Objectives: To report a child with early-onset autosomal recessive Best vitelliform macular dystrophy and compound heterozygous BEST1 mutations, the management of a choroidal neovascular membrane with intravitreal bevacizumab in the proband, the benefits of amblyopia therapy in the fellow eye, and the findings in the parents, carriers of heterozygous BEST1 mutations.
Methods: A 5-year-old white girl presented with monocular visual acuity loss and bilateral vitelliform macular lesions. Her parents were also examined. Examinations included electro-oculograms (EOGs), electroretinograms, imaging studies, and BEST1 gene testing. Interventions included off-label treatment with intravitreal bevacizumab in the left eye and amblyopia therapy in the right eye.
Results: The proband presented with visual acuity of 20/200 OD with an atypical subfoveal vitelliform scar and 20/16 OS with asymptomatic vitelliform deposits. Subfoveal choroidal neovascularization developed at age 6 years, causing marked vision loss (20/200 OS). Visual acuity recovered to 20/20 OS after serial intravitreal bevacizumab injections. Amblyopia therapy improved visual acuity to 20/50 OD. The proband showed subnormal EOG Arden ratios and mild electroretinogram changes. Molecular testing showed missense BEST1 mutations (R141S and R141H) in the proband. Unlike dominant Best vitelliform macular dystrophy, in the heterozygous parents EOGs were normal and minimal autofluorescence changes were seen.
Conclusions: Choroidal neovascularization treatment with bevacizumab was associated with vision restoration. Amblyopia treatment also yielded significant benefit. Patients presenting with vitelliform lesions should be screened for BEST1 mutations, even when parents have normal EOG and imaging results.
Clinical relevance: Prompt recognition and treatment of choroidal neovascularization and amblyopia management effectively restores vision. Awareness and recognition of recessive inheritance permits correct diagnosis and counseling.