Florid neovascularization of the iris with a normal-appearing fundus: What next?

A 55-year-old gentleman, a known case of type 2 diabetes for 6 months, presented with pain and redness in the left eye, 3 months after a complicated cataract surgery performed elsewhere, with best corrected visual acuity (BCVA) of 6/24 and intraocular pressure (IOP) of 32 mmHg. There was an anterior chamber intraocular lens (ACIOL) with florid neovascularization of the iris (NVI) in the left eye [Fig. 1a]. Gonioscopy showed open angles (Shaffer's grade 3) with neovascularization in all quadrants. The right eye had early senile immature cataract without any NVI. The fundus examination of both eyes appeared normal with a healthy disc (cup-to-disc ratio of 0.3 in both eyes). Fundus fluorescein angiography (FFA) was normal in the right eye and revealed delayed venous filling with mid-peripheral microaneurysms [Fig. 1b] and paravenous staining [Fig. 1c] in the left eye.Figure 1: (a) Slit lamp image of the left eye showing florid NVI. (b) FFA of the left eye revealing delayed venous filling (yellow arrowhead) with mid-peripheral microaneurysms (yellow arrows). (c) Late-phase FFA of the left eye showing staining of retinal veins. (d) Carotid Doppler image showing no color flow (yellow arrow) in right CCA and ICA suggestive of complete thrombosis. (e) CTA showing non-visualization of right CCA (yellow arrow) suggestive of complete thrombosis. (f) MRI showing visualization of the right intracranial ICA, being perfused from branches of the circle of WillisWhat is Your Next Step in Management? Explantation of the ACIOL Carotid Doppler and computed tomography angiography (CTA) Glaucoma filtration surgery Laser cyclodestructive procedure. Correct Answer b. Carotid Doppler and computed tomography angiography (CTA). Findings Carotid Doppler [Fig. 1d] and CTA [Fig. 1e] showed complete thrombosis of the right common carotid artery (CCA) and internal carotid artery (ICA) and 75% stenosis of the left ICA. Furthermore, CTA and magnetic resonance imaging (MRI) [Fig. 1f] showed perfusion of the right intracranial ICA from branches of the circle of Willis, but no such collaterals were found on the left side. The patient was treated with intravitreal anti-vascular endothelial growth factor (VEGF) injection followed by pan-retinal photocoagulation, which led to prompt resolution of NVI. IOP was controlled with a single antiglaucoma medication and stable vision at the end of 3 months. Neurology and interventional radiology opinions were sought for the management of carotid stenosis. He has been on regular follow-up with angle and iris examination to detect recurrence of neovascularization. Clinical Diagnosis Left-eye neovascular glaucoma (NVG) secondary to ocular ischemic syndrome (OIS). Discussion NVG is a severe form of secondary glaucoma commonly seen in ischemic retinal vascular conditions such as venous occlusions and proliferative diabetic retinopathy.[1] Identification and management of the primary cause are an integral part of managing NVG. Chronic ocular ischemia due to severe carotid artery disease was the cause identified in our patient. Though carotid occlusion was bilateral in our patient and the right carotids were completely occluded, the right eye was probably protected by the maintenance of flow within the intracranial ICA from the circle of Willis. The development of collaterals to supply the ICA is an important protective factor against the development of OIS.[2,3] The absence of such collaterals to the left ICA could be a precipitating event for the development of neovascularization in the left eye even with 75% stenosis of the left ICA. Complicated cataract surgery could also have a contributory role in the onset of iris neovascularization. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.