Functional and clinical data of Best vitelliform macular dystrophy patients with mutations in the BEST1 gene

PURPOSE To analyze functional and clinical data of Best vitelliform macular dystrophy (VMD) patients with mutations in the BEST1 gene. METHODS Best VMD patients with BEST1 mutations were evaluated prospectively regarding age, age of onset, best-corrected visual acuity (BCVA), fundus autofluorescence, fluorescein angiography, optical coherence tomography, and electro-oculography. Mutations in BEST1 were established by direct sequencing. RESULTS Forty-six eyes of 23 patients (10 male, 13 female) were included in the study. We identified nine different BEST1 mutations (3/9 novel), in ten unrelated families. The age of patients ranged between 3 and 75 years; age of onset varied between 2 and 67 years. BCVA ranged between 20/20 and 20/200. On the basis of fundus biomicroscopy with direct illumination, using one widely accepted classification, the macular lesions could be counted as follows: 1. no lesion (normal fovea): eight eyes, five patients carrying a mutation on the BEST1 gene; 2. previtelliform lesions: six eyes, three affected patients; 3. vitelliform lesions: four eyes, two affected patients; 4. pseudohypopyon: three eyes, three affected patients; 5. vitelliruptive lesions (scrambled egg aspect with dispersion of the vitelliform material without sign of atrophy or fibrosis): ten eyes, six affected patients; 6. atrophic lesions (atrophy with or without residual dispersed material): seven eyes, five patients; 7. fibrotic lesions: eight eyes, five patients. Two patients presented unilateral Best VMD. Both eyes of two patients presented multifocal Best VMD features on fundus examination. Six eyes of four patients have been treated for choroidal neovascularization by thermic photocoagulation [one eye], photodynamic therapy [three eyes], and intravitreal ranibizumab injection [two eyes]. Comparison of interfamilial and intrafamilial clinical data between patients did not reveal differences in age, BCVA, and stage of the disease as evaluated by fundus autofluorescence, fluorescein angiography, and optical coherence tomography (p>0.05). Mean BCVA impairment showed a statistically significant correlation to a more advanced stage of the disease (p<0.001). CONCLUSIONS BEST1 mutations were not correlated with the severity of the functional and clinical data in the Best VMD patients examined.