Asymmetric presentations of familial exudative vitreoretinopathy

Introduction

Familial exudative vitreoretinopathy (FEVR) is a relatively rare vitreoretinal disorder that is clinically similar to Retinopathy of Prematurity, except that there is usually a positive family history and no history of prematurity or oxygen supplementation.[1] Patients with FEVR could present with a high degree of symmetry between eyes or with findings that are entirely unilateral.[2] We report herein two cases of FEVR from North-East India to highlight the asymmetric presentations of FEVR and the need of high index of suspicion to detect such cases.

Case Reports

Case 1

A 15-year-old boy presented with poor vision in his left eye since birth. His best corrected visual acuity (BCVA) was 20/63 in the right eye and finger counting close to face (FCCF) in the left eye. Left eye had enophthalmos with exotropia of 30°. Anterior segment was normal in both eyes. Right fundus showed mild temporal dragging of disc, straightening of temporal vessels, subretinal exudations and scarring at the periphery of temporal retina [Figure 1]. Left fundus showed dragging of the disc with a falciform retinal fold and an aberrant retinal vascular pattern [Figure 2]. Pigmentation and scarring of retina were seen. Fundus fluorescein angiography [FFA] showed abrupt cessation of vasculature at the temporal retina of right eye [Figure 3]. There was brush like anastomoses and shunts at the vascular-avascular border with mild leakage from the vessels. Left eye showed mild leakage from the disc and falciform retinal fold.

Figure 1.

Fundus photo of case 1 showing mild temporal dragging of disc, straightening of temporal vessels, subretinal exudation and retinal scarring in the right eye

Figure 2.

Fundus photo of case 1 showing dragging of disc with a knife-like falciform retinal fold, aberrant retinal vascular pattern, retinal scarring and pigmentation in the left eye

Figure 3.

Fundus fluorescein angiography image of case 1 showing a zone of avascular retina with abrupt cessation of vessels at the vascular-avascular border and mild leakage from vessels in the right eye

There was no history of prematurity. The parents and four siblings were normal.

Case 2

A 17-year-old girl presented with poor vision in her left eye since birth. Her BCVA was 20/80 in the right eye and FCCF in the left eye. Left eye had exotropia of 30°. There was nystagmus in both eyes. Anterior segment was normal in the right eye whereas the left eye had an early posterior subcapsular cataract. Right fundus was grossly normal except mild straightening of vessels in the periphery. Left fundus showed dragging of disc with a broad falciform retinal fold, macular detachment, peripheral retinal tears and subretinal exudations [Figure 4a]. There was a clear vascular-avascular border in peripheral retina temporally [Figure 4b].

Figure 4.

(a) Fundus photo of case 2 showing a broad falciform retinal fold running inferotemporally with large retinal tears, macular detachment and subretinal exudation in the left eye. (b) Fundus photo of case 2 showing a zone of avascular retina with the vascular-avascular border in the temporal retina of left eye

FFA in right eye showed grossly normal retinal vasculature except for mild straightening of vessels in the periphery. Left retina showed abrupt cessation of vessels in the temporal retina [Figure 5].

Figure 5.

Fundus fluorescein angiography image of case 2 showing the vascular-avascular border in the left eye

Only one of the 11 siblings and the child's mother were available for examination and were found to be normal.

Discussion

Canny and Oliver were the first to describe the cessation of peripheral vascular growth with FFA in FEVR.[1,2,3]

Both of our cases had asymmetric presentations and such presentations have been infrequently described in the literature.[2,3] Both had exotropia and case 2 had subcapsular cataract. FEVR has been reported to be associated with strabismus,[2,3,4] cataract,[2] retinal scar[2] and nystagmus.[4]

The pattern of inheritance in FEVR is mostly autosomal dominant but X-linked and sporadic cases are also known.[1,2,3,5] Our cases are probably sporadic in nature.

The results of prophylactic treatment in FEVR remains controversial and most authors suggest treatment only for progressive lesions.[3] The results of surgical interventions are also variable.[3,5]

FEVR needs to be differentiated from other disorders that mimic its presentation. It poses a diagnostic challenge and needs high index of suspicion to diagnose.