Logistic Regression Analysis for Early Glaucoma Diagnosis Using Optical Coherence Tomography

Purpose To determine and validate the diagnostic ability of a linear discriminant function(LDF) based on the retinal nerve fiber layer thickness at each of the 12 clockhour positions obtained using optical coherence tomography for discriminating between healthy eyes and eyes with early glaucomatous visual field loss Methods We prospectively selected 62 consecutive healthy individuals and 73 patients with open‐angle glaucoma to calculate the LDF. Another independent prospective sample of 280 healthy eyes and 302 glaucomatous eyes was used to evaluate the diagnostic accuracy of the LDF Results The proposed function was LDF=15.584 – (12‐ o’clock segment thickness_0.032) – (7‐o’clock segment thickness_0.041) – (3‐o’clock segment thickness[nasal side]_0.121). The greatest area under the receiver operating characteristic curve was observed for our LDF in both populations: 0.962 and 0.922. Our LDF and the average thickness yielded sensitivities of 74.5% and 67.8%, respectively, at a fixed specificity of 95% Conclusion The LDF increased the diagnostic ability of the isolated retinal nerve fiber layer thickness at the 12 clock‐hour positions. Compared with optical coherence tomography–provided parameters, our LDF had the highest sensitivities at 85% and 95% fixed specificities to discriminate between healthy and early glaucomatous eyes

To study the significance of optic disc tomography and retinal nerve fiber layer (RNFL) thickness measurement by spectral-domain optical coherence tomography (OCT) in the diagnosis of glaucoma. It was a noninterventional, observational study. The optic disc topographic parameters and total and regional RNFL thickness were measured by RTVue OCT in 60 normal eyes and 97 glaucomatous eyes. One-way analysis of variance was used to compare the parameters above mentioned between normal and glaucomatous groups. The area under the receiver operating characteristic curve (AUC) and the sensitivity at 80% specificity were used to assess the ability of each testing parameter in the differentiation between normal and glaucoma eyes. There were statistically significant differences in all RTVue OCT measurement parameters (F = 1.024, P = 0.596;F = 36.519, 54.464, 27.659, 36.176, 20.562, 63.833, 30.031, 54.652, 98.146, 78.705, 99.839, 43.728, 75.720, 45.709, 39.380, 33.590, 66.887, 78.335, 45.485;P = 0.000) except disc area. The average RNFL thickness in normal, early, moderate and advanced glaucomatous eyes was 109.950, 93.313, 80.374 and 65.570 µm, respectively. Among the eight regions around the optic disc, the thickest RNFL was located at the inferotemporal (150.066 µm) and superotemporal (146.285 µm) regions in normal eyes, and the superotemporal (108.569, 103.420 and 88.708 µm in early, moderate and advanced glaucomatous eyes, respectively) and inferotemporal (108.201, 102.830 and 86.369 µm in early, moderate and advanced glaucomatous eyes, respectively) regions in glaucomatous eyes. Both in normal and glaucomatous eyes, the thinnest RNFL was located at the nasal and temporal regions, respectively. For optic disc topographic parameters, the highest AUC was vertical cup/disc ratio (AUC = 0.762, 0.946 and 0.988 in early, moderate and advanced glaucomatous eyes, respectively), and the sensitivity at 80% specificity was 62.2%, 76.5% and 99.2% in early, moderate and advanced glaucomatous eyes, respectively. For RNFL thickness, the highest AUC was superotemporal region RNFL thickness (AUC = 0.915) and the sensitivity at 80% specificity was 89.5% in early glaucomatous eyes. The highest AUC was inferior average RNFL thickness (AUC = 0.967) and the sensitivity at 80% specificity was 94.1% in moderate glaucomatous eyes. The highest AUC was average RNFL thickness (AUC = 0.985) and the sensitivity at 80% specificity was 99.2% in advanced glaucomatous eyes. Among the eight regions around the optic disc, RNFL thickness of region ST (AUC = 0.915, 0.926 and 0.966 in early, moderate and advanced glaucomatous eyes, respectively) achieved the highest AUC. RNFL thicknesses of the nasal and temporal regions showed the lowest AUCs. RTVue OCT shows fair discriminating ability in distinguishing normal from glaucomatous eyes. RTVue OCT is a useful equipment for the diagnosis of glaucoma.

