A 50-year-old male presented to the outpatient services with gradual, progressive diminution of vision in both eyes (OU) for 20 years. On examination, the best corrected visual acuity was 20/200 in the right eye (OD) and 20/120 in the left eye (OS) with normal intraocular pressures. Anterior segment evaluation was unremarkable. Fundus examination revealed symmetric hypopigmented multifocal lesions involving the macula and superior to optic nerve in both eyes with neurosensory detachments at the macula [Fig. 1a and b]. Surrounding these hypopigmented lesions were yellowish subretinal fleck-like deposits.
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Figure 1: Ultra-widefield fundus photograph of bilaterally symmetric pigmentary changes with perilesional yellow-white deposits (a and b: blue arrow). Fundus autofluorescence imaging demonstrating speckled hyper- and hypo-autofluorescence at the macula with perilesional hyper-autofluorescent flecks (c and d: blue arrow). OCT suggestive of neurosensory detachment with underlying pigment epithelial degeneration (e and f: red arrow). OCT = optical coherence tomography
Next Step
- Electrooculogram (EOG) and observation
- Start oral mineralocorticoid receptor antagonists
- Intravitreal anti-VEGF injections
- Intravitreal steroid injection.
Findings
Bilaterally symmetric neurosensory detachment with underlying degenerative retinal pigment epithelium on optical coherence tomography (OCT) [Fig. 1e and f] and speckled autofluorescence at the macula with perilesional hyper-autofluorescent subretinal fleck-like deposits [Fig. 1c and d] in both eyes was suggestive of vitello-eruptive stage of Best vitelliform dystrophy. A reduced Arden ratio of 1.3 on electrooculogram confirmed the diagnosis. The prognosis was explained, and the patient continues to remain on follow-up.
Diagnosis
Best vitelliform dystrophy
Correct Answer: A
Discussion
Best vitelliform dystrophy is an autosomal dominant disorder of the retinal pigment epithelium, which is associated with the mutation of BEST1 gene.[1] The gene encodes for the protein bestrophin, which modulates ionic transport across the pigment epithelial cell, thereby affecting normal fluid transport and phagocytosis of photoreceptor outer segments. These processes when altered result in the clinical phenotype of subretinal fluid with vitelliform deposits. Over decades, the vitelliform aggregates through a series of chronic sequential degenerative processes – pre-vitelliform through atrophic-neovascular – resulting in retinal pigment epithelial degeneration and subsequent visual impairment.[2]
The resulting neurosensory detachments may be confused for other retinal degenerative disorders like age-related macular degeneration and central serous chorioretinopathy. A high index of suspicion of Best disease in slowly progressive, bilaterally symmetric neurosensory detachments may hence obviate a misdiagnosis and unwarranted medical/surgical interventions. EOG is often performed to confirm the diagnosis.
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.
References
1. Ramsden SC, Davidson AE, Leroy BP, Moore AT, Webster AR, Black GCM, et al. Clinical utility gene card for:BEST1-related dystrophies (Bestrophinopathies) Eur J Hum Genet EJHG 2012;20. doi: 10.1038/ejhg. 2011.251.
2. Gundlach BS, Tsui I. Optical coherence tomography in pediatric patients:A clinical review Ther Adv Ophthalmol 2020;12:2515841420904612.
