Purpose: To describe outcomes of customized peripheral anterior lamellar keratoplasty (PALK) for late ectasia of the donor-recipient junction after penetrating keratoplasty (PK) for keratoconus.
Methods: This was a single-center, retrospective review of 33 eyes (28 patients) that developed ectasia restricted to the graft-host junction; 17 eyes underwent PALK using lamellar resections of 8- to 11-mm width starting at the external margin of the previous PK and suturing a same-size donor graft (annular or segmental). Five eyes were excluded from analysis because of postoperative complications unrelated to the technique.
Results: The average time between PK and diagnosis of secondary ectasia was 28 years (range 9-49 years). Slit-lamp examination showed localized thinning and elongation of the scar at the graft-host junction with well-defined biomicroscopic limits. Preoperatively, the mean keratometric measures were K1: 44.8 ± 4.8 D and K2: 54.1 ± 4.8 D and postoperatively K1: 47.5 ± 3.5 D and K2: 50.8 ± 2.6 D. The mean improvement in corrected visual acuity was 10 lines, and mean cylinder improved from 9.3 ± 2.1 D to 3.3 ± 1.4 D. All cases showed anatomical and refractive improvement.
Conclusions: With long-term follow-up, late post-PK ectasia becomes an increasing problem. PALK can be a successful surgical option to reinforce the ectatic area while preserving a functional clear PK. By adding donor corneal tissue, PALK restores the ectatic area, improves visual acuity, keratometric values, and astigmatism, and preserves the functional graft while avoiding the higher risks of a larger diameter PK.