Central corneal haze increased by radial keratotomy following photorefractive keratectomy

PURPOSE: To report a case of central corneal haze induced by minimally invasive radial keratotomy (mini-RK) after photorefractive keratectomy (PRK) and subsequent deep lamellar keratoplasty. METHODS: We report a case (one eye of one patient) of central corneal haze that worsened after mini-RK was performed 2 years following PRK. Four years later, a second PRK was done, myopic regression was subsequently observed, and corneal haze persisted. Deep lamellar keratoplasty was performed and a corneal graft was taken, which was examined by light and electron microscopy. RESULTS: In the ablated area, irregularity of the basal membrane and hypertrophy of the corneal epithelium were observed. In the stromal layer, collagen fibers showed disorder in their disposition. Aggregated activated keratocytes were observed. An epithelial plug filling the gap of the RK incision persisted for 6 years after the mini-RK. The RK incision was easily divided when deep lamellar keratoplasty was performed and the patient obtained a stable visual outcome. CONCLUSIONS: It is possible that mini-RK enhancement after PRK induces central corneal haze and reduces corneal integrity. Deep lamellar keratoplasty for refractory corneal haze after refractive surgery was useful in this eye.