To compare confocal and biomechanical features of grafts following deep anterior lamellar keratoplasty (DALK) using a donor without Descemet’s membrane (DM) versus a full-thickness donor with intact DM.

In this non-randomized cross-sectional comparative study, 45 eyes with keratoconus that underwent DALK using the big-bubble technique were enrolled. Of which, 27 received a donor without DM (group1) while in 18 eyes; a full-thickness donor with an intact DM was used (group 2). A group of normal eyes (n=28, group 3) served as controls. Confocal microscopy was used to determine cellular profiles of grafts and the features of donor-recipient interface. Additionally, corneal hysteresis (CH) and corneal resistance factor (CRF) were measured. The results were compared between the study groups using ANOVA test.

A bared DM was achieved in all DALK patients. Mean follow-up duration was 20.2±8.6 months and 29.6±17.0 months in groups 1 and 2, respectively (P=0.13). CH was 9.82±1.93 mmHg in group 1, 9.51±1.22 mmHg in group 2 and 9.84±1.59 mmHg in group 3 (P=0.76). CRF was 9.57±1.87 mmHg, 9.04±1.55 mmHg and 9.89±1.73 mmHg, respectively (P=0.24). Confocal scan demonstrated that the keratocyte profiles and distribution were more similar to normal corneas in group 2. Additionally, significantly more severe interface haziness was observed when donor DM was retained.

Two techniques of donor preparation for DALK provide comparable results in terms of graft biomechanics. However, graft cellular profiles and healing response at the donor-recipient interface can profoundly be affected depending on whether donor DM is removed or retained.