Is there a relationship between outer retinal destruction and choroidal changes in cone dystrophy?

Purpose:: The aim of the present study was to use enhanced depth imaging optical coherence tomography (EDI-OCT) to investigate choroidal changes in patients with cone dystrophy (CD) and to correlate these findings with clinical and electroretinography (ERG) findings.

Methods:: This case-control study included 40 eyes of 20 patients with CD and 40 eyes of 40 age- and refraction-matched healthy individuals. Choroidal thickness (CT) measurements were obtained under the foveal center and at 500 and 1,500 μm from the nasal and temporal regions to the center of the fovea, respectively. EDI-OCT and ERG data were analyzed, and the correlations of CT with the best-corrected visual acuity (BCVA) and the central foveal thickness (CFT) were evaluated.

Results:: The mean subfoveal CTs in the CD and control groups were 240.70 ± 70.78 and 356.18 ± 48.55 μm, respectively. The subfoveal CT was significantly thinner in patients with CD than in the controls (p<0.001). The patients with CD also had significantly thinner choroids than the controls at each measurement location relative to the fovea (p<0.001). The subfoveal CT in the CD group correlated with CFT (p=0.012), but no significant correlation was found between the subfoveal CT and BCVA or photopic ERG responses.

Conclusions:: The present study demonstrated a significant thinning of the choroid in patients with CD. EDI-OCT is a useful technique for describing the choroidal changes occurring in CD. Future studies investigating the association between choroidal changes and outer retinal destruction or the disease stage may provide a better understanding of the pathophysiology of CD.