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Purpose To describe the prevalence of vertical cup-to-disc ratio (vCDR) asymmetry in U.S. adults and assess the utility of vCDR asymmetry in the diagnosis of glaucoma. Design Cross-sectional study. Participants A total of 5359 subjects aged ≥40 years from the 2005–2008 National Health and Nutrition Examination Survey (NHANES). Methods Subjects completed retinal photography and had vCDR determined in both eyes, with vCDR asymmetry calculated as the absolute value of the difference between the 2 eyes. Frequency Doubling Technology perimetry was used to assess for visual field (VF) defects. Subjects were categorized as having "disc defined glaucoma" if either disc demonstrated glaucomatous features, and VF data were combined with optic disc grading to determine "disc plus field defined glaucoma." Main Outcome Measures Association between vCDR asymmetry and disc plus field defined glaucoma. Results In U.S. adults without glaucoma, the 50th, 97.5th, and 99.5th percentiles of vCDR asymmetry are 0.05, 0.19, and 0.26, respectively. Vertical cup-to-disc ratio asymmetry ≥0.20 occurs in 2.1% of U.S. adults without glaucoma. The prevalence of vCDR asymmetry ≥0.20 among white, black, and Hispanic adults without glaucoma is 2.4%, 0.7%, and 1.8%, respectively. The odds of vCDR asymmetry ≥0.20 are 1.44 times higher per 10-year increase in age (odds ratio [OR], 1.44; 95% confidence interval [CI], 1.20–1.72; P P Conclusions Vertical cup-to-disc ratio asymmetry is predictive of prevalent glaucoma, but the PPV remains low even at high degrees of asymmetry. Vertical cup-to-disc ratio asymmetry should initiate a more comprehensive glaucoma workup, especially in individuals with additional risk factors, but it is not appropriate as a screening metric for glaucoma.

PURPOSE: Genome-wide association studies have identified multiple genetic variants associated with vertical cup-disc ratio (VCDR). Genetic risk scores (GRS) examine the aggregate genetic effect of individual variants on a trait by combining these separate genetic variants into a single measure. The purpose of this study is to construct GRS for VCDR and determine whether the GRS are associated with VCDR and whether the GRS increase the discriminatory ability for primary open angle glaucoma (POAG) in a Latino population. DESIGN: Population-based genetic association study. PARTICIPANTS: A total of 4,018 Latino participants recruited from Los Angeles. METHODS: Weighted and unweighted GRS were constructed using 68 previously reported VCDR single nucleotide polymorphisms (SNPs), as well as SNPs from our own genome-wide association data. Linear and logistic regression analyses examined the associations of GRS with VCDR and POAG, respectively. To evaluate the discriminatory ability of the GRS for POAG, we conducted receiver operating characteristic (ROC) analyses. MAIN OUTCOME MEASURES: The relationship between GRS and VCDR in Latinos. RESULTS: The GRS were significantly associated with VCDR (P < 0.0001), after adjusting for age, gender, central corneal thickness, intraocular pressure, and education. The weighted GRS explained an additional 2.74% of the variation in VCDR. Adding the weighted GRS derived from previously reported SNPs resulted in a moderate improvement in the discriminatory ability for POAG during ROC analyses, yielding an AUC of 0.735 (95% CI: [0.701, 0.768]). When our own SNPs were used, the AUC significantly increased to 0.809 (95% CI: [0.781, 0.837], P < 0.0001). We obtained similar results for the unweighted GRS. CONCLUSION: To our knowledge, we are the first to report the association between GRS and VCDR, and its improvement in the discriminatory ability of POAG, in a Latino population.

