Corneal ectasia after photorefractive keratectomy

Two patients developed corneal ectasia after photorefractive keratectomy (PRK). Case 1 had evidence of early keratoconus preoperatively, with manifest refractions of −4.00 +2.50 × 160 (20/20) in the right eye and −7.00 +3.00 × 180 (20/30) in the left eye; thin corneas (472 μm and 441 μm, respectively); and inferior paracentral steepening in the right eye and central steepening in the left eye on topography. Case 2 had manifest refractions of −8.50 +3.75 × 123 (20/20−2) in the right eye and −9.25 +4.00 × 077 (20/20−1) in the left eye; corneal thickness of 509 μm and 508 μm, respectively; and symmetric bow-tie patterns in both eyes on topography. Case 2 had a family history suspicious for keratoconus, with a sibling who had bilateral corneal transplantation at a young age. Both patients developed bilateral corneal ectasia after PRK.