Features Associated with Visible Lamina Cribrosa Pores in Individuals of African Ancestry with Glaucoma: Primary Open-Angle African Ancestry Glaucoma Genetics (POAAGG) Study.

There are scarce data regarding the rate of the occurrence of primary open-angle glaucoma (POAG) and visible lamina cribrosa pores (LCPs) in the eyes of individuals with African ancestry; the potential impact of these features on disease burden remains unknown. We recruited subjects with POAG to the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. Through regression models, we evaluated the association between the presence of LCPs and various phenotypic features. In a multivariable analysis of 1187 glaucomatous eyes, LCPs were found to be more likely to be present in eyes with cup-to-disc ratios (CDR) of ≥0.9 (adjusted risk ratio (aRR) 1.11, 95%CI: 1.04-1.19, p = 0.005), eyes with cylindrical-shaped (aRR 1.22, 95%CI: 1.11-1.33) and bean pot (aRR 1.24, 95%CI: 1.13-1.36) cups versus conical cups (p < 0.0001), moderate cup depth (aRR 1.24, 95%CI: 1.06-1.46) and deep cups (aRR 1.27, 95%CI: 1.07-1.50) compared to shallow cups (p = 0.01), and the nasalization of central retinal vessels (aRR 1.33, 95%CI: 1.23-1.44), p < 0.0001). Eyes with LCPs were more likely to have a higher degree of African ancestry (q0), determined by means of SNP analysis (aRR 0.96, 95%CI: 0.93-0.99, p = 0.005 for per 0.1 increase in q0). Our large cohort of POAG cases of people with African ancestry showed that LCPs may be an important risk factor in identifying severe disease, potentially warranting closer monitoring by physicians.

Prevalence and factors associated with optic disc grey crescent in the Primary Open-Angle African Ancestry Glaucoma Genetics (POAAGG) Study.

AIM: To investigate the prevalence and factors associated with optic disc grey crescent (GC) in African Americans with glaucoma. METHODS: Stereo optic disc image features from subjects with glaucoma in the Primary Open-Angle African Ancestry Glaucoma Genetics Study were evaluated independently by non-physician graders and discrepancies adjudicated by an ophthalmologist. Risk factors for GC were evaluated by logistic regression models with intereye correlation accounted for by generalised estimating equations. Adjusted ORs (aORs) were generated. RESULTS: GC was present in 227 (15%) of 1491 glaucoma cases, with 57 (3.82%) bilateral and 170 (11.4%) unilateral. In multivariable analysis, factors associated with GC were younger age (aOR 1.27, 95% CI 1.11 to 1.43 for every decade younger in age, p=0.001), diabetes (aOR 1.46, 95% CI 1.09 to 1.96, p=0.01), optic disc tilt (aOR 1.84, 95% CI 1.36 to 2.48, p<0.0001), a sloping retinal region adjacent to the outer disc margin (aOR 2.37, 95% CI 1.74 to 3.32, p<0.0001) and beta peripapillary atrophy (aOR 2.32, 95% CI 1.60 to 3.37, p<0.0001). Subjects with GC had a lower mean (SD) value of the ancestral component q0 than those without GC (0.22 (0.15) vs 0.27 (0.20), p=0.001), consistent with higher degrees of African ancestry. CONCLUSIONS: More than 1 in 10 glaucoma cases with African ancestry have GC, occurring more frequently in younger subjects, higher degrees of African ancestry and diabetes. GC was associated with several ocular features, including optic disc tilt and beta peripapillary atrophy. These associations should be considered when evaluating black patients with primary open-angle glaucoma.

A Precise Method to Evaluate 360 Degree Measures of Optic Cup and Disc Morphology in an African American Cohort and Its Genetic Applications.

(1) Background: Vertical cup-to-disc ratio (CDR) is an important measure for evaluating damage to the optic nerve head (ONH) in glaucoma patients. However, this measure often does not fully capture the irregular cupping observed in glaucomatous nerves. We developed and evaluated a method to measure cup-to-disc ratio (CDR) at all 360 degrees of the ONH. (2) Methods: Non-physician graders from the Scheie Reading Center outlined the cup and disc on digital stereo color disc images from African American patients enrolled in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study. After converting the resultant coordinates into polar representation, the CDR at each 360-degree location of the ONH was obtained. We compared grader VCDR values with clinical VCDR values, using Spearman correlation analysis, and validated significant genetic associations with clinical VCDR, using grader VCDR values. (3) Results: Graders delineated outlines of the cup contour and disc boundaries twice in each of 1815 stereo disc images. For both cases and controls, the mean CDR was highest at the horizontal bisector, particularly in the temporal region, as compared to other degree locations. There was a good correlation between grader CDR at the vertical bisector and clinical VCDR (Spearman Correlation OD: r = 0.78 [95% CI: 0.76-0.79]). An SNP in the MPDZ gene, associated with clinical VCDR in a prior genome-wide association study, showed a significant association with grader VCDR (p = 0.01) and grader CDR area ratio (p = 0.02). (4) Conclusions: The CDR of both glaucomatous and non-glaucomatous eyes varies by degree location, with the highest measurements in the temporal region of the eye. This method can be useful for capturing innate eccentric ONH morphology, tracking disease progression, and identifying genetic associations.