To develop a classifier for differentiating between healthy and early stage glaucoma eyes based on peripapillary retinal nerve fiber layer (RNFL) thicknesses measured with optical coherence tomography (OCT), using machine learning algorithms with a high interpretability. Ninety patients with early glaucoma and 85 healthy eyes were included. Early glaucoma eyes showed a visual field (VF) defect with mean deviation >-6.00 dB and characteristic glaucomatous morphology. RNFL thickness in every quadrant, clock-hour and average thickness were used to feed machine learning algorithms. Cluster analysis was conducted to detect and exclude outliers. Tree gradient boosting algorithms were used to calculate the importance of parameters on the classifier and to check the relation between their values and its impact on the classifier. Parameters with the lowest importance were excluded and a weighted decision tree analysis was applied to obtain an interpretable classifier. Area under the ROC curve (AUC), accuracy and generalization ability of the model were estimated using cross validation techniques. Average and 7 clock-hour RNFL thicknesses were the parameters with the highest importance. Correlation between parameter values and impact on classification displayed a stepped pattern for average thickness. Decision tree model revealed that average thickness lower than 82 µm was a high predictor for early glaucoma. Model scores had AUC of 0.953 (95%CI: 0.903-0998), with an accuracy of 89%. Gradient boosting methods provide accurate and highly interpretable classifiers to discriminate between early glaucoma and healthy eyes. Average and 7-hour RNFL thicknesses have the best discriminant power.

To evaluate the correlation and agreement between optical coherence tomography (Cirrus HD-OCT) retinal nerve fiber layer (RNFL) thickness map and scan circle RNFL thickness measurements. ImageJ and custom Perl scripts were used to derive RNFL thickness measurements from RNFL thickness maps of optic disc scans of healthy and glaucomatous eyes. Average, quadrant, and clock-hour RNFL thickness of the map, and RNFL thickness of the areas inside/outside the scan circle were obtained. Correlation and agreement between RNFL thickness map and scan circle RNFL thickness measurements were evaluated using R and Bland-Altman plots, respectively. A total of 104 scans from 26 healthy eyes and 120 scans from 30 glaucomatous eyes were analyzed. RNFL thickness map and scan circle measurements were highly reproducible (eg, in healthy eyes, average RNFL thickness coefficients of variation were 2.14% and 2.52% for RNFL thickness map and scan circle, respectively) and highly correlated (0.55 ≤ R ≤ 0.98). In general, the scan circle provided greater RNFL thickness than the RNFL thickness map in corresponding sectors and the differences tended to increase as RNFL thickness increased. The width of the 95% limits of agreement ranged between 5.28 and 36.80 μm in healthy eyes, and between 11.69 and 42.89 μm in glaucomatous eyes. Despite good correlation between RNFL thickness map and scan circle measurements, agreement was generally poor, suggesting that RNFL thickness assessment over the entire scan area may provide additional clinically relevant information to the conventional scan circle analysis. In the absence of available measurements from the entire peripapillary region, the RNFL thickness maps can be used to investigate localized RNFL thinning in areas not intercepted by the scan circle.

PurposeThe purpose of this study was to compare retinal nerve fiber layer (RNFL) thickness and optical coherence tomography angiography (OCT-A) retinal vasculature measurements in healthy, glaucoma suspect, and glaucoma patients.MethodsTwo hundred sixty-one eyes of 164 healthy, glaucoma suspect, and open-angle glaucoma (OAG) participants from the Diagnostic Innovations in Glaucoma Study with good quality OCT-A images were included. Retinal vasculature information was summarized as a vessel density map and as vessel density (%), which is the proportion of flowing vessel area over the total area evaluated. Two vessel density measurements extracted from the RNFL were analyzed: (1) circumpapillary vessel density (cpVD) measured in a 750-μm-wide elliptical annulus around the disc and (2) whole image vessel density (wiVD) measured over the entire image. Areas under the receiver operating characteristic curves (AUROC) were used to evaluate diagnostic accuracy.ResultsAge-adjusted mean vessel density was significantly lower in OAG eyes compared with glaucoma suspects and healthy eyes. (cpVD: 55.1 ± 7%, 60.3 ± 5%, and 64.2 ± 3%, respectively; P < 0.001; and wiVD: 46.2 ± 6%, 51.3 ± 5%, and 56.6 ± 3%, respectively; P < 0.001). For differentiating between glaucoma and healthy eyes, the age-adjusted AUROC was highest for wiVD (0.94), followed by RNFL thickness (0.92) and cpVD (0.83). The AUROCs for differentiating between healthy and glaucoma suspect eyes were highest for wiVD (0.70), followed by cpVD (0.65) and RNFL thickness (0.65).ConclusionsOptical coherence tomography angiography vessel density had similar diagnostic accuracy to RNFL thickness measurements for differentiating between healthy and glaucoma eyes. These results suggest that OCT-A measurements reflect damage to tissues relevant to the pathophysiology of OAG.

