Photoreceptor Function and Structure in Autosomal Dominant Vitelliform Macular Dystrophy Caused by BEST1 Mutations.

Area of Science:

• Ophthalmology
• Genetics
• Retinal Diseases

Background:

• Autosomal dominant Best vitelliform macular dystrophy (Best disease) is an inherited retinal disorder caused by mutations in the BEST1 gene.
• It is characterized by progressive degeneration of the macula, leading to vision loss.

Purpose of the Study:

• To evaluate rod and cone function in macular lesions and surrounding areas.
• To assess outer retinal structure in patients with Best disease.
• To investigate the relationship between BEST1 mutations and disease phenotype.

Main Methods:

• Seventeen patients from seven families with Best disease were studied.
• Evaluations included dark- and light-adapted chromatic perimetry and optical coherence tomography.
• Long-term follow-up and dark-adaptation kinetics were assessed in subsets of patients.

Main Results:

• Rod sensitivity was significantly reduced in central lesions, while cone sensitivity was relatively preserved.
• Subretinal widening was observed in extralesional areas, correlating with slower dark-adaptation.
• Long-term follow-up revealed de novo lesion formation and progressive outer nuclear layer thickening.

Conclusions:

• Rod function is more vulnerable than cone function in Best disease.
• Outer retinal structural changes, including subretinal widening and outer nuclear layer thickening, are important indicators of disease progression.
• Future clinical trials should focus on rod sensitivity and structural changes in surrounding retinal areas.