Comparison of refractive changes after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus

Abstract

Purpose

To compare refractive changes occurring after deep anterior lamellar keratoplasty (DALK) or penetrating keratoplasty (PKP) in patients with keratoconus.

Methods

We retrospectively reviewed the medical records of 57 patients with keratoconus who received DALK (19 eyes of 19 patients) or PKP (38 eyes of 38 patients) before and after surgery between January 1996 and January 2008, in an effort to evaluate the surgical results and clinical courses. The principal outcome measures were as follows: preoperative and postoperative uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest refraction, and corneal topography including anterior chamber depth (ACD).

Results

We noted no significant difference between the DALK and PKP groups in terms of postoperative UCVA, BCVA, astigmatism, or donor-recipient graft size disparities. For the PKP and DALK groups, the mean postoperative spheres were −1.64 D and −4.29 D at 6 months (P = 0.01) and −2.73 D and −4.22 D at 12 months, respectively (P = 0.04). Postoperative mean central corneal powers (3.0/5.0 mm zone) were 45.01/45.03 D and 46.94/47.84 D, respectively (P = 0.04 and P = 0.02). ACD after surgery was 3.25 and 3.37 mm at the final follow-up, respectively (P = 0.02).

Conclusions

Although DALK is a safe alternative in cases of keratoconus, the DALK group evidenced significantly higher myopia than did the PKP group, which was related to steeper central corneal power and deeper ACD.