Corneal flattening by shallow circular trephination in human eye bank eyes

Recent reports documenting central keratometric changes after removal of failed epikeratoplasty lenticules, compared to preoperative keratometry measurements, suggest that the annular corneal wound alters corneal curvature. Central corneal steepening has also been reported following circular and hexagonal keratotomy. We performed standard epikeratoplasty trephination with a Hessburg-Barron suction trephine followed by a peripheral lamellar spreading keratotomy on seven human eye bank eyes to determine the effect of these incisions on corneal topography. In seven human eye bank eyes, the mean acute central keratometric flattening from the shallow trephine incision was 2.81 D (SD 2.28, P = .017), with no significant change in keratometry due to peripheral lamellar spreading (P = .916). Computerized numeric and three-dimensional graphic analysis of the keratographs demonstrated this central topographic flattening. Further studies are needed to investigate the reversibility of host corneal changes induced by epikeratoplasty procedures.