Progression of visual field loss in open angle glaucoma in the Melbourne Visual Impairment Project

To quantify the progression of visual field loss in participants with open angle glaucoma.

Cluster random samples of 3271 participants participated in this study. Each participant underwent a standardized ophthalmic examination, which included intraocular pressure measurement, Humphrey 24-2 Fastpac visual field testing and stereophotography of the optic disc. At baseline 118 participants were identified as possible, probable or definite open angle glaucoma and 74 (62.7%) of these were seen again at the follow-up examination. Progression of visual field loss was defined using three methods: the Advanced Glaucoma Intervention Study criteria, the modified Anderson criteria and the Blumenthal method.

In total, 49% of subjects showed progressive visual field loss with at least one method. The Blumenthal criteria yielded the highest rate of progression (37%), followed by the modified Anderson method (33%) and the Advanced Glaucoma Intervention Study method (16%). The progressive visual field loss was associated with baseline glaucoma status (P = 0.02); 65% of the definite glaucoma progressed, compared with 57% of the probable glaucoma and 25% of the possible glaucoma. Participants who had been previously diagnosed with glaucoma had a higher rate of progression (54%) when compared with those who had not been diagnosed previously (47%). In total, 50% (four of eight) of those receiving glaucoma medication at baseline had progressive visual field loss; all were in the definite glaucoma category.

Despite use of glaucoma medications the majority of glaucoma patients managed by their regular ophthalmologist experienced progressive visual field loss over a 5-year period.