A two-year follow-up of oral antioxidant supplementation in primary open-angle glaucoma: an open-label, randomized, controlled trial

Abstract

Purpose: To evaluate the effect of oral antioxidant supplementation (OAS) on primary open-angle glaucoma (POAG) over a 2-year follow-up period.

Patients and methods: In this open-label, randomized controlled trial, 117 eyes of 117 patients with mild or moderate POAG and intraocular pressure under control with topical antiglaucoma medications were recruited and randomly divided into three groups according to supplementation: (1) OAS with (ICAPS R(®) - Alcon Laboratories, n = 26); (2) OAS without ω-3 fatty acids (OFTAN MACULA(®) - Laboratorios Esteve, n = 28); and (3) a control group without OAS (n = 63). They all underwent visual field (VF) tests (Humphrey 24-2) and scans using a Fourier-domain optical coherence tomography (FD-OCT) device (RTVue-100) at the beginning of the study and 2 years later. Mean deviation (MD), standard pattern deviation (PSD), peripapillary retinal nerve fibre layer (RNFL) and macular ganglion cell complex (GCC) parameters were considered for the analysis. Patients were also classified according to MD deterioration (fast deterioration vs. slow deterioration).

Results: Visual field global indices, peripapillary RNFL thickness and macular GCC thickness showed no differences among the groups at the beginning and end of the follow-up. Besides all the comparisons among groups for differences before and after the follow-up of the MD, PSD, RNFL and GCC parameters were also non-significant. The proportions of patients according to MD deterioration were similar among the groups and subgroups (p > 0.05 for all the comparisons).

Conclusion: Oral antioxidant supplementation with or without ω-3 fatty acids does not appear useful as an adjuvant treatment of mild/moderate POAG in the short term.

Keywords: antioxidant; ganglion cell; glaucoma; omega-3 fatty acids; optical coherence tomography; oxidative stress.