The GDx is a scanning laser polarimeter that has been developed to allow the quantitative analysis of retinal nerve fibre layer (RNFL) thickness. The purpose of this study was to determine whether differences in the RNFL thickness between normal, ocular hypertensive and glaucomatous eyes could be detected using the GDx. RNFL analysis was carried out using the GDx on 33 normal, 145 ocular hypertensive (OHT) and 44 glaucomatous (POAG) eyes. The inclusion criteria for entry into the study did not include the clinical appearance of the RNFL or optic disc, thus eliminating an important source of selection bias. The Kruskal-Wallis one-way analysis of variance was used to determine whether any significant differences existed among the groups in mean total and quadrantic RNFL thickness. When significant differences were found, specific inter-group analysis was carried out using the Mann-Whitney U-test. Significant differences in RNFL thickness were found for the mean total, superior and inferior quadrant values between normals and OHT eyes as compared with POAG eyes. No significant differences were found for these values between the normal and OHT eyes. Analysis of RNFL thickness using the GDx was able to detect differences between POAG eyes compared with normal and OHT eyes, although there was considerable overlap between groups. Further assessment of the technique is required to determine whether it may be useful in screening for the presence of early glaucomatous damage.

PurposeThis study was performed to investigate the interocular symmetry of peripapillary retinal nerve fibre layer (RNFL) thickness, as measured by Cirrus high‐definition spectral‐domain optical coherence tomography (OCT), in healthy eyes. A wide range of subject ages and refractive errors was examined.MethodsThe retinal nerve fibre layer thickness was measured in 1,234 healthy eyes from 617 subjects using OCT. Interocular differences (right eye minus left eye) in global area and quadrant nerve fibre layer thicknesses were measured. The effect of age and refractive error on interocular nerve fibre layer thickness difference was also examined.ResultsMeans (and standard deviations) of subjects' ages and average subject refractive errors were 36.4 ± 19.8 years (range: five to 80 years) and ‐2.67 ± 2.91 (range: ‐14.13 to +5.75 D), respectively. Cutoff limits for normal interocular nerve fibre layer thickness differences (2.5th and 97.5th percentiles of normative data) in the global area and in the superior, nasal, inferior and temporal quadrants were 9.5, 23.0, 15.6, 20.0 and 22.6 μm, respectively. Mean interocular retinal nerve fibre layer thickness differences in global area and in superior, nasal, inferior and temporal quadrants were 0.7 (p < 0.001), ‐3.9 (p < 0.001), 2.6 (p < 0.001), 1.1 (p = 0.007) and 3.0 (p < 0.001) μm, respectively. Interocular nerve fibre layer thickness differences were not significantly correlated with age or refractive error (average of right and left eyes, both p > 0.05).ConclusionsSignificant interocular differences in peripapillary retinal nerve fibre layer thickness exist in healthy eyes, particularly in the superior quadrant. This finding should be considered when comparing retinal nerve fibre layer thickness between right and left eyes.

Purpose: To evaluate the relationship between age and retinal nerve fiber layer (RNFL) thickness in normal subjects, as measured by optical coherence tomography (OCT). Methods: One hundred and forty-four normal subjects (144 eyes), ranging from 16 to 84 years of age, were enrolled in this cross-sectional study. The RNFL thickness was determined using OCT with three circle scans 3.4 mm in diameter. Results: The average RNFL thickness was inversely correlated with age (r = –0.348, p < 0.001). Analyzing the quadrants as a parameter, RNFL thickness in the superior, temporal and inferior quadrants also decreased with age. Using 30-degree segments, there were significant correlations between age and the RNFL thickness of temporal segments (7–11 o’clock). The average RNFL thickness had the highest correlation among all parameters (r = –0.348, p < 0.001). Regarding nasal quadrant thickness, RNFL ratios (average, superior, temporal and inferior RNFL thickness relative to the nasal quadrant thickness) were not significantly correlated with age. The refractive error did not affect RNFL thickness (r = 0.091, p = 0.276). Conclusion: Our study revealed that RNFL thickness, in particular in the temporal quadrant, measured by OCT significantly decreased with age. Age has to be taken into consideration when we compare RNFL thickness between normal and glaucomatous eyes.

