Glaucoma filtering surgery and retinal oxygen saturation
Sveinn Hakon Hardarson 1*,
Maria Soffia Gottfredsdottir 2,
Gisli Hreinn Halldorsson 3,
Robert Arnar Karlsson 3,
Jon Atli Benediktsson 4,
Thor Eysteinsson 2,
James Melvin Beach 3,
Alon Harris 5,
and
Einar Stefansson 2
1 Ophthalmology, University of Iceland/Landspitali-University Hospital, Reykjavik, Iceland; Oxymap ehf., Reykjavik, Iceland
2 Ophthalmology, University of Iceland/Landspitali-University Hospital, Reykjavik, Iceland
3 Oxymap ehf., Reykjavik, Iceland
4 Electrical and Computer Engineering, University of Iceland, Reykjavik, Iceland
5 School of Medicine, Indiana University, Indianapolis, Indiana, United States
* To whom correspondence should be addressed. E-mail: sveinnha{at}gmail.com.
 |
Abstract |
|---|
Purpose: Glaucoma may involve disturbances in retinal oxygenation and blood flow. The purpose of this study was to measure the effect of glaucoma filtering surgery on retinal vessel oxygen saturation.
Methods: A noninvasive spectrophotometric retinal oximeter was used to measure hemoglobin oxygen saturