Age-related macular degeneration and hyperbaric oxygen.

We read with interest the study by Dr. Jeffrey Weiss concerning age-related macular degeneration (ARMD/ AMD) and hyperbaric oxygen [1]. Dr. Weiss is to be commended for his interest in this area of research. However, we disagree with the data Dr. Weiss cites to support his conclusion that all 14 patients showed improvement. We believe that visual field examination plays no important role in assessing central macular function. Formal visual field testing requires fixation of the macular retina upon an immovable central target. Aside from providing a reproducible result, the macula plays no other role in visual field testing. We believe assessment of changes in ARMD is better managed by ocular computed tomography (OCT) or angiography than peripheral visual field testing, which was developed to test and follow patient responses to threshold targets presented to the non-macular retina. Visual field testing is also dependent upon the time of day, level of patient fatigue, amount of prior light exposure and the patient’s experience with the test and machine. We feel that the results of visual field tests are of limited import regarding patient outcomes in response to hyperbaric oxygen. We are concerned that Dr. Weiss appears to be the treating ophthalmic physician and the follow-up physician reporting outcomes. The potential for selection and outcome bias is significant in this paper. In addition, all 14 of his patients are reported to have positive outcomes in visual acuity or visual fields examination. This result alone raises further question of treatment and/or observational bias. We studied six patients with ARMD in a nonrandomized fashion similar to the Weiss study. Entrance criteria were that the patient has dry ARMD with no other treatment options. Two of the six patients had geographic atrophy (GA). A general ophthalmologist was the referring physician who recruited patients for our study. All patients met the examination criteria suggested in the Weiss paper. In addition, these patients were seen by one of two retina surgeons for retinal examination and ocular computed tomography (OCT) prior to entering the study. Evaluations in the posttreatment period now date between two and three years. Age-related macular degeneration and hyperbaric oxygen