Band keratopathy and conjunctival calcification in end-stage kidney disease: epidemiology, pathophysiology and clinical management

Conjunctival and corneal calcification, particularly its severe manifestation, band keratopathy, represents a prevalent yet frequently overlooked form of metastatic calcification in end-stage kidney disease (ESKD). This review integrates current evidence on the epidemiology, pathophysiology and interdisciplinary management of uraemic ocular calcification. The pathogenesis is conceptualized through a 'two-hit' model: the systemic 'first hit' involves the specific milieu of chronic kidney disease-mineral and bone disorder driven by hyperphosphataemia, calcium load, secondary hyperparathyroidism and a critical deficiency in calcification inhibitors such as fetuin-A and Klotho. The 'second hit' comprises local ocular triggers, including tear film instability, inflammation and localized alkalosis, which precipitate mineral deposition in the supersaturated environment.