Purpose To compare the initial visual field (VF) defect pattern and the spectral-domain optical coherence tomography (OCT) parameters and investigate the effects of distinct types of optic disc damage on the diagnostic performance of these OCT parameters in early glaucoma. Design Retrospective, observational study. Participants A total of 138 control eyes and 160 eyes with early glaucoma were enrolled. The glaucomatous eyes were subdivided into 4 groups according to the type of optic disc damage: focal ischemic (FI) group, myopic (MY) group, senile sclerotic (SS) group, and generalized enlargement (GE) group. Methods The values of total deviation (TD) maps were analyzed, and superior-inferior (S-I) differences of TD were calculated. The optic nerve head (ONH) parameters, peripapillary retinal nerve fiber layer (pRNFL), and ganglion cell-inner plexiform layer (GCIPL) thicknesses were measured. Main Outcome Measures Comparison of diagnostic ability using area under the receiver operating characteristic curves (AUCs). Results The S-I and central S-I difference of the FI group were larger than those of the GE group. The rim area of the SS group was larger than those of the 3 other groups, and the vertical cup-to-disc ratio (CDR) of the GE group was larger than that of the MY group. In addition, the minimum and inferotemporal GCIPL thicknesses of the FI group were smaller than those of the GE group. The AUC of the rim area (0.89) was lower than that of the minimum GCIPL (0.99) in the SS group, and the AUC of the vertical CDR (0.90) was lower than that of the minimum GCIPL (0.99) in the MY group. Furthermore, the AUCs of the minimum GCIPL thicknesses of the FI and MY group were greater than those of the average pRNFL thickness for detecting glaucoma, as opposed to the SS and GE. Conclusions The OCT parameters differed among the 4 groups on the basis of the distinct optic disc appearance and initial glaucomatous damage pattern. Clinicians should be aware that the diagnostic capability of OCT parameters could differ according to the type of optic disc damage in early glaucoma.

Purpose To investigate the prevalence of vitreopapillary traction (VPT) and its effect on peripapillary structure and visual function in eyes with idiopathic epiretinal membrane (ERM). Design Observational, comparative study. Participants Patients with idiopathic ERM (n = 116 eyes) and controls with similar age (n = 62 eyes). Methods Spectral domain optical coherence tomography (SD-OCT) axial optic disc scans were evaluated to identify VPT in eyes with idiopathic ERM. Based on VPT presence/absence, eyes were categorized as ERM with VPT (ERM +VPT , n = 52 eyes) or ERM without VPT (ERM −VPT , n = 64 eyes). Optic nerve head (ONH) parameters, average and sectoral retinal nerve fiber layer (RNFL) thickness, and central macular thickness (CMT) were compared between groups. Best-corrected visual acuity (BCVA) and visual field (VF) (automated Humphrey central 30-2 perimetry) mean deviation (MD) and pattern standard deviation (PSD) were compared between groups. Main Outcome Measures The ONH parameters, peripapillary RNFL thickness, BCVA, VF MD, and PSD. Results Fifty-two of 116 eyes (44.8%) with idiopathic ERM had VPT. The ERM +VPT group had larger rim area, smaller average and vertical cup-to-disc ratios, and smaller cup volume than ERM −VPT and normal groups (all P P = 0.006). Average and temporal RNFL thickness was higher in ERM +VPT (98.64±9.33 μm and 93.90±23.42 μm) than in normal eyes (94.02±8.45 μm and 66.42±12.71 μm). No significant difference in BCVA was found between ERM −VPT and ERM +VPT eyes, but MD was lower in ERM +VPT than in ERM −VPT (−3.91±3.68 dB vs. −2.18±2.42 dB; P = 0.005). Additionally, PSD was greater in ERM +VPT . Multivariate logistic regression analysis revealed that age (odds ratio [OR], 1.190; P = 0.014) and increased CMT (OR, 1.013; P = 0.005) were associated with vision loss, whereas VPT presence was associated with VF defects (OR, 6.290; P = 0.024). Conclusions Vitreopapillary traction was observed in >40% of eyes with idiopathic ERM, as confirmed by SD-OCT imaging. Vitreopapillary traction with idiopathic ERM was associated with altered optic disc architecture, increased average and temporal RNFL thickness, and VF defects.

