Abstract
Purpose :
Corneal endothelial cell (CEC) density continuously decreases for many years post trabeculectomy (TLE), yet the underlying mechanisms of the CEC loss remains unknown. Here we investigated whether the filtering bleb plays a role in CEC density loss post TLE.
Methods :
This study involved 63 eyes of 46 glaucoma patients (23 males and 23 females; age range: 62-83 years) who underwent TLE at Kyoto Prefectural University of Medicine from 2004 to 2015. Corneal endothelium was evaluated by scanning slit contact specular microscopy. CEC density was then evaluated at 3 areas; 1) the cornea center, 2) the area close to the TLE filtering bleb, and 3) the area contralateral to the bleb. The eyes were divided into 5 groups based on the number of years followed post surgery: 0-1 year (Group 1: n=31), 1-2 years (Group 2: n=7), 2-3 years (Group 3: n=8), 3-4 years (Group 4: n=9), and 5 years or more (Group 5: n=8). The Jonckheere-Terpstra trend test or the Dunnett's test was used for statistical analysis.
Results :
In Groups 1, 2, 3, 4, and 5, the CEC density at the cornea center was 1857, 1906, 1652, 1834, and 1521 cells/mm2, respectively, and at the peripheral area contralateral to the bleb was 1993, 2087, 1915, 2050, and 1746 cells/mm2, respectively. Both at the cornea center and the peripheral area contralateral to the bleb, CEC density was not significantly decreased among the 5 groups (p=0.142 and p=0.132, respectively). However, the CEC density close to the bleb tended to decrease in a time dependent manner; i.e., 1559 (Group 1), 1412 (Group 2), 1337 (Group 3), 1143 (Group 4), and 1066 cells/mm2 (Group 5) (p<0.01). The mean CEC density of all eyes at contralateral to the bleb, the cornea center, and the bleb was 1979, 1794, and 1404 cells/mm2, respectively, showing that CEC density close to the bleb was significantly lower than that contralateral to the bleb and at the cornea center (p<0.01)
Conclusions :
We found that CEC density close to the bleb decreased post TLE, even though that at the cornea center did not decrease, suggesting that evaluation of CEC density close to the bleb is beneficial for corneal endothelial prognosis post TLE. Involvement of the bleb in CEC density loss should be further examined to elucidate the pathology of CEC loss post TLE.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.