Journal of Clinical and Experimental Ophthalmology
Open Access

Abstract

Retinal Photocoagulation Density in the Treatment of Neovascular Glaucoma due to Diabetic Retinopathy

Teruhiko Hamanaka, Takayasu Omata, Noriko Akabane, Toshihiro Yajima and Nobuo Ishida

Purpose: The risk factors for pan-retinal photocoagulation (PRP) failure and the efficacy of achieving a PRP burn density of ≥ 40% in the mid-periphery against diabetic neovascular glaucoma (NVG) were retrospectively evaluated.
Methods: All eyes were treated in order to exceed more than 40% PRP density by fluorescein fundus angiography before and after PRP. Risk factors for failed IOP control (≤22 mmHg or baseline) were evaluated by dividing into two groups; eyes received previous retinal photocoagulation (RP) before NVG (group I) and eyes with no RP before NVG (group II).
Results: Thirty one eyes of 25 patients were used (group I: 12 eyes, group II: 19 eyes).RP density before NVG in all eyes in group I was less than 40%. Risk factors for failed IOP control were prolonged PRP treatment of more than 12 months in group I (p=0.00053), and higher IOP at the diagnosis of NVG (p=0.01157), preexisting glaucoma or ocular hypertension (OH) (p=0.04664) and the persistence of optic disc neovascularization (NVD) in group II (p=0.01766).
Conclusion: Eyes with RP density of less than 40% may have a risk for later development of NVG. The prompt initiation of PRP, a PRP burn density of greater than 40%, and the completion of PRP within 6 months are strongly recommended for the treatment of NVG. Special care should be taken in NVG-affected eyes with small pupils, preexisting glaucoma or OH, or persistent NVD as well as those that are subjected to PRP for more than 12 months.