Supplementary Material for: Morphological changes in the saw-tooth pattern of cuticular drusen associated with immune complex-mediated membranous proliferative glomerulonephritis type III: a case report

Background: Patients with membranoproliferative glomerulonephritis (MPGN) type III may exhibit the saw-tooth pattern of cuticular drusen. This study reports a four-and-a-half-year retrospective time-dependent observation of cuticular drusen associated with immune complex-mediated MPGN type III patients.
Case presentation: A 32-year-old woman was referred for ocular evaluation due to systemic steroids used for nephrotic syndrome caused by immune complex-mediated MPGN type Ⅲ. She had no ocular symptoms. The initial examination showed that her best-corrected visual acuity (BCVA) was 1.0 oculi uterque (OU). Color fundus photographs revealed pigmentary abnormalities in the macular and perimacular regions OU. Fundus autofluorescence (FAF) images demonstrated numenous tiny dots with a hypoautofluorescent center surrounded by a rim of hyperautofluorescence. Enhanced depth imaging-optical coherence tomography (OCT) revealed triangular morphologic features, represented by a saw-tooth pattern with internal hyporeflectivity. Over 4.5 years, the internal reflectivity of the drusen gradually increased. Moreover, depigmentation and yellow color changes in the macular and perimacular regions worsened, without obvious changes on FAF. Her BCVA remained at 1.0 OU, without new ocular symptoms or cataract progression during the 4.5 years follow-up period.
Results: Both eyes had a significant positive correlation between OCT-based mean internal reflectivity measured by the Image J software and the observation period. However, no correlation was found between estimated glomerular filtration rate (eGFR) and the observation period or between eGFR and mean internal reflectivity.
Conclusion: The internal reflectivity of cuticular drusen associated with immune complex-mediated MPGN type III showed time-dependent changes on OCT and worsened depigmentation and yellow color changes in the macular and perimacular regions, independent of renal function.

背景：III型膜增生性肾小球肾炎（membranoproliferative glomerulonephritis, MPGN）患者可表现出表皮玻璃膜疣（cuticular drusen）的锯齿状形态。本研究针对免疫复合物介导的III型膜增生性肾小球肾炎患者的表皮玻璃膜疣，开展了为期4.5年的回顾性时间依赖性随访观察。

病例报告：一名32岁女性因使用全身性激素治疗免疫复合物介导的III型膜增生性肾小球肾炎所致肾病综合征，前来接受眼科评估。该患者无眼部自觉症状。初始检查显示，其双眼（oculi uterque, OU）最佳矫正视力（best-corrected visual acuity, BCVA）为1.0。彩色眼底照相可见双眼黄斑及黄斑周围区域存在色素异常。眼底自发荧光（fundus autofluorescence, FAF）图像显示大量微小病灶，中心呈低自发荧光，周围环绕高自发荧光环。增强深度成像-光学相干断层扫描（enhanced depth imaging-optical coherence tomography, EDI-OCT）可见特征性三角形形态，表现为锯齿状外观伴内部低反射性。在4.5年随访期间，玻璃膜疣的内部反射性逐渐升高。此外，黄斑及黄斑周围区域的色素脱失与黄色样改变逐渐加重，但眼底自发荧光无明显变化。随访4.5年间，患者双眼最佳矫正视力维持在1.0，未出现新发眼部症状或白内障进展。

结果：通过Image J软件测量的光学相干断层扫描平均内部反射性，与随访时长呈显著正相关。然而，估算肾小球滤过率（estimated glomerular filtration rate, eGFR）与随访时长之间，以及估算肾小球滤过率与平均内部反射性之间均未发现相关性。

结论：与免疫复合物介导的III型膜增生性肾小球肾炎相关的表皮玻璃膜疣，其内部反射性在光学相干断层扫描中呈现时间依赖性变化，且黄斑及黄斑周围区域的色素脱失与黄色样改变逐渐加重，上述变化与肾功能无关。