Validation of iCare IC200 tonometry during natural sleep in children under 3 years with glaucoma: reducing anesthesia dependence in clinical monitoring

Abstract Background To assess the agreement between intraocular pressure (IOP) measurements obtained with the iCare IC200 rebound tonometer during natural sleep and under general anesthesia (EUA) in children under 3 years of age with glaucoma, and to evaluate the impact of this approach on clinical follow-up frequency and anesthesia exposure. Methods This prospective study included 74 eye-session pairs from 74 eyes of 27 patients aged 0–36 months diagnosed with pediatric glaucoma. IOP was measured during natural sleep within ≤ 2 h prior to EUA under end-tidal sevoflurane 2–3%. Measurements were performed by the same examiner under both conditions. Office and EUA frequencies were compared to a historical cohort (2009–2012) to evaluate changes in clinical monitoring trends. Results Mean age was 18.07 ± 13.97 months; 78% had primary congenital glaucoma. Natural sleep IOP (21.01 ± 11.77 mmHg) was consistently higher than EUA IOP (17.69 ± 9.85 mmHg), with mean difference of 3.32 ± 3.83 mmHg (14.96 ± 16.60%) (p < 0.05). A very strong correlation was observed between the two measurement conditions (r = 0.95, R² = 0.91). Current surveillance demonstrated 4.45 ± 2.70 EUA procedures versus 3.18 ± 2.44 office visits per patient, compared to pre-iCare era ratio of 7.39 ± 2.65 EUA versus 0.80 ± 0.70 office visits, representing a 40% reduction in anesthesia dependence. Conclusion Natural-sleep rebound tonometry supports bias-aware, clinic-based trend monitoring and can reduce anesthesia exposure in children under 3 years.