Progressive Changes in the Neuroretinal Rim and Retinal Nerve Fiber Layer in Glaucoma: Impact of Baseline Values and Floor Effects.

PURPOSE: To determine whether more severe baseline damage impedes measurement of minimum rim width (MRW) and peripapillary retinal nerve fiber layer thickness (RNFLT) change in glaucoma patients because of a floor effect. DESIGN: Prospective, longitudinal cohort study in a hospital-based setting. PARTICIPANTS: The study included patients with open-angle glaucoma and healthy control subjects. Participants had at least 5 years of follow-up with OCT every 6 months. METHODS: Baseline global and sectorial MRW and RNFLT values were classified as within normal limits, borderline, or outside normal limits based on reference normative values. Regression analysis was used to determine the magnitude and significance of MRW and RNFLT change. Additionally, the follow-up period for each participant was divided into 2 equal halves (first and second periods) to determine whether there was attenuation of MRW and RNFLT change with follow-up time. MAIN OUTCOME MEASURES: Rates of global and sectoral MRW and RNFLT changes (slopes). RESULTS: A total of 97 patients with glaucoma (median age, 70.3 years) and 42 healthy subjects (median age, 64.8 years) were followed for a median of 6.9 years and 7.0 years, respectively. The median mean deviation of the visual field in glaucoma patients was -4.30 decibels (dB) (interquartile range, -7.81 to -2.06 dB; range, -20.68 to 1.37 dB). Statistically significant changes in global and sectoral MRW and RNFLT were detected across all baseline classifications; however, there was a tendency for less change with increasing baseline damage. In glaucoma patients, RNFLT slopes, but not MRW slopes, were significantly more positive (less change) in the second period compared with the first. There were also no differences in MRW or RNFLT slopes in the first and second periods in healthy subjects. CONCLUSIONS: Significant MRW and RNFLT changes were detected at all levels of baseline damage. However, an attenuation in the rate of RNFLT change compared with MRW indicates an earlier floor effect in RNFLT measurements globally and in equivalent sectors. Because the axonal component of these measurements should be equivalent, our results suggest important differences in tissue remodeling at the level of the optic nerve head and peripapillary retina. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Variability of scan quality and perfusion density in longitudinal optical coherence tomography angiography imaging.

BACKGROUND/AIMS: Optical coherence tomography angiography (OCT-A) images are subject to variability, but the extent to which learning impacts OCT-A measurements is unknown. We determined whether there is a learning effect in glaucoma patients and healthy controls imaged with OCT-A. METHODS: Ninety-one open-angle glaucoma patients and 54 healthy controls were imaged every 4 months over a period of approximately 1 year in this longitudinal cohort study. We analysed 15°×15° scans, centred on the fovea, in one eye of each participant. Two-dimensional projection images for the superficial, intermediate and deep vascular plexuses were exported and binarised after which perfusion density was calculated. Linear mixed-effects models were used to investigate the association between perfusion density and follow-up time. RESULTS: The mean (SD) age of glaucoma patients and healthy controls was 67.3 (8.1) years and 62.1 (9.0) years, respectively. There was a significant correlation between perfusion density and scan quality in both glaucoma patients (r=0.50 (95% CI 0.42 to 0.58); p<0.05) and healthy controls (r=0.41 (95% CI 0.29 to 0.52); p<0.05). An increase in perfusion density occurred over time and persisted, even after adjustment for scan quality (1.75% per year (95% CI 1.14 to 2.37), p<0.01). CONCLUSIONS: Perfusion density measurements are subject to increasing experience of either the operator or participant, or a combination of both. These findings have implications for the interpretation of longitudinal measurements with OCT-A.

Non-arteritic anterior ischemic and glaucomatous optic neuropathy: Implications for neuroretinal rim remodeling with disease severity.

