Background. Untreated age-related macular degeneration (AMD) complicated by choroidal neovascularization (CNV) is one of the most common causes of blindness among people >50 years old. Neovascular AMD involves multiple angiogenic agents to develop choroidal anomalous blood vessels disrupting the anatomy and the function of retinal tissue. Current main treatment for neovascular AMD is the intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents, which have been resulted effective at reducing retinal fluid and regressing the new vessels.
Rare side effects of intravitreal injection are conjunctival hyperemia, eye pain and bleeding in the point of injection, detachment of the retinal pigmented epithelium (RPE), cataract, increase in intraocular pressure (IOP) and vitreous detachment. Rarely, major adverse events like hypersensitivity reactions, endophthalmitis, retinal detachment, uveitis and hypopyon can affect patients after an anti-VEGF injection.
More than AMD, glaucoma (GL) is the world's leading cause of irreversible blindness. Evidences show that optic disc perfusion is reduced in GL and the injection of anti-VEGF agents in patients with GL and CNV could worsen this feature.
Purpose. The present study aims to evaluate by angio-OCT the differences in optic nerve fibers and macular thickness between patients with CNV and GL, with CNV, with GL and healthy patients. The study also intends to evaluate how anti-VEGF treatment affects these parameters, in order to investigate the possible side effects of the intravitreal injection of anti-VEGF agents in glaucomatous patients.
Design. Observational, prospective study.
Methods. 40 patients (10 with GL and CNV, 10 with CNV, 10 with GL, 10 healthy controls) will undergo a complete ophthalmological evaluation, incuding angio-OCT of macula and optic disc.
Results. Optic nerve fibers thickness will be evaluated in all patients to find differences between the groups and after the treatment.
In many cases, eye disease such as AMD constitute a healthcare need that current available treatments are unable to meet. Nowadays, the most effective treatment is represented by intreavitreal anti-VEGF injection, but the results are evaluated only by BCVA and OCT macular thickness.
In addition, there are no evidences about the impact of this therapy on the optic nerve thickness: several studies have shown a reduced disc flow index and vessel density in open-angle glaucoma (5) and anti-VEGF treatment could even worsen this feature. Moreover, there are no evidences that transitory increase of IOP caused by intravitreal injection has a long-term effect (6), even if individual risk factors could predispose to IOP elevation (7, 8).
The only non-invasive way that we currently have to assess how anti-VEGF therapy affects optic nerve is the angio-OCT examination, as it affords to evaluate the perfusion and the vessel density of optic disc. This study will allow to clarify this relation and to identify potential side effects of the anti-VEGF treatment, in order to customize therapy in patients with CNV and glaucoma for a better management and to improve clinical outcomes. In fact, the actual therapeutic schema doesn't provide for a different timing of treatment based on clinical features of patients.
5. Wang X et al. Correlation between optic disc perfusion and glaucomatous severity in patients with open-angle glaucoma: an optical coherence tomography angiography study. Graefes Arch Clin Exp Ophthalmol. 2015 Sep;253(9):1557-64
6. Moraru A et al. Incidence of ocular hypertension after intravitreal injection of anti-VEGF agents in the treatment of neovascular AMD. Rom J Ophthalmol. 2017 Jul-Sep;61(3):207-211.
7. Lamprakis I et al. The Impact of Multiple Intravitreal Anti-VEGF Injections on Intraocular Pressure. Klin Monbl Augenheilkd. 2017 Oct 25.
8. Lanzl I et al. Can Anti-VEGF Injections Cause Glaucoma or Ocular Hypertension? Klin Monbl Augenheilkd. 2017 Feb;234(2):191-193