Does Nitrous Oxide Affect the Corneal Endothelium? A Prospective Randomized Study in Pediatric Patients

Aim: To evaluate the mean changes for endothelial cell and corneal pachymetry in eyes which underwent general anesthesia with N2O and O2 with sevoflurane. Material and methods: 40 eyes of 40 patients who had extraocular surgery under general anesthesia included in this prospective study. The cases divided to two groups as O2 and N2O. %50 O2 (total flow rate; 2 L/min in O2-air mixture) and %50 O2 (total flow rate; 2 L/min in O2-N2O mixture) were used in each group respectively. The duration of surgery was recorded. CD (Cell Density), CV (Cell Variation), Hex (Hexagonality Rate) and pachymetric specular microscopy results were evaluated before surgery, 1. week and 4. week after surgery. Results: The duration of surgery and demographic data of groups were similar and statistically there was no significant difference between the groups. The value of CV for O2 group was 26 ± 2 cell/mm2 and for N2O group was 30 cell/mm2 at the 1. week. Statistically there was significant increase in N2O group compared with preoperative values (p=0,008). The value of Hex for O2 group was 52 ± 10% and for N2O was 62 ± 11% at the 1.week and statistically there was significant increase in N2O group compared with preoperative values (p=0,007). There was no significant difference between groups in terms of CD, CV, Hex, pachymetry at other times. Conclusion: There is only significant change at the 1.week after surgery in corneal variation and hexagonality rate in pediatric cases who had general anesthesia with nitrous oxide and further work is needed in this regard