Abstract
Purpose: :
Best's macular dystrophy (BMD) has been described previously as a dominantly inherited disease, caused by mutations in the VMD2 gene. BMD usually manifests with visual failure in the first or second decade of life, however, there is a large variability in expressivity of the disease. A normal full–field electroretinography (full–field ERG) and a pathological electrooculography (EOG) have been considered as characteristic. In order to examine the variable phenotype further, patients with BMD from more than five families (harbouring the dominant mutations Val89Ala, Tyr85His, Val9Ala, Asp104Glu and the compound heterozygous mutations Arg141His/Tyr29stop in VMD2) were also examined with multifocal electroretinography (mfERG) and Optical Coherence Tomography (OCT).
Methods: :
Patients were examined with clinical examination, fundus photography, EOG, full–field ERG, mfERG and OCT.
Results: :
EOG was pathological and mfERG showed variable reduction of central retinal function. Interestingly, a few patients also had alterations in the full field ERG 30 Hz flicker, with delayed implicit times, indicating widespread retinal degeneration. Optical Coherence Tomography (OCT) presented variable patterns, according to clinical stage of disease, ranging from normal findings to cystoid macular edema and thickening of the outer retina–RPE–choroid complex.
Conclusions: :
In BMD, the combination of molecular genetics, electrophysiology and OCT, is useful in diagnosis and assessment of severity.
Keywords: electrophysiology: clinical • macula/fovea • degenerations/dystrophies