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.

引言
类Purtscher视网膜病变（Purtscher-like retinopathy, PLR）是一类罕见的视网膜血管病，以急性视力丧失为核心特征，常与肾脏损害等全身性疾病相关。Purtscher视网膜病变（Purtscher retinopathy, PuR）与PLR的联合年发病率估计为每百万人口0.24例。PLR的典型表现为突发视力下降，伴随特征性视网膜体征，包括Purtscher斑、视网膜出血及棉绒斑。
病例报告
本文报告1例46岁男性患者，既往有慢性高血压、血脂异常、冷球蛋白血症及多次病毒感染病史，因突发双眼视力丧失就诊。眼底检查可见视网膜肿胀、出血及渗出。实验室检查提示肾功能受损（采用CKD-EPI肌酐公式计算的估算肾小球滤过率为19 mL/min/1.73 m²）、冷球蛋白血症，符合慢性肾脏病表现。肾活检证实为伴免疫复合物沉积的膜增生性肾小球肾炎。患者接受了糖皮质激素、治疗性血液成分单采术及支持治疗，住院期间单眼视力部分恢复。
结论
PLR是一类罕见疾病，常与肾衰竭等全身性疾病相关，其病理生理机制涉及视网膜微血管损伤，可能由补体激活介导。诊断需结合特征性眼底表现及伴随的全身性疾病。糖皮质激素仍是最常用的治疗手段，但其疗效证据有限。本病例凸显了PLR与肾功能损害的罕见重叠情况，强调早期识别及多学科管理的重要性。未来仍需开展进一步研究以阐明PLR的病理生理机制并优化其治疗方案。