Abstract
Purpose :
To describe visual field defect after acute primary angle closure (APAC). To identify risk factors for visual field loss, and time to significant visual field loss after onset of APAC.
Methods :
This is a cross-sectional study of consecutive adult patients who were diagnosed with APAC from January to June 2017 in 5 eye centers in Northern China. Patient clinical characteristics were documented, including time from symptom to treatment (TST). Patients underwent Humphrey visual field (HVF) 24-2 testing after diagnosis and treatment for APAC. HVF defect severity for each eye was classified according to the enhanced glaucoma staging system (GSS2), as well as the Ocular Hypertension Treatment Study (OHTS) classification system. Univariate and multivariate analyses were conducted to identify risk factors associated with visual field loss after APAC using linear mixed model. A mathematical model was created by fitting TST to the rate of visual field loss at each time point.
Results :
A total of 127 patients (including 131 eyes) with an average age of 65.46±7.86 years were included in the study; 80.2% were female patients. The mean intraocular pressure (IOP) by non-contact tonometry at the time of diagnosis was 43.10±19.14 mmHg. According to the GSS2 staging, 16 (12.2%) patients was categorized as stage 0; 22 (16.8%) patients, stage 1; 25 (19.1%) patients, stage 2; 7 (5.3%) patients stage 3; 18 (13.8%) patients, stage 4; and 43 (32.8%) patients, stage 5. Univariate analysis showed that patients with more severe GSS2 staging were older (p = 0.029), had longer TST (p = 0.030), traveled farther from home to eye center (p = 0.050). Similar results were found using the OHTS severity classification. Multivariate logistic regression analysis showed that older age (p = 0.004), longer TST (p = 0.001), farther distance from home to eye center (p = 0.017), and higher IOP at the time of diagnosis (p < 0.001) were associated with more severe GSS2 staging on HVF 24-2. The probability of having any visual field damage was 1% if treatment was initiated within 3.7 hours of symptom onset (TST). Probability of visual field damage increased to 5% when TST increased to 6.6 hours.
Conclusions :
Risk factors for visual field loss after APAC attack include older age, longer time from symptom to treatment, farther distance from eye center, and higher IOP at diagnosis. The time window associated with a visual field loss rate of 1% was 3.7 hours.
This is a 2020 ARVO Annual Meeting abstract.