Clinical Efficacy of Pocketing Air-Visco Expanding Detachment Deep Lamellar Keratoplasty for Keratoconus with Scars after Acute Hydrops

Abstract Background To analyze the clinical efficacy of PAVED (Pocketing Air-Visco Expanding Detachment) deep anterior lamellar keratoplasty (DALK) for the treatment of keratoconus with scarring after acute hydrops Methods 50 eyes from 50 patients with keratoconus who developed scarring after acute hydrops and who underwent PAVED DALK from 2011 to 2021 were included. Patients with irrelevant ocular diseases or surgical history were excluded. Patients who underwent DALK with either femtosecond laser-assisted or manual trephination techniques were followed-up for at least one year. Preoperative corneal characteristics, refractive status, and endothelial cell counts, as well as postoperative vision, refractive status, endothelial cell counts, and complications, were recorded and compared between different surgery groups. Results Intraoperative findings revealed that in 28 eyes (56.00%), the scarred stroma was mildly adherent to Descemet's membrane (DM), which could be easily separated, and the DM could be fully exposed. In 12 eyes (24.00%), there was significant adhesion, which required careful multiangle and multiround pushing to achieve complete separation, revealing 1-4 mm long microfissures within the DM scar. In 9 eyes (18.00%), the adhesion was tight, separation was not feasible, and a large fissure was observed within the scar, leaving an extremely thin layer of residual stroma. The last recorded uncorrected visual acuity (UCVA) was 0.46±0.24 (logMAR), and the best-corrected visual acuity (BCVA) was 0.21±0.13 (logMAR), with 16 eyes achieving ≥0.8 and 40 eyes achieving ≥0.5. There was a statistically significant difference in postoperative BCVA (logMAR) (P value = 0.04), with the femtosecond laser group having a BCVA of 0.16±0.11 and the manual trephination group having a BCVA of 0.24±0.14. Conclusions Keratoconus with scarring after acute hydrops involving the deep stroma and DM can be effectively treated with PAVED DLK because of the advantage at exposing the DM in most patients. For patients who have DM microfissures or an extremely thin layer of residual stroma, the postoperative vision is generally well restored with few complications. Femtosecond laser assistance not only has limited risk of DM rupture, but also manifests better postoperative best-corrected visual acuity compared to manual trephination.