Objective To determine the 6-year incidence of primary open-angle glaucoma (POAG) and its associated predictors. Design Population-based cohort study. Participants A total of 4316 subjects without POAG at baseline who were 40 years of age and older from a south Indian population. Methods Participants were examined at baseline and after a 6-year interval. Detailed ophthalmic examination included applanation tonometry, gonioscopy, pachymetry, optic disc evaluation, and automated perimetry. Glaucoma was defined using the International Society of Geographical and Epidemiological Ophthalmology Classification. Multivariable logistic regression was performed to identify the baseline risk factors that could predict the incident POAG. Main Outcome Measures Six-year incidence of POAG and its associated risk factors. Results In 6 years, incident POAG developed in 129 subjects (2.9%; 95% confidence interval [CI], 2.4–3.4; male-to-female ratio, 65:64). Baseline age was a risk factor. In reference to the group 40 to 49 years of age, the incidence increased from 2.3 (95% CI, 1.4–3.7) for the group 50 to 59 years of age to 3.5 (95% CI, 2.2–5.7) for the group 60 to 69 years of age ( P 0.001). Other baseline risk predictors were urban residence (odds ratio [OR], 1.6; 95% CI, 1.1–2.2; P = 0.01), higher intraocular pressure (IOP; OR, 2.0; 95% CI, 1.5–2.6 per 10 mmHg; P 0.001), myopia (OR, 1.7; 95%, CI, 1.1–2.5; P 0.001), and axial length (OR, 1.5; 95% CI, 1.0–2.2 per millimeter; P = 0.03). Thinner corneas with higher IOP at baseline had the highest incidence of POAG. In 80% of the urban population and 100% of the rural population, incident glaucoma was previously undetected. Conclusions A significant proportion of this population demonstrated incident POAG. The baseline risk factors could help in identifying those at highest risk of disease.

To compare anterior segment optical coherence tomography (ASOCT) angle morphology before and after laser peripheral iridotomy (LPI) in a cohort of South Indian subjects with primary angle-closure suspect (PACS) or primary angle-closure/primary angle-closure glaucoma (PAC/PACG) and to examine baseline parameters associated with angle widening.Prospective observational study.A total of 244 subjects aged ≥30 years with PACS or PAC/PACG in at least 1 eye.The ASOCT images and angle gonioscopic grades were analyzed for all subjects at baseline and 2 weeks after LPI. Multivariable linear and logistic regression models were used to determine predictors of angle widening (change in mean angle opening distance [AOD750]) and angle opening (all 4 quadrants with trabecular meshwork [TM] visible on gonioscopy after LPI).Change in ASOCT parameters with LPI and baseline predictors of angle widening.Laser peripheral iridotomy resulted in angle widening on ASOCT with significant increases in AOD750, angle recess area, and trabecular iris surface area (P0.05 for all). Gonioscopically, 44.7% of all subjects had open angles in all 4 quadrants after LPI, with a greater percentage of angles open in the PACS group compared with the PAC/PACG group (52.4% vs. 36.4%; P = 0.01). In multivariable regression analyses, greater postoperative angle widening as defined by change in AOD750 was associated with shorter baseline AOD750 and axial length, and greater baseline anterior chamber depth, iris curvature, and lens vault (P ≤ 0.002 for all). Gonioscopic angle opening after LPI was more common with wider baseline angle width (modified Shaffer grade) and lower cup-to-disc ratio (P0.001 for both).In a South Indian population with PACS or PAC/PACG, LPI results in significant anterior chamber angle widening seen on both ASOCT and gonioscopy, although some degree of persistent iridotrabecular contact was present in approximately half of PACS eyes and approximately two thirds of PAC/PACG eyes on gonioscopy. The greatest widening by ASOCT was observed in eyes with features most consistent with greater baseline pupillary block.

