Background & Objective: Corneal endothelial cells (ECD) are characterized by limited regenerative
potential, which is additionally impaired in patients with diabetes. This retrospective study
included 27 patients aged 58.1±13.6, 16 female and 11 males, who underwent 23-gauge vitrectomy in
combination with cataract surgery (phacovitrectomy) and further Ex-PRESS shunt implantation
throughout 2013-2017 at St. Barbara Hospital in Sosnowiec, Poland.
Methods: In our study, we distinguished 4 periods: initial period; post phacovitrectomy and removal of
oil tamponade; and 3 and 12 months post implantation of the Ex-PRESS shunt. Statistical analysis was
performed at the level of statistical significance of p<0.05. It included an analysis of variance (ANOVA)
and Tukey’s post-hoc test in order to determine the differences in the density of ECD cells/mm2
between the periods of observation. The paired-samples t-Student test was also performed to determine
whether the differences in visual acuity values before and after PPV and before and after Ex-PRESS
shunt were statistically significant.
Results: The initial count of ECD cells was 2381.1±249, which decreased to 1872.8±350.7 cell/mm2
and finally to 1677.9±327 at the endpoint. Differences in the density of ECD cells/mm2 were observed
to be statistically significant between the periods: after PPV vs. initial number of ECD (p = 0.000138);
before 3 months after Ex-PRESS shunt vs. initial number of ECD (p = 0.000138); 12 months after Ex-
PRESS shunt vs. initial number of ECD (p = 0000138). Analyzing the changes in visual acuity, we observed
a deterioration both before and 3 months after Ex-PRESS shunt (p = 0.007944) and before and
after PPV (p = 0.060334). In turn, correlation analysis indicated that there is a statistically significant,
moderate, positive relationship. The relationship between visual acuity after Ex-PRESS shunt and ECD
cells/mm2 density turned out to be statistically significant (r = +0.521381; p < 0.05).
Conclusion: Regardless of the period of observation and the choice of ophthalmic treatment of diabetic
complications, we observed a decrease in the number of ECD cells and a deterioration in visual acuity.
It is, therefore, reasonable to provide the patient with complete information about the proposed procedures
and to consider the risk-benefit balance.