DALK for Spontaneous Posterior Corneal Layer Detachment in Recurrent Ectasia After Keratoplasty

The aim of this study was to describe 3 keratoconic eyes referred for painless visual loss approximately 2 decades after penetrating keratoplasty, initially misdiagnosed as immunologic rejection but instead found to have detachment of a thin posterior corneal layer, which was successfully managed with deep anterior lamellar keratoplasty (DALK).

This retrospective case series was conducted at Villa Igea, Ospedali Privati Forlì (Forlì, Italy). The main outcomes were best spectacle-corrected visual acuity, imaging findings, and endothelial cell density (ECD).

All patients presented with sectorial corneal edema extending into the host cornea, in the absence of intraocular inflammation. Anterior segment optical coherence tomography confirmed the extensive detachment of a thin posterior layer of the cornea, associated with ectatic thinning of the host stroma. Specular microscopy was possible in the nondetached area and showed a mean ECD of 1096 ± 235 cells/mm2. To simultaneously address both the detachment and the recurring ectasia, each patient underwent a 9.0-mm DALK with complete preservation of the detached layer, thus also capping the ectatic portion of the recipient bed. Postoperatively, all corneas remained clear with no subsequent edema, best spectacle-corrected visual acuity improved to 20/30 or better, and average ECD showed minimal decline.

Detachment of a thin posterior layer from the grafted cornea in post-penetrating keratoplasty keratoconic eyes may mimic endothelial rejection. Sectorial corneal edema extending beyond the graft-host junction should prompt consideration of a mechanical rather than an immunologic etiology. This case series highlights the possibility of successfully handling both the recurrent ectasia and the detachment with a 9.0-mm DALK.