Development of Unilateral Corneal Ectasia After PRK With Ipsilateral Preoperative Forme Fruste Keratoconus

Abstract

PURPOSE: To describe clinical and topographic features of keratectasia after photorefractive keratectomy (PRK) in a patient with abnormal preoperative topography. METHODS: A 25-year-old man underwent uneventful bilateral PRK for moderate myopia of -5.75 -1.75 x 95 in the right eye and -7.50 -1.25 x 80 in the left eye with best spectacle-corrected visual acuity (BSCVA) of 20/25 in both eyes. Preoperative corneal thickness was 500 microm in the right eye and 460 microm in the left eye. The total calculated ablation depth was 70 microm in the right eye and 100 microm in the left eye. Preoperative corneal topography revealed forme fruste keratoconus in the right eye with an inferior-superior ratio of 4. RESULTS: Five years postoperatively, the patient developed unilateral inferior keratectasia in the right eye with refraction of +0.50 -5.50 x 90, BSCVA of 20/100, and central corneal thickness of 481 microm with inferior corneal thickness of 374 microm. CONCLUSIONS: This case report adds to the growing body of evidence in the ophthalmic literature suggesting that patients with preoperative forme fruste keratoconus or early keratoconus may develop clinically significant progression of corneal ectasia after PRK.