Familial exudative vitreoretinopathy with retinitis pigmentosa: A rare association

Sampurna Bhattacharyya; Ahana Sen; Bristi Majumdar; Sanatombi Thounaojam; Ankeeta Baliarsingh; Nikita Goel; Zubin D'souza; Kumar Saurabh; Rupak Roy

doi:10.4103/IJO.IJO_3316_22

CASE REPORT

Year : 2023 | Volume : 3 | Issue : 2 | Page : 399-401

Familial exudative vitreoretinopathy with retinitis pigmentosa: A rare association

Sampurna Bhattacharyya¹, Ahana Sen¹, Bristi Majumdar¹, Sanatombi Thounaojam¹, Ankeeta Baliarsingh¹, Nikita Goel¹, Zubin D'souza¹, Kumar Saurabh², Rupak Roy¹
¹ Department of Vitreo Retina, Aditya Birla Sankara Nethralaya, Kolkata, West Bengal, India
² Department of Vitreo Retina, Netralayam, Kolkata, West Bengal, India

Date of Submission	21-Dec-2022
Date of Acceptance	20-Feb-2023
Date of Web Publication	28-Apr-2023

Correspondence Address:
Rupak Roy
Aditya Birla Sankara Nethralaya, 147, Mukundapur, E.M.Bypass, Kolkata-700 099, West Bengal
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/IJO.IJO_3316_22

Abstract

Familial exudative vitreoretinopathy (FEVR) is a rare inherited slowly progressive disorder characterized by failure of vascularization of the peripheral retina and poor vascular differentiation. Retinitis pigmentosa (RP) is a group of clinically and genetically heterogeneous inherited retinal disorders characterized by diffuse progressive dysfunction of predominantly rod photoreceptors with subsequent involvement of cone photoreceptors. A 13-year-old boy presented with nyctalopia and low vision for 10 years. Fundus evaluation showed retinal pigmentary changes in the mid-periphery. The fundus fluorescein angiogram showed straightening of retinal vessels, vascular leakage, and avascularity of the peripheral retina, suggestive of FEVR. Full-field electroretinogram (FFERG) showed grossly reduced scotopic and photopic responses in both eyes, pointing toward retinitis pigmentosa (RP). To the best of our knowledge, this case is the second one internationally, and the first in India to show the coexistence of FEVR and RP in the same patient.

Keywords: EYS/LRP5 digenic mutation, familial exudative vitreoretinopathy (FEVR), full-field electroretinogram (FFERG), fundus fluorescein angiogram (FFA), reduced scotopic and photopic responses, retinal pigmentary changes, retinitis pigmentosa (RP), straightening of vessels, vascular leakage

How to cite this article:
Bhattacharyya S, Sen A, Majumdar B, Thounaojam S, Baliarsingh A, Goel N, D'souza Z, Saurabh K, Roy R. Familial exudative vitreoretinopathy with retinitis pigmentosa: A rare association. Indian J Ophthalmol Case Rep 2023;3:399-401

How to cite this URL:
Bhattacharyya S, Sen A, Majumdar B, Thounaojam S, Baliarsingh A, Goel N, D'souza Z, Saurabh K, Roy R. Familial exudative vitreoretinopathy with retinitis pigmentosa: A rare association. Indian J Ophthalmol Case Rep [serial online] 2023 [cited 2023 Jun 2];3:399-401. Available from: https://www.ijoreports.in/text.asp?2023/3/2/399/375038

Familial exudative vitreoretinopathy (FEVR) is a rare inherited disorder characterized by anomalous vascularization of the peripheral retina and poor vascular differentiation leading to peripheral retinal non-perfusion, lipid exudation, fibrovascular proliferation, peripheral retinal traction and dragging, and retinal detachment.^[1],[2] Cases can be inherited in an autosomal dominant (most common), autosomal recessive, or X-linked recessive fashion, or can occur in individuals having no family history. Mutations in FZD4 (responsible for AD form), LRP5 (for AR or sporadic), TSPAN12 (for AD and AR), NDP (X-linked), ZNF408, and KIFF11 genes, which have been implicated in abnormal signaling of various known biological pathways, including the Wnt signaling, are associated with FEVR.^[3],[4],[5] Wnt signaling cascade regulates cell survival, differentiation, proliferation, and migration and thereby retinal vascular formation.^{[5],[6],[7],[8]}

