MICROPERIMETRY in BEST VITELLIFORM MACULAR DYSTROPHY

Purpose: To investigate retinal sensitivity in eyes with all the clinical stages of Best vitelliform macular dystrophy (VMD). Methods: Thirty-two patients affected by VMD in subclinical, vitelliform, pseudohypopyon, vitelliruptive, and atrophic stages were enrolled in this prospective cross-sectional study. Patients underwent a complete ophthalmologic examination, including determination of best-corrected visual acuity (BCVA), staging of the disease (Gass's classification), and microperimetry by means of the macular integrity assessment microperimeter. The primary outcome measure was to describe the alterations in the retinal sensitivity of eyes affected by VMD in different stages. Secondary outcome measures included correlations between retinal sensitivity and best-corrected visual acuity and the correlation between the VMD stage and the specific microperimetry pattern. Results: Mean retinal sensitivity was reduced in all the VMD stages. Nevertheless, vitelliform, pseudohypopyon, and vitelliruptive stages turned out to be very similar, especially within 10°. Fixation was classified as stable in 27 eyes (44.2%), relatively unstable in 16 eyes (26.2%), and unstable in 18 eyes (29.5%). Fixation stability correlated both with the disease stage and best-corrected visual acuity. Conclusion: VMD is characterized by complex microperimetric abnormalities, involving the whole macular area. Microperimetry may contribute to the global clinical assessment of patients affected by VMD and could be used in future therapeutic approaches.