference between the 2 measurements by Zeiss and Tomey were 3.41 ± 3.98 μm and 8.62 ± 9.52 μm (P < 0.0001), respectively. For Zeiss, the CR was 10.3 μm with 95% LoA of -10.5 to 10.1 μm. For Tomey, the CR was 25.2 μm with 95% LoA of -25.2 to 25.2 μm. The mean CCT measurements ± standard deviation by Zeiss and Tomey were 544.0 ± 38.1 μm and 532.6 ± 40.0 μm, respectively (P = 0.003). The 95% LoA in CCT between the 2 methods was -15.8 to 38.7 μm. CONCLUSIONS Zeiss IOL Master 700 has superior intraobserver repeatability and consistency than Tomey EM-3000. Zeiss produced higher CCT measurements than Tomey; hence, in clinical practice, interchangeability between these 2 methods is limited.
Collapse
|
13
|
Sorkhabi R, Najafzadeh F, Sadeghi A, Ahoor M, Mahdavifard A. Corneal biomechanical changes after trabeculectomy with mitomycin C in primary open-angle glaucoma and pseudoexfoliation glaucoma. Int Ophthalmol 2019; 39:2741-2748. [PMID: 31134423 DOI: 10.1007/s10792-019-01118-4] [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: 01/04/2019] [Accepted: 05/22/2019] [Indexed: 11/24/2022]
Abstract
PURPOSE This study aimed to examine the effect of trabeculectomy with mitomycin C on corneal biomechanical characteristics in PEXG and POAG patients. METHODS In this prospective comparative case series study, 32 glaucoma patients of whom 17 patients were suffering from PEXG and 15 patients from POAG were enrolled. All patients underwent complete ocular examination, CCT using ultrasound pachymetry and corneal biomechanical study using ORA. The patients were hospitalized, and trabeculectomy surgery with mitomycin was done. Three months after surgery, patients were examined and ORA was obtained again. RESULTS The mean CH in patients with PEXG was lower compared to patients with POAG (5.66 ± 1.13, 7.49 ± 0.88, respectively) before surgery, which had a statistically significant difference (P < 0.001). CRF in patients with PEXG was significantly lower compared to patients with POAG (8.19 ± 1.48 vs. 9.35 ± 1.60, respectively) before surgery, with P = 0.049. CH remarkably increased and reached 6.69 ± 0.78 (P < 0.001) in the PEXG group after TBX + MMC surgery. CH increased in the POAG group after TBX + MIC surgery and reached 8.23 ± 1.09, which was statistically significant (P = 0.001). There was a significant relationship between CH and IOPg changes in both PEXG and POAG groups (P < 0.001 and P = 0.01, respectively). Although TBX + MMC surgery changed the amount of CH in PEXG and POAG groups, no significant difference was shown in the parameters between the two groups comparing the CH changes (P = 0.33). CONCLUSION According to the results of this study, the biomechanical characteristics of cornea, particularly CH, shows certain changes following surgery and is increased, reflecting the dynamic nature of these parameters. Our knowledge of the biomechanical changes after glaucoma surgery can help us better understand the pathophysiology of glaucoma diseases and make the right decisions for follow-up of the patients.
Collapse
Affiliation(s)
- Rana Sorkhabi
- Nikookari Hospital (Eye Center), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Farhad Najafzadeh
- Nikookari Hospital (Eye Center), Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Ali Sadeghi
- Eye Research Center, Rassoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Mohamadhosein Ahoor
- Nikookari Hospital (Eye Center), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ali Mahdavifard
- Nikookari Hospital (Eye Center), Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|
14
|
Kazaili A, Lawman S, Geraghty B, Eliasy A, Zheng Y, Shen Y, Akhtar R. Line-Field Optical Coherence Tomography as a tool for In vitro characterization of corneal biomechanics under physiological pressures. Sci Rep 2019; 9:6321. [PMID: 31004101 PMCID: PMC6474860 DOI: 10.1038/s41598-019-42789-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 04/03/2019] [Indexed: 12/02/2022] Open
Abstract
There has been a lot of interest in accurately characterising corneal biomechanical properties under intraocular pressure (IOP) to help better understand ocular pathologies that are associated with elevated IOP. This study investigates the novel use of Line-Field Optical Coherence Tomography (LF-OCT) as an elastographic tool for accurately measuring mechanical properties of porcine corneas based on volumetric deformation following varying IOPs. A custom-built LF-OCT was used to measure geometrical and corneal surface displacement changes in porcine corneas under a range of IOPs, from 0-60 mmHg. Corneal thickness, elastic properties and hysteresis were calculated as a function of pressure. In addition, the effects of hydration were explored. We found that the elastic modulus increased in a linear fashion with IOP. Corneal thickness was found to reduce with IOP, decreasing 14% from 0 to 60 mmHg. Prolonged hydration in phosphate buffered saline (PBS) was found to significantly increase the elastic modulus and corneal hysteresis. Our study demonstrates that LF-OCT can be used to accurately measure the elastic properties based on volumetric deformation following physiological pressures. Furthermore, we show that prolonged hydration in PBS has a significant effect on the measured corneal properties.
Collapse
Affiliation(s)
- Ahmed Kazaili
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK
- Department of Biomedical Engineering, College of Engineering, University of Babylon, Hillah, Iraq
| | - Samuel Lawman
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Brendan Geraghty
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Ashkan Eliasy
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK
| | - Yalin Zheng
- Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, L7 8TX, UK
| | - Yaochun Shen
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
| | - Riaz Akhtar
- Department of Mechanical, Materials and Aerospace Engineering, School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK.
| |
Collapse
|
15
|
Janjetović Ž, Bušić M, Bosnar D, Barać J, Genda I. SPECIFIC CHARACTERISTICS OF OCULAR BIOMETRIC FACTORS IN GLAUCOMATOUS PATIENTS WITH PSEUDOEXFOLIATIVE SYNDROME AS MEASURED BY OPTICAL LOW-COHERENCE REFLECTOMETRY. Acta Clin Croat 2019; 58:87-94. [PMID: 31363329 PMCID: PMC6629193 DOI: 10.20471/acc.2019.58.01.11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The aim of the study was to assess biometric factor aberrations and differences among groups of eyes with cataract and pseudoexfoliative syndrome, cataract and pseudoexfoliative glaucoma, and cataract and primary open-angle glaucoma (POAG), and to determine biometric factors of the eye specific for the group of glaucomatous patients with pseudoexfoliative syndrome by use of optical low-coherence reflectometry. This retrospective study included 72 patients, and the study sample of 102 eyes was divided into the following three groups according to diagnosis: 29 eyes with pseudoexfoliative syndrome and cataract; 36 eyes with POAG and cataract; and 37 eyes with pseudoexfoliative glaucoma and cataract. Data on biometric measurements (central corneal thickness, pupillary diameter, anterior chamber depth, lens thickness, axial length, retinal thickness, astigmatism and white-to-white) obtained by use of optical low-coherence reflectometry on a Lenstar LS 900® (Haag-Streit International) were collected and analyzed by thorough survey of medical documentation of patients scheduled for cataract surgery at Department of Ophthalmology, Sveti Duh University Hospital in Zagreb, Croatia. Comparative analysis of the groups yielded statistically significant differences in central corneal thickness (F2/99=7.066; p=0.001) and lens thickness (F2/96=5.133; p=0.008). The group of eyes diagnosed with pseudoexfoliative glaucoma and cataract had a significantly thinner cornea as compared with the other two groups and a significantly thicker lens as compared with the group of eyes with POAG and cataract. In conclusion, optical low-coherence reflectometry revealed differences in biometric factors among the three groups of eyes, with a statistically significantly thinner cornea and thicker lens in the group of glaucomatous patients with pseudoexfoliative syndrome.
Collapse
Affiliation(s)
| | - Mladen Bušić
- 1Department of Ophthalmology and Optometry, Dr Josip Benčević General Hospital, Slavonski Brod, Croatia; 2Department of Ophthalmology, Sveti Duh University Hospital, Zagreb, School of Medicine, Josip Juraj Strossmayer University, Osijek, Croatia; 3Department of Ophthalmology, Osijek University Hospital Center, School of Medicine, Josip Juraj Strossmayer University, Osijek, Croatia
| | - Damir Bosnar
- 1Department of Ophthalmology and Optometry, Dr Josip Benčević General Hospital, Slavonski Brod, Croatia; 2Department of Ophthalmology, Sveti Duh University Hospital, Zagreb, School of Medicine, Josip Juraj Strossmayer University, Osijek, Croatia; 3Department of Ophthalmology, Osijek University Hospital Center, School of Medicine, Josip Juraj Strossmayer University, Osijek, Croatia
| | - Josip Barać
- 1Department of Ophthalmology and Optometry, Dr Josip Benčević General Hospital, Slavonski Brod, Croatia; 2Department of Ophthalmology, Sveti Duh University Hospital, Zagreb, School of Medicine, Josip Juraj Strossmayer University, Osijek, Croatia; 3Department of Ophthalmology, Osijek University Hospital Center, School of Medicine, Josip Juraj Strossmayer University, Osijek, Croatia
| | - Ivanka Genda
- 1Department of Ophthalmology and Optometry, Dr Josip Benčević General Hospital, Slavonski Brod, Croatia; 2Department of Ophthalmology, Sveti Duh University Hospital, Zagreb, School of Medicine, Josip Juraj Strossmayer University, Osijek, Croatia; 3Department of Ophthalmology, Osijek University Hospital Center, School of Medicine, Josip Juraj Strossmayer University, Osijek, Croatia
| |
Collapse
|
16
|
Özkan Aksoy N, Çakır B, Doğan E, Alagöz G. Evaluation of Anterior Segment Parameters in Pseudoexfoliative Glaucoma, Primary Angle-Closure Glaucoma, and Healthy Eyes. Turk J Ophthalmol 2018; 48:227-231. [PMID: 30405943 PMCID: PMC6216528 DOI: 10.4274/tjo.03271] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 03/30/2018] [Indexed: 12/01/2022] Open
Abstract
Objectives: To evaluate anterior segment parameters measured by dual Scheimpflug corneal topography in pseudoexfoliative glaucoma (PEXG), primary angle-closure glaucoma (PACG), and healthy eyes. Materials and Methods: One hundred forty-three eyes of 86 patients were included in this study. Forty-seven eyes of 38 patients with PEXG, 30 eyes of 15 patients with PACG, and 66 eyes of 33 healthy subjects were evaluated. Patients who underwent previous ophthalmic surgery and contact lens wearers were excluded. After full ophthalmological examination, mean central corneal thickness (CCT), white-to-white horizontal corneal diameter (WTW), pupillary diameter (PD), anterior chamber volume (ACV), anterior chamber depth (ACD), and mean anterior chamber angle were measured by dual Scheimpflug corneal topography and compared between the three groups. Statistical analyses were done using Statistical Package for Social Sciences for Windows 18.0 program. Results: No statistical difference was found in mean age or gender among the study groups (p>0.05). There were also no statistical differences in CCT, WTW, or PD among the groups (p=0.568, p=0.064, p=0.321, respectively). ACV, ACD, and mean anterior chamber angle values were significantly lower in the PACG group compared to the other groups (p=0.000 for all). There was no statistically significant difference in these measurements between the PEXG and normal eyes. Conclusion: ACV and depth and mean anterior chamber angle were statistically different (lower) in PACG when compared with PEXG and healthy eyes. Dual Scheimpflug corneal topography can be used as an objective method for the measurement of anterior segment parameters in glaucoma.
Collapse
Affiliation(s)
- Nilgün Özkan Aksoy
- Sakarya University Training and Research Hospital, Department of Ophthalmology, Sakarya, Turkey
| | - Burçin Çakır
- Sakarya University Training and Research Hospital, Department of Ophthalmology, Sakarya, Turkey
| | - Emine Doğan
- Sakarya University Training and Research Hospital, Department of Ophthalmology, Sakarya, Turkey
| | - Gürsoy Alagöz
- Sakarya University Training and Research Hospital, Department of Ophthalmology, Sakarya, Turkey
| |
Collapse
|
17
|
Muhsen S, Alkhalaileh F, Hamdan M, AlRyalat SA. Central corneal thickness in a Jordanian population and its association with different types of Glaucoma: cross-sectional study. BMC Ophthalmol 2018; 18:279. [PMID: 30373555 PMCID: PMC6206916 DOI: 10.1186/s12886-018-0944-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 10/16/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Central corneal thickness (CCT) has long been implicated to affect glaucoma predisposition. Several reports have identified that thinner CCT is a risk factor for open-angle glaucoma, and that CCT can be very variable between different ethnic groups. In this study, we aim to identify the relation between CCT and different glaucoma parameters in different types of glaucoma in an Arabian ethnicity. METHODS We classified our participants into four main groups: primary open-angle glaucoma (POAG), primary angle-closure glaucoma (PACG), pseudoexfoliative glaucoma (PXFG), and a control group. We obtained demographics, intraocular pressure (IOP), cup to disc ratio (CDR), visual field mean deviation (MD) and pattern standard deviation (PSD), CCT, and retinal nerve fiber layer (RNFL) thickness for each participant. RESULTS We included A total of 119 eyes with glaucoma, including POAG (54 eyes), PXFG (31 eyes) and PACG (34 eyes), we also included 57 control eyes. We found that PACG eyes have the thinnest CCT. Mean measurements of CCT for our groups were: 538.31 μm (SD = 36.30) in eyes with POAG, 544.45 μm (SD = 28.57) in eyes with PXFG, 506.91 μm (SD = 34.55) in eyes with PACG and 549.63 μm (SD = 42.9) in the control group. We found that CCT is significantly correlated with CDR (p = 0.012, r = - 0.231), MD (p < 0.001, r = 0.327),and RNFL thickness (p = .007, r = .283). CONCLUSION In Arabian ethnicity, PACG patients have the thinnest CCT compared to other types of glaucoma, namely POAG and PXFG. We demonstrated that glaucomatous eyes with thinner corneas will probably have more advanced glaucomatous optic neuropathy. Our results emphasize the importance of taking ethnicity into account upon glaucoma management.
