Influence of Graft–Host Interface on the Quality of Vision After Deep Anterior Lamellar Keratoplasty in Patients With Keratoconus

Abstract

In selected patients, quality of vision after DALK was comparable to that after PK when stromal excision was extended to the DM and inferior to vision after PK when layers of stroma were left adherent to the DM. Advances in DALK technique are required to allow easier and repeatable baring of the DM.

Determinants of visual quality after endothelial keratoplasty

“…One study of DALK in patients with keratoconus compared visual results of those with a stroma-stroma interface (pre-DM-DALK) against those with a DM-stroma interface (DM-DALK). 37 Low-contrast visual acuity was significantly inferior to PKP in the pre-DM-DALK group, but equivalent to PKP in the DM-DALK group. Pelli-Robson contrast sensitivity was comparable after PKP and DM-DALK, but significantly worse in the pre-DM-DALK group.…”

“…Non-significant trends for better high-contrast VA after DM-DALK compared with pre-DM-DALK have been found. 1,37 In a similar study of 236 keratoconic eyes, Sarnicola et al found no difference in highcontrast VA outcomes between DM-DALK and pre-DM-DALK at a mean follow-up of 2.5 years.…”

“…A quarter of DALK eyes had some interface opacity, and HOAs were similar between both types of DALK and PKP. 37 This suggests the difference in interface may influence contrast sensitivity and low-contrast visual acuity, but not necessarily HOAs or high-contrast acuity. Non-significant trends for better high-contrast VA after DM-DALK compared with pre-DM-DALK have been found.…”

Big Bubble DALK After CXL in Keratoconic Patients

“…4,5 Overall success in separating DM from the overlying tissue with this technique has been reported to be approximately 70% to 80% worldwide. 4,5 CXL produces a compaction of collagen fibers that is confined to the anterior 250 µm of the corneal stroma, as has been shown on electrophoresis ex vivo and confocal scanning laser microscopy in vivo.…”

“…4,5 Overall success in separating DM from the overlying tissue with this technique has been reported to be approximately 70% to 80% worldwide. 4,5 CXL produces a compaction of collagen fibers that is confined to the anterior 250 µm of the corneal stroma, as has been shown on electrophoresis ex vivo and confocal scanning laser microscopy in vivo. [6][7][8][9] Nonetheless, compaction of the anterior stroma could theoretically hinder formation of the "Big Bubble" cleavage plane in the posterior stroma and therefore concerns have been raised about the possibility of performing a successful "Big Bubble" technique in corneas previously treated with CXL.…”