Pre- and Post-POAG Rate of Visual Field Progression in the Ocular Hypertension Treatment (OHTS) Study

Abstract

Purpose : To compare the rate of visual field (VF) loss (mean deviation dB/year) before and after POAG diagnosis

Methods : 282 participants developed POAG in OHTS 1 and 2. VF tests (30-2 and 24-2 test strategies) HFA were completed every 6 months for 12 years in OHTS 1 and 2 and at 20-year visit in OHTS 3. Diagnosis of POAG required: 1. Reproducible optic disc deterioration and/or VF abnormality as determined by Reading Centers. 2. Attribution of change to POAG by a masked Endpoint Committee. Calculation of pre-POAG slope required at least 3 VF’s over 3 years prior to POAG. Calculation of post-POAG slope required at least 3 VF’s over 3 years after POAG. Slope coefficient (MD dB/year) was calculated for each eye separately using simple linear regression.

Results : 83% (1,354 of 1,636) of the participants did not develop POAG in either eye in OHTS 1 or 2. The slope of MD from baseline to last f/up visit was -0.07 dB/yr among these participants. 360 eyes of 282 participants developed POAG in OHTS 1 or 2. The mean (SD) age of participants at the time of POAG diagnosis was 66 (10 SD) years, median (range) time to POAG from baseline was 7.0 (0.6 to 14) years and median follow-up after the diagnosis of POAG was 8 years.

66% of 179 participants developed unilateral VF POAG and 34% were bilateral. Mean post-POAG slopes were markedly greater than pre-POAG slopes (Table 1). Mean post-POAG slopes were linear through 20 years of f/up. 41% of the eyes that developed VF POAG progressed at a rate of -0.5 dB/year or more and 23% of these eyes progressed at a rate of -1.0 dB/year or more.

Conclusions : Among eyes that developed POAG, the rate of change in MD dB/year increased substantially after the diagnosis of POAG. The slope of VF loss after the diagnosis of POAG was linear through 20 years.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.