Collapse
Affiliation(s)
- Sana' Muhsen
- Ophthalmology, Glaucoma and Anterior Segment Surgeon, University of Jordan Hospital, The University of Jordan, Amman, Jordan
| | | | - Mohammad Hamdan
- School of Medicine, The University of Jordan, Amman, 11942, Jordan
| | - Saif Aldeen AlRyalat
- Department of Ophthalmology, University of Jordan Hospital, The University of Jordan, Amman, 11942, Jordan.
| |
Collapse
|
18
|
Razeghinejad MR, Lee D. Managing normal tension glaucoma by lowering the intraocular pressure. Surv Ophthalmol 2018; 64:111-116. [PMID: 30300624 DOI: 10.1016/j.survophthal.2018.07.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/23/2018] [Accepted: 07/30/2018] [Indexed: 11/28/2022]
Affiliation(s)
| | - Daniel Lee
- Wills Eye Hospital, Glaucoma Service, Philadelphia, Pennsylvania, USA.
| |
Collapse
|
19
|
Gokcinar NB, Yumusak E, Ornek N, Yorubulut S, Onaran Z. Agreement and repeatability of central corneal thickness measurements by four different optical devices and an ultrasound pachymeter. Int Ophthalmol 2018; 39:1589-1598. [PMID: 29984376 DOI: 10.1007/s10792-018-0983-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 06/26/2018] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare the repeatability and agreement of central corneal thickness (CCT) measurements by spectral-domain optical coherence tomography (OCT), corneal topography (CT) with a combined Scheimpflug-Placido system, optical biometry (OB), specular microscopy (SM), and ultrasound pachymetry (UP). METHODS A single observer measured CCT twice in 150 eyes of 150 subjects with each of five devices: Nidek RS-3000 Advance OCT, CSO Sirius combined Scheimpflug-Placido disc system CT, Nidek AL-Scan partial coherence interferometry-based OB, Tomey EM-3000 SM, and Reichert iPac ultrasonic pachymeter. Pachymetry values corrected by the SM device software were also recorded. Levels of agreement between devices were evaluated by Bland-Altman plots with 95% limits of agreement, and repeatability for each device was analysed with intraclass correlation coefficients. RESULTS The mean CCTs measured by OCT, CT, OB, SM, corrected SM, and UP were 544.60 ± 29.56, 536.19 ± 32.14, 528.29 ± 29.45, 524.88 ± 32.38, 537.88 ± 32.38, and 545.29 ± 30.75 μm, respectively. Mean CCT differed significantly between the devices (p < 0.05) apart from between OCT and UP, and between CT and corrected SM. Mean paired differences between devices ranged between 0.68 and 20.41 μm. Repeatability with all devices was excellent (> 0.99). The range of limits of agreement was the least between OCT and UP. CONCLUSIONS Different CCT measurement techniques produce quite different results, so CCT evaluation and follow-up should be performed using the same device or devices with close compatibility.
Collapse
Affiliation(s)
- Nesrin Buyuktortop Gokcinar
- Department of Ophthalmology, Faculty of Medicine, Kırıkkale University Hospital, Yahşihan, Kırıkkale, Turkey.
| | - Erhan Yumusak
- Department of Ophthalmology, Faculty of Medicine, Kırıkkale University Hospital, Yahşihan, Kırıkkale, Turkey
| | - Nurgul Ornek
- Department of Ophthalmology, Faculty of Medicine, Kırıkkale University Hospital, Yahşihan, Kırıkkale, Turkey
| | - Serap Yorubulut
- Department of Statistics, Faculty of Science and Letters, Kırıkkale University, Kırıkkale, Turkey
| | - Zafer Onaran
- Department of Ophthalmology, Faculty of Medicine, Kırıkkale University Hospital, Yahşihan, Kırıkkale, Turkey
| |
Collapse
|
20
|
Assessment of Central Corneal Thickness Using OCT, Ultrasound, Optical Low Coherence Reflectometry and Scheimpflug Pachymetry. Eur J Ophthalmol 2018; 21:132-7. [DOI: 10.5301/ejo.2010.1093] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2010] [Indexed: 11/20/2022]
|
21
|
Bayraktar Ş, Bayraktar Z. Central Corneal Thickness and Intraocular Pressure Relationship in Eyes with and without Previous LASIK: Comparison of Goldmann Applanation Tonometer with Pneumatonometer. Eur J Ophthalmol 2018. [DOI: 10.1177/112067210501500113] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Ş. Bayraktar
- Istanbul Surgery Hospital, Istanbul
- Beyoælu Eye Education and Research Hospital, Istanbul - Turkey
| | | |
Collapse
|
22
|
Comparison of Central Corneal Thickness Measurements Using Ultrasonic Pachymetry, Anterior Segment OCT and Noncontact Specular Microscopy. J Glaucoma 2017; 26:860-865. [PMID: 28834824 DOI: 10.1097/ijg.0000000000000745] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate and compare central corneal thickness (CCT) values measured with anterior segment optical coherence tomography (AS-OCT), noncontact specular microscopy (NCSM), and ultrasound pachymetry (USP). MATERIALS AND METHODS CCT was measured in 182 healthy eyes without ocular abnormalities other than refractive errors. Three consecutive measurements of CCT by the same examiner were obtained during the same session. The testing sequence of AS-OCT and NCSM was randomly selected. The USP always was performed after the noncontact examinations. RESULTS The average CCT measured by AS-OCT, NCSM, and USP were 535.8±35.5, 547.7±38.2, and 537.4±37.5 μm, respectively. The mean differences between modalities were 11.8±14.7 μm (P<0.01) between NCSM and AS-OCT, 10.3±17.7 μm (P<0.01) between NCSM and USP and 1.6±8.6 μm (P=0.02) between USP and AS-OCT. CONCLUSIONS AS-OCT, NCSM, and USP showed an overall strong agreement in measuring CCT. However, CCT measurements with AS-OCT showed a good correlation to those obtained by USP, NCSM tended to give statistically significant higher CCT readings than either alternative and showed the worse repeatability indices. On the basis of our results, CCT measurement obtained with different instruments cannot be considered directly interchangeable.
Collapse
|
23
|
Measurements of Corneal Thickness in Eyes with Pseudoexfoliation Syndrome: Comparative Study of Different Image Processing Protocols. JOURNAL OF HEALTHCARE ENGINEERING 2017; 2017:4315238. [PMID: 29081937 PMCID: PMC5610886 DOI: 10.1155/2017/4315238] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 08/07/2017] [Indexed: 11/17/2022]
Abstract
Purpose Comparative analysis of central and peripheral corneal thickness in PEX patients using three different imaging systems: Pentacam-Scheimpflug device, time-domain optical coherence tomography (OCT) Visante, and swept-source OCT Casia. Materials and Methods 128 eyes of 80 patients with diagnosed PEX were examined and compared with 112 normal, non-PEX eyes of 72 cataract patients. The study parameters included 5 measured zones: central and 4 peripheral (superior, inferior, nasal, and temporal). Results The mean CCT in eyes with PEX syndrome measured with all three instruments was thicker than that in normal eyes. Corneal thickness measurements in the PEX group were statistically significantly different between Pentacam and OCT Casia: central corneal thickness (p = 0.04), inferior corneal zone (p = 0.01), and nasal and temporal corneal zones (p < 0.01). Between Pentacam and OCT Visante inferior, nasal and temporal corneal zones were statistically significantly different (p < 0.01). Between OCT Casia and OCT Visante, there were no statistically significant differences in measured parameters values. Conclusion The central corneal thickness in eyes with PEX syndrome measured with three different independent methods is higher than that in the non-PEX group, and despite variable peripheral corneal thickness, this one parameter is still crucial in intraocular pressure measurements.
