Abstract
Abstract: :
Purpose: To compare outcomes of patients undergoing partial or full thickness corneal grafting for endothelial dysfunction. Methods: Patients were randomized to deep lamellar endothelial keratoplasty (DLEK) through a 9 mm limbal incision or standard penetrating keratoplasty (PK). Postoperative measurements included automated ETDRS visual acuity, confocal microscopy, esthesiometry, keratometry, scatterometry and pachymetry. Three–month postoperative data were compared between the two groups by using student t–tests or rank–sum tests. Results: Four DLEK eyes and 6 PK eyes completed at least three months postoperative follow–up. Two additional eyes randomized to DLEK were converted to PK during the operation and dropped from the study. Mean corrected acuity was better in the PK group (20/40 vs. 20/80, p=0.05), but mean uncorrected acuity tended to be better in the DLEK group (20/160 vs, 20/100, p=0.38). Mean keratometric astigmatism was 1.0 ± 0.9 D in the DLEK group and 5.0 ± 3.1 D in the PK group (p=0.04). Endothelial cell density, coefficient of variation, and % hexagonal cells were not significantly different for DLEK (1778 ± 953 cells/mm2, 0.25 ± 0.02, 64 ± 8%) compared with PK (2584 ± 419 cells/mm2, 0.28 ± 0.07, 62 ± 13%). Mean corneal thickness was 457 ± 100 µm for DLEK eyes and 522 ± 25 µm for PK eyes (p=0.16). By scatterometry, reflected light intensity was greater in both anterior (108 ± 35 vs. 72 ± 8 units, p = 0.04) and posterior (86 ± 29 vs. 38 ± 9 units, p=0.005) halves of DLEK corneas. Confocal microscopy of DLEK corneas revealed a peak in reflectivity at the graft–host interface, and mean graft thickness of 131 ± 46µm (range 67–167µm). Cochet–Bonnet esthesiometry values were 0 cm (anesthetic) in all PK corneas vs. 3.4 ± 2.3 cm in DLEK corneas (p=0.01). Conclusions: Results from 10 patients 3 months after surgery show that keratometric astigmatism and corneal sensation were better in DLEK eyes, and that corrected visual acuity and light scatter were better in PK eyes. Continued studies will show if these differences are transient or sustained.
Keywords: cornea: clinical science • microscopy: confocal/tunneling • transplantation