Purchase this article with an account.
D. L. Davis-Boozer, D. Friend, M. A. Terry, N. Shamie, M. Straiko; DSAEK: Do Graft Diameter and Thickness Affect Endothelial Cell Damage?. Invest. Ophthalmol. Vis. Sci. 2010;51(13):750.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
As cornea specialists continue to perfect their DSAEK techniques, a variety of methods have been proposed to improve visual outcomes or increase the procedure’s safety. Some surgeons have begun requesting ultra-thin grafts in hopes of improving patient vision; however, some reports suggest that thin grafts are difficult to manipulate and tend to fold on themselves, which may result in increased endothelial damage during insertion. There is also the possibility that larger grafts (in terms of thickness and/or diameter) experience greater compressive trauma during insertion. This study aims to determine whether donor tissue diameter and/or thickness are associated with post-op ECD.
All patients from a series of consecutive DSAEKs with complete data sets and without graft dislocation, rejection, or a glaucoma drainage device (all known to result in elevated endothelial damage) were included in analysis. 285 eyes of 226 patients were analyzed. All grafts were folded and inserted through a 5.0mm scleral tunnel with non-coapting forceps. Graft thickness was measured by pachymetry and graft diameter was recorded by the attending surgeon. Specular microscopy was conducted pre-operatively by eye bank technicians and again at 6 months post-op, and % change in ECD was calculated for each patient. Pearson’s correlation analysis and linear regression were performed with SPSS 12.0.
Mean graft diameter was 8.23 mm (Range 7.0-9.0, SD= 0.3 mm); 94.4% of grafts were 8.0 or 8.5 mm; 3.5% were < 8 mm and 2.1% were 9.0 mm. Mean graft thickness was 170 um (Range 99-367, SD=31.3 um). Mean % cell change was -24.8% (Range +17 to -80, SD=15%). No significant correlations were found, and no predictive model was generated: r2 change=0.021, p=0.2.
Linear regression revealed no significant relationships between graft thickness or diameter and endothelial cell loss at 6 months. Our standardized technique appears to be safe for grafts of any thickness and diameter, within the range studied. This study is limited by a relatively small range of donor tissue thickness; it therefore cannot speak to the safety of tissues below 100 um or above 250 um in thickness. Similarly, this analysis is most applicable to tissues trephinated to a diameter of 8.0 or 8.5 mm and cannot adequately conclude whether other diameters would result in greater endothelial damage.
This PDF is available to Subscribers Only