Collapse
|
24
|
Abstract
PURPOSE To assess agreement between one ultrasonic (US) and nine optical instruments for the measurement of central corneal thickness (CCT), and to evaluate intra- and inter-operator reproducibility. METHODS In this observational cross-sectional study, two masked operators measured CCT thickness twice in 28 healthy eyes. We used seven spectral-domain optical coherence tomography (SD-OCT) devices, one time-domain OCT, one Scheimpflug camera, and one US-based instrument. Inter- and intra-operator reproducibility was evaluated by intraclass correlation coefficient (ICC), coefficient of variation (CV), and Bland-Altman test analysis. Instrument-to-instrument reproducibility was determined by ANOVA for repeated measurements. We also tested how the devices disagreed regarding systemic bias and random error using a structural equation model. RESULTS Mean CCT of all instruments ranged from 536 ± 42 μm to 577 ± 40 μm. An instrument-to-instrument correlation test showed high values among the 10 investigated devices (correlation coefficient range 0.852-0.995; p values <0.0001 in all cases). The highest correlation coefficient values were registered between 3D OCT-2000 Topcon-Spectral OCT/SLO Opko (0.995) and Cirrus HD-OCT Zeiss-RS-3000 Nidek (0.995), whereas the lowest were seen between SS-1000 CASIA and Spectral OCT/SLO Opko (0.852). ICC and CV showed excellent inter- and intra-operator reproducibility for all optic-based devices, except for the US-based device. Bland-Altman analysis demonstrated low mean biases between operators. CONCLUSIONS Despite highlighting good intra- and inter-operator reproducibility, we found that a scale bias between instruments might interfere with thorough CCT monitoring. We suggest that optimal monitoring is achieved with the same operator and the same device.
Collapse
|
25
|
Ayala M, Karlsson J. No differences in central corneal thickness between open-angle and pseudoexfoliation glaucoma patients. Clin Ophthalmol 2017; 11:733-738. [PMID: 28458512 PMCID: PMC5402997 DOI: 10.2147/opth.s136007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Introduction Measurements of intraocular pressure (IOP) with Goldmann applanation tonometry are affected by central corneal thickness (CCT), as thinner corneas underestimate and thicker corneas overestimate the true IOP value. The literature is controversial regarding CCT values in patients with primary open-angle glaucoma (POAG) and exfoliation glaucoma (XFG). The aim of this study was to evaluate CCT in patients with XFG and POAG. Methods CCT was evaluated with optical coherence tomography (OCT). All participants who were previously diagnosed with either POAG or XFG underwent ophthalmological examinations. Contact lens users and patients with corneal diseases were excluded. Results Totally, 145 patients were enrolled in this study. The mean CCT was 535±30.4 µm in patients with POAG and was 536±33.7 µm in patients with XFG. The result was not statistically significant (P=0.98). The mean age for all participants was 73.8±7.7 years. The study included totally 61 women and 84 men. The two groups were similar in their demographic data, and mean deviation was the only parameter that differed statistically when comparing POAG with XFG (P=0.02). Conclusion Our data indicate that patients with XFG do not have thinner corneas than those with POAG, and therefore, CCT can not explain why they progress differently.
Collapse
Affiliation(s)
- Marcelo Ayala
- Eye Department, Skaraborg Hospital, Skövde, Sahlgrenska Academy, Gothenburg University and Karolinska Institute
| | | |
Collapse
|
26
|
Swierkowska J, Gajecka M. Genetic factors influencing the reduction of central corneal thickness in disorders affecting the eye. Ophthalmic Genet 2017; 38:501-510. [DOI: 10.1080/13816810.2017.1313993] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Marzena Gajecka
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
- Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
| |
Collapse
|
27
|
|
28
|
Akdemir MO, Kirgiz A, Ayar O, Kaldirim H, Mert M, Cabuk KS, Taskapili M. The Effect of Pseudoexfoliation and Pseudoexfoliation Induced Dry Eye on Central Corneal Thickness. Curr Eye Res 2015; 41:305-10. [PMID: 25974410 DOI: 10.3109/02713683.2015.1030505] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE/AIM OF THE STUDY The aim of this study is to investigate the effect of pseudoexfoliation (PEX) and PEX-induced dry eye on central corneal thickness (CCT). MATERIALS AND METHODS This cross-sectional study consists of total 270 eyes of 135 patients (67 females, 68 males) in total. After excluding the PEX (-) 32 eyes with PEX in the other eye, totally 130 eyes in PEX (-) group and 108 eyes in the PEX (+) group were included in the study. The PEX (+) group was regrouped as PEX syndrome (80 eyes of 50 patients) and PEX glaucoma (28 eyes of 20 patients). RESULTS In the PEX (-) group, the mean Schirmer test result was 12 ± 4 mm (4-25 mm), in the PEX syndrome group 10 ± 4 mm (4-22 mm), in the PEX glaucoma group 9 ± 3 mm (4-15 mm). The difference among the PEX (-) group, the PEX syndrome and the PEX glaucoma groups was statistically significant (p < 0.001, p < 0.001, respectively). In the PEX (-) group, the mean tear break up time test result was 11 ± 2 s (5-16 s), in the PEX syndrome group 8 ± 3 (3-16 s), in the PEX glaucoma group 8 ± 3 s (5-15 s). Mean CCT result was 544 µm in the PEX (-), 521 µm in the PEX syndrome group and 533 µm in the PEX glaucoma group. The difference among the PEX (-) group, the PEX syndrome and the PEX glaucoma groups was significant (p < 0.001, p = 0.030, respectively). There was a significant (+) correlation between intraocular pressure and CCT in the eyes with PEX (r = 0.307, p = 0.001). However, there was no statistically significant correlation between CCT, Schirmer and tear break up time tests in the eyes with PEX. CONCLUSIONS PEX material can cause decrease in tear film secretion and disturb tear film stability. There is no effect of PEX-induced dry eye on CCT. Lower CCT values in the eyes with PEX material may be a result of decrease in corneal stromal cell density. Moreover, higher CCT values may be because of decreased endothelial cells in PEX glaucoma patients.
Collapse
Affiliation(s)
- M Orcun Akdemir
- a Department of Ophthalmology , School of Medicine, Bulent Ecevit University , Zonguldak , Turkey and
| | - Ahmet Kirgiz
- b Bagcilar Education and Research Hospital, Eye Clinic , Istanbul , Turkey
| | - Orhan Ayar
- a Department of Ophthalmology , School of Medicine, Bulent Ecevit University , Zonguldak , Turkey and
| | - Havva Kaldirim
- b Bagcilar Education and Research Hospital, Eye Clinic , Istanbul , Turkey
| | - Metin Mert
- b Bagcilar Education and Research Hospital, Eye Clinic , Istanbul , Turkey
| | | | - Muhittin Taskapili
- b Bagcilar Education and Research Hospital, Eye Clinic , Istanbul , Turkey
| |
Collapse
|
29
|
Tan HK, Ahmad Tajuddin LS, Lee MY, Ismail S, Wan-Hitam WH. A Study on the Central Corneal Thickness of Primary Angle Closure and Primary Angle Closure Glaucoma and Its Effect on Visual Field Progression. Asia Pac J Ophthalmol (Phila) 2015; 4:161-5. [PMID: 26065503 DOI: 10.1097/apo.0000000000000058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To determine the mean central corneal thickness (CCT) and the relationship between the CCT and visual field progression in primary angle closure (PAC) and primary angle closure glaucoma (PACG). DESIGN A combined cross-sectional and prospective study on PAC and PACG. METHODS A total of 35 eyes were included in the study for each group of normal control, PAC, and PACG patients from eye clinics in Kota Bharu, state of Kelantan, Malaysia, from January 2007 to November 2009. The PAC and PACG patients were divided into thin and thick CCT groups. They were followed up for 12 to 18 months for visual field progression assessment with their mean Advanced Glaucoma Intervention Study (AGIS) score. RESULTS The CCT was 516.8 ± 26.0 µm for PAC and 509.7 ± 27.4 µm for PACG. Both were significantly thinner compared with the control group with CCT of 540 ± 27.8 µm (P < 0.001). There was a statistically significant increase in the mean AGIS score after 12.9 ± 1.7 months of follow-up in the thin CCT group for PACG (P = 0.002). However, no significant increase in the mean AGIS score was found for the thick CCT group in PACG and for both thin and thick CCT in PAC. CONCLUSIONS The PAC and PACG had statistically significant thinner CCT compared with the controls. Thin CCT was associated with visual field progression based on the mean AGIS score in PACG.