PURPOSE: Post-acute non-arteritic ischemic optic neuropathy (NAION) and glaucomatous optic neuropathy (GON) can be difficult to differentiate clinically. Our objective was to identify optical coherence tomography (OCT) parameters to help differentiate these optic neuropathies. METHODS: We compared 12 eyes of 8 patients with NAION and 12 eyes of 12 patients with GON, matched for age and visual field mean deviation (MD). All patients underwent clinical assessment, automated perimetry (Humphrey Field Analyzer II; Carl Zeiss Meditec, Dublin, CA, USA), and OCT imaging (Spectralis OCT2; Heidelberg Engineering, Heidelberg, Germany) of the optic nerve head and macula. We derived the neuroretinal minimum rim width (MRW), peripapillary retinal nerve fibre layer (RNFL) thickness, central anterior lamina cribrosa depth, and macular retinal thickness. RESULTS: MRW was markedly thicker, both globally and in all sectors, in the NAION group compared to the GON group. There was no significant group difference in RFNL thickness, globally or in any sector, with the exception of the temporal sector that was thinner in the NAION group. The group difference in MRW increased with increasing visual field loss. Other differences observed included lamina cribrosa depth significantly greater in the GON group and significantly thinner central macular retinal layers in the NAION group. The ganglion cell layer was not significantly different between the groups. CONCLUSIONS: The neuroretinal rim is altered in a dissimilar manner in NAION and GON and MRW is a clinically useful index for differentiating these two neuropathies. The fact that the difference in MRW between the two groups increased with disease severity suggests distinct remodelling patterns in response to differing insults with NAION and GON.

Elucidating macular structure-function correlations in glaucoma.

Correlation between structural data from optical coherence tomography and functional data from the visual field may be suboptimal because of poor mapping of OCT measurement locations to VF stimuli. We tested the hypothesis that stronger structure-function correlations in the macula can be achieved with fundus-tracking perimetery, by precisely mapping OCT measurements to VF sensitivity at the same location. The conventional 64 superpixel (3° × 3°) OCT grid was mapped to VF sensitivities averaged in 40 corresponding VF units with standard automated perimetry (conventional mapped approach, CMA) in 38 glaucoma patients and 10 healthy subjects. Similarly, a 144 superpixel (2° × 2°) OCT grid was mapped to each of the 68 locations with fundus-tracking perimetry (localized mapped approach, LMA). For each approach, the correlation between sensitivity at each VF unit and OCT superpixel was computed. Vector maps showing the maximum correlation between each VF unit and OCT pixel was generated. CMA yielded significantly higher structure-function correlations compared to LMA. Only 20% of the vectors with CMA and < 5% with LMA were within corresponding mapped OCT superpixels, while most were directed towards loci with structural damage. Measurement variability and patterns of structural damage more likely impact correlations compared to precise mapping of VF stimuli.

Rates of Visual Field Change in Patients With Glaucoma and Healthy Individuals: Findings From a Median 25-Year Follow-up.

Importance: Estimating the rate of glaucomatous visual field change provides practical assessment of disease progression and has implications for management decisions. Objective: To assess the rates of visual field change in patients receiving treatment for glaucoma compared with healthy individuals over an extensive follow-up period and to quantify the impact of important covariates for these rates. Design, Setting, and Participants: This prospective longitudinal cohort study was conducted in a hospital-based setting from January 1991 to February 2020. The study included 40 patients receiving treatment for open-angle glaucoma and 29 healthy participants. One eye of each participant was randomly selected as the study eye. Exposures: Patients with glaucoma and healthy participants received testing with standard automated perimetry every 6 months. Individual rates of mean sensitivity change were computed using ordinary least-squares regression analysis, and linear mixed-effects modeling was used to estimate the mean rates of mean sensitivity change in the 2 groups and the impact of baseline mean sensitivity, baseline age, and follow-up intraocular pressure for rate estimates. Main Outcomes and Measures: Rate of mean sensitivity change in patients with glaucoma and healthy participants. Results: A total of 40 patients with glaucoma (median age, 53.07 years [IQR, 48.34-57.97 years]; 21 men [52%]) and 29 healthy participants (median age, 48.80 years [IQR, 40.40-59.07 years], 17 women [59%]) were followed up for a median of 25.65 years (IQR, 22.49-27.02 years) and 19.56 years (IQR, 16.19-26.21 years), respectively. Most participants (65 individuals [94%]) self-identified as White, with the exception of 2 patients with glaucoma (1 self-identified as Black and 1 as South Asian) and 2 healthy participants (both self-identified as South Asian). The mean follow-up intraocular pressure of patients with glaucoma (median, 15.83 mm Hg [IQR, 13.05-17.33 mm Hg]) was similar to that of healthy participants (median, 14.94 mm Hg [IQR, 13.28-16.01 mm Hg]; P = .25). In an ordinary least-squares regression analysis, 31 patients (78%) with glaucoma had rates of mean sensitivity change within the range of healthy participants (ie, between -0.20 dB/y and 0.15 dB/y). Linear mixed-effects modeling revealed that the mean (SE) rate of mean sensitivity change in healthy participants was 0.003 (0.033) dB/y (95% CI, -0.062 to 0.068; P = .93). In comparison, patients with glaucoma had a mean (SE) rate of mean sensitivity change that was -0.032 (0.052) dB/y faster, but this difference was not statistically significant (95% CI, -0.134 to 0.070; P = .53). Among covariates, only baseline mean sensitivity was associated with the rate of mean sensitivity change (mean [SE], 0.021 [0.010] dB/y/dB; 95% CI, 0.002-0.041; P = .03). Conclusions and Relevance: The results of this cohort study suggest that over a median follow-up of more than 25 years, the rate of visual field change in patients receiving treatment for glaucoma was comparable to that of healthy individuals. These findings could guide practitioners in making management decisions.

