Corneal haze after superficial excimer laser ablation: pathogenesis, risk factors, prevention, and current management approaches

Purpose: to systematize current literature data on the cellular and molecular mechanisms underlying corneal haze, risk factors, prevention, and management of this complication following surface excimer laser ablation. Materials and methods. An analytical review of scientific publications addressing the pathogenesis, risk factors, prevention, and treatment of corneal haze was conducted. The results of experimental and clinical studies, systematic reviews, and meta-analyses were analyzed using methods of analysis, comparison, and synthesis of scientific data. Results. The development of corneal haze was found to be associated with impaired regeneration of the epithelial basement membrane, activation of TGF-β-mediated mechanisms, keratocyte transdifferentiation into myofibroblasts, and excessive deposition of disorganized extracellular matrix. The main risk factors include ablation depth, degree of ametropia, ultraviolet exposure, and ocular surface disorders. The most well-established preventive approach is the use of mitomycin C. Established corneal haze is managed with topical corticosteroids and, in cases of insufficient response, phototherapeutic keratectomy combined with mitomycin C. Antifibrotic approaches remain promising. Conclusion. Prevention of corneal haze is based on risk-factor assessment and control of pathological fibrotic remodeling. A differentiated treatment approach according to the characteristics of the opacity may help optimize clinical outcomes.

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