Background Glaucoma is the neuropathy of the optic nerve with accelerated apoptosis of the retinal ganglion cells. Optical coherence tomography angiography provides valuable information about the optic nerve and the retinal circulation as an auxiliary tool for glaucoma diagnosis and optic nerve saving. Purpose To evaluate the performance of optical coherence tomography angiography in distinguishing primary open-angle glaucoma from healthy eyes by measuring the radial peripapillary capillary (RPC) vessel density (VD)% and macular superficial capillary plexus (SCP) VD%. Patients and methods A descriptive prospective cross-sectional case–control study was conducted on 60 participants, who were categorized into two groups: group A (30 patients with primary open-angle glaucoma and group B (30 healthy controls of matched age and sex with group A). Structural (retinal nerve fiber layer and ganglion cell complex thickness), functional (the mean deviation, and pattern standard deviation), and vascular parameters [the VD of RPC in scan 4.5×4.5 mm (in whole image, and the peripapillary region) and macular SCP in scan 6×6 mm] were compared between the two groups. Results Statistically significant decreases of VD of RPC of the whole disk, the peripapillary region, and the macular superficial plexus layer were observed in glaucoma eyes compared with controls (all P&lt;0.001). As for the VD of the RPC of the whole disk, the mean value in the healthy control was (51.83±2.31) and in the glaucoma group was (46.21±2.98). For the VD of the RPC of the peripapillary region, the mean value in the healthy control was (52.56±0.2.61), while it was (46.9±3.1) in glaucoma eyes. Regarding VD of the macular superficial plexus layer, the mean value in healthy controls was 47.53±2.1, while it was 43.91±2.81 in glaucoma eyes. Structural, regarding the comparison of the retinal nerve fiber layer thickness between the two groups, the glaucoma patients had a significant (P=0.0001) lower mean value (81.34±0.11) than healthy controls (103.85±0.6.2). Also, for comparing the ganglion cell complex thickness between the two groups, the glaucoma patients had a significant (P=0.0001) lower mean value (80.72±6.9) than healthy controls (99.67±5.8). Functional, significant statistical differences (P=0.0001) of both, the mean deviation [between healthy control (0.18±0.86) and glaucoma group (−4.2±1.9)] and the mean of pattern deviation (P=0.0001) [between healthy control (1.22±0.91) and glaucoma group (4.6±1.72)] were determined. Conclusion Quantitative assessment of the VD of RPC and superficial macular capillary plexus is a promising tool for glaucoma decision making. As compared with healthy controls, the VD of RPC and SCP in glaucoma patients is reduced.

To determine which retinal nerve fiber layer (RNFL) measures obtained with scanning laser polarimetry are most useful in detecting early to moderate glaucomatous visual field loss. One eye from 84 healthy individuals and 83 patients with early to moderate glaucomatous visual field loss (167 eyes) was assessed with a scanning laser polarimeter (Laser Diagnostic Technologies, San Diego, Calif). Three separate scans were obtained, and a baseline scan was created and used in the analyses. Integrated software (program GDx, version 1.0.02; Laser Diagnostic Technologies) was evaluated by assessing its sensitivity and specificity for detecting early and moderate glaucomatous visual field loss. Fisher linear discriminant functions also were developed in this population to assess sensitivity and specificity and were compared with the GDx analyses. There were statistically significant differences between the healthy and glaucomatous eyes for 14 of the 15 RNFL measures (P = .001). However, considerable overlap in measurements between groups was found. With the GDx number, the area under the receiver operator characteristic (ROC) curve was 0.78, and the sensitivity and specificity were 82% and 62%, respectively. Applying the best discriminant function using 3 variables (average thickness, ellipse modulation, and average ellipse thickness) to our study population resulted in an area under the ROC curve of 0.89 and a sensitivity and specificity of 74% and 92%, respectively. A combination of RNFL measures obtained using the scanning laser polarimeter improved the ability to differentiate between healthy eyes and eyes with early and moderate glaucomatous visual field loss. Analyses using GDx software did not differentiate between healthy and glaucomatous eyes as well as the discriminant analysis function did.

