This prospective randomized controlled trial evaluated the effect of two upper extremity positions on intraocular pressure (IOP) in adult patients undergoing surgery under spinal anesthesia. Participants were randomly assigned to either an arms-at-sides position or a hands-on-chest position. IOP was measured in the right eye using an Icare ic200 rebound tonometer at predefined perioperative time points. Hemodynamic parameters, including mean arterial pressure, heart rate, and oxygen saturation, were also recorded. The primary outcome was the change in IOP from baseline to 30 minutes between the two upper extremity position groups.

Intraocular pressure (IOP) may be influenced by systemic hemodynamics, venous return, episcleral venous pressure, and patient positioning. Although the effects of head and body position on IOP have been investigated, the impact of upper extremity positioning during spinal anesthesia has not been clearly established.

This prospective randomized controlled trial was conducted at Elazig Fethi Sekin City Hospital. Adult patients scheduled for elective surgery under spinal anesthesia were enrolled. After written informed consent, participants were randomly assigned to one of two upper extremity positions: arms positioned alongside the body or hands positioned on the chest.

IOP was measured in the right eye using an Icare ic200 rebound tonometer. Measurements were obtained at baseline, 15 minutes, and 30 minutes after spinal anesthesia and positioning. Head and neck position was maintained neutral throughout the measurement period.

Hemodynamic parameters, including mean arterial pressure, heart rate, and peripheral oxygen saturation, were recorded simultaneously. The primary outcome was the change in IOP from baseline to 30 minutes between the two study groups. Secondary outcomes included IOP change at 15 minutes and perioperative hemodynamic changes.

Inclusion Criteria:

• Age between 18 and 80 years
• ASA physical status I-III
• Scheduled for elective open inguinal hernia repair under spinal anesthesia
• Ability to undergo intraocular pressure measurement
• Provision of written informed consent

Exclusion Criteria:

• History of glaucoma or ocular hypertension
• Previous ocular surgery or ocular trauma
• Active ocular disease or infection
• Contraindication to spinal anesthesia
• Inability to cooperate with intraocular pressure measurements
• Refusal to participate

Due to the nature of the intervention, participants and care providers could not be blinded. However, intraocular pressure measurements were performed by an outcome assessor blinded to group allocation.