In this issue of JOVR, Derakhshan and coauthors1 describe the results of CROSSLINKING for patients with early keratoconus. Collagen CROSSLINKING is a recently described technique of corneal tissue strengthening using riboflavin as a photosensitizer and ultraviolet A (UVA) radiation to promote the formation of intra- and interfibrillar covalent bonds by photosensitized oxidation.To date, it is the only published intervention that may retard the progression of keratoconus. Collagen CROSSLINKING has also been sequentially combined with other treatment modalities, namely intrastromal ring segments and photorefractive keratectomy, for treatment of keratoconus.Other possible indications include keratectasia following laser in situ keratomileusis (LASIK), infectious keratitis and bullous keratopathy.In vitro studies on human and porcine corneas have shown a significant increase in corneal rigidity after CROSSLINKING as indicated by an increase in Young’s modulus.

Purpose: To report a keratoconic eye that developed severe sterile keratitis and corneal scar after collagen CROSSLINKING necessitating corneal transplantation.Case Report: A 26-year-old man with progressive keratoconus underwent collagen CROSSLINKING and presented with severe keratitis 72 hours after the procedure. The initial impression was infectious corneal ulcer and a fortified antibiotic regimen was administered. However, the clinical course and confocal microscopy results prompted a diagnosis of sterile keratitis. The eye developed severe corneal scars leading to reduced visual acuity and necessitating corneal transplantation.Conclusion: Sterile keratitis may develop after collagen CROSSLINKING resulting in profound visual loss leading to corneal transplantation.