Objective To measure RNFL thickness by Frequency-domain optical coherence tomography (OCT) in patients with different stages of primary glaucoma (CACG and POAG),to evaluate the correlation between RNFL thickness and visual field mean defect (MD),to detect RNFL thickness change of early stage primary glaucoma,and to discuss the clinical significance in the early diagnosis of primary glaucoma objectively. Methods Ninety-two subjects of 40 normal and 52 with different stages of primary glaucoma were enrolled in this study.RNFL thickness was measured by Zeiss Cirru HD-OCT,and visual field was tested by Zeiss Humphrey-750.The association between visual field MD and RNFL thickness was evaluated with Pearson correlation coefficients. Results In the normal group,mean RNFL thickness was 112.91±9.36μm; the early period glaucoma group 94.43±7.67μm; the middle period glaucoma group 80.82±10.36μm; the later period glaucoma group 67.86±8.01μm.Visual field MD in each group was-0.88±1.53dB,-4.26±1.83dB,-7.43±2.64dB and -17.06±5.85dB.The differences in mean RNFL thickness and visual field MD between normal and each stage glaucoma group were significant (P ＜0.05) by independent sample t-test.In each stages of glaucoma group,mean RNFL thickness and visual field MD (early period:r =-0.537,middle period:r =-0.615,later period:r=-0.804) correlated significantly (P ＜0.05).In the early period glaucoma group,superior RNFL thickness was 116.32±11.65μm,inferior RNFL thickness 105.58±9.73μm,nasal RNFL thickness 75.40±10.91μm,and temporal RNFL thickness 70.28±13.08μm.In group B,superior RNFL thickness was 140.15±8.79μm,inferior RNFL thickness 137.29±10.07μm,nasal RNFL thickness 90.20±14.19μm,and temporal RNFL thickness 88.43±10.85μm.The difference of superior and inferior RNFL thickness between group A1 and group B had statistical significance tested by independent sample t-test,P ＜0.05; nasal and temporal RNFL thickness between group A1 and group B was tested by independent sample t-test,P ＞0.05,there was no statistical significance difference. Conclusions Frequency-domain OCT detected that the average of RNFL thickness become thinning with the progression of disease in the primary glaucoma patients,have negative correlation with vision MD,it is able to objectively reflect the degree of glaucomatous optic nerve damage.Frequency-domain OCT can show significantly decreased superior and inferior RNFL thickness of the early period primary glaucoma,which shows good ability in distinguishing normal from early period primary glaucomatous eyes. Key words: Optical coherence tomography (OCT); Retinal nerve fiber layer (RNFL); Mean defect (MD); Early diagnosis primary glaucoma

BACKGROUND:The aim of this study was to evaluate responses on multifocal electroretinogram (mfERG) with ganglion cell-inner plexiform layer (GCIPL) thickness on cirrus spectral-domain optical coherence tomography (SD-OCT) in glaucoma.METHODS:All diagnosed glaucoma patients attending glaucoma services at our institute from November 2012 to April 2013 were screened for this observational hospital-based study. Controls included patients attending our outpatient services for general eye checkup. Structural parameters on SD-OCT including GCIPL and retinal nerve fiber layer (RNFL) thickness were compared with functional parameters on mfERG in early (mean deviation <−6 dB), moderate (−6 to − 12 dB), and controls.RESULTS:A total of 54 cases and 33 controls fulfilling inclusion criteria were recruited for the study. The average and minimum GCIPL thickness did not vary significantly between early and control eyes while moderate glaucoma eyes had marginally lower GCIPL thickness than early glaucoma eyes. The GCIPL minimum thickness on univariate regression was found to be influenced by N2 amplitudes (β = −0.5, P = 0.012) and global N2P1amplitudes (β =0.6, P = 0.01) in moderate glaucoma. In early glaucoma, these were influenced only by RNFL parameters with no association with functional mfERG responses. Multivariate logistic regression identified global N2P1 amplitude to be significantly influencing GCIPL average and minimum thickness (P = 0.01 and 0.02, R2 = 47.8% and 52.3%, respectively) in moderate glaucoma. Maximum area under the curve was found for GCIPL minimum (95% confidence interval [CI] 0.53–0.81) and N2P1 amplitude (95% CI 0.55–0.80).CONCLUSIONS:The second order responses N2P1 and N2 amplitude on mfERG predict function that correlated with structural GCIPL thickness in moderate glaucoma. Early glaucoma may be best predicted by RNFL thickness rather than on mfERG responses.

