Supplementary Material for: Purtscher-like retinopathy with renal impairment: a case report and review of the literature

Introduction
Purtscher-like retinopathy (PLR) is a rare retinal vasculopathy characterized by acute vision loss. It is typically associated with systemic diseases such as renal impairment. The combined incidence of Purtscher retinopathy (PuR) and PLR is estimated at 0.24 cases per million annually. The hallmark of PLR is sudden-onset visual acuity reduction accompanied by retinal findings, including Purtscher-flecken, hemorrhages, and cotton-wool spots.
Case Presentation
We report a 46-year-old male with a history of chronic hypertension, dyslipidemia, cryoglobulinemia, and multiple viral infections, presenting with sudden bilateral vision loss. Fundoscopy revealed retinal swelling, hemorrhages, and exudation. Laboratory findings indicated impaired renal function (eGFR by CKD-EPI Cr 19 mL/min/1.73 m²), cryoglobulinemia, and signs of chronic kidney disease. A renal biopsy confirmed membranoproliferative glomerulonephritis with immune complex deposition. The patient was treated with corticosteroids, therapeutic apheresis, and supportive care. Visual acuity partially improved in one eye during hospitalization.
Conclusion
PLR is a rare condition often linked to systemic diseases such as renal failure. Its pathophysiology involves retinal microvascular damage, potentially mediated by complement activation. Diagnosis is based on characteristic fundoscopic findings and associated systemic conditions. Corticosteroids remain the most commonly used treatment, although evidence for their efficacy is limited. This case highlights the rare overlap between PLR and renal impairment, emphasizing the importance of early recognition and multidisciplinary management. Further research is needed to elucidate the pathophysiology and optimize treatment protocols for PLR.

Introduction
类Purtscher视网膜病变（Purtscher-like retinopathy, PLR）是一种以急性视力丧失（acute vision loss）为特征的罕见视网膜血管病变（retinal vasculopathy），通常与肾功能损害（renal impairment）等系统性疾病（systemic diseases）相关。Purtscher视网膜病变（Purtscher retinopathy, PuR）与PLR的合并发病率（incidence）估计为每年每百万人口0.24例。PLR的核心特征是突发视力下降（sudden-onset visual acuity reduction），伴随视网膜表现（retinal findings），包括Purtscher斑（Purtscher-flecken）、出血（hemorrhages）及棉絮斑（cotton-wool spots）。

Case Presentation
我们报告1例46岁男性病例，其有慢性高血压（chronic hypertension）、血脂异常（dyslipidemia）、冷球蛋白血症（cryoglobulinemia）及多种病毒感染史，表现为突发双侧视力丧失（sudden bilateral vision loss）。眼底检查（Fundoscopy）显示视网膜水肿（retinal swelling）、出血及渗出（exudation）。实验室检查提示肾功能损害（CKD-EPI Cr公式估算的eGFR为19 mL/min/1.73 m²）、冷球蛋白血症及慢性肾病（chronic kidney disease）征象。肾活检（renal biopsy）证实为膜增生性肾小球肾炎（membranoproliferative glomerulonephritis）伴免疫复合物沉积（immune complex deposition）。患者接受皮质类固醇（corticosteroids）、治疗性单采术（therapeutic apheresis）及支持治疗（supportive care），住院期间单眼视力部分改善。

Conclusion
PLR是一种常与肾衰竭（renal failure）等系统性疾病相关的罕见疾病，其病理生理机制（pathophysiology）涉及视网膜微血管损伤（retinal microvascular damage），可能由补体激活（complement activation）介导。诊断基于特征性眼底表现及相关系统性疾病。皮质类固醇仍是最常用的治疗手段，但其疗效（efficacy）证据有限。本病例凸显了PLR与肾功能损害的罕见重叠（rare overlap），强调了早期识别（early recognition）及多学科管理（multidisciplinary management）的重要性。需进一步研究阐明PLR的病理生理机制并优化治疗方案（optimize treatment protocols）。