Very late-onset corneal scar triggered by trauma after photorefractive keratectomy

Abstract

A 54-year-old woman who had photorefractive keratectomy (PRK) more than 10 years earlier presented with a history of being hit in the eye by a tree branch and developing blurred vision a short time later. The corrected visual acuity was 20/100 with localized grade 3 stromal haze. The haze intensified despite initial response to corticosteroids and cyclosporine, and treatment with phototherapeutic keratectomy and 0.02% mitomycin-C (MMC) was effective in restoring corneal clarity and normal vision. Late-onset stromal scar can be triggered by trauma years after PRK. Phototherapeutic keratectomy with MMC can be an effective treatment for late-onset scar. Persistent haze or scar after trauma if PRK had not been performed previously is exceedingly rare.

Very Late-Onset Corneal Scarring After Photorefractive Keratectomy Induced by Cataract Surgery

“…6 Late-onset haze/scarring after PRK has been described anecdotally, especially after triggering events such as light damage and trauma. [7][8][9] We present two cases with central subepithelial scarring triggered by otherwise uneventful phacoemulsification more than 20 years after PRK.…”

“…6 In contrast, postoperative subepithelial scarring occurs more frequently after correction of high myopia or repeated treatments and usually develops during the first postoperative year. 5 Late-onset corneal haze, which is described with onset later than 6 months postoperatively, has been correlated to high ultraviolet irradiation, 9 trauma, 7 and retinal surgery. 8 The two cases presented developed a corneal scar more than 20 years after PRK and we assume that cataract surgery triggered the scarring process because visual loss did not occur until months after phacoemulsification.…”

Corneal Complications During and After Vitrectomy for Retinal Detachment in Photorefractive Keratectomy Treated Eyes

“…High myopia with a greater ablation depth has been suggested to contribute to haze formation. 3 , 10 , 11 Ablation depth does not explain haze and LOCH formation completely, since larger ablation zones are associated with better refractive and scarring outcomes. 1 In fact, the smoothness of the stromal surface after ablation and persistent structural and functional defects of the epithelial basement membrane have been demonstrated to play an important role.…”

“… 1 In fact, the smoothness of the stromal surface after ablation and persistent structural and functional defects of the epithelial basement membrane have been demonstrated to play an important role. 4 – 7 , 10 , 11 The complexity of haze pathogenesis and its unpredictability are confirmed by the occurrence of subepithelial corneal scarring many months after PRK, following a new triggering event such as epithelial debridement, retreatment, trauma, and even after PPV for RRD. 11 – 15 …”

“…LOCH is more frequent in eyes that have not been treated with mitomycin-C (MMC) prophylaxis but has also been reported following MMC prophylaxis, confirming the very complex and sometimes unpredictable biological response at its basis. 3 , 11 , 12 Severe LOCH has been reported in PRK-treated eyes without MMC prophylaxis after epithelial debridement, 13 retreatment, 14 or trauma 11 and, spontaneously 12 or after trauma, 3 in laser-assisted subepithelial keratectomy (LASEK) with MMC prophylaxis.…”