Types of Visual Field Abnormalities that Subsequently Become Visual Field Primary Open–Angle Glaucoma in the Ocular Hypertension Treatment Study (OHTS)

Abstract

Abstract: : Purpose:To determine whether certain types of visual field abnormalities are predictive of visual field primary open–angle glaucoma (POAG) in the Ocular Hypertension Treatment Study (OHTS). Methods: In the OHTS, follow–up visual fields are performed every six months and are considered abnormal if the Glaucoma Hemifield Test is outside of normal limits and/or the Corrected Pattern Standard Deviation is P < 5%. A visual field POAG endpoint requires 3 consecutive, abnormal and reliable visual fields with the abnormality in the same location and on the same index(es). This report evaluates first abnormal and reliable visual fields from 1,076 eyes (785 patients) through 6/1/02. Of these 1,076 eyes, 81 eyes (from 74 patients) eventually developed a visual field POAG endpoint. The type of abnormality was used to predict POAG in a multivariate survival analysis, while adjusting for effects of treatment, baseline intraocular pressure, and correlation between eyes from the same patient. Results: Of the 81 visual field POAG endpoint eyes, 58 eyes (72%) had initial partial arcuate (PArc) or nasal step (NS) abnormalities. The remaining 23 eyes (28%) had initial abnormalities of other types. The relative risk of a visual field POAG endpoint when comparing NS or PArc abnormalities vs. abnormalities of other types is 3.3 (p<0.0001). The initial abnormality was reproduced in three consecutive visual fields in 30 of the 58 eyes. In the remaining 28 eyes, a median of 487 days intervened before confirmation of POAG. Conclusions:Partial arcuate and nasal step visual field abnormalities were the most common initial visual field abnormalities to be reproducible and subsequently become an OHTS visual field POAG endpoint.

Keywords: visual fields