PurposeThis study compared retinal vessel oxygen saturation before and after glaucoma surgery.
MethodsRetinal oxygen saturation in glaucoma patients was measured using a non-invasive spectrophotometric retinal oximeter. Adequate image quality was found in 49 of the 108 consecutive glaucoma patients recruited, with 30 undergoing trabeculectomy, 11 EX-PRESS and eight trabeculotomy. Retinal oxygen saturation measurements in the retinal arterioles and venules were performed at 1day prior to and at approximately 10days after surgery. Statistical analysis was performed using a Student's t-test.
ResultsAfter glaucoma surgery, intraocular pressure (IOP) decreased from 19.87.7mmHg to 9.0 +/- 5.7mmHg (p<0.001). Although oxygen saturation in retinal arterioles remained unchanged before and after surgery (104.7 +/- 10.6% before and 105.4 +/- 9.3% after surgery, p=0.58), the oxygen saturation in the venules increased from 54.9 +/- 7.4% to 57.4 +/- 5.7% (p=0.01).
ConclusionIntraocular pressure (IOP) decreases caused by glaucoma surgery had an effect on the retinal venous oxygen saturation.