Collapse
Affiliation(s)
- Hui-Ken Tan
- From the *Department of Ophthalmology, Universiti Sains Malaysia, Kubang Kerian, Kota Bharu, Kelantan; and †Department of Ophthalmology, Tengku Ampuan Rahimah Klang Hospital, Klang, Malaysia
| | | | | | | | | |
Collapse
|
30
|
Williams D, Zheng Y, Bao F, Elsheikh A. Fast segmentation of anterior segment optical coherence tomography images using graph cut. EYE AND VISION 2015; 2:1. [PMID: 26605357 PMCID: PMC4657268 DOI: 10.1186/s40662-015-0011-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 01/11/2015] [Indexed: 10/11/2023]
Abstract
Background Optical coherence tomography (OCT) is a non-invasive imaging system that can be used to obtain images of the anterior segment. Automatic segmentation of these images will enable them to be used to construct patient specific biomechanical models of the human eye. These models could be used to help with treatment planning and diagnosis of patients. Methods A novel graph cut technique using regional and shape terms was developed. It was evaluated by segmenting 39 OCT images of the anterior segment. The results of this were compared with manual segmentation and a previously reported level set segmentation technique. Three different comparison techniques were used: Dice’s similarity coefficient (DSC), mean unsigned surface positioning error (MSPE), and 95% Hausdorff distance (HD). A paired t-test was used to compare the results of different segmentation techniques. Results When comparison with manual segmentation was performed, a mean DSC value of 0.943 ± 0.020 was achieved, outperforming other previously published techniques. A substantial reduction in processing time was also achieved using this method. Conclusions We have developed a new segmentation technique that is both fast and accurate. This has the potential to be used to aid diagnostics and treatment planning.
Collapse
Affiliation(s)
- Dominic Williams
- Ocular Biomechanics and Biomaterials Group, School of Engineering, University of Liverpool, Brownlow Hill, Liverpool, L69 3GH UK ; Department of Eye and Vision Science, University of Liverpool, 3rd Floor, UCD Building, Daulby Street, Liverpool, L69 3GA UK
| | - Yalin Zheng
- Department of Eye and Vision Science, University of Liverpool, 3rd Floor, UCD Building, Daulby Street, Liverpool, L69 3GA UK
| | - Fangjun Bao
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, No. 270, Xueyuanxi Road, Wenzhou City, Zhejiang Province 325027 China
| | - Ahmed Elsheikh
- Ocular Biomechanics and Biomaterials Group, School of Engineering, University of Liverpool, Brownlow Hill, Liverpool, L69 3GH UK
| |
Collapse
|
31
|
Das P, Gokani A, Bagchi K, Bhaduri G, Chaudhuri S, Law S. Limbal epithelial stem-microenvironmental alteration leads to pterygium development. Mol Cell Biochem 2015; 402:123-39. [PMID: 25559558 DOI: 10.1007/s11010-014-2320-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 12/23/2014] [Indexed: 12/13/2022]
Abstract
Maintenance of tissue homeostasis relies on the accurate regulation of tissue specific stem cell activity which is governed by the dynamic interaction between the positive and negative feedback modulating mechanism of stem cell microenvironmental niche. Alteration or deregulation of the "stem-microenvironmental networking" provokes disease development. Limbal epithelial stem cells (LESC) are the initiator hierarchy that maintains corneal integrity. Compartmentalization of LESC within the limbal vicinity provides an opportunity to understand the stem-microenvironmental relationship. The purpose of this study was to determine the microenvironmental alteration associated with LESCs fate in pterygium condition in comparison with healthy state. Clinical observations evaluated the ocular surface disorder with respect to corneal vascularization, tear film abnormality, and thickening of limbal area in pterygium patients. Structural alteration of limbal stem/progenitor cells and its neighboring niche components were observed using histology and scanning electron microscopy. Receptor overexpression of TGFβ-R1, EGF-R1, and IL6-Rα and alteration of IL2-Rα expression pointed toward aberration of "stem-microenvironmental networking" in the limbal vicinity during disease development. Increased cell proliferation index along with TERT, Cyclin-D1, and PCNA over-expression in limbal part of pterygium epithelial cells indicated increased cellular proliferation and disturbed homeostatic equilibrium. We postulate that pterygium is associated with limbal microenvironmental anomaly where the resident epithelial cells became hyperproliferative.
Collapse
Affiliation(s)
- Prosun Das
- Stem Cell Research and Application Unit, Department of Biochemistry and Medical Biotechnology, Calcutta School of Tropical Medicine, 108 C R Avenue, Kolkata, 700073, India
| | | | | | | | | | | |
Collapse
|
32
|
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. JOURNAL OF OPTOMETRY 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] [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.
