Changing Strategies in Keratoplasty After Corneal Hydrops: From Penetrating to Lamellar Approaches – A Narrative Review

The hallmark of acute corneal hydrops (CH) is Descemet membrane (DM) rupture that leads to the influx of fluid into the cornea causing corneal edema. Multiple risk factors have been related to an increased incidence of CH in keratoconus (KC) patients, such as Down's syndrome, atopy, vernal keratoconjunctivitis, eye rubbing, and an earlier age of KC onset. Penetrating keratoplasty (PKP), deep anterior lamellar keratoplasty (DALK), compression sutures, cyanoacrylate tissue adhesive with bandage contact lens (BCL), intracameral gas injection, and amniotic membrane transplant (AMT) are some of the conservative and surgical methods used to treat CH. Compared to KC without a history of CH, the need for PKP in patients with healed hydrops is higher due to preexisting DM rupture. Thus, the majority of surgeons conduct PKP after CH. On the other hand, some corneal surgeons choose to perform DALK over PKP as it spares the host endothelium. In this narrative review, we compare DALK to PKP for corneal hydrops in KC, evaluating the challenges, advantages, and visual and refractive outcomes.