Corneal endothelial cell loss after trabeculectomy or after phacoemulsification, IOL implantation and trabeculectomy in 1 or 2 steps

To assess endothelial cell damage after glaucoma surgery and combined glaucoma and cataract surgery in one or two steps using confocal biomicroscopy.

This is an observational retrospective study. Eighty eyes from 62 patients between 60 and 83 years of age were studied. Eyes fell into a control group (n = 21) and three experimental groups, in which trabeculectomy (group 1; n = 21) or trabeculectomy and phacoemulsification and intraocular lens implantation had been performed, in one (group 2; n = 21) or two (group 3; n = 17) steps between 6 months and 5 years before.

In the control group, mean corneal endothelial cell density (±SD) was 2,619 ± 319 cells/mm², whereas in the experimental groups 1, 2 and 3 it was 2,447 ± 425, 1,968 ± 342 and 1,551 ± 323 cells/mm² respectively. Cell densities found in the combined surgery groups were significantly smaller than the densities of the control or trabeculectomy groups. The variation coefficient of the endothelial cell area (±SD) was 41.19 ± 7.46% in the control group and 38.9 ± 6.02, 42.37 ± 9.53 and 45.71 ± 11.96% in groups 1, 2 and 3 respectively, differences that were not statistically significant. The percentage of hexagonality (±SD) was 51.10 ± 8.41% in the control group and 51.4 ± 6.88, 45.13 ± 8.40 and 42.37 ± 9.53% in the experimental groups 1, 2 and 3 respectively, but again there were no significant differences between them.

Combined trabeculectomy, phacoemulsification and intraocular lens implantation causes more endothelial cell damage than trabeculectomy alone, and the two-step combined procedure causes more damage to the endothelium than the one-step combined procedure.