Comparison of the Effects of Spinal Versus General Anesthesia on the Perioperative Intraocular Pressure: A prospective, randomized clinical trial.

OBJECTIVES

To evaluate the effects of spinal and general anesthesia on the intraocular pressure (IOP) in patients, who had lumbar spine and lower extremity orthopedic surgeries.

METHODS

Sixty adult were randomly classified into Group spinal anesthesia (SA) and Group general anesthesia (GA). The IOP, mean systemic arterial pressure, and heart rhythm were measured at 6 pre-determined timepoints (T0: Baseline, T1: Before spinal procedure or anesthesia induction, T2: After injection with intrathecal or anesthesia induction, T3: 5th minutes (min) after spinal procedure or tracheal intubation, T4: 30th min intraoperative, T5: At the end of surgery, T6: 5th min after surgery or tracheal extubation in the operation room.

RESULTS

The baseline IOP and IOP1 measurements during were not significantly different between the groups (SA = 14.28 ± 0.8 mmHg; GA = 14.62 ± 0.9 mmHg, p = 0.923; and IOP1: SA = 15.83 ± 0.9 mmHg; GA = 15.88 ± 0.9 mmHg, p = 0.929). The most significant decrease in IOP in both groups was recorded at T2 (SA: 12.37 ± 0.6. GA: 12.24 ± 0.4, p < 0.001). The decrease in IOP2 was more significant in the GA group. The IOP3 was significantly higher in GA group after intubation (GA: 19.82 ± 1.2, SA: 12.86 ± 1.0)(p < 0.05). The IOP4 and IOP5 in the SA group were lower than those in the GA group. The IOP6 in both groups was higher (SA: 15.20 ± 0.8, GA: 16.50 ± 1.0) than the baseline IOP values, albeit not significant (p > 0.05). In prone position, IOP at the T4 and T5 timepoints were significantly higher than the initial values in both the SA and the GA groups; however, the increase in the GA group was more higher than that of the SA group.

CONCLUSION

In intraoperative period, intraocular pressure may increase in both management of anesthesia, but this increase is higher in the general anesthesia group.