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

To compare clinical outcomes following penetrating keratoplasty (PK) versus deep anterior lamellar keratoplasty (DALK) for keratoconic patients with vernal keratoconjunctivitis (VKC). 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. 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 of20/40 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). 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.