CHOROIDAL THICKNESS IN BEST VITELLIFORM MACULAR DYSTROPHY

Purpose:To assess the changes in choroidal thickness in different stages of Best vitelliform macular dystrophy (VMD).Methods:Thirty-four patients affected by VMD were prospectively enrolled and underwent a complete ophthalmologic examination, including best-corrected visual acuity measurement, biomicroscopic examination, and spectral domain optical coherence tomography. The Gass classification was used in defining the stages of VMD. Twenty healthy subjects served as the control group. Main outcome measures were the identification of choroidal changes in different stages of VMD and detection of a correlation between choroidal thickness and best-corrected visual acuity.Results:No significant difference was found in the subfoveal choroidal thickness (SFCT) between eyes displaying Stage 1 and the control group (P = 0.181). Stages 2 and 3 showed an increased SFCT (320.4 and 319.1 m, respectively) compared with that of control patients (P < 0.001 and P = 0.004, respectively). Stage 4 had a significantly inferior SFCT compared with Stages 2 and 3 (P = 0.007 and P = 0.025, respectively) but no significant difference was found between Stage 4 and control patients (P = 0.733). The Stage 5 group displayed a significant decrease in SFCT compared with that of the control group (181.3 m and 238.4 m, respectively, P = 0.002). Analyzing the association between SFCT and best-corrected visual acuity in patients affected by clinical VMD (Stages 2-5), the authors found that the best-corrected visual acuity decreased as the choroid thinned (P = 0.004).Conclusion:Choroidal thickness varies according to the stage of VMD, being higher in the vitelliform stage and thinner in the atrophic/cicatricial stage. Long-term studies are warranted to provide a more precise evaluation of the morphofunctional alterations in the different stages of VMD.