Patients undergoing long-term treatment with antihypertensive eye drops responded positively with respect to their ocular surface disorder to oral supplementation with antioxidants and essential fatty acids

Carmen Galbis-Estrada,^1,* Maria D Pinazo-Durán,^1,* Jorge Cantú-Dibildox,² Carla Marco-Ramírez,¹ Manuel Díaz-Llópis,^1,3 Javier Benítez-del-Castillo<sup>2

1</sup>Ophthalmic Research Unit Santiago Grisolia, Department of Surgery/Ophthalmology, Faculty of Medicine, University of Valencia, Valencia, Spain; ²Department of Ophthalmology, Hospital of Jerez, Jerez de la Frontera, Cádiz, Spain; ³University and Polytechnic Hospital La Fe, Valencia, Spain

^*These authors contributed equally to this work

Background: Glaucoma and dry eye disorders (DEDs) are frequent comorbidities. The antioxidant and anti-inflammatory properties of essential polyunsaturated fatty acids have been extensively studied in relation to eye diseases.
Objective: Our objective was to determine the effects of oral supplementation with a combined formulation of antioxidants and essential polyunsaturated fatty acids on expression of cytokines and chemokines in tears from patients with DEDs or primary open-angle glaucoma (POAG).
Methods: Participants (n = 97) were distributed into three groups: (1) individuals with nonsevere DEDs (DEDG), (2) individuals with nonadvanced POAG (POAGG), and (3) healthy controls. These groups were randomized into two subgroups: one received a daily antioxidant and essential polyunsaturated fatty acid supplement (two pills) for 3 months (+S), and the other did not (−NS). Participants were interviewed and ophthalmologically examined. Concentrations of specific cytokines and chemokines in reflex tears were determined by multiplexed particle-based flow cytometry. The data were analyzed statistically (SPSS version 15.0).
Results: Comparison of the results from the DEDG and POAGG patients showed significant differences in tear expression of granulocyte-macrophage colony-stimulating factor (P = 0.008), tumor necrosis factor α (P = 0.005), vascular endothelial growth factor (P = 0.038), interleukin-4 (P = 0.030), and interleukin-6 (P = 0.044). The main signs and symptoms of dry eyes such as dryness, burning, photophobia, eye heaviness, and blurred vision, as well as positive changes in eyelashes, hair, nails and skin, were significantly improved in DEDG +S and POAGG +S patients relative to unsupplemented patients.
Conclusion: Inflammation biomarkers were differentially expressed in glaucomatous tears, but the differences changed upon antioxidant/essential polyunsaturated fatty acid supplementation. Chronic instillation of antihypertensive eye drops must be considered for integrating protocols to glaucoma standards of care.

Keywords: glaucoma, dry eye disorders, tears, cytokines, antioxidants, essential fatty acids