Impact of Glaucoma Severity on Rates of Neuroretinal Rim, Retinal Nerve Fiber Layer, and Macular Ganglion Cell Layer Thickness Change.

PURPOSE: To determine the impact of glaucoma severity on rates of change of minimum rim width (MRW), peripapillary retinal nerve fiber layer (RNFL), and macular ganglion cell layer (GCL) thickness. DESIGN: Prospective, cohort study. METHODS: Glaucoma patients and healthy subjects had optical coherence tomography scans at 6-month intervals. Individual rates of change for MRW, RNFL, and GCL thickness were estimated with ordinary least-squares regression. Linear mixed-effect models were used to estimate the rate of change of each parameter and evaluate the impact of glaucoma severity (expressed by visual field mean deviation, MD) and age on these rates. RESULTS: A total of 132 glaucoma patients and 57 healthy subjects were followed for a median of 4.3 years and 3.7 years, respectively. Healthy subjects had a statistically significant deterioration in MRW (-1.66 µm/year), RNFL (-0.46 µm/year), and GCL thickness (-0.22 µm/year). While glaucoma patients had a faster rate of change in each parameter compared with healthy subjects, only GCL thickness showed a statistically significant group difference (mean difference: -0.17 µm/year; P = .03). Older baseline age was associated with faster GCL thickness change (-0.07 µm/year; P = .03), but not other parameters. Baseline MD had no impact on the subsequent rates of change in any of the parameters. CONCLUSIONS: The rates of MRW, RNFL, and GCL thickness change were not significantly influenced by glaucoma severity at baseline; however, GCL thickness was able to statistically contrast the rate of change between healthy subjects and glaucoma patients throughout the disease spectrum.

Comparing Five Criteria for Evaluating Glaucomatous Visual Fields.

PURPOSE: No consensus exists on the relative superiority among criteria for evaluating glaucomatous visual field (VF) damage. We compared the sensitivities and specificities of 5 criteria-Glaucoma Hemifield Test (GHT), Hoddap-Anderson-Parrish 2 (HAP2), Foster, United Kingdom Glaucoma Treatment Study (UKGTS), and Low-pressure Glaucoma Treatment Study (LoGTS)-across various levels of functional and structural glaucomatous damage. DESIGN: Retrospective cross-sectional study. METHODS: This single-center study included patients with suspect or known glaucoma with reliable VF (Humphrey 24-2 Swedish Interactive Thresholding Algorithm) and optical coherence tomography (OCT; Spectralis, Heidelberg Engineering) examinations within a 4-month period. One eye per patient was included. The level of functional and structural damage was defined by mean deviation (MD) and by an OCT score, respectively. We created the OCT score by counting the number of abnormal (MD percentile [P] <1%) global and sectoral averages of optic nerve head MRW, circumpapillary RNFL thickness, and macular GCL thickness. We inferred specificities and sensitivities from positive rates of the criteria in patients with low glaucomatous damage (MD at P ≥ 10% or OCT score = 0) and with higher damage (MD at P < 10% or OCT score > 0), respectively. RESULTS: We included 1230 patients. In patients with low glaucomatous damage, HAP2 and UKGTS had higher positive rates, suggesting lower specificities, whereas GHT, Foster, and LoGTS had lower positive rates, suggesting higher specificities. In patients with higher glaucomatous damage, HAP2 and UKGTS had higher positive rates, indicating higher sensitivities, whereas GHT, Foster, and LoGTS had lower positive rates, indicating lower sensitivities. CONCLUSIONS: No criteria had uniformly superior performance. Selection of criteria should consider the degree of damage anticipated and the desire for either higher sensitivity or specificity.