Purpose To evaluate the association between refractive error and the prevalence of glaucoma by race or ethnicity. Design Cross-sectional study. Participants Kaiser Permanente Northern California Health Plan members with refractive error measured at 35 years of age or older between 2008 and 2014 and with no history of cataract surgery, refractive surgery, or a corneal disorder. Methods We identified 34 040 members with glaucoma or ocular hypertension (OHTN; cases) and 403 398 members without glaucoma (controls). Glaucoma cases were classified as primary angle-closure glaucoma (PACG); 1 of the 4 forms of open-angle glaucoma: primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), pigmentary glaucoma (PIGM), and pseudoexfoliation glaucoma (PEX); or OHTN. Refractive error, expressed as spherical equivalent (SE), was coded as a continuous trait and also as categories. Logistic regression analyses were used to estimate the association between refractive error and the prevalence of glaucoma overall and in specific racial or ethnic groups. Main Outcome Measures The association between refractive error and glaucoma subtypes evaluated as odds ratios (ORs) with 95% confidence intervals (CIs). Results In controls, the mean SE was −0.59 diopters (D) (standard deviation, 2.62 D). Each 1-D reduction in SE was associated with a 22% decrease in the odds of PACG (OR, 0.78; 95% CI, 0.77–0.80) and with increases in the odds of open-angle glaucoma ranging from 1.23 (95% CI, 1.20–1.26) for PIGM, to 1.07 (95% CI, 1.03–1.11) for PEX, and to 1.05 (95% CI, 1.04–1.06) for OHTN. In addition, we observed a stronger association between myopia and POAG among non-Hispanic whites (OR, 1.12; 95% CI, 1.11–1.13) and NTG among Asians (OR, 1.17; 95% CI, 1.15–1.20) and non-Hispanic whites (OR, 1.19; 95% CI, 1.15–1.22). Conclusions Myopia was associated with an increased prevalence of all forms of open-angle glaucoma and OHTN, whereas hyperopia was associated with a substantially increased prevalence of PACG. Although high myopia is a strong risk factor for glaucoma subtypes, low and moderate myopia also have a significant effect on glaucoma risk. Additionally, there were moderate racial differences in the association of myopia with the risk of POAG and NTG.

Purpose To investigate the heritability of intraocular pressure (IOP) and cup-to-disc ratio (CDR) in an older well-defined population. Design Family-based cohort study. Participants Through the population-based Salisbury Eye Evaluation study, we recruited 726 siblings (mean age, 74.7 years) in 284 sibships. Methods Intraocular pressure and CDR were measured bilaterally for all participants. The presence or absence of glaucoma was determined by a glacuoma specialist for all probands on the basis of visual field, optic nerve appearance, and history. The heritability of IOP was calculated as twice the residual between-sibling correlation of IOP using linear regression and generalized estimating equations after adjusting for age, gender, mean arterial pressure, race, self-reported diabetes status, and history of systemic steroid use. The heritability of CDR was calculated using the same model and adjustments as above, while also adjusting for IOP. Main Outcome Measures Heritability and determinants of IOP and CDR, and impact of siblings' glaucoma status on IOP and CDR. Results We estimated the heritability to be 0.29 (95% confidence interval [CI], 0.12–0.46) for IOP and 0.56 (95% CI, 0.35–0.76) for CDR in this population. Mean IOP in siblings of glaucomatous probands was statistically significantly higher than in siblings of normal probands (mean difference, 1.02 mmHg; P = 0.017). The mean CDR in siblings of glaucomatous probands was 0.07 (or 19%) larger than in siblings of glaucoma suspect referrals ( P = 0.045) and siblings of normal probands ( P = 0.004). Conclusions In this elderly population, we found CDR to be highly heritable and IOP to be moderately heritable. On average, siblings of glaucoma patients had higher IOPs and larger CDRs than siblings of nonglaucomatous probands.

