Foveal neovascularization in a patient with Type 2 diabetes mellitus.

Retinal neovascularization in Diabetes mellitus (DM) is commonly seen at the optic disc and mid-periphery. It is rare at the fovea as the fovea is an avascular zone and there are very few case reports of foveal neovascularization in Type 1 DM. We report a case of unilateral foveal neovascularization in Type 2 DM.

Introduction

Retinal neovascularization in Diabetes mellitus(DM) is rare at the fovea as fovea is an avascular zone. Few cases of neovascularization at fovea (NVF) are reported but all in younger patients with type 1 DM.[1234] We describe the first case of unilateral NVF in type 2 DM.

Case Report

A 52-year-old male patient, a known case of Type 2 DM for 5 years, presented with decrease in vision in both eyes for 1 month. He had received 2 sittings of laser treatment to both eyes in the last month. His best-corrected visual acuity was 20/80 in the right eye and 20/200 in the left eye. The anterior segment was unremarkable in both eyes. The fundus examination revealed high-risk proliferative diabetic retinopathy (PDR) with clinically significant macular edema, with scattered laser photocoagulation scars in both eyes and neovascularization at the fovea (NVF) in the left eye [Figure 1]. Fluorescein angiography confirmed PDR with mild leakage at macula in the right eye and PDR with NVF and enlarged foveal avascular zone in the left eye [Figure 2]. Optical coherence tomography of macula showed spongy macular edema with hard exudates in both eyes and NVF projecting into the vitreous cavity in the left eye [Figure 3]. We completed pan-retinal photocoagulation in both eyes, following which all neovascularization regressed.

Figure 1

Fundus photograph of the left eye showing high-risk proliferative diabetic retinopathy with clinically significant macular edema, with scattered laser photocoagulation scars and neovascularization at the fovea

Figure 2

Fluorescein angiography of the left eye showing proliferative diabetic retinopathy with neovascularization at the fovea and enlarged foveal avascular zone

Figure 3

Optical coherence tomography of the left eye macula showing spongy macular edema with hard exudates, and neovascularization at the fovea, projecting into the vitreous cavity in the left eye

Discussion

Retinal neovascularization in DM is commonly seen at optic disc and mid-periphery. It is rare at the fovea as fovea is an avascular zone and receives its nutrition from underlying choriocapillaris. The choriocapillaris is densely vascular, and oxygen supply to the fovea is maintained even in the presence of severe capillary nonperfusion areas in the retina. However, it has been seen that choroidal blood flow in the foveal region is significantly decreased in DM, especially in patients with macular edema.[5] Hence, there are rare case reports of neovascularization at the fovea. Finkelstein et al. reported three patients with bilateral white foveal lesions that they called abortive neovascularization.[1] Joondeph et al. described NVF in seven cases, but all had macular ischemia.[2] Kurz et al. and Rajagopal et al. also reported cases with bilateral and unilateral NVF respectively and perfused macula.[34] All the described cases are younger patients with Type 1 DM. We describe the first case of unilateral NVF in Type 2 DM.

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Conflicts of interest

There are no conflicts of interest.