DLK may induce fewer aberrations than PK, study finds

Paris—Deep lamellar keratoplasty (DLK) seems to be more optically beneficial because of the significant differences in higher-order aberrations induced by DLK compared with penetrating keratoplasty (PK), according to Thomas John, MD.

Dr. John reported his findings at the annual meeting of the European Society of Cataract and Refractive Surgeons. He and colleague Raymond Corwin, MD, compared the topography, aberrometry, and refractive values from patients who underwent PK (n = 10) and DLK (n = 8) with those values from normal controls (n = 48). The investigators measured coma, trefoil, higher-order aberrations, and tilt.

In the DLK group, Dr. John, from Loyola University at Chicago, reported that all the parameters measured, calculated in a 4-mm zone, were decreased and that their topographic features were closer to those of the normal controls compared with the values in the eyes that underwent PK.

There was also a significant decrease in higher-order aberrations in data calculated from 4.8-mm zones in the patients who underwent DLK compared with the patients who underwent PK. The reasons for these differences are that in DLK no corneal wound is created and no sutures are used.

"Wavefront aberrations are much lower after DLK compared with PK. These differences in wavefront aberrations between the two procedures are significant and have a profound effect on glare, contrast, visual acuity, and perception," Dr. John stated.