Combined cilioretinal artery and central vein occlusions in juvenile glaucoma

To the Editor:

We report the course of a 15-year old boy with juvenile glaucoma (JG) due to a myocilin (MYOC) missense mutation who presented with elevated intraocular pressure (IOP) and combined cilioretinal artery occlusion and central retinal vein occlusion (CRVO) OS.

Case Description

A 15-year old healthy boy, diagnosed with JG at 10 years, presented to his local ophthalmologist with painless vision loss OS for three days. He denied illicit drug use. His IOPs were 34mmHg OD and 30 mmHg OS on timolol, brimonidine, and latanoprost. Upon referral, best-corrected visual acuity (BCVA) was 20/20 OD and 20/40 OS. With addition of acetazolamide, IOPs were 36 mmHg OD and 27 mmHg OS. The pupils, anterior segments, and anterior chamber angles were normal. Fundus examination OS showed dilated and tortuous veins, disc and dot hemorrhages, and retinal whitening along the distribution of the cilioretinal artery (Figure 1A, B). The fundus OD was unremarkable. Visual fields were reliable and full, but Amsler grid showed an inferocentral scotoma OS. Angiography demonstrated delayed venous and cilioretinal arteriolar filling (Figure 1C) and disc leakage.

Figure 1.

(A) Fundus photo OS demonstrates dilated, tortuous veins with retinal whitening superior to fovea with scattered dot hemorrhages. (B) Disc photo shows nasal disc hyperemia and hemorrhage. (C) Angiogram at 20 seconds reveals delayed venous filling. (D) Grayscale and pattern standard deviation plots of a reliable visual field confirm a residual paracentral scotoma.

He was diagnosed with a mild CRVO and cilioretinal artery occlusion. Evaluation for a hypercoaguable state (complete blood count, serum homocysteine, anti-cardiolipin antibody, lupus anticoagulant, erythrocyte sedimentation rate, and serum protein electrophoresis) was unremarkable. Using established molecular methods, his genotype revealed the same Pro370Leu MYOC mutation previously reported in other members of his family, UM:JG1 (Figure 2).¹

Figure 2.

Pedigree of UM:JG1, as previously reported in Rozsa et al.¹. Arrow indicates the proband. “+” indicates Pro370Leu MYOC mutation confirmed with molecular diagnosis. Insert shows resequenced DNA from the proband demonstrating the Pro370Leu mutation. Pedigree created using Madeline 2.0.

Seven months following trabeculectomies, initially OS, then OD, his BCVA was 20/20 OU and IOPs were 16 mmHg OU on brimonidine. He noted a smaller, inferior paracentral scotoma (Figure 1D). Fundus examination OS revealed significantly decreased venous dilation, resolution of hemorrhages and retinal whitening.

Discussion

Combined CRVO with cilioretinal artery occlusion is a rare entity described in 1968.² Previously thought to be due to thromboembolus, cilioretinal artery occlusions are now thought to be secondary to CRVO.³ The proposed mechanisms include a sudden occlusion of the central retinal vein transmitting a rise in intraluminal pressure within the retinal capillary bed to a level higher than that of the cilioretinal artery to cause transient blockage of the cilioretinal artery.^{3, 4} Recently, McLeod speculated that CRVO may shunt blood flow from the cilioretinal artery and divert flow to the choroidal circulation, with the degree of hypoperfusion of the cilioretinal artery depending on where it branches from the PCA circulation.⁵

Blurred vision is the most common presentation.^{3, 4} Severe vision loss occurs from foveal ischemia from cilioretinal artery occlusion and/or macular edema from CRVO. The most commonly reported visual field defect is a cecocentral scotoma of varying impact according to location and distribution of the occluded cilioretinal artery. Visual acuity and visual field recovery are common in cilioretinal artery occlusion with non-ischemic CRVO cases.^{3, 4} If the cilioretinal artery involves the entire perifoveal capillary net or there is an ischemic CRVO, then prognosis is guarded with concern for subsequent rubeosis and neovascular glaucoma.^{3, 4}

Although glaucoma and ocular hypertension have been highly associated with vein occlusions,⁶ to the best of our knowledge, this is the first reported case of JG with increased IOP associated with combined CRVO and cilioretinal artery occlusion. Cilioretinal artery occlusions are rare in young patients, so systemic hypercoagulable states must be excluded. Surgical intervention resulted in decreased IOP, and because our patient had a mild CRVO with some foveal involvement of the cilioretinal artery, his visual outcome was good with a limited paracentral scotoma. As JG is typically a bilateral disease, the IOP of the fellow eye should be monitored vigilantly and prophylactic surgery performed aggressively to prevent similar vascular complications from occurring.