Background/AimsTo investigate the relationship between the lamina cribrosa (LC) curvature and the microvasculature within the LC in treatment-naïve eyes with normal-tension glaucoma (NTG) and in healthy eyes.MethodsForty-one eyes with treatment-naïve...

Background Both functional and morphological changes in amblyopic development are known to occur at various levels in the central visual pathway.However,whether the retina is involved or not during amblyopic progression remains controversial.Objective This study was designed to compare the thicknesses of the fovea and retinal nerve fiber layer (RNFL) of the normal fellow eye of amblyopic eye using optical coherence tomography (OCT) in children with myopic anisometropia.Methods Twenty-two patients with unilateral myopic anisometropic amblyopia were included as the anisometropia amblyopia group.Ten unilateral myopic anisometropic amblyopia subjects received treatment and recovered were used as the amblyopic cure group,and 11 individuals with simple myopic anisometropia without amblyopia were enrolled as the control group.OCT was performed on both eyes of all the subjects with informed consent.Fovea retinal thickness and RNFL thickness from the superior,inferior,nasal and temporal quadrants in the peripapillary region were evaluated.The measurement parameters were bilaterally compared in all the individuals by paired t test.The multiple regression model was used to analyze the correlation of retinal thickness with amblyopia patients.This study was approved by the Ethic Committee of this hospital.Written informed consent was obtain from each subject prior to the eye examination.Results Fovea retinal thickness increased in the amblyopic eyes compared with the fellow eyes,showing a statistically significant difference between them (P =0.001).However,no significant differences were found in the fovea retinal thickness between both eyes in the amblyopic cure group and simple myopic anisometropia without amblyopia group (P =0.778,0.943).Among the anisometropia amblyopia group,amblyopia cure group and simple myopic anisometropia without amblyopia group,the RNFL thicknesses of the temporal quadrant was significantly thicker in the higher myopic lateral eyes than those of the fellow eyes (P＜0.001,P =0.003,P =0.046).However,the differences in the superior,inferior,nasal and the average RNFL thickness were not statistically significant between the two eyes (P＞0.05).A negative correlation was found between the inferior retinal thickness with age (r=-0.559,P=0.016).Conclusions The fovea may be affected in unilateral myopic anisometropic amblyopia.There is no significant difference in the RNFL thickness between simple myopic eye and unilateral myopic anisometropia amblyopic eye.Improvement in amblyopia is coming along with the reduction of the thickness of the fovea. Key words: Refractive error/myopia; Anisometropia; Amblyopia; Optical coherence tomography; Foveal thickness; Retinal nerve fiber layer thickness

To establish normative data of retinal nerve fibre layer (RNFL) thickness in the elderly and to determine the factors influencing its thickness. Peripapillary RNFL thickness was measured with spectral domain OCT (SD-OCT) in 210 elderly participants from the Alienor population-based study who were aged 75 years or older. The measure was assessed in six segments (the superotemporal, temporal, inferotemporal, inferonasal, nasal and superonasal segments). RNFL data were analysed across age and sex strata in non-glaucoma participants. Mixed linear models were used to evaluate the associations of RNFL thickness with age, sex, ocular parameters and vascular risk factors. The mean global RNFL thickness was 91.4 μm (SD: 12.6), ranging from 55 to 122; the highest values were found in the inferotemporal and superotemporal segments. After adjustment for sex and ocular parameters, including axial length, increasing age was significantly associated with lower thickness globally (mean thinning per decade = 5.6 μm, p = 0.003), in the superotemporal (-12.7 μm per decade, p < 0.0001) and inferotemporal (-8.1 μm per decade, p = 0.022) segments. RNFL thickness tended to be higher in women than in men, but this trend was significant only in the inferotemporal segment (+6.6 μm for women, p = 0.012). The axial length was associated with RNFL thickness globally and in most segments. RNFL thickness did not differ according to cataract extraction. There were no associations between vascular factors and RNFL thickness. Retinal nerve fibre layer thickness decreased with age globally and in the supero- and inferotemporal segments, even after 75 years; it also tended to be higher in women, particularly in the inferotemporal segment. Normative data on RNFL thickness should consider these characteristics as well as ocular parameters, particularly axial length.