Background: Glaucoma's biggest treatable risk factor is elevated intraocular pressure (IOP).
Many factors have an impact on IOP, including body posture. Due to its convenience, lack of requirement for topical anaesthetic, and repeatable results, rebound tonometry has been claimed to be equivalent to the Goldmann applanation tonometer (GAT).

Aim of The Study: To study the effect of body posture (supine position versus sitting position) on the intraocular pressure (IOP) measurements in normal healthy children and glaucomatous children by using a Rebound tonometry.
Patients and methods: The study was carried out on 80 children, divided into 20 cases of children with glaucoma, and 60 children with normal healthy eyes as control, all children attending the outpatient pediatric ophthalmology clinics, of Memorial Institute Kids Eye Center, Giza, Egypt between December 2020 and August 2021.
Results: With reference to IOP measurement among children, we found significant increase in IOP in supine position than in sitting position in both glaucomatous children and control groups. However, that increase in IOP were higher among glaucomatous children than healthy control group. However, there was no significant relation between gender, age of glaucomatous children and glaucoma treatment modalities with IOP measurement on sitting or supine position.
Conclusion: iCare PRO tonometer is a good, safe and reliable method for IOP measurement in children at age range from 4-12 years in both sitting and supine position. IOP is significantly increased in supine positions compared to sitting positions in healthy children, and more significant in children with glaucoma