Diffuse lamellar keratitis: sporadic and cluster forms

Diffuse lamellar keratitis (DLK) is a known complication of lamellar corneal surgery. The underlying mechanism of the cellular response in DLK is well described. There are two clinical forms — sporadic and cluster — each largely influenced by surgical triggers. Objective. This study analyzes the incidence of different variants of DLK, identifies surgical causes, and outlines distinguishing features and preventive strategies. Material and methods. The study included data from 19783 patients aged 18—45 years, among them 97% had myopia, and 3% had hyperopia. Patients in all examined cases underwent Laser-Assisted in Situ Keratomileusis (LASIK). Results. The incidence of the sporadic form of DLK was 1:110, and the cluster form — 1:20. The main causes of cluster-form DLK were related to toxic surgical agents used in eyelid sanitation, keratomes, and medical gloves. Elimination of these factors stopped the progression of the cluster form. Sporadic DLK was associated with transient triggers disrupting the state of the interface. No DLK cases were recorded in patients undergoing hyperopia correction. Conclusion. The primary surgical trigger for diffuse lamellar keratitis during LASIK is instability of the stromal interface resulting from improper flap repositioning, specific features of planar ablation, and exposure to toxic agents during surgery.