Abstract
Purpose: :
To determine changes in corneal sensitivity and nerves after three keratoplasty procedures for Fuchs’ endothelial dystrophy.
Methods: :
Seventy-one eyes of 64 patients with Fuchs’ dystrophy were prospectively examined by using a Cochet-Bonnet esthesiometer before and at intervals after three types of keratoplasty: Descemet-stripping endothelial keratoplasty (DSEK) with a 5-6 mm limbal incision (n=47), deep lamellar endothelial keratoplasty (DLEK) with a 9-10 mm limbal incision (n=11), or penetrating keratoplasty (PK) with a 7.5-7.75 mm recipient diameter (n=13). Cochet-Bonnet filament lengths ranged from 6 cm to 0.5 cm, which corresponded to pressures that ranged from 0.4 g/mm2 to ≥16 g/mm2. Postoperative sensitivities were compared to preoperative by using generalized estimating equation models to account for possible correlation between fellow eyes of the same subject; p-values were adjusted for multiple comparisons. Subbasal and stromal nerves were qualitatively assessed by confocal microscopy.
Results: :
Preoperatively, sensitivity of Fuchs’ corneas did not differ between treatment groups (DSEK, 1.1 ± 1.6 g/mm2; DLEK, 1.1 ± 0.9 g/mm2; PK, 0.8 ± 0.4 g/mm2; p≥0.23). Sensitivity was decreased at 1 month after DSEK (4.2 ± 4.6 g/mm2; p<0.001), DLEK (7.2 ± 4.8 g/mm2; p<0.001), and PK (no detectable sensation in all eyes, p<0.001); the decrease was greater after DLEK than after DSEK (p=0.02). After DSEK, sensitivity remained decreased at 1 year (2.7 ± 3.7 g/mm2; p=0.02) but returned to preoperative by 2 years (1.1 ± 0.8 g/mm2; p=0.99). After DLEK, sensitivity remained decreased at 3 months (6.1 ± 4.8 g/mm2; p<0.001) and did not differ from preoperative at 6 months (3.7 ± 4.1 g/mm2; minimum detectable difference was 5.2 g/mm2, α=0.05/6, β=0.20, n=11). After PK, sensitivity did not return to preoperative by 3 years (8.8 ± 4.6 g/mm2; p<0.001). Subbasal nerves were not visible in 26 eyes (37%) preoperatively because of anterior corneal haze. Stromal nerves were tortuous in 11 eyes (15%) preoperatively and this abnormal morphology persisted in some eyes after endothelial keratoplasty.
Conclusions: :
Corneal sensitivity in Fuchs’ dystrophy is lower than we previously found in normal eyes. Corneal sensitivity loss is lower, and recovery is faster, after keratoplasty with smaller incisions. In a third of Fuchs’ dystrophy corneas subbasal nerves cannot be assessed by confocal microscopy because of anterior corneal haze. Abnormally tortuous stromal nerves are present in 15% of eyes with Fuchs’ dystrophy that require keratoplasty.
Clinical Trial: :
www.clinicaltrials.gov NCT00346138
Keywords: cornea: clinical science • transplantation • clinical (human) or epidemiologic studies: outcomes/complications