Intraocular and ocular perfusion pressure changes during pediatric laparoscopic appendectomy

To evaluate intraocular pressure (IOP) and ocular perfusion pressure (OPP) changes during pediatric laparoscopic appendectomy performed in the Trendelenburg position and to identify potential perioperative ocular risks. In this prospective observational study, IOP and OPP were measured in 25 ASA I pediatric patients undergoing emergency laparoscopic appendectomy. OPP was calculated as the difference between mean arterial blood pressure (MABP = diastolic BP + 1/3 [systolic BP – diastolic BP]) and IOP. Measurements were obtained with a Tono-Pen Avia® tonometer at eight standardized intraoperative timepoints (T1–T8), including the pneumoperitoneum and Trendelenburg phases. Statistical analysis was performed using repeated-measures ANOVA with Bonferroni post hoc correction. A significant rise in IOP was observed during Trendelenburg positioning, with peak values at T6 (approximately the 10th minute in Trendelenburg). Paired-samples comparisons demonstrated significantly higher left-eye IOP during Trendelenburg (T5–T6), with mean interocular differences of 1.32 mmHg (T5, p < 0.001) and 1.32 mmHg (T6, p = 0.00001). A mixed-effects model (fixed factors: time × eye; random intercept for subject) confirmed a strong time effect (p < 0.001) and a trend-level interaction (p ≈ 0.08), supporting side-dependent IOP elevation. OPP showed a transient decline during pneumoperitoneum and Trendelenburg, with a minimum mean of 48.5 ± 4.0 mmHg at T6 (p < 0.01). Transient IOP elevations above 21 mmHg occurred in 5 of 25 patients (20%), all resolving within minutes after desufflation. No postoperative ocular complications were observed. Trendelenburg positioning during pediatric laparoscopy causes transient but statistically significant alterations in IOP and OPP. Although these changes were short-lived and clinically asymptomatic in healthy children, perioperative ocular risk assessment remains important in patients with glaucoma, elevated baseline IOP, or optic nerve vulnerability.