Visual Field Progression Patterns in the Ocular Hypertension Treatment Study Correspond to Vulnerability Regions of the Disc

Abstract

Abstract Objectives To determine the locations on the 24-2 visual field (VF) testing grid that are most likely to progress in patients with ocular hypertension (OHTN). Based on a structural model of superior and inferior areas of relative vulnerability at the optic disc, we hypothesized that the nasal and paracentral regions are more prone to show a reduction in sensitivity. Methods This is a posthoc analysis of the data from a randomized controlled clinical trial. Data collected from patients enrolled in the Ocular Hypertension Treatment Study (OHTS) Phases 1 and 2 were used. A pointwise analysis was applied to determine the progression patterns in the early and delayed treatment groups. Each group's progression rate and frequency were calculated for each of the 52 locations corresponding to the 24-2 VF strategy, using trend- and event-based analyses, respectively. Results For the event-based analysis, the events were most commonly found in the nasal and paracentral regions. The same regions, with some modest variation, were found to have the fastest rates of progression (ROP) measured with trend analysis. A similar pattern of progression was observed in both the early and delayed treatment groups. Conclusions Development of VF loss in ocular hypertensive eyes is consistent with the vulnerability zones previously described in glaucomatous eyes with established VF loss. This suggests that these locations need to be most carefully monitored.