Penetrating Keratoplasty versus Deep Anterior Lamellar Keratoplasty for Keratoconus with Concomitant Vernal Keratoconjunctivitis

Purpose: To compare clinical outcomes following penetrating keratoplasty (PK) versus deep anterior lamellar keratoplasty (DALK) for keratoconic patients with vernal keratoconjunctivitis (VKC). Methods: In this retrospective comparative study, the records of 69 keratoconic eyes with VKC that underwent PK (n=43, group 1) or DALK (n=26, group 2) were compiled. Postoperative best-corrected visual acuity (BCVA), refractive error, complications and graft clarity rate were compared between the groups. Results: Mean follow-up period was 42.1±21.7 months in group 1 and 34.9±21.1 months in group 2 (P=0.18). The mean postoperative BCVA was 0.15±0.09 logMAR in group 1 and 0.20±0.15 logMAR in group 2 (P=0.08), with a BCVA of 20/40 in 95.2% and 88.5% of the eyes, respectively (P=0.31). Problems in the epithelia were encountered in 7.0% and 42.3% of the eyes in groups 1 and 2, respectively (P=0.001). Suture complications, including stitch abscesses (16.3% versus 53.8%, respectively; P=0.001) and suture tract vascularization (2.3% and 34.6%, respectively; P<0.001), were more frequently observed in group 2. At the 31-month follow-up examination, the rejection-free graft survival rates were 50.0% in group 1 and 33.3% in group 2, with mean durations of 33.0 and 32.1 months, respectively (P=0.89). At the final follow-up examination, all grafts in group 1 and 96.2% of grafts in group 2 remained clear (P=0.75). Conclusion: The clinical outcomes of PK and DALK in eyes with keratoconus and VKC are comparable. However, because certain complications, such as epithelial problems and suture-related complications are more common following DALK, closer monitoring is necessary in these cases.