Retinitis pigmentosa (RP) is a group of clinically and genetically heterogeneous inherited retinal disorders characterized by diffuse progressive dysfunction of predominantly rod photoreceptors with subsequent involvement of cone photoreceptors and the retinal pigment epithelium (RPE).^[8] It may occur as an isolated sporadic disorder or be inherited as autosomal dominant, autosomal recessive, or X-linked.^[8] Patients present with bilateral but often asymmetric progressive loss of night vision, peripheral visual field constriction, and eventually tunnel vision in the later stages of the disease.^[8] The classic clinical triad of RP consists of retinal arteriolar attenuation, retinal pigmentary changes (hypopigmented and/or hyperpigmented bony spicule lesions and pigment clumpings) most characteristically in the mid-peripheral fundus, and waxy optic disc pallor.^[8] To date, more than 60 genes including EYS (RP25- AR), RHO (AD), RP1, USHA2A, RPGR, BEST1, NR2E3, NRL, RPE65, ABCA4, PROM1, PRPH 2, have been found to be associated with RP.^[9]

There exists only one report in the literature documenting both these entities together in the same patient.^[10] Herein we report a case of FEVR with RP. Our case report is the second one internationally and the first in India to report the co-existence of FEVR and RP.

Case Report

A 13-year-old Indian boy presented with a complaint of gradual diminution of vision, especially at night for 10 years. According to his parents, the symptoms presented in early childhood and progressed with time. The boy was born at term at 2710 g via normal vaginal delivery with no history of hospitalization during the postnatal period. There is no evidence of a similar condition in their family so far.

The best-corrected visual acuity (BCVA) was 3/60 and 6/60 in the right eye and the left eye, respectively. On cover–uncover examination, the right eye revealed convergent strabismus with all extraocular muscles functioning fully in all directions. On slit-lamp examination, the anterior segment showed no abnormality and both eyes had an intraocular pressure of 13 mm Hg (with Goldmann applanation tonometer). Dilated fundus examination showed a few vitreous floaters, pale optic disc, pigmentary changes in the mid-periphery, straightening of retinal vessels in the periphery, and degenerative changes in the macula along with foveal thinning bilaterally [Figure 1]. Old marks of laser photocoagulation performed on the peripheral capillary non-perfusion areas were seen in the temporal periphery in both eyes.

Figure 1: Multicolor and color fundus images of the right eye (a and c) and the left eye (b and d), showing pale optic disc, pigmentary changes in the mid-periphery, and degenerative changes at the macula

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A fundus fluorescein angiogram was performed and confirmed the diagnosis of straightening of retinal vessels, peripheral vascular leakage, and avascularity of the peripheral retina confirming FEVR [Figure 2]. Spectral-domain optical coherence tomography (SD-OCT) revealed foveal thinning bilaterally[Figure 3]. Fundus autofluorescence (FAF) showed no abnormalities in either eye [Figure 3]. The patient also underwent a full-field electroretinogram (FFERG), which showed grossly reduced scotopic and photopic responses [Supplementary Fig. 1][Additional file 1].

Figure 2: Fundus fluorescein angiography images of the right eye (a and c) and the left eye (b and d) showing straightening of retinal vessels in the periphery (a and b), peripheral vascular leakage, and peripheral avascular areas (c and d)

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Figure 3: Optical coherence tomography images of the right eye and the left eye (a and b) showing foveal thinning bilaterally along with loss of foveal contour in the right eye. Fundus autofluorescence images of the right eye and the left eye (c and d) showing no abnormalities

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Clinical evaluation and imaging supported the diagnosis of RP with FEVR in this case. The patient was further sent for a low vision aid trial so that he can conduct his day-to-day activities with a little more ease.

Discussion

In this report, we have described a case of FEVR with features of RP. The clinical diagnosis of RP is based on the history of nyctalopia and the clinical triad of waxy disc pallor, retinal arterial attenuation, and pigmentary changes. However, FEVR is characterized by the straightening of retinal vessels, lipid exudation, peripheral retinal avascular zones, and retinal detachment.^[1],[2],[3] Our patient presented with childhood-onset gradually progressive nyctalopia, retinal pigmentary changes in the mid-periphery, and grossly reduced scotopic and photopic responses in FFERG, all three features being consistent with the diagnosis of RP. Moreover, the retinal angiogram showed a straightening of vessels, and peripheral vascular leakages with avascular zones suggestive of FEVR, pointing toward the coexistence of FEVR and RP.

According to genetic studies, a mutation in LRP5 is associated with AR and a sporadic type of FEVR.^{[4],[5],[6],[7],[8]} Feng et al.^[9] reported a case where digenic heterozygous mutations in EYS/LRP5 genes were found in a Chinese family with retinitis pigmentosa. A coexistence of the two above conditions was previously reported by Abdullah et al. in 2014.^[10] However, the fact that genetic mutation analysis had not been performed in the current or the previous similar case is a drawback. The coexistence of FEVR and RP in the same eye could be coincidental or could be the result of underlying common genetic alterations, which further studies can only answer. Genetic analyses and detailed clinical descriptions should be provided in further case reports to find out any possible mutation interlinking both entities.

Conclusion

This is possibly the second report that describes the coexistence of features of FEVR and RP. Genetic studies including molecular mutation analyses should be provided in further case reports to find out any possible common genetic mutation shared by both entities.

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 initial s 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.

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