Collapse
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
| | | |
Collapse
|
33
|
Chang IB, Paik DW, Kim TJ, Ha HS, Park JH. Central Corneal Thickness and Corneal Endothelial Cells in Pseudoexfoliation Syndrome. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2013. [DOI: 10.3341/jkos.2013.54.7.1060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- In Boem Chang
- Department of Ophthalmology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Dong Won Paik
- Department of Ophthalmology, Sanggye Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Tai Jin Kim
- Department of Ophthalmology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Hyo Shin Ha
- Department of Ophthalmology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea
| | - Jung Hyun Park
- Department of Ophthalmology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Korea
| |
Collapse
|
34
|
Rhew JY, Choi KR. Corneal Biomechanical Properties of Normal Tension Glaucoma in Young Patients Evaluated with the Ocular Response Analyzer. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2013. [DOI: 10.3341/jkos.2013.54.2.280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Jin Young Rhew
- Department of Ophthalmology, Ewha Womans University School of Medicine, Ewha Institute of Ophthalmology and Optometry, EIOO, Seoul, Korea
| | - Kyu Ryong Choi
- Department of Ophthalmology, Ewha Womans University School of Medicine, Ewha Institute of Ophthalmology and Optometry, EIOO, Seoul, Korea
| |
Collapse
|
35
|
Thompson-Hom AL, Gerding Jr PA. Evaluation of intraocular pressure measurements obtained by use of a rebound tonometer and applanation tonometer in dogs before and after elective phacoemulsification. Am J Vet Res 2012; 73:709-13. [DOI: 10.2460/ajvr.73.5.709] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
36
|
Morita T, Shoji N, Kamiya K, Fujimura F, Shimizu K. Corneal biomechanical properties in normal-tension glaucoma. Acta Ophthalmol 2012; 90:e48-53. [PMID: 21914145 DOI: 10.1111/j.1755-3768.2011.02242.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To investigate the intraocular pressure (IOP) and corneal biomechanical properties of normal and normal-tension glaucoma (NTG) eyes. METHODS This study included 83 normal and 83 NTG eyes. We measured corneal-compensated IOP (IOPcc), Goldmann-correlated IOP (IOPg), corneal resistance factor (CRF), corneal hysteresis (CH) and central corneal thickness (CCT) three times each for normal and NTG eyes using an Ocular Response Analyzer (ORA). RESULTS No significant difference in CCT was seen between normal eyes (541.4 ± 26.8 μm) and NTG eyes (535.4 ± 24.9 μm; p = 0.16). IOPcc was significantly higher in NTG eyes (16.1 ± 2.6 mmHg) than in normal eyes (15.1 ± 2.9 mmHg; p = 0.01), while IOPg was significantly lower in NTG eyes (14.1 ± 2.7 mmHg) than in normal eyes (15.1 ± 3.0 mmHg; p = 0.04). CRF and CH were significantly lower in NTG eyes (CRF, 8.9 ± 1.5 mmHg; CH, 9.2 ± 1.3 mmHg) than in normal eyes (CRF, 10.6 ± 1.4 mmHg; CH, 10.8 ± 1.3 mmHg; p < 0.0001 each). CONCLUSION IOPcc was significantly higher in NTG eyes than in normal eyes. The ORA may be useful for distinguishing between the IOPcc of NTG eyes with normal IOP and that of normal eyes. In addition, the ORA enables CRF and CH to be measured in vivo, and weakness of the lamina cribrosa may be clinically inferred from the fact that CRF and CH were reduced in NTG eyes in our study. Low CRF and CH may be clues to the pathology of NTG.
Collapse
Affiliation(s)
- Tetsuya Morita
- Department of Ophthalmology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
| | | | | | | | | |
Collapse
|
37
|
Central corneal thickness and corneal curvature in pseudoexfoliation syndrome with and without glaucoma. J Glaucoma 2012; 20:410-3. [PMID: 21278594 DOI: 10.1097/ijg.0b013e3181f7afb8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To determine the central corneal thickness (CCT) and corneal curvature (CC) in pseudoexfoliative (PE) eyes with and without glaucoma. METHODS Charts of 551 consecutive patients undergoing preoperative examinations for cataract surgery between April 2006 and May 2009 in our clinic were reviewed retrospectively. Fourty-eight PE patients (48 eyes; 19 with glaucoma, 29 without glaucoma) and 48 age-matched and sex-matched control patients were enrolled in the study. The CCT, CC, intraocular pressure, and axial length were measured by ultrasonic pachymeter, autorefractokeratometer, Goldmann applanation tonometry, and ultrasound biometry, respectively. The independent samples t test and paired samples t test was used for the comparisons of the groups. RESULTS Mean CCT was significantly thinner in all PE and nonglaucomatous PE (Pseudoexfoliation syndrome "PES") eyes than in control eyes (P=0.004 and P=0.005, respectively). There was no difference in CCT between PE glaucoma (PEG) and control eyes (P=0.089). There was no difference in mean keratometry (K) and axial length in the study and control groups. In 22 unilateral PE eyes, mean CCT and K readings were insignificant between the PE eyes and fellow non-PE eyes. CONCLUSIONS CCT was significantly thinner in eyes with PES compared with control eyes; however, difference between the PEG and control eyes was insignificant. In addition, mean K readings were not different in study and control eyes. Thinner CCT in eyes with PES, both as it is an independent risk factor and as a result of artificially lower intraocular pressure readings, may be an illuminating cause for development and rapid progression of glaucoma in the patients with PES.
Collapse
|
38
|
Cho HJ, Yoo ES, Kim CG, Kim JW. Comparison of spectral-domain and time-domain optical coherence tomography in solar retinopathy. KOREAN JOURNAL OF OPHTHALMOLOGY 2011; 25:278-81. [PMID: 21860577 PMCID: PMC3149141 DOI: 10.3341/kjo.2011.25.4.278] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Accepted: 01/03/2011] [Indexed: 11/23/2022] Open
Abstract
The purpose of this article is to compare spectral-domain (SD) and time-domain (TD) optical coherence tomography (OCT) findings in patients with solar retinopathy. Complete ocular examinations and OCT were performed in two patients presenting with acute solar retinopathy soon after observation of an eclipse. Both patients were evaluated with SD-OCT and TD-OCT at the same time. SD-OCT demonstrated characteristic defects at the level of the inner and outer segment junction of the photoreceptors in all the affected eyes and decreased reflectiveness of the retinal pigment epithelium layer. TD-OCT images showed unremarkable findings in two eyes with deteriorated visual acuity. SD-OCT improves diagnosis and assessment of the degree and nature of foveal damage in patients with solar retinopathy and may be an important tool for use in identifying foveal damage not detected by TD-OCT. SD-OCT may be preferable to TD-OCT for confirmation or assessment of the degree of foveal damage in patients with solar retinopathy.
Collapse
Affiliation(s)
- Han Joo Cho
- Department of Ophthalmology, Kim's Eye Hospital, Konyang University College of Medicine, #156Yeongdeungpo-dong 4-ga, Yeongdeungpo-gu, Seoul, Korea. -medical-@hanmail.net
| | | | | | | |
Collapse
|
39
|
Comparison of Oculus Pentacam and Stratus Optical Coherence Tomography for Measurement of Central Corneal Thickness. Cornea 2011; 30:670-4. [PMID: 21242780 DOI: 10.1097/ico.0b013e31820128a4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
40
|
Kohli PG, Randhawa BK, Singh KD, Randhawa GS, Kohli AK. Relation between central corneal thickness and intraocular pressure in Punjabi population. J Med Eng Technol 2009; 34:1-6. [PMID: 19995146 DOI: 10.3109/03091900903247919] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE The motive of this study was to determine the variation of central corneal thickness (CCT) in the Punjabi population and to examine its relationship with intraocular pressure (IOP) using a non-contact tonometer. The study and results emphasize the effects of age, sex and refraction on this relationship, which is important for the diagnosis and prevention of glaucoma in adequate time. METHODS The study design was a cross-sectional, population-based survey. The participants were 279 females and 253 males of Punjab Province, India, in the age group of 21-70 years. The CCT was measured using an ultrasonic pachymeter, and the IOP was measured using an air-puff tonometer in all subjects. RESULTS The mean values of CCT and IOP were observed to vary imprecisely with age. The measurement of both parameters was also affected by sex and refraction. The linear regression analysis suggests that the mean value of CCT grows progressively with increasing value of mean IOP. A significant positive correlation was identified between CCT and IOP in the age group of 21-70 years. The authors inferred that this correlation value varies prominently with age for both sexes, which needs to be investigated further. CONCLUSIONS The authors suggest that CCT is a noteworthy source of variation in IOP measurements for males as well as females belonging to different age groups, when assessing IOP as a risk for glaucoma in the Punjabi population.
