Introduction: This study aims to analyze macular structure by using SD-OCT in a cohort of patients affected by autosomal recessive retinitis pigmentosa and Usher syndrome, due to genetic variants in USH2A gene, and to correlate OCT parameters with functional and genetic data. Methods: The subjects of this study were 92 patients, 46 syndromic (Ush2) and 46 non-syndromic (arRP), with clinical and genetic diagnosis of USH2A-related retinal dystrophy, who underwent a complete ophthalmic examination and spectral domain OCT analysis. The study focused on evaluating the differences between the two groups in the following parameters: best corrected visual acuity (BCVA), ellipsoid zone width (EZ), presence of epiretinal membrane (ERM) and cystic macular lesions (CML). Variants in USH2A gene were divided in 3 categories, according to the expected impact (low/high) at protein level of the different variants on each allele. Results: BCVA and EZ width were significantly lower in Ush2 than in arRP patients (p < 0.0001 and p = 0.001). ERM was detected in 34.8% (16/46) of arRP patients and in 65.2% (30/46) of Ush2 patients (p = 0.003). CML was detected in 17.4% (8/46) of arRP patients and 30.4% (14/46) of Ush2 patients (p = 0.14). The allelic distribution was statistically different (p = 0.0003) by dividing the two diseases: for Ush2 patients it was 45.7% (high/high), 39.1% (low/high) and 15.2% (low/low); for arRP patients it was 8.7% (high/high), 56.5% (low/high) and 34.8% (low/low). The severity class of the variants significantly affected VA and EZ width parameters (p = 0.004 and p = 0.002, respectively). Conclusion: Retinal disease, as evaluated by means of SD-OCT, shows more advanced degeneration signs in the syndromic than the non-syndromic form of retinal dystrophy related to USH2A gene. Variant types and allelic profiles are determining factors for the onset of syndromic features. However, since the three allelic profiles can be found in both Usher and RP patients, other factors must necessarily play a determining role.


中文翻译：

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由 USH2A 基因突变引起的色素性视网膜炎综合征和非综合征形式的 SD-OCT 分析

简介：本研究旨在通过使用 SD-OCT 在一组因 USH2A 基因的遗传变异而受常染色体隐性视网膜色素变性和 Usher 综合征影响的患者中分析黄斑结构，并将 OCT 参数与功能和遗传数据相关联。方法：本研究的受试者为 92 名患者，46 名综合征（Ush2）和 46 名非综合征（arRP），临床和基因诊断为 USH2A 相关的视网膜营养不良，他们接受了完整的眼科检查和光谱域 OCT 分析。该研究侧重于评估两组在以下参数方面的差异：最佳矫正视力 (BCVA)、椭球区宽度 (EZ)、视网膜前膜 (ERM) 和囊性黄斑病变 (CML)。USH2A基因的变异分为3类，根据每个等位基因上不同变体在蛋白质水平上的预期影响（低/高）。结果：Ush2 患者的 BCVA 和 EZ 宽度显着低于 arRP 患者（p < 0.0001 和 p = 0.001）。在 34.8% (16/46) 的 arRP 患者和 65.2% (30/46) 的 Ush2 患者中检测到 ERM (p = 0.003)。在 17.4% (8/46) 的 arRP 患者和 30.4% (14/46) 的 Ush2 患者中检测到 CML (p = 0.14)。通过划分两种疾病，等位基因分布具有统计学差异（p = 0.0003）：对于 Ush2 患者，分别为 45.7%（高/高）、39.1%（低/高）和 15.2%（低/低）；arRP 患者为 8.7%（高/高）、56.5%（低/高）和 34.8%（低/低）。变体的严重性等级显着影响 VA 和 EZ 宽度参数（分别为 p = 0.004 和 p = 0.002）。结论：视网膜疾病，通过 SD-OCT 评估，与 USH2A 基因相关的视网膜营养不良的非综合征形式相比，在综合征中显示出更高级的退化迹象。变异类型和等位基因谱是综合征特征发作的决定因素。然而，由于在 Usher 和 RP 患者中都可以找到这三个等位基因谱，因此其他因素必须发挥决定性作用。