Purpose To investigate the association of cup-to-disc ratio (CDR), intraocular pressure (IOP), and primary open-angle glaucoma (POAG) with the site of retinal venous occlusion (RVO) and optic nerve head swelling (ONHS). Design Prospective observational case series. Participants Four hundred fifty consecutive cases from a single tertiary referral center. Methods Fundus photography of the retinopathy, 30° stereo photography of the optic disc, and Goldmann applanation tonometry were the main parameters studied. The diagnosis of POAG was obtained from the referring ophthalmologist. Main outcome measures The main outcome measures were the CDR, measured vertically through the center of the optic disc, and the site of RVO, identified as an arteriovenous (AV) crossing, optic cup, or optic nerve. Retinal venous occlusions occurring within the optic nerve were subdivided on the basis of the presence or absence of ONHS. Results There were poor correlations between CDR and IOP ( r = 0.18; P = 0.000209) and CDR and age ( r = 0.21; P = 0.000012). There were 197 AV crossing-sited RVOs (AV-RVOs) (43.8%) and 46 optic cup (OC)-sited RVOs (10.2%). The remainder occurred within the optic nerve; the ONHS group had 80 cases (17.8%) and the nonoptic nerve head swelling group (NONHS) had 127 cases (28.2%). The OC-RVO group tended to be the oldest of the four groups, whereas the ONHS group was the youngest ( P P = 0.000012) for IOP in the OC-RVO group (19.0 mmHg) and NONHS group (17.6 mmHg); the proportion of cases with IOP more than 21 mmHg was also higher in these cases ( P = 0.00033). The prevalence of POAG was highest ( P Conclusions Optic cup and optic nerve-sited RVO without ONHS are associated with raised IOP and may share a common management strategy aimed at controlling ocular pressure. Glaucomatous optic disc cupping, in contrast, seems to be important in the OC-sited RVO group only. Intraocular pressure, POAG, and glaucomatous optic disc cupping do not significantly seem to contribute to the development of RVO at an AV crossing or when the occlusion occurs within the optic nerve in association with ONHS.

Purpose High intraocular pressure (IOP) and large vertical cup-to-disc ratio (VCDR) are important risk factors of glaucoma. Recent genome-wide association studies have discovered several genetic variants associated with IOP and VCDR. In this study, we examined the aggregate effects of these IOP-, VCDR-associated variants on glaucoma. Design Case-control genetic association study. Participants A total of 6881 participants, including 194 glaucoma and 158 primary open-angle glaucoma (POAG) cases in the Singapore Epidemiology of Eye Diseases Study. Methods We first identified IOP and VCDR risk single nucleotide polymorphisms (SNPs) that were located in previously discovered IOP, VCDR genetic loci and showed strongest associations with IOP and VCDR in our study. We then constructed multi-locus IOP-, VCDR-specific genetic risk scores (GRSs) for each individual by summing the number of risk alleles for each SNP weighted by the respective effect estimates on glaucoma. Associations between tertiles of IOP- and VCDR-specific GRSs with glaucoma and POAG were determined using logistic regression analyses. Discriminating ability of the GRSs was determined by the area under receiver operating characteristic curve (AUC). Main Outcome Measures Odds ratios on glaucoma. Results Participants in the top tertile of IOP-specific GRS were 2.00 (95% CI, 1.32–3.03, P = 1.1×10 −3 ) and 2.50 times (95% CI, 1.54–4.02, P = 2.0×10 −4 ) likely to have glaucoma and POAG, respectively, compared with those in the bottom. Participants in the top tertile of VCDR-specific GRS were 2.09 (95% CI, 1.43–3.07, P = 1.6×10 −4 ) and 2.31 times (95% CI, 1.50–3.55, P = 1.4×10 −4 ) likely to have glaucoma and POAG, respectively. Participants with both GRSs in the top tertile were 5.54 (95% CI, 2.57–11.93, P = 1.1×10 −5 ) and 7.77 times (95% CI, 3.03–19.93, P = 2.0×10 −5 ) likely to have glaucoma and POAG, respectively, compared with participants with both GRSs in bottom tertiles. The GRSs improved AUC for glaucoma modestly when added to traditional factors (AUC difference = 0.03, P = 0.06). Conclusions Higher IOP-, VCDR-specific GRSs were associated with greater risk of glaucoma. Participants with both GRSs in the top tertiles had a 5.5-fold increased risk of glaucoma compared with those in the bottom tertiles. These findings may provide insights into the genetic pathogenesis of glaucoma.

