Outcomes of deep anterior lamellar keratoplasty and penetrating keratoplasty in keratoconic eyes with and without previous hydrops

Purpose The study aims to compare outcomes after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in keratoconic eyes with or without previous hydrops. Methods Retrospective analysis of 211 eyes who received PK (group 1, n = 74 [history of hydrops: n = 33]) or DALK (group 2, n = 137 [history of hydrops: n= 9]) from 2012 to 2019 at the Department of Ophthalmology, University of Cologne, Germany. Analysis included best spectacle-corrected visual acuity (BSCVA), complications, immune reactions, graft survival and keratometry, and subgroup analyses for subjects with or without previous hydrops. Results Follow-up was 34.0 +/- 23.6 months in group 1 and 30.7 +/- 22.5 months in group 2. No significant difference was found in the course of BSCVA between groups 1 and 2 (p = 0.182) and in postoperative BSCVA between eyes with and without previous hydrops, regardless of the surgical method (p = 0.768). Endothelial immune reactions occurred exclusively in group 1 and did not occur more frequently in eyes with previous hydrops (p = 0.377). A higher risk of complications for eyes with previous hydrops was observed (p = 0.022). There was no difference in astigmatism and maximum keratometry (K-max) preoperatively and postoperatively between eyes with and without history of hydrops. Conclusion The prognosis for visual outcome after keratoplasty including visual acuity, astigmatism, and K-max for keratoconic eyes with previous hydrops is as good as for keratoconic eyes without previous hydrops, irrespective of the surgical method. However, eyes after hydrops seem to have an increased risk of complications.