Visual field change in low-tension glaucoma over a five-year follow-up.

There is some evidence that the nature and progression of disease in low-tension glaucoma may be distinct from other open-angle glaucomas. The authors assessed visual field change by retrospective case review of all patients treated for low-tension glaucoma by the Glaucoma Service, Wills Eye Hospital, for at least 5 years. Sixty-two glaucomatous eyes of 36 patients were identified. All eyes were treated medically and 40 (65%) underwent at least one surgical procedure. Twenty-eight eyes (47%) had initial field loss confined to a single hemi-field and in the remainder both hemi-fields were involved. Thirty of 57 eyes (53%) showed progression at 3 years and 38 (62%) of 57 had progressed by 5 years. A dense scotoma extending from the nasal periphery toward fixation was the most common visual field defect. The rate of field change in this population is significantly greater than in a cohort of primary open-angle glaucoma patients also seen at Wills Eye Hospital, but who had elevated intraocular pressures. Patterns of field loss and rate of progression in this low-tension glaucoma population suggest that the natural history of low-tension glaucoma differs from high-tension open-angle glaucoma.