Objective To determine the correlations between ophthalmoscopic estimations and the measurements with a semiautomated image-analysis device of the vertical cup-to-disc ratio (VCDR) in the human optic disc. Design Population-based, cross-sectional study. Participants All subjects 55 years of age and older from the population-based sample of 6777 ophthalmologically examined subjects from The Rotterdam Study of whom gradable optic disc transparencies of at least 1 eye and ophthalmoscopic data of the same eye were available. Main outcome measures Ophthalmoscopic assessment of the VCDR and semiautomated measurement of the VCDR. Methods Indirect and direct ophthalmoscopy were performed in mydriasis to assess the VCDR. Optic disc transparencies made with a simultaneous stereoscopic telecentric fundus camera were analyzed with a semiautomated measurement system (Topcon Imagenet). Results In 5143 subjects, the mean ophthalmoscopic VCDR was 0.30 (standard error [SE], 0.0021; range, 0.00, 1.00) compared with a semiautomatically measured VCDR of 0.49 (SE, 0.0019; range, 0.04, 0.86; difference, 0.19; P Conclusion Semiautomated measurements of the VCDR are larger than the ophthalmoscopic VCDR estimate with a moderate correlation. The interobserver variability using Imagenet was smaller compared with the ophthalmoscopic assessments, and Imagenet was better standardized, which is important for epidemiologic surveys and follow-up studies.

Purpose To assess the association between the genetic variants associated with the optic nerve vertical cup-to-disc ratio (VCDR) and the phenotypic features in patients with primary open-angle glaucoma (POAG), including normal-tension glaucoma (NTG) and high-tension glaucoma (HTG). Design Case-control study. Participants and Controls Japanese patients with NTG (n = 213) and HTG (n = 212) and 191 control subjects without glaucoma. Methods DNA samples were genotyped for 7 single nucleotide polymorphisms (SNPs) associated with VCDR: rs1063192 (near gene: CDKN2B ), rs10483727 ( SIX1 ), rs17146964 ( SCYL1 ), rs1547014 ( CHEK2 ), rs1900004 ( ATOH7 ), rs1926320 ( DCLK1 ), and rs12015126 ( RERE ). Main Outcome Measures The VCDR was compared between genotypes, and allele frequency differences were compared between NTG or HTG subjects and control subjects. Demographic and clinical features were compared between alleles in patients with NTG or HTG. Results There were significant VCDR differences ( P = 0.0077 and P = 0.019) between the genotypes for rs1063192 ( CDKN2B ) and rs1547014 ( CHEK2 ), respectively. There were significant differences in the rs1063192 ( CDKN2B ) and rs1900004 ( ATOH7 ) allele frequencies between the NTG subjects and control subjects ( P = 0.0023 and P = 0.028, respectively) and a significant difference ( P = 0.013) in the rs1547014 ( CHEK2 ) allele frequencies between the HTG subjects and control subjects. Ages at diagnosis were significantly different in the NTG subjects with and without the rs10483727 ( SIX1 ) C allele ( P = 0.017) or the rs1926320 ( DCLK1 ) T allele ( P = 0.040). Likewise, the age at diagnosis was significantly different ( P = 0.037) in the HTG subjects with and without the rs12025126 ( RERE ) T allele. There were no significant associations between the maximum intraocular pressure (IOP) and 7 genotyped SNP alleles in patients with NTG or HTG. Conclusions The rs1063192 ( CDKN2B ) and rs1900004 ( ATOH7 ) seem to be non–IOP-related genetic risk factors for NTG, and the rs1547014 ( CHEK2 ) is a genetic risk factor for HTG. Although the rs10483727 ( SIX1 ), rs1926320 ( DCLK1 ), or rs12025126 ( RERE ) alone may not be sufficient for the development of POAG, the association of these SNPs with a phenotypic feature in patients with NTG or HTG suggests that these loci contribute to the pathogenesis of POAG. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Purpose To evaluate the correlations between pupil ruff changes and associated gonioscopy findings with intraocular pressure (IOP) and cup-to-disc ratio (CDR). Design Prospective, observational, comparative study. Participants A total of 103 patients from a glaucoma clinic population. Patients with pseudoexfoliation, previous intraocular surgery, and IOP-lowering medication were excluded. Methods Pupillary ruff and associated gonioscopy findings were graded from photographs based on the pupil ruff atrophy (PRA) grading system. Parameters evaluated include pupillary ruff absence and abnormality, pupil edge pigment, and trabecular meshwork pigment. Inter-eye differences were determined and analyzed for correlations with inter-eye differences in IOP and CDR based on Heidelberg Retinal Tomograph II imaging (Heidelberg Engineering, Dossenheim, Germany). Main Outcome Measures Correlations between inter-eye PRA grading differences and inter-eye IOP and CDR differences. Results A total of 103 patients were included, with a mean age of 64 years. The average amount of abnormal and missing ruff was 9.5 and 5 clock hours, respectively. Inter-eye IOP asymmetry was significantly associated with asymmetry of amount of abnormal ruff ( P = 0.034) and amount of missing ruff ( P = 0.022). Inter-eye CDR asymmetry was significantly associated with asymmetry of the amount of missing ruff ( P = 0.001) and trabecular meshwork pigmentation ( P = 0.006). The eye with the most pupillary ruff loss was 25% more likely to have the greater CDR. Conclusions Asymmetric pupillary ruff changes were associated with asymmetry in both IOP and CDR. However, the clinical significance of this finding requires further evaluation. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

