Optical Coherence Tomography Findings in Glaucoma With Coexisting Vitamin A Deficiency.

This case study reports on the presence of vitamin A deficiency in an adult with asymmetric normal tension glaucoma. The retinal OCT findings demonstrated not only expected loss of the outer retinal layers, typically seen in vitamin A deficiency, but also severe and bilateral loss of the inner retinal layers. After vitamin A supplementation, visual acuity, dark adaptation, and color vision normalized. The outer retinal layers had a restoration of thickness after vitamin A supplementation, but the inner layers did not change. This case is unique because it may give us an insight into the role of vitamin A on the inner retina and demonstrate the recovery of the outer retinal layers with vitamin A supplementation.

The connective tissue phenotype of glaucomatous cupping in the monkey eye - Clinical and research implications.

In a series of previous publications we have proposed a framework for conceptualizing the optic nerve head (ONH) as a biomechanical structure. That framework proposes important roles for intraocular pressure (IOP), IOP-related stress and strain, cerebrospinal fluid pressure (CSFp), systemic and ocular determinants of blood flow, inflammation, auto-immunity, genetics, and other non-IOP related risk factors in the physiology of ONH aging and the pathophysiology of glaucomatous damage to the ONH. The present report summarizes 20 years of technique development and study results pertinent to the characterization of ONH connective tissue deformation and remodeling in the unilateral monkey experimental glaucoma (EG) model. In it we propose that the defining pathophysiology of a glaucomatous optic neuropathy involves deformation, remodeling, and mechanical failure of the ONH connective tissues. We view this as an active process, driven by astrocyte, microglial, fibroblast and oligodendrocyte mechanobiology. These cells, and the connective tissue phenomena they propagate, have primary and secondary effects on retinal ganglion cell (RGC) axon, laminar beam and retrolaminar capillary homeostasis that may initially be "protective" but eventually lead to RGC axonal injury, repair and/or cell death. The primary goal of this report is to summarize our 3D histomorphometric and optical coherence tomography (OCT)-based evidence for the early onset and progression of ONH connective tissue deformation and remodeling in monkey EG. A second goal is to explain the importance of including ONH connective tissue processes in characterizing the phenotype of a glaucomatous optic neuropathy in all species. A third goal is to summarize our current efforts to move from ONH morphology to the cell biology of connective tissue remodeling and axonal insult early in the disease. A final goal is to facilitate the translation of our findings and ideas into neuroprotective interventions that target these ONH phenomena for therapeutic effect.

Effect of palmitoylethanolamide on visual field damage progression in normal tension glaucoma patients: results of an open-label six-month follow-up.

The purpose of this study is to assess the effect of palmitoylethanolamide (PEA) oral administration on intraocular pressure (IOP) and visual field damage progression in normal-tension glaucoma (NTG) patients. Thirty-two consecutive patients affected by NTG were enrolled and randomized in a 1:1 ratio to receive PEA treatment (group A) or no treatment (group B). Group A patients took ultramicronized 300 mg PEA tablets two times per day for six months. Best-corrected visual acuity (BCVA), IOP, and visual field test were evaluated at baseline and at the end of the six-month follow-up. No significant differences in clinical parameters between the two groups were observed at baseline. At six months, group A patients showed significant IOP reduction (from 14.4±3.2 mm Hg to 11.1±4.3 mm Hg, p<0.01). No statistically significant changes were seen in BCVA in either group. Visual field parameters significantly diminished in patients receiving PEA compared to baseline values (-7.65±6.55 dB vs. -4.55±5.31 dB, p<0.001; 5.21±4.08 dB vs. 3.81±3.02 dB, p<0.02; mean deviation [MD] and pattern standard deviation [PSD] respectively), while no significant changes were seen in group B. A generalized linear model demonstrated that the final IOP, MD, and PSD was affected only by the systemic PEA treatment (p<0.01 each) and not affected by demographic or clinical characteristic between the groups. Hence, systemic administration of PEA reduces IOP and improves visual field indices in individuals affected by NTG. Neither ocular nor systemic side effects were recorded during the study period.