Effect of circular keratotomy on keratoconus.

Circular keratotomy was performed in 3 eyes of 3 patients with keratoconus before planned lamellar keratoplasty. After peribulbar anesthesia, a circular 400 microm cut centered on the geometrical corneal center was made using a Hessburg-Barron 7.0 mm trephine (Altomed). The circular cut was deepened with a guarded diamond blade set at 90% of the thinnest point in the circumference and closed with a single 10-0 nylon running suture. Videokeratography revealed increased astigmatism and increased central curvature in all eyes. In 1 patient, a 0.2 improvement in best spectacle-corrected visual acuity (BSCVA) was noted, associated with overall corneal steepening. In the other 2 patients, refraction, BSCVA, and corneal profile worsened, requiring lamellar keratoplasty. Circular keratotomy increased corneal curvature and worsened keratoconus and is therefore not recommended.