Assessment of Triamcinolone Treatment for Neovascular Glaucoma

Abstract

Abstract: : Purpose: Previously we showed reduction of intravitreal levels of both stromal derived factor–1 (SDF–1) and vascular endothelial growth factor (VEGF) with clinical improvement of macular edema in diabetic retinopathy (DR) following triamcinolone administration. SDF–1 is implicated in cell trafficking, recruitment of circulating stem cells, and is a regulator of VEGF expression. Thus, SDF–1 may be a key factor modulating angiogenesis in PDR. In this study we examined the effect of intraocular triamcinolone on SDF–1 and VEGF levels in patients with severe proliferative DR (PDR) and neovascular glaucoma (NVG). Methods: Ten patients with NVG were included in this study. Nine patients had severe PDR in one or both eyes; one patient had a central retinal artery occlusion one month earlier. The 8 eyes of patients receiving triamcinolone were not initially treated with panretinal photocoagulation (PRP) due to media opacities. Each of these 8 eyes received 4 mg intraocular triamcinolone. These patients received PRP as the media cleared an average of 2.4 months later. Two patients with clear media did not receive triamcinolone, but were treated with PRP alone. Vitreous (0.5–0.6 ml) was obtained prior to injection of triamcinolone or application of laser in all 10 eyes, and was used to measure VEGF and SDF–1 by ELISA. Results: Of the 8 patients treated with triamcinolone, intraocular VEGF was reduced 35–fold; SDF–1 was reduced 4.6–fold after treatment. In the 2 patients that received PRP alone, intraocular VEGF was reduced 68–fold; SDF–1 was reduced 1.5–fold. Iris neovascularization regressed equally with triamcinolone or laser that first month. Average intraocular pressure (IOP) was 42mm Hg before treatment. At 3 months the average IOP was 19mm Hg with 9 patients on 2 anti–glaucomatous drops and 1 patient off drops after destruction of a portion of the ciliary body using cryotherapy. Average preoperative vision was hand motions with postoperative vision increasing to counting fingers. Conclusions: NVG is a devastating eye condition resulting from massive retinal ischemia. Intraocular triamcinolone lowers VEGF and SDF–1 equivalent to complete PRP, therefore offering an excellent alternative treatment in cases where complete PRP is precluded by media opacity. SDF–1 may represent a key modulator of retinal angiogenesis. The development of agents targeting SDF–1 and VEGF such as triamcinolone may offer alternative therapeutic approaches to treating visual defects associated with angiogenesis.

Keywords: diabetic retinopathy • corticosteroids • clinical (human) or epidemiologic studies: outcomes/complications