Collapse
Affiliation(s)
- Poonam G Kohli
- Department of Physiology, Rajindra Government Medical College and Hospital, Patiala, Punjab, India.
| | | | | | | | | |
Collapse
|
41
|
Abstract
Exfoliation syndrome (XFS) is a major risk factor for glaucoma. It is characterized by a pathological accumulation of polymorphic fibrillar material in the anterior segment of the eye. It is likely that the increase in intraocular pressure (IOP) seen in XFS patients is at least in part because of flakes of material clogging up the trabecular meshwork, and thereby increasing the resistance to outflow and increasing IOP. XFS glaucoma progresses more rapidly, is more resistant to medical treatment and has worse prognosis than other glaucomas. The prevalence of XFS has been found to vary greatly between different studies, raising the possibility of racial and/or environmental modulators. XFS has also been linked to other changes in ophthalmological structures such as; changes in central corneal thickness (CCT), steeper corneal curvature (CC) and nuclear lens opacifications. Some studies have found XFS to be associated with systemic diseases, mostly cardiovascular and cerebrovascular. Exposure to ultra-violet (UV) light has also been investigated as a possible culprit, along with several other plausible factors. The aim of the present study was to determine the prevalence and 5-year incidence of XFS, to establish possible risk factors and/or concomitant symptoms and finally to investigate the relationship between XFS and glaucomatous changes. The Reykjavík Eye Study (RES) is a prospective study based on a random sample from the Icelandic national population sample. The baseline examination was performed in the autumn of 1996, when 1045 persons older than 50 years participated. Of these, 846 (88.2% of survivors) participated in a follow-up 5 years later. All participants went through a standard examination protocol, and answered a comprehensive questionnaire on health and life style. In the prevalence study, XFS was found in 10.7% of subjects, more frequently in women and older persons. Five years later, a further 5.2% of those that participated in the follow-up study and had no signs of XFS at baseline were diagnosed having XFS. We found a strong correlation between IOP and XFS. No difference was found in the anterior segment parameters measured, but there was a significant loss of neural tissue in the XFS as demonstrated by measurements of cup/disk ratio. In conclusion, we find XFS to be frequent among Icelanders, increasing with age and more in women. Our diagnostic criteria are reliable over time. We have also identified possible risk factors that point to a role of antioxidants in the development of XFS. We find changes in corneal curvature and thickness more related to age than XFS.
Collapse
|
42
|
Kitsos G, Gartzios C, Asproudis I, Bagli E. Central corneal thickness in subjects with glaucoma and in normal individuals (with or without pseudoexfoliation syndrome). Clin Ophthalmol 2009; 3:537-42. [PMID: 19898625 PMCID: PMC2770864 DOI: 10.2147/opth.s6484] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Indexed: 11/23/2022] Open
Abstract
Objective: The evaluation of central corneal thickness (CCT) in subjects with pesudoexfoliation glaucoma (PEXG), primary open-angle glaucoma (POAG), and in normotensive individuals with or without pseudoexfoliation syndrome (PXS). Study design/patients and methods: CCT was evaluated with ultrasound pachymetry in a total of 179 individuals: 32 had bilateral PEXG, 55 had bilateral POAG, 35 had PXS, and 57 were healthy individuals without PXS. Results: CCT in PEXG eyes (526.00 ± 34.30 μm) was significantly thinner compared to POAG eyes (549.36 ± 39.3 μm) (P = 0.027) and normal control eyes with (550.64 ± 39.0 μm) or without PXS (547.36 ± 33.1 μm), (P = 0.039 and 0.048 respectively). No statistically significant difference was found comparing CCT values of POAG eyes to control group eyes. Conclusion: The evaluation of CCT is necessary in all patients with glaucoma and especially in those with PEXG due to the thinner cornea and the risk of underestimation of intraocular pressure.
Collapse
Affiliation(s)
- Georgios Kitsos
- Ophthalmology Department, University of Ioannina, Ioannina, Greece
| | | | | | | |
Collapse
|
43
|
Topouzis F, Harris A, Wilson MR, Koskosas A, Founti P, Yu F, Anastasopoulos E, Pappas T, Coleman AL. Increased likelihood of glaucoma at the same screening intraocular pressure in subjects with pseudoexfoliation: the Thessaloniki Eye Study. Am J Ophthalmol 2009; 148:606-613.e1. [PMID: 19427989 DOI: 10.1016/j.ajo.2009.03.024] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 03/18/2009] [Accepted: 03/20/2009] [Indexed: 11/16/2022]
Abstract
PURPOSE To compare the clinical characteristics of primary open-angle glaucoma (POAG) and pseudoexfoliative glaucoma (PEXG) identified in the Thessaloniki Eye Study and to evaluate the proportion of subjects with and without pseudoexfoliation (PEX) who have glaucoma by screening intraocular pressure (IOP). DESIGN Cross-sectional, population-based study. METHODS Randomly selected subjects > or =60 years (n = 2,554) participated in the Thessaloniki Eye Study. Subjects were classified as having POAG or PEXG according to specific criteria. POAG and PEXG cases were compared for various clinical characteristics. The proportion with glaucoma among subjects with PEX and the proportion with glaucoma among subjects without PEX were estimated by IOP levels. RESULTS Among the clinic-visit participants (n = 2,261), 94 subjects (4.2%) had POAG and 41 (1.8%) had PEXG. The prevalence of glaucoma among subjects with PEX was 15.2% and the prevalence of glaucoma among subjects without PEX was 4.7%. In subjects without treatment, the mean IOPs were 19.8 mm Hg and 24.3 mm Hg for POAG and PEXG, respectively. For IOP level >20 mm Hg, the proportion with glaucoma among subjects with PEX was higher than that for glaucoma among subjects without PEX (37% vs 15%; P = .004), while no statistically significant difference was found for IOP level < or =20 mm Hg (2.1% vs 2.1%; P = .999), Fisher exact test. CONCLUSIONS In the Thessaloniki Eye Study, for screening IOP </=20 mm Hg the proportion with glaucoma was similar in subjects with and without PEX. For IOP level >20 mm Hg, the proportion with glaucoma increased highly in subjects both with and without PEX, while it was much higher among those with PEX at the same screening IOP.
Collapse
Affiliation(s)
- Fotis Topouzis
- Department of Ophthalmology, School of Medicine, Aristotle University of Thessaloniki, Ahepa Hospital, Thessaloniki, Greece.
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
PURPOSE During deswelling of organ-cultured human corneas, endothelial cell loss occurs. Therefore, it is necessary to minimize the deswelling time and achieving an optimal central corneal thickness (CCT) of approximately 550 microm at the same time. We investigated the minimal deswelling time necessary and analyzed endothelial cell loss. METHODS Fifty-eight human corneas were stored between 13 and 81 days in organ culture. CCT was measured by optical coherence tomography. Measurements were performed before preparation, during culturing, before deswelling, and after varying deswelling periods (1-72 hours) using 5% dextran. Additionally, vital staining was performed in 6 human corneas to assess endothelial cell loss between 24 and 30 hours of deswelling. To evaluate absolute cell loss, endothelial cells were counted on human corneal pairs after 24 and 30 hours of deswelling. RESULTS After organ culture, mean CCT was 1194 microm. After 24 hours of deswelling in dextran-containing medium, mean CCT was 600 microm, whereas after 30 hours, mean CCT was 510 microm and hardly any corneas showed a CCT of more than 550 microm. Almost no further decrease in CCT was observed thereafter. No factors could be identified predicting the necessary deswelling time; however, paired corneas showed significant correlation of deswelling characteristics. We did not see any differences in endothelial cell loss 24 and 30 hours of deswelling or the ratio of living to dead endothelial cell counts. CONCLUSIONS Deswelling for 24 hours does not provide an optimal corneal thickness. Because endothelial cell loss does not increase between 24 and 30 hours of deswelling, a period of 30 hours is more suitable for obtaining sufficient corneal thickness.
