Abstract: To evaluate the refractive efficacy of penetrating keratoplasty（PKP）following refraction control directed by the corneal refractive law of the springy hemisphere. MethodsPKP was performed on 85 eyes of 68 patients. The sutures were selectively detached directed by the corneal refractive law of the springy hemisphere. Visual acuity, corneal curvature and spherical equivalent were determined before and 1,3,6,12 and 15 months after the operations. Results15 months after the operations, the mean uncorrected visual acuity of 59 eyes was ≥0.5 and of 20 eyes ≥1.0. The mean corneal curvature was 37.26±2.85D before the first suture removal and was 43.52±2.25D after all suture removal (P＜0.05). The mean corneal astigmatism was 4.83±4.16D before the suture removal and was 1.97±2.69D 15 months after the operations (P＜0.01). The spherical equivalent of the corneas was different between post-operative 1 month and post-operative 3,6,12 and 15 months (P＜0.05), also it was statistically different between post-operative 15 months and 18 months (P＞0.05). ConclusionSuture removal selectively directed by the corneal refractive law of the springy hemisphere combined with other techniques can reduce post-operative refractive errors, improve visual acuity and control post-operative visual performance.

Key words: penetrating, Refraction, Keratoplasty, Corneal refractive law of the springy hemisphere