Abstract
Purpose:
Descemet’s stripping automated endothelial keratoplasty (DSAEK) is a widely used method of posterior lamellar keratoplasty. Recently however, a Cochrane review and a large register study indicated that DSAEK causes lower endothelial cell counts and more frequent graft failures when compared to the former used method, penetrating Keratoplasty (PK). In order to investigate the potential for long-term graft survival after DSAEK we examined the functional capacity of the endothelial cells by first inducing corneal oedema, and subsequently monitoring the reduction of oedema.
Methods:
In a prospective study, we included 16 patients with Fuchs’ endothelial dystrophy (Fuchs’) eligible for DSAEK surgery and a control group of 14 age-matched cataract patients with normal corneas eligible for cataract surgery. Corneal edema was induced by placing a contact lens (Contaflex, 500 mm, polymacon 38 %, Dk = 7.9, Contamac, UK) and taping the eyelid for 2 hours. Corneal thickness was measured by Anterior OCT (Spectralis HRT, Heidelberg). Experiments were performed preoperatively and 12 months after surgery. Deswelling curves were analysed by regression models using the least squares method, and compared using the extra-sum-of-squares F-test or slope analysis when appropriate. All patients gave informed consent and the Regional Ethics committee approved the study.
Results:
Before surgery, deswelling was significantly slower in the Fuchs’ group when compared to normal controls (p< 0.01). Twelve months after DSAEK surgery, deswelling was significantly faster than preoperatively (p= 0.03) and similar to the deswelling speed in the control group 12 months after cataract surgery (p=0.35). In the control group there was no difference between preoperative deswelling and postoperative deswelling (p=0.72).
Conclusions:
The deswelling capacity of the cornea is lower in FED patients when compared to patients with normal corneas. Twelve months after DSAEK surgery the deswelling capacity is increased significantly and is similar to normal corneas.