Characteristics of Eyes With Asymptomatic Primary Angle Closure Glaucoma With Varying Severity of Visual Field Loss at Presentation

Precis: Approximately 38% of 467 asymptomatic primary angle closure glaucoma subjects had severe visual field loss (<-20 dB) at first presentation. Sex-based differences in prevalence and biometry suggest the need for an integrated approach for assessing risk. Purpose: To compare the clinical characteristics of patients with asymptomatic primary angle closure glaucoma (PACG) across varying disease severity at presentation. Methods: Of 681 PACG patients recruited, 196 were excluded due to acute primary angle closure and 18 due to pretreatment. Clinical data from 467 patients were analysed, including age at presentation, presenting intraocular pressure (IOP), pre-intervention gonioscopy, vertical cup-to-disc ratio, biometry, pre-surgery refractive data, and visual field (VF) mean deviation (MD) at presentation (excluding the first VF). Disease severity was classified based on the VF MD as early-to-moderate (>=-12 dB), advanced (-12.01 to -20 dB), and severe (<-20 dB). Results: Of the 467 patients, 304 had reliable VFs within 1.5 years of presentation and were categorized as early-to-moderate (n=129; 42.4%), advanced (n=57; 18.8%), and severe PACG (n=118; 38.8%). The mean age at presentation was 64.7 +/- 8.6 years and 52.6% were male. Patients with severe PACG were more likely to be male (61.9%), with the highest presenting IOP (P<0.001), and narrowest anterior chamber angle (P<0.001). Significantly smaller anterior chamber depth and shorter axial length across worsening disease severity were only observed in female but not in male subjects. There was no significant difference in mean age at presentation across groups (P=0.12). Presenting IOP of <= 21 mm Hg was observed in 49.1% (n=28) advanced and 29.7% (n=35) severe PACG. Conclusions: Similar age at presentation of severe PACG and those with less severe disease suggests that the severe group either developed PACG at an earlier age or underwent rapid disease progression. Sex-based differences of prevalence and biometry may also impact disease risk.