Comparison of penetrating keratoplasty and deep anterior lamellar keratoplasty in keratoconus eyes with vernal keratoconjunctivitis

PURPOSE: The purpose of the study is to compare outcomes after penetrating keratoplasty (PK) against deep anterior lamellar keratoplasty (DALK) for keratoconus in patients with vernal keratoconjunctivitis (VKC). METHODS: Keratoconic patients with VKC who received PK (n = 55, group 1) or DALK (n = 62, group 2) were retrospectively enrolled. The Student’s t test, Mann–Whitney test, Fisher’s exact test, chi-square test, and Kaplan–Meier survival curve were used to compare outcomes between the groups. RESULTS: The follow-up period was 59.4 ± 44.1 and 62.4 ± 38.9 months in groups 1 and 2, respectively (p = 0.70). Postoperative best spectacle-corrected visual acuity was 0.24 ± 0.18 and 0.29 ± 0.19 logMAR, respectively (p = 0.13). Graft rejection occurred in 34.6% and 25.8% of eyes in groups 1 and 2, respectively (p = 0.30). Groups 1 and 2 were comparable in the rates of cataract (3.6% and 12.9%, respectively, p = 0.07) and high intraocular pressure (3.6% and 8.1%, respectively, p = 0.31). Compared with the eyes with inactive VKC, PK eyes that experienced postoperative disease reactivation had a higher rate of suture abscesses (10.9% versus 50.0%, respectively, p = 0.01) and suture-tract vascularization (6.5% versus 33.3%, respectively, p = 0.03). Similarly, disease reactivation significantly increased suture abscesses from 27.3% to 51.7% (p = 0.03) and suture-tract vascularization from 18.2% to 49.6% (p = 0.005) in the DALK group. The graft survival rates were 95.3% in group 1 and 87.9% in group 2 at the 4-year follow-up, with mean durations of 14.4 and 11.1 months, respectively (p = 0.20). CONCLUSION: The results indicate no difference in outcomes between PK and DALK for keratoconus in patients with VKC. Postoperative VKC reactivation increased the rate of suture-related problems after both techniques of keratoplasty.