Abstract
Purpose: :
The goal of this study was to compare the outcomes of penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK) in the treatment of keratoconus.
Methods: :
A retrospective, nonrandomized comparative case series was performed. Forty-seven patients who underwent either PKP (36 eyes, 36 patients) or DALK (11 eyes, 11 patients) between January 1, 2000 and December 31, 2006 at the University of Iowa Hospitals and Clinics were included in the study. Baseline data included age, best-corrected visual acuity (BCVA), pre-operative refraction, and pre-operative keratometry. Outcome measures included BCVA, refractive results, keratometry, and complications.
Results: :
Among 35 patients who were treated with PKP, the mean age was 37 years (range, 17 to 78) and the mean follow-up was 44 months (range, 13 to 74). Among 11 patients treated with DALK, the mean age was 44 years (range, 26 to 58) and the mean follow-up was 24 months (range, 6 to 41). There were no statistically significant differences between PKP and DALK with respect to final BCVA, spherical or cylindrical refraction, and keratometry. Final BCVA of 20/40 or better was obtained in 30 (83.3%) eyes after PKP and 9 (82%) eyes after DALK (P = 1.0). Final visual acuity of 20/25 or better was obtained in 27 (75.0%) eyes after PKP compared to 5 (45.5%) eyes after DALK (P = 0.13). Final visual acuity of 20/20 or better was obtained in 20 (55.6%) eyes after PKP compared to 3 (27.3%) eyes after DALK (P = 0.16). Complications that occurred after PKP included endothelial rejection episodes (14 eyes), wound dehiscence (7 eyes), endophthalmitis (1 eye), bacterial keratitis (1 eye), and interface scar (2 eyes). Complications that occurred after DALK included interface scar (4 eyes), and wound dehiscence (3 eyes).
Conclusions: :
Treatment of keratoconus with PKP or DALK is associated with similar visual outcomes and complication rates. While DALK offers the benefit of elimination of the risk of immune-mediated endothelial rejection, PKP provides a higher percentage of patients with final BCVA of 20/25 or better. This work provides guidance to ophthalmologists when selecting the best keratoplasty procedure to meet the visual rehabilitation needs of patients with keratoconus.
Keywords: keratoconus • transplantation