To determine if an increased cup-to-disc ratio (CDR) and retinal nerve fiber layer (RNFL) loss occur after acute primary angle closure (APAC).Prospective, observational case series.Twenty participants with unilateral APAC provided 20 affected eyes and 20 fellow eyes (controls) for analysis.After initial presentation, participants attended 3 further assessments over a 12-month period (visit 2, within 2 weeks; visit 3, 2-3 months; and visit 4, 6-12 months), in which they underwent the following investigations: Heidelberg Retinal Tomography (Heidelberg Engineering, Dossenheim, Germany), optical coherence tomography of the RNFL and macula, and automated perimetry.Cup-to-disc ratio, optic cup area, neuroretinal rim area, RNFL thickness, macular thickness, and volume.There was no change from visits 2 to 4 in CDR (0.46 ± 0.17 vs. 0.47 ± 0.20; P = 0.94), neuroretinal rim area (1.64 ± 0.55 vs. 1.64 ± 0.57; P = 0.96), or other optic nerve head parameters analyzed in eyes with APAC. The mean overall RNFL thickness decreased from 106.6 ± 17.9 μm to 92.9 ± 18.3 μm between visits 2 and 3 (P0.01) in affected eyes. The superior quadrant RNFL thickness decreased from 134.8 ± 25.9 μm to 113 ± 25.7 μm (P0.01), and the inferior quadrant RNFL thickness decreased from 139.1 ± 28.4 μm to 115.6 ± 24.9 μm (P0.01). There was no significant change in macular thickness or volume.This study demonstrated that an increase in CDR does not occur after APAC that is treated promptly, although RNFL loss does occur.

The optic disc appearance in the normal fellow eye of 126 patients with nonarteritic anterior ischemic optic neuropathy (n-AION) was compared with the discs in 23 patients with arteritic AION (a-AION) and 122 normal subjects. The number of discs with no cup was significantly greater (P less than 0.001) and the number of discs with a large cup was significantly fewer (P less than 0.001) in the n-AION group compared to the other two groups. No significant differences were found in cup size between the a-AION and normal groups. The pathogenesis of n-AION appears to be multifactorial. There is overwhelming evidence that ischemia is the primary factor. The size of the optic disc also plays a role, probably through a compressive effect at the level of the lamina cribrosa on axons subjected to ischemia. In contrast, a-AION occurs from posterior ciliary artery occlusion and disc size is not a factor.