Neuroprotection in Primary Open-Angle Glaucoma: The Role of a Fixed Citicoline-Homotaurine-Vitamin E Combination

Abstract

Glaucomatous optic neuropathy is a chronic degenerative neuropathy characterized by progressive damage of the retinal ganglion cells despite good compensation of intraocular pressure. The purpose of this study was to assess the effect of oral administration of a fixed combination of citicoline 500 mg + homotaurine 50 mg + vitamin E 12 mg (CIT/HOMO) on retinal ganglion cell function as examined by pattern electroretinogram (PERG) in subjects with primary open-angle glaucoma. A prospective, randomized, single-blind, balanced, crossover study was performed on a population of 40 patients with POAG-HT and fully-compensated IOP with topical hypotensive therapy. Recruited patients were allocated by balancing randomization to two treatment groups: - group A: patients continued current hypotensive eye-drop for 4 months and subsequently took 1 tablet of CIT/HOMO each morning for 4 months; - group B: patients took 1 tablet of CIT/HOMO each morning for 4 months in addition to current hypotensive eye-drop and subsequently continued with current hypotensive eye-drop alone for 4 months. Patients were examined at baseline (T0), after 4 (T1) and 8 months (T2). At every single time was performed a whole eye examination, 3 IOP measurements, 30.2 SITA Standard Humphrey visual field test, OCT cup/disc ratio and PERG glaucoma Hemifield test with central amplitude analysis. 38 patients completed the study for a total of 76 eyes. In both groups of patients tonometry, cup/disc ratio and visual field did not reveal any statistically significant difference. In both groups, adding the CIT/HOMO at hypotensive eye-drop resulted in an improvement in PERG after 4 months of therapy that disappeared when CIT/HOMO was withdrawn. Four months supplementation with a fixed combination of citicoline, homotaurine and vitamin E was seen to significantly increase the amplitude of the PERG bioelectric potential transmitted by the optical pathway to the visual cortex in subjects with primary open-angle glaucoma with compensated IOP and initial damage of the visual field and optic disc. During this study, the IOP remained compensated with the current hypotensive therapy and no deterioration was observed in the visual field or the cup/disc ratio.