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

ABSTRACT 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.

摘要
目的：本研究旨在采用增强深度成像光学相干断层扫描（enhanced depth imaging optical coherence tomography，EDI-OCT），探讨视锥细胞营养不良（cone dystrophy，CD）患者的脉络膜变化，并将上述发现与临床及视网膜电图（electroretinography，ERG）结果进行关联分析。
方法：本病例对照研究纳入20例视锥细胞营养不良患者的40只眼，以及40例年龄与屈光度匹配的健康个体的40只眼。分别于黄斑中心凹中心，以及距黄斑中心凹中心鼻侧和颞侧500μm、1500μm处测量脉络膜厚度（choroidal thickness，CT）。对EDI-OCT及ERG数据进行分析，并评估脉络膜厚度与最佳矫正视力（best-corrected visual acuity，BCVA）及中心凹中央厚度（central foveal thickness，CFT）的相关性。
结果：视锥细胞营养不良组与对照组的黄斑中心凹下平均脉络膜厚度分别为240.70±70.78μm与356.18±48.55μm。视锥细胞营养不良患者的黄斑中心凹下脉络膜厚度显著薄于对照组（p<0.001）。相较于对照组，视锥细胞营养不良患者在所有黄斑中心凹相关测量位点的脉络膜厚度均显著更薄（p<0.001）。视锥细胞营养不良组的黄斑中心凹下脉络膜厚度与中心凹中央厚度呈显著相关（p=0.012），但未发现黄斑中心凹下脉络膜厚度与最佳矫正视力或明适应ERG反应存在显著相关性。
结论：本研究证实视锥细胞营养不良患者的脉络膜存在显著变薄现象。EDI-OCT是用于描述视锥细胞营养不良患者脉络膜变化的有效检测技术。未来可通过探讨脉络膜变化与视网膜外层破坏或疾病分期之间的关联，进一步加深对视锥细胞营养不良病理生理学机制的理解。