Comparison Between Deep Lamellar and Penetrating Keratoplasty in the Treatment of Keratoconus

Abstract

Abstract: : PURPOSE: To compare morphological, clinical and refractive outcomes after deep lamellar keratoplasty (DLKP) and penetrating keratoplasty (PKP) in keratoconus patients. METHODS: Between March 1999 and November 2003, 40 eyes of 39 patients affected by keratoconus underwent a corneal graft. Manual DLKP by intrastromal delamination was performed in 20 eyes and a standard PKP in other 20 eyes. Keratoconus with more than 60 diopters (D) of apex corneal power and/or less than 300 µm at the minimum thickness point were selected for PKP. A complete ophthalmic examination including uncorrected and best corrected visual acuities (BCVA), applanation tonometry, corneal topography, endothelial cell count and pachymetry was analized before and after surgery at 1–3–6–12 months. RESULTS: Mean age of DLKP group was 37.1 ± 11.4 (range, 19–59) and 45.5 ± 15.5 (range, 25–80) for PKP group. At the end of follow up, mean BCVA was 0.82 ± 0.19 (range, 0.50–1.00) with a mean SE of –3.1 ± 1.9 D (range, –8–+1 D) for DLKP group, and 0.83 ± 0.19 (range, 0.30–1.00) with a mean SE of –4.2 ± 5.2 D (range, –17––7 D) for PKP group. At the same time mean topographic astigmatism was 3.8 ± 1.5 D (range, 1.0–7.2) for DLKP group, and 4.0 ± 1.3 D (range, 1.7–6.6) for PKP group. 12 months postoperative we found an endothelial cell count of 2463 ± 458 cell/mm² (range 1838–3184) in DLKP group and 1612 ± 363 cell/mm² (range, 767–2123) in PKP group (p=.002). Mean pachymetry was 594.25 ± 29.91 (range, 561–638 µm) in DLKP group and 510.44 ± 36.72 (range, 439–567) µm in PKP group. The suture was removed after 8.8 ± 3.4 months (range, 3–13) for DLKP group and 12.1 ± 2.0 (range, 6–16) for PKP group (p=.004). During DLKP follow up we recorded 1 case of intraocular hypertension, 1 case of stromal rejection and 1 case of interface neovascularization. As for PKP follow up we had 3 cases of endothelial rejections, 2 cases of intraocular hypertension and 1 case of corneal neovascularization. CONCLUSIONS: DLKP and PKP have similar refractive and visual outcome, but DLKP seems to have less complications, preserves endothelial cells and avoid endothelial rejection.

Keywords: keratoconus • transplantation • cornea: clinical science