Retinal Nerve Fiber Layer Thickness Measured by Spectral Domain Optical Coherence Tomography in Healthy Koreans

PURPOSE: To determine normal retinal nerve fiber layer (RNFL) thickness by age and to investigate the relationships of the RNFL with clinical variables using spectral domain optical coherence tomography (SD-OCT) in healthy Koreans. METHODS: The peripapillary RNFL thicknesses were measured around the optic disc using consecutive circular B-scans with 3.5 mm diameter and automatically calculated using a SD-OCT. RESULTS: Three hundreds fifty-two eyes of 205 healthy subjects were included in the study and RNFL thickness were measured by SD-OCT. Overall average RNFL thickness was 100.2 ± 10.9 µm, and significantly and negatively correlated with age (r = −0.164, p = 0.002). The overall average RNFL thickness decrease per decade was 0.8 µm (95% confidence interval, −0.3 to −1.3, p = 0.019). Mean RNFL thickness of each quadrant was significantly correlated with axial length except in the superior quadrant. CONCLUSIONS: This study describes the normal RNFL thickness values of Koreans as determined by SD-OCT. Furthermore, age was found to be correlated with normal RNFL thickness, however age-related changes were not uniform across every region.

Evaluation of subjects with a moderate cup to disc ratio using optical coherence tomography and Heidelberg retina tomograph 3: Impact of the disc area.

Aim: The aim was to evaluate subjects with a moderate cup to disc ratio using optical coherence tomograph (OCT) and Heidelberg retina tomograph (HRT) 3. Settings and Design: We included 80 patients with early glaucoma and 80 nonglaucomatous subjects with moderate cup/disc ratio (range of 0.5–0.8) to this cross‑sectional study. Subjects and Methods: We compared results of color‑coded algorithms of HRT 3 (Moorfields regression analysis [MRA] and Glaucoma probability score [GPS]) and OCT. All outputs are classified into three categories: Within normal limits (WNLs), borderline and outside normal limits (ONLs). Diagnostic accuracies of algorithms were determined using the highest sensitivity criteria. Results: The sensitivities of global MRA, GPS and OCT were 0.75, 0.925 and 0.725, respectively, in average disc area group and 0.85, 1.0 and 0.425, respectively, in large disc area group. The specificities of global MRA, GPS and OCT were 0.55, 0.15 and 0.85, respectively, in average disc area group and 0.425, 0.025 and 0.80, respectively, in large disc area group. Area under receiver operating characteristic curve (AUROC) of global MRA, GPS and OCT were 0.667, 0.617 and 0.792, respectively, in average disc area group and 0.746, 0.576 and 0.627, respectively, in large disc area group. AUROC of global MRA and OCT combination in the average and large disc area groups were 0.828 and 0.825, respectively. Conclusions: In contrast to GPS and OCT algorithms, diagnostic performance of MRA algorithm increased in large disc area group. Combining MRA and OCT algorithms produced satisfactory diagnostic performance in subjects with an average and large disc area.

Associations between Optic Cup-to-disc Ratio and Systemic Factors in the Healthy Korean Population

PURPOSE: To assess the relationships between optic cup-to-disc ratio (CDR) and age, sex, and other demographic and health characteristics in the healthy Korean population. METHODS: The study design was retrospective and population-based. A total of 28,377 subjects who participated in the Korea National Health and Nutrition Examination Survey between 2008 and 2011 were enrolled in this study. Participants underwent structured interviews as well as systemic and ophthalmic examinations. Patients with glaucoma who were diagnosed using the International Society of Geographical and Epidemiological Ophthalmology classification were excluded. Changes in vertical CDR were examined by age in relation to systemic variables on multiple regression analysis. RESULTS: The mean vertical CDR was 0.34 +/- 0.12. The vertical CDR increased with age from subjects in their 20s to those in their 80s (p < 0.001). The mean CDR in males was significantly higher than that of females (p < 0.001). On multiple regression analysis, the vertical CDR was positively associated with age (p < 0.001), male sex (p < 0.001), diastolic blood pressure (p = 0.009), and intraocular pressure (p < 0.001) but was negatively associated with body mass index (p < 0.001). CONCLUSIONS: Greater vertical CDR was related to age, male sex, higher diastolic blood pressure, higher intraocular pressure, and lower body mass index in healthy Koreans.

Cup-to-Disc Ratio, Intraocular Pressure, and Occlusion Site in Branch Retinal Vein Occlusion

PURPOSE: To investigate correlations among the cup-to-disc ratio (CDR), intraocular pressure (IOP), and the occlusion site in branch retinal vein occlusion (BRVO). METHODS: This prospective study involved 62 eyes with a diagnosis of BRVO. Fundus photography, fluorescein angiography, Goldmann applanation tonometry, and optical coherence tomography were performed. Correlations among CDR, IOP, and the occlusion site were analyzed. RESULTS: A negative correlation was found between the occlusion site and IOP (p<0.001, Pearson's correlation analysis) and between the occlusion site and CDR (p<0.001, Pearson's correlation analysis). However, the correlation between IOP and CDR was poor (p=0.092, Pearson's correlation analysis). CONCLUSIONS: BRVOs with an occlusion site near the optic disc are associated with raised IOP and CDR values. This study suggests that the occurrence of BRVO with an occlusion site near the optic disc indicates that the patient should be evaluated for glaucoma.

Comparison of Cup-to-disc Ratio Using the Superfield Lens and Optical Coherence Tomography

PURPOSE: The author compared the effect of the cup-to-disc ratio using the Volk Superfield lens and optical coherence tomography (OCT) to evaluate its usefulness in glaucoma diagnosis and follow-up. METHODS: One hundred ninety-seven eyes of 100 patients were enrolled: 34 normal, 75 glaucoma suspected, 43 normal tension glaucoma (NTG), 45 primary open angle glaucoma (POAG). Routine ophthalmic examinations, fundus examinations, and cup-to-disc ratio measurement using the Superfield lens after pupil dilatation, visual field test, OCT optic nerve head analysis, and OCT retinal nerve fiber layer analysis were performed. The author compared cup-to-disc ratio using the Superfield lens and OCT in normal, glaucoma suspected, normal tension glaucoma, and primary open angle glaucoma. RESULTS: Using the Superfield lens, the mean cup-to-disc ratio was 0.36+/-0.07 in normal eyes, 0.61+/-0.12 in suspected glaucoma, 0.75+/-0.11 in NTG, 0.70+/-0.17 in POAG. Using OCT, the mean cup-to-disc ratio was 0.58+/-0.13 in normal eyes, 0.69+/-0.12 in suspected glaucoma, 0.80+/-0.10 in NTG, and 0.76+/-0.15 in POAG. In all groups, cup-to-disc ratio using OCT were greater than using the Superfield lens and were statistically significant. CONCLUSIONS: Considering these differences in the clinical assessment of glaucoma, the combined use of the Superfield lens and OCT would be helpful in its diagnosis and follow-up.