A Prospective Study of Endothelial Cell Loss during the 2 Years after Deep Lamellar Endothelial Keratoplasty
Presented in part as a paper at: American Academy of Ophthalmology Annual Meeting, October 17, 2005, Chicago, Illinois.
Received 19 July 2006; accepted 24 November 2006.
Purpose
To report the endothelial survival over a 2-year period after 2 techniques of deep lamellar endothelial keratoplasty (DLEK) in the treatment of endothelial dysfunction.
Design
Prospective, noncomparative, interventional case series.
Participants
One hundred eyes of 88 patients with corneal edema.
Methods
One hundred consecutive eyes with endothelial failure were entered into a prospective study of endothelial keratoplasty, and the donor central endothelial cell density (ECD) was recorded postoperatively at 6 months (n = 98), 12 months (n = 96), and 24 months (n = 85) and then compared with the preoperative eye bank measurements. The subsets of eyes with large-incision DLEK (n = 36) and small-incision DLEK (n = 62) were also evaluated and compared.
Main Outcome Measures
Preoperative and postoperative central ECDs were prospectively evaluated and the cell loss calculated for each postoperative time point.
Results
The average (and standard deviation) ECD at 6 months was 2140±426 cells/mm2, representing a mean cell loss from preoperative donor cell measurements of 25±15%. At 12 months, ECD was 2090±448 cells/mm2 (26±16% cell loss), and at 24 months, it was 1794±588 cells/mm2 (37±27% cell loss). The additional cell loss from 1 to 2 years was significant (P<0.001). In the subset of large-incision DLEK eyes (n = 36), the cell loss from preoperatively to 6 months was 23%; 12 months, 22%; and 24 months, 27%. In the subset of small-incision DLEK eyes (n = 62), the cell loss from preoperatively to 6 months was 25%; 12 months, 28%; and 24 months, 43%. The cell loss from small-incision DLEK surgery was significantly greater than that from large-incision DLEK surgery at the 12-month (P = 0.013) and 24-month (P<0.001) postoperative measurements.
Conclusions
Although the initial cell loss from DLEK surgery is minimally changed from 6 to 12 months postoperatively, there is an acceleration of cell loss from 1 year to 2 years postoperatively. The small-incision DLEK technique, which involves folding of the donor tissue, results in a significantly higher endothelial cell loss at 1 and 2 years than that found after large-incision DLEK surgery, wherein the tissue is not folded.
2Lions Vision Research Laboratory of Oregon, Portland, Oregon.
Correspondence and reprint requests to Mark A. Terry, MD, Director, Corneal Services, Devers Eye Institute, 1040 NW 22nd Avenue, Portland, OR 97210.
Manuscript no. 2006-801.
Dr Terry has a financial interest in the specialized instruments used in the surgery. Bausch and Lomb Surgical manufactured and supplied the specially designed instruments free of charge.
Supported by the Oregon Lions Sight and Hearing Foundation, Portland, Oregon.
ABSTRACT