Retinal oxygen saturation before and after glaucoma surgery

This study compared retinal vessel oxygen saturation before and after glaucoma surgery.

Retinal 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 1 day prior to and at approximately 10 days after surgery. Statistical analysis was performed using a Student's t-test.

After glaucoma surgery, intraocular pressure (IOP) decreased from 19.8 ± 7.7 mmHg to 9.0 ± 5.7 mmHg (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).

Intraocular pressure (IOP) decreases caused by glaucoma surgery had an effect on the retinal venous oxygen saturation.