Collapse
|
45
|
Corneal Thickness and Anterior Chamber Depth by Orbscan in Normal and Primary Open-angle Glaucoma Patients in Korea. J Glaucoma 2008; 17:465-9. [DOI: 10.1097/ijg.0b013e31815f52f6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
46
|
Abstract
Short-wavelength visible light (blue light) of the Sun has caused retinal damage in people who have stared fixedly at the Sun without adequate protection. The author quantified the blue-light hazard of the Sun according to the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines by measuring the spectral radiance of the Sun. The results showed that the exposure limit for blue light can be easily exceeded when people view the Sun and that the solar blue-light hazard generally increases with solar elevation, which is in accordance with a model of the atmospheric extinction of sunlight. Viewing the Sun can be very hazardous and therefore should be avoided except at very low solar elevations.
Collapse
Affiliation(s)
- Tsutomu Okuno
- National Institute of Occupational Safety and Health, Japan, Kawasaki, Japan.
| |
Collapse
|
47
|
Chihara E. Assessment of True Intraocular Pressure: The Gap Between Theory and Practical Data. Surv Ophthalmol 2008; 53:203-18. [DOI: 10.1016/j.survophthal.2008.02.005] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
48
|
Kim HY, Budenz DL, Lee PS, Feuer WJ, Barton K. Comparison of central corneal thickness using anterior segment optical coherence tomography vs ultrasound pachymetry. Am J Ophthalmol 2008; 145:228-232. [PMID: 18054888 DOI: 10.1016/j.ajo.2007.09.030] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 09/14/2007] [Accepted: 09/20/2007] [Indexed: 11/20/2022]
Abstract
PURPOSE To determine if there is a systematic difference in central corneal thickness (CCT) measured using anterior segment optical coherence tomography (AS-OCT) as compared with ultrasound pachymetry. DESIGN Prospective observational study. METHODS Consecutive subjects with clinically normal corneas underwent CCT measurement by both ultrasound and AS-OCT while participating in a population-based study in Ghana, West Africa. One eye of each subject was randomly selected for analysis. Two measurements were taken and averaged. Agreement and interobserver variability were also analyzed. RESULTS One hundred and fifty-five subjects of African ethnicity and average age 57 years (standard deviation [SD] 12; range, 40 to 98 years) were included. Measurements by AS-OCT and US were taken a mean of 15 days (maximum, six weeks) apart. The mean (SD) [range] US CCT was 525.3 microm (33.5) [422, 653] and 499.0 microm (32.0) [428, 613] with AS-OCT. Measurements by the two modalities were strongly correlated (r(2) = 0.82; P < .001), and a significant difference was observed between mean US and AS-OCT CCT (SD) [range] of 26.3 microm (14.2) [-63, 12] (P < .001). The width of the limits of agreement was 28 microm, about 6% of the average pachymetry reading. In 50 eyes randomly remeasured with OCT by a second observer, the intraclass correlation coefficient was 0.91. There was a small but significant systematic difference between observers (mean 6.9 microm, SD 10.9 microm), or 1.4% (P < .001), increasing the difference noted above. CONCLUSION There is a reproducible systematic difference between CCT measurements taken with ultrasound and OCT. It is important to note in clinical practice, that measurements acquired by these two modalities are not directly interchangeable.
Collapse
Affiliation(s)
- Hanna Y Kim
- Department of Ophthalmology, Stanford University, Stanford, CA, USA
| | | | | | | | | |
Collapse
|
49
|
Arnarsson A, Damji KF, Sverrisson T, Sasaki H, Jonasson F. Pseudoexfoliation in the Reykjavik Eye Study: prevalence and related ophthalmological variables. ACTA ACUST UNITED AC 2008; 85:822-7. [PMID: 18028119 DOI: 10.1111/j.1600-0420.2007.01051.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE To examine the age and sex-specific prevalence of pseudoexfoliation syndrome (PEX) and its relationship with some ophthalmological variables. METHODS We carried out a population-based study using a random sample taken from the national population census for citizens of Reykjavik, aged > or = 50 years. A total of 1045 individuals participated in all parts of the study. Pseudoexfoliation was established by slit-lamp examination with a maximally dilated pupil carried out by two experienced ophthalmologists, who were masked to one another's results except in cases of disagreement where they had to reach a consensus. RESULTS In all, 108 (10.7%) persons were found to have PEX in at least one eye. Prevalence increased from 2.5% in those aged 50-59 years to 40.6% in those aged > or = 80 years. Women were more frequently affected than men (12.3% versus 8.7%). This difference remained statistically significant after controlling for the effect of age (p < 0.001). Eyes with PEX were found to have higher intraocular pressure (IOP) than eyes without PEX (p < 0.05). However, PEX was not found to be related to central corneal thickness, anterior chamber depth, lens thickness, nuclear lens opacifications or optic disc morphology in a multivariate model. CONCLUSIONS Pseudoexfoliation is an age-related phenomenon commonly found in Iceland. It is more commonly found in women than in men and is associated with elevated IOP.
Collapse
Affiliation(s)
- Arsaell Arnarsson
- Department of Ophthalmology, University of Iceland, Reykjavik, Iceland
| | | | | | | | | |
Collapse
|
50
|
Hepsen IF, Yağci R, Keskin U. Corneal curvature and central corneal thickness in eyes with pseudoexfoliation syndrome. Can J Ophthalmol 2007; 42:677-80. [PMID: 17891195 DOI: 10.3129/i07-145] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
BACKGROUND Previous studies have reported different central corneal thickness (CCT) values in eyes with pseudoexfoliation syndrome (PXS). There has been no report about corneal curvature (CC) in PXS eyes. The aim of this study was to investigate the CCT together with the CC in PXS eyes with and without glaucoma. METHODS The CC (simulated keratometry 1 [SimK1], SimK2, and mean K) and CCT were prospectively studied by rotating a Scheimpflug camera in 72 PXS eyes and comparing them with 65 normal eyes. RESULTS In all PXS eyes, the mean K was significantly steeper than in control eyes (44.1 [SD 1.5] diopters (D) vs. 43.2 [SD 2.0] D, p = 0.04). When PXS eyes were subcategorized, the mean K was significantly steeper in both normotensive PXS eyes (44.6 [SD 1.6] D) and pseudoexfoliation glaucoma (PEXG) eyes (44.0 [SD 1.2] D) than normal eyes (43.2 [SD 2.0] D) (p = 0.001 and 0.02, respectively). In all PXS eyes, the mean CCT (546.4 [SD 39.6] microm) was not significantly different than the control eyes (542.9 [SD 32.2] microm) (p = 0.56). When PXS eyes were subcategorized, however, the CCT was significantly thinner in normotensive PXS eyes and significantly thicker in PEXG eyes. INTERPRETATION It appears that PEXG eyes have a significantly steeper CC and higher CCT than normal eyes. This could be of clinical significance because overestimation of true intraocular pressure may then occur in these eyes.
Collapse
Affiliation(s)
- Ibrahim F Hepsen
- Department of Ophthalmology, School of Medicine, Fatih University, Ankara, Turkey.
| | | | | |
Collapse
|