Longitudinal Quantitative Assessment of Retinal Crystalline Deposits in Bietti Crystalline Dystrophy

Background This study aims to quantitatively analyze retinal crystalline deposits in patients with Bietti Crystalline Dystrophy (BCD) and examine their progression over time in a longitudinal study. Methods We retrospectively reviewed consecutive patients diagnosed with BCD at a single center. Retinal crystalline deposits were quantified from fundus photographs using semi-automated software, which divided the macular area into a central foveal circle, inner ring, and outer ring. We then analyze changes in the amount and intensity of these deposits over a two-year period. Results The study included 30 eyes from 16 patients. Mean crystal intensity was 1.158 ± 1.425% in the central foveal circle, 1.043 ± 1.444% in the inner ring, and 0.990 ± 0.969% in the outer ring, with no significant differences observed between the regions (all P  > 0.05). Over the two-year study period, there was a gradual decrease in both the amount and intensity of the crystals in all zones. However, these changes were not statistically significant (all P  > 0.05). Conclusions The use of semi-automated software to analyze fundus photographs provided a quantitative method for assessing retinal crystalline deposits in BCD. This longitudinal study enhanced our understanding of the disease’s natural progression.