Effect of 2 Versus 3 mL Sub-Tenon Anesthesia and Ocular Massage on Intraocular Pressure among Cataract Surgical Cases in a Nigerian Tertiary Hospital

Objective: To determine the effect of 2 versus 3mL sub-Tenon anesthesia and ocular compression on intraocular pressure (IOP) among cataract surgical patients. Methods: A cross-sectional comparative study conducted at the University of Ilorin Teaching Hospital, Ilorin, Nigeria. Two hundred cataract patients were randomly allocated into two groups: group 1 (2 mL) and group 2 (3 mL). Intraocular pressure (IOP) was measured before and 5 minutes after administration of xylocaine for sub-Tenon anesthesia. Thereafter, a metallic weight was placed over the lid for ocular massage for a duration of 2 minutes, after which a repeat IOP check was done. Student’s t -test was employed to compare pre- and post-sub-Tenon injection mean IOP between the two groups, and any P value less than 0.05 was considered significant. Results: The mean age was 63.8 ± 12.64 years in group 1 and 64.14 ± 14.14 years in group 2. In both groups, a statistically significant rise in IOP was observed 5 minutes post-injection of xylocaine ( P = 0.005 for group 1 and P <0.001 for group 2). Though not statistically significant, the mean 5-minute post-injection IOP was slightly higher in group 2 compared to group 1. Compared with the 5-minute post-injection values, ocular massage reduced IOP by 15.4% in Group 1 and 13.01% in Group 2 ( P <0.001). Conclusion: Both the 2mL and 3mL sub-Tenon injections resulted in a modest, statistically significant elevation in IOP at five minutes, with no significant difference between the two volumes. Two minutes of ocular massage effectively reduced the mean IOP in both groups to below pre-injection values.