Value of 10-2 Visual Field Testing in Glaucoma Patients with Early 24-2 Visual Field Loss.

PURPOSE: To determine whether the 10-2 test of the Humphrey Field Analyzer detected a higher proportion of abnormal visual fields compared with the 24-2 test in the central 10° of patients with early glaucomatous visual field damage. DESIGN: Prospective observational study. PARTICIPANTS: Patients with open-angle glaucoma and healthy control participants. METHODS: All participants underwent a 24-2 and 10-2 test. Only the 12 central test locations of the 24-2 test were included to analyze equivalent visual field areas. The performance of the 2 tests was compared across 4 pointwise criteria: total deviation (TD) and pattern deviation (PD) analyses at the 5% and 2% levels. Analyses also were conducted for 2 pairs of follow-up tests, each performed 4 months apart. MAIN OUTCOME MEASURES: (1) Area under the receiver operating characteristic curve (AUC), (2) sensitivity at identically matched specificity for the 4 criteria, (3) overlap (entire field and by quadrant) of abnormal visual fields with both tests, and (4) repeatability of the findings in 2 subsequent follow-up tests. RESULTS: One eye each of 97 glaucoma patients (median mean deviation, -2.31 dB) and 65 control participants were included in the study. The AUCs for the 24-2 and 10-2 tests were not significantly different for any of the 4 criteria and ranged from 0.88 to 0.93 and from 0.91 to 0.94, respectively. At matched specificity, the sensitivity of the 24-2 test was significantly higher for all criteria except for PD analysis at 5%. In patients with an abnormal field with either test, the overlap varied from 60% to 86% depending on the criterion, whereas by quadrant, concordance ranged from 70% to 87%. Over the follow-up, the repeatability of test results (both 24-2 and 10-2 abnormal, either abnormal, or both normal) was achieved in 55% to 70% of patients. CONCLUSIONS: In this study of glaucoma patients with early damage with the 24-2 test, there was little evidence that adding the 10-2 test revealed additional undetected defects in the central visual field. It may be more prudent to reserve 10-2 testing for following up selected patients with higher risk of central visual field progression.

Discrepancy in Loss of Macular Perfusion Density and Ganglion Cell Layer Thickness in Early Glaucoma.

PURPOSE: To identify characteristics of patients with early open-angle glaucoma exhibiting greater macular perfusion density (PD) loss compared with macular ganglion cell layer (GCL) thickness loss. DESIGN: Cross-sectional study. METHODS: Optical coherence tomography (OCT) imaging of the optic nerve head and macula was conducted in patients and healthy control subjects. Minimum rim width, retinal nerve fiber layer and GCL thickness, and PD from OCT angiography were derived. Only high-quality images were included. For direct comparison, raw PD and GCL thickness values in patients were converted to relative age-corrected loss values based on data from controls. Demographic and ocular variables related to greater PD loss compared with GCL thickness loss were identified with multivariate logistic regression. RESULTS: Data from 89 patients (median mean deviation with the 24-2 and 10-2 tests, Humphrey Field Analyzer: -1.96 dB and -1.49 dB, respectively) and 54 controls were analyzed. Sixty-three (71%) patients had relatively more GCL thickness loss, whereas 26 (29%) had relatively more PD loss. More PD loss was associated with lower OCT and OCT-angiography signal strength (odds ratio [95% confidence interval], 0.64 [0.40, 0.96] and 0.60 [0.38, 0.86], per dB, respectively), thicker retinal nerve fiber layer thickness (1.08 [1.01, 1.16] per µm), and female sex (6.57 [1.25, 48.79]). CONCLUSION: Less than one-third of patients with early glaucoma had more loss of perfusion compared with conventional structural loss in the macula. Even within a range of high-quality images, lower signal strength may be at least partially responsible for apparent perfusion loss.

Asymmetry analysis of macular optical coherence tomography angiography in patients with glaucoma and healthy subjects.

BACKGROUND/AIMS: Quantitative analysis of optical coherence tomography angiography (OCT-A) images requires a reproducible approach that accounts for sectoral loss. The objective of this study was to determine whether an index that accounts for both global (perfusion density, PD) and asymmetric loss of perfusion, rather than PD alone, more reliably measures loss of perfusion in patients with glaucoma. METHODS: We analysed macular OCT-A scans of 95 glaucoma patients and 59 control subjects. Two-dimensional projection images corresponding to the superficial vascular plexus were exported and analyses performed to calculate global PD and image asymmetry. An unsigned perfusion asymmetry index (PAI) that included PD and asymmetry (with 1:1 wt) was calculated. Perfusion density and PAI were compared with 10-2 visual field mean deviation and ganglion cell layer (GCL) thickness. RESULTS: Median (IQR) visual field mean deviation was -1.73 (-3.76, 0.30) dB for the glaucoma group and 0.67 (0.16, 1.18) dB for the control group. The strength of the correlation with mean deviation was stronger for PAI (r=0.47), compared with PD (r=0.35), whereas with GCL thickness they were comparable (r=0.45 and 0.43, respectively). Compared with controls, mean PD was 12% lower in patients with glaucoma (0.27 vs 0.30), while PAI was 17% lower (0.40 vs 0.48). However, diagnostic accuracy of either PD or PAI was worse than GCL thickness. CONCLUSIONS: While PAI yielded better correlation with mean deviation and GCL thickness, and a slightly improved separation between patients with glaucoma and healthy controls, diagnostic accuracy was inferior compared with GCL thickness.

Outer retinal layer thickness in patients with glaucoma with horizontal hemifield visual field defects.

BACKGROUND/AIMS: To determine the effect of glaucoma on outer retinal layer thickness in eyes with horizontal hemifield visual field (VF) defects. METHODS: We conducted a cross-sectional study in glaucomatous eyes with repeatable (in three or examinations) horizontal hemifield VF (programme 24-2) defect defined as: all five nasal VF locations immediately either above or below the horizontal midline abnormal in the pattern deviation plot with p<0.5%; no mirror-image adjacent 5 VF locations abnormal in the pattern deviation plot and no non-edge VF locations in the non-affected hemifield abnormal in the pattern deviation plot with p<1%. We used optical coherence tomography to measure thickness of each retinal layer in the temporal macula (12° horizontally and 24° vertically) and computed the absolute (µm) and relative (%) intraindividual asymmetry between the perimetrically normal and abnormal hemimacula. RESULTS: We included 10 eyes of 8 patients with median age of 67 years and median VF mean deviation of -8.85 dB. The nerve fibre, ganglion cell and inner plexiform layers were significantly thinner in the perimetrically abnormal hemimacula (median asymmetry of -6.4, -11.5 and -3.8 µm, (corresponding to -27.7, -40.5 and -15.7 %), respectively, all p≤0.01). The inner nuclear layer was slightly thicker in the perimetrically abnormal hemimacula (median asymmetry of 1.3 µm (5.0 %), p=0.01). The outer plexiform, outer nuclear and photoreceptor layers asymmetry values were negligible. CONCLUSION: Our study showed no evidence that glaucoma has an effect on the outer retinal layer thickness. In contrast, a large impact was observed in inner layer thickness.

Serial Changes in Lamina Cribrosa Depth and Neuroretinal Parameters in Glaucoma: Impact of Choroidal Thickness.

PURPOSE: To determine whether: (1) change in lamina cribrosa depth occurs more frequently than change in neuroretinal parameters in glaucoma, and (2) Bruch's membrane or anterior sclera should be used as a reference plane when measuring laminar depth. DESIGN: Prospective observational study. PARTICIPANTS: One hundred fifty-five glaucoma patients and 35 healthy controls. METHODS: Anterior laminar depth from a Bruch's membrane (LD-BM) or anterior sclera (LD-AS) reference plane were measured with optical coherence tomography. Two neuroretinal parameters, minimum rim width and retinal nerve fiber layer thickness, in addition to peripapillary choroidal thickness were measured. Factors related to laminar depth were determined with mixed-effects modeling. Cutoffs for significant change in each parameter were estimated from variability in healthy controls over 1 year. The occurrences of significant change in laminar depth and neuroretinal parameters were compared with survival models. Because normal aging has a clear effect on neuroretinal parameters, but not on laminar depth, changes in neuroretinal parameters were adjusted for age-related reduction. MAIN OUTCOME MEASURES: Longitudinal changes in laminar depth and neuroretinal parameters. RESULTS: Glaucoma patients were followed up for a mean of 3.90 years (range, 2.03-5.44 years). The LD-BM was influenced significantly more by choroidal thickness (1.14 µm/µm; 95% confidence interval, 1.07-1.21) than was the LD-AS (0.15 µm/µm; 95% confidence interval, 0.08-0.22). Posterior movement of the lamina (LD-BM increase or LD-AS increase) occurred with the same frequencies as thinning in neuroretinal parameters. Anterior movement of the lamina was detected more frequently with the Bruch's membrane (LD-BM decrease) compared with the anterior sclera (LD-AS decrease) reference plane (hazard ratio, 3.23; P < 0.01). Significant choroidal thinning occurred in most patients (25/28 [89%]) in whom anterior movement of the lamina occurred with the Bruch's membrane, but not the anterior sclera, reference plane (LD-BM decrease without LD-AS decrease). Patients had a wide range of individual rates of change of choroidal thickness, from -20.00 to 17.09 µm/year (mean, -1.62 µm/year). CONCLUSIONS: Lamina cribrosa depth should be measured from an anterior sclera reference plane to reduce the influence of choroidal thickness changes. In glaucoma patients, lamina cribrosa depth changes are detected with similar frequency as neuroretinal parameter changes.

Optic Disc Hemorrhages and Laminar Disinsertions in Glaucoma.

PURPOSE: To determine whether structural abnormalities of the lamina cribrosa explain the presence of optic disc hemorrhages, we determined the spatial concordance between disc hemorrhages and laminar disinsertions from the sclera. DESIGN: Prospective noninterventional study. PARTICIPANTS: From open-angle glaucoma patients followed up prospectively, we identified 52 eyes of 46 open-angle glaucoma patients with optic disc hemorrhage (ODH+ group) in at least 1 optic disc photograph during follow-up. We also identified 52 control eyes of 46 glaucoma patients in whom no disc hemorrhage was detected (ODH- group). METHODS: Enhanced depth imaging optical coherence tomography of the optic nerve head (24 radial scans) was performed. The scans were de-identified and a trained observer masked to all clinical information determined the presence of laminar disinsertions in each of the 48 positions with a confidence score of 1 (least certain) to 5 (most certain). Only disinsertions with a score of 3 or more were included in the analysis. MAIN OUTCOME MEASURES: Frequency and spatial concordance between disc hemorrhages and laminar disinsertions. RESULTS: The median age, visual field mean deviation, and follow-up period of the ODH+ and ODH- groups was 77.5 and 70.8 years, -5.20 and -4.70 dB, and 10.4 and 9.9 years, respectively. There were 84 hemorrhages recorded in the ODH+ group. There were laminar disinsertions in 50 eyes (96%) in the ODH+ group and in 27 eyes (52%) in the ODH- group, with 2 or more disinsertions in 30 eyes (58%) and 5 eyes (10%), respectively. Most hemorrhages and disinsertions were located in the inferotemporal and superotemporal sectors. However, in individual patients, only 33 of the ODHs (39%) were located within a laminar disinsertion. CONCLUSIONS: Laminar disinsertions occurred twice as frequently in eyes with ODHs; however, in individual patients, the spatial concordance between ODHs and laminar disinsertions was poor.

Beta and Gamma Peripapillary Atrophy in Myopic Eyes With and Without Glaucoma.

PURPOSE: To determine whether beta and gamma peripapillary atrophy (PPA) areas measured with optical coherence tomography (OCT) enhances glaucoma diagnosis in myopic subjects. METHODS: We included 55 myopic glaucoma patients and 74 myopic nonglaucomatous controls. Beta-PPA comprised the area external to the clinical disc margin, with absence of retinal pigment epithelium and presence of Bruch's membrane. Gamma-PPA comprised the area external to the disc margin, with absence of both RPE and Bruch's membrane. OCT scans colocalized to fundus photographs were used to measure PPA, choroidal thickness, border tissue of Elschnig configuration, optic disc area, and optic disc ovality. RESULTS: Beta-PPA area was larger in glaucoma patients compared with controls (median [interquartile range], 1.0 [0.66-1.53] mm2 and 0.74 [0.50-1.38] mm2, respectively), whereas gamma-PPA was smaller in glaucoma patients compared with controls (0.28 [0.14-0.50] mm2 and 0.42 [0.17-0.74] mm2, respectively). However, the distributions of both beta- and gamma-PPA in the two groups overlapped widely. The areas under the receiver operating characteristic curve of beta- and gamma-PPA areas were 0.60 and 0.59, respectively. Larger beta-PPA area was associated with larger disc area, thinner choroidal thickness, longer axial length, less oblique border tissue configuration, older age, and greater disc ovality. Larger gamma-PPA area was associated with greater disc ovality, more oblique border tissue configuration, and longer axial length. CONCLUSIONS: Subclassifying PPA with OCT into beta and gamma zones reveals association with different covariates, but does not enhance the diagnostic performance for glaucoma in a population of predominantly Caucasians myopic subjects.

Diagnostic Accuracy of Optical Coherence Tomography and Scanning Laser Tomography for Identifying Glaucoma in Myopic Eyes.

PURPOSE: Ruling out glaucoma in myopic eyes often poses a diagnostic challenge because of atypical optic disc morphology and visual field defects that can mimic glaucoma. We determined whether neuroretinal rim assessment based on Bruch's membrane opening (BMO), rather than conventional optic disc margin (DM)-based assessment or retinal nerve fiber layer (RNFL) thickness, yielded higher diagnostic accuracy in myopic patients with glaucoma. DESIGN: Case-control, cross-sectional study. PARTICIPANTS: Myopic patients with glaucoma (n = 56) and myopic normal controls (n = 74). METHODS: Myopic subjects with refraction error greater than -2 diopters (D) (spherical equivalent) and typical myopic optic disc morphology, with and without glaucoma, were recruited from a glaucoma clinic and a local optometry practice. The final classification of myopic glaucoma or myopic control was based on consensus assessment by 3 clinicians of visual fields and optic disc photographs. Participants underwent imaging with confocal scanning laser tomography for measurement of DM rim area (DM-RA) and with spectral domain optical coherence tomography (SD OCT) for quantification of a BMO-based neuroretinal rim parameter, minimum rim width (BMO-MRW), and RNFL thickness. MAIN OUTCOME MEASURES: Sensitivity of DM-RA, BMO-MRW, and RNFL thickness at a fixed specificity of 90% and partial area under the curves (pAUCs) for global and sectoral parameters for specificities ≥90%. RESULTS: Sensitivities at 90% specificity were 30% for DM-RA and 71% for both BMO-MRW and RNFL thickness. The pAUC was higher for the BMO-MRW compared with DM-RA (P < 0.001), but similar to RNFL thickness (P > 0.5). Sectoral values of BMO-MRW tended to have a higher, but nonsignificant, pAUC across all sectors compared with RNFL thickness. CONCLUSIONS: Bruch's membrane opening MRW is more sensitive than DM-RA and similar to RNFL thickness for the identification of glaucoma in myopic eyes and offers a valuable diagnostic tool for patients with glaucoma with myopic optic discs.

Diagnostic Accuracy of Glaucoma With Sector-Based and a New Total Profile-Based Analysis of Neuroretinal Rim and Retinal Nerve Fiber Layer Thickness.

PURPOSE: To compare the diagnostic accuracy of conventional sector-based analysis with a method devised to detect the smallest localized neuroretinal rim and retinal nerve fiber layer thickness (RNFLT) damage. METHODS: One eye of 151 glaucoma patients and 83 healthy controls (median age and MD, 71.7 and 66.7 years, and -3.6 and -0.3 dB, respectively) was imaged with spectral-domain optical coherence tomography (OCT). Bruch's membrane opening-minimum rim width (BMO-MRW) and RNFLT were determined at 1° intervals and also averaged for each sector. A classification of glaucoma was made with sectoral analysis when the sectoral value was below the 1%, 5%, or 10% normative limit (from an independent normative dataset); and with total analysis when a given number of measurements was below the 1%, 5%, or 10% normative limit. RESULTS: With the 1% normative limit, BMO-MRW sectoral analysis yielded sensitivity of 87% and specificity of 92%; while at the same specificity (92%), total analysis yielded sensitivity of 88%. With RNFLT, sectoral analysis yielded sensitivity of 85% and specificity of 95%; while at the same specificity (95%), total analysis yielded sensitivity of 83%. The results for the 5% and 10% normative limits yielded lower specificity but higher sensitivity. In the whole glaucoma population, none of the sensitivity values of the sectoral and total analysis at the same specificities were statistically different. CONCLUSIONS: The diagnostic accuracy of sectoral analysis was equivalent to total analysis. These results indicate that BMO-MRW and RNFLT defects were wide and deep enough for detection by conventional sectoral analysis.

Importance of Normal Aging in Estimating the Rate of Glaucomatous Neuroretinal Rim and Retinal Nerve Fiber Layer Loss.

PURPOSE: To describe longitudinal rates of change of neuroretinal parameters in patients with glaucoma and healthy controls, and to evaluate the influence of covariates. DESIGN: Prospective longitudinal study. PARTICIPANTS: Treated patients with glaucoma (n = 192) and healthy controls (n = 37). METHODS: Global disc margin-based neuroretinal rim area (DMRA) was measured with confocal scanning laser tomography, while Bruch's membrane opening-minimum rim width (BMO-MRW), BMO area (BMOA), and peripapillary retinal nerve fiber layer thickness (RNFLT) were measured with optical coherence tomography at 6-month intervals. Individual rates of change were estimated with ordinary least-squares regression, and linear mixed effects modeling was used to estimate the average rate of change and differences between the groups, and to evaluate the effects of baseline measurement and baseline age on rates of change. MAIN OUTCOME MEASURES: Rates of change for each parameter. RESULTS: Subjects were followed for a median (range) of 4 (2-6) years. The proportion of controls who had significant reduction of neuroretinal parameters was 35% for BMO-MRW, 31% for RNFLT, and 11% for DMRA. The corresponding figures for patients with glaucoma were not statistically different (42%, P = 0.45; 31%, P = 0.99; 14%, P = 0.99, respectively). Controls had a significant reduction of BMO-MRW (mean: -1.92 µm/year, P < 0.01) and RNFLT (mean: -0.44 µm/year, P = 0.01), but not DMRA (mean: -0.22×10(-2) mm(2)/year, P = 0.41). After adjusting for covariates, patients with glaucoma had faster, but not statistically different, rates of deterioration compared with controls, by -1.26 µm/year (P = 0.07) for BMO-MRW, -0.40 µm/year (P = 0.11) for RNFLT, and -0.38×10(-2) mm(2)/year (P = 0.23) for DMRA. Baseline BMO-MRW and RNFLT significantly influenced the respective rates of change, with higher baseline values relating to faster reductions. Older age at baseline was associated with a slower reduction in rates of BMO-MRW. Reductions in intraocular pressure were related to increases in BMO-MRW and DMRA. There was a tendency for BMOA to decrease over time (-0.38×10(-2) mm(2)/year; P = 0.04). CONCLUSIONS: Age-related loss of neuroretinal parameters may explain a large proportion of the deterioration observed in treated patients with glaucoma and should be carefully considered in estimating rates of change.