Difference in IOP (Intraocular Pressure) with and without eye speculum during examination under general anaesthesia using perkins tonometer.

Abstract

Objective: To compare intraocular pressure measurements obtained with and without an eyelid speculum during examination under general anaesthesia using Perkins tonometry. Study Design: Prospective Observational study. Setting: Department of Ophthalmology, Mughal Eye Hospital, Lahore. Periods: 1^st October 2025 to 1^st March 2026. Methods: Included 25 children (40 eyes) aged 1–12 years undergoing EUA. IOP was measured using a Perkins handheld applanation tonometer after induction of standardized general anaesthesia. Three readings were obtained first within 5 minutes of given general anaesthesia and subsequently after insertion of a pediatric eyelid speculum. Mean IOP values were compared using a paired t-test, and correlation analysis was performed to assess associations with demographic variables. Results: The mean age of participants was 3.5 ± 2.1 years. Mean baseline IOP without speculum was 11.2 ± 3.8 mmHg, which increased to 12.8 ± 3.2 mmHg after speculum application. The mean IOP difference was 1.6± 0.6 mmHg, which was statistically significant (p < 0.001). No significant correlation was observed between age and IOP change (r ≈ 0.10, p > 0.05). A weak positive correlation was observed between baseline IOP and IOP change (r ≈ 0.30, p < 0.05). Conclusion: Eyelid speculum use during examination under general anaesthesia results in a statistically significant increase in intraocular pressure measurements using Perkins tonometry. Although the magnitude of change is modest, it may be clinically relevant in pediatric glaucoma management, where treatment decisions are often based on single IOP readings.