Retention of the Pre-Descemet's Layer Reduces Endothelial Graft Scrolling: Digital Morphometric Analysis of Precut Endothelial Grafts.

Purpose: To evaluate the biomechanical impact of the Pre-Descemet's Layer (PDL) on central graft width (CGW) and Scrolling Score (SS) using a standardized digital morphometric approach in pre-Descemet endothelial keratoplasty (PDEK) and Descemet membrane endothelial keratoplasty (DMEK) grafts.

Methods

This experimental study analyzed 47 donor corneoscleral buttons. Grafts were prepared via pneumatic dissection into PDEK or DMEK. CGW and SS were quantified using FIJI-ImageJ software from standardized video frames. Statistical analysis included Student's t-tests, Pearson's correlation, and Chi-Square tests. Endothelial viability and global integrity were assessed in representative PDEK grafts using confocal microscopy with triple vital staining (Hoechst 33342, Ethidium-homodimer, and Calcein-AM).

Results

Forty-one grafts were successfully prepared (24 PDEK; 17 DMEK). The failure rate was significantly higher in diabetic donors (50% vs. 7.3% in non-diabetics, p < 0.001). PDEK grafts exhibited a significantly higher mean CGW (2.35 ± 0.36 mm) compared to DMEK (1.95 ± 0.41 mm; p < 0.05). A clear inverse relationship was established between CGW and SS; SS-2 was predominant in PDEK (50%), while SS-3 prevailed in DMEK (70.5%). Donor age showed a weak correlation with CGW in DMEK (R2 = 0.283) and no correlation in PDEK (R2 = 0.0004). Trypan blue staining did not significantly alter CGW or SS in either group (p > 0.05). Confocal microscopy confirmed high endothelial viability (2407 cells/mm2) with minimal iatrogenic damage in tissue folds.

Conclusions

Retention of the PDL significantly reduces endothelial graft scrolling and increases CGW values in PDEK compared with DMEK. Although donor age demonstrated a weak association with CGW in DMEK grafts, no such relationship was observed in PDEK. Digital morphometric analysis represents a reproducible approach for preoperative characterization of graft behavior in eye banks.