INTRODUCTION A large number of studies using different neuroimaging methods showed various structural changes both in patients and their unaffected first-degree relatives (FDRs) over the past years. Optical coherence tomography (OCT) is a relatively new, non-invasive imaging method used to obtain high-resolution cross-sectional images of the retina. A growing body of evidence reports thinning of retinal layers in patients with schizophrenia which is considered as a proxy for CNS alterations. We hypothesized that retinal layer changes would be observed in FDRs, in parallel with those seen in patients, as a potential endophenotype candidate. METHODS Thirty-eight schizophrenia patients, 38 FDRs of schizophrenia and 38 age and gender-matched healthy subjects with no family history (HCs) were recruited to this study. OCT measurements were performed and peripapillary retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL) and macular thicknesses were measured. RESULTS The groups did not differ on RNFL, macular or GCL thickness. However, IPL thickness was significantly lower in both patients and FDRs than HCs (p = .025 and p = .041, respectively). The difference between groups remained significant after controlling for confounders such as age, gender, smoking status, comorbid medical diseases and BMI (p = .016 patients vs HCs and p = .014 FDRs vs HCs). CONCLUSION Our findings suggest that IPL thinning may hold promise as a useful endophenotype for genetic and early detection studies. The evaluation of this area could provide an important avenue for elucidating some of the neurodevelopmental aberrations in the disorder.

中文翻译：

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精神分裂症患者未受影响的一级亲属视网膜层厚度的调查

引言 使用不同神经影像学方法的大量研究表明，在过去几年中，患者及其未受影响的一级亲属 (FDR) 发生了各种结构变化。光学相干断层扫描 (OCT) 是一种相对较新的非侵入性成像方法，用于获取视网膜的高分辨率横截面图像。越来越多的证据报告了精神分裂症患者视网膜层变薄，这被认为是 CNS 改变的代表。我们假设在 FDR 中观察到视网膜层变化，与在患者中观察到的相同，作为潜在的内表型候选者。方法 本研究招募了 38 名精神分裂症患者、38 名精神分裂症 FDR 和 38 名年龄和性别匹配的无家族史 (HC) 的健康受试者。进行 OCT 测量并测量视盘周围视网膜神经纤维层 (RNFL)、神经节细胞层 (GCL)、内丛状层 (IPL) 和黄斑厚度。结果 各组在 RNFL、黄斑或 GCL 厚度方面没有差异。然而，患者和 FDR 的 IPL 厚度显着低于 HC（分别为 p = .025 和 p = .041）。在控制了年龄、性别、吸烟状况、合并症和 BMI 等混杂因素后，组间差异仍然显着（p = .016 患者与 HC，p = .014 FDR 与 HC）。结论我们的研究结果表明，IPL 变薄可能有望成为遗传和早期检测研究的有用内表型。对该领域的评估可以为阐明该疾病中的一些神经发育异常提供重要途径。