Post-operative visual loss occurs more commonly in spinal surgery. Increased intra-ocular pressure is often implicated in the etiology of postoperative visual impairment. We investigated intraocular pressure in 20 patients undergoing lumber disc surgery. We classified the patients into two groups: Group I: patients were in the knee-elbow position with the head resting on a cushion and turned to one side and group H: patients were in prone position and the head neutral. We classified patients in knee-elbow position into two sub-groups; subgroup A where we measured 10P in nondependant eye and subgroup B where we measured 10P in dependant eye. In both groups we measured 10P during 2 times, the first time in both group when the patients were awake and in supine position and the second time was in group I at the end of surgery when the patients were still anesthetized and in knee elbow position and in group 1/ at the end of surgery when the patients were still anesthetized and in prone position. In group I after mean duration of surgery 120+18 min. (mean ± SD), the mean intra-ocular pressure in the non-dependant eye was unchanged when compared to awake state 16.3+2.1 vs. 17.2±3.2 rrintHg (p>0.05), whereas the intraocular pressure in the dependant eye had significantly increased 17.1+2.2 vs. 19.2+1.1 mmHg (p 0.05). In group H after mean duration of surgery 119+19 mmHg, mean infra-ocular pressure had highly significant increase compared to awake state 16.7+2.2 vs. 21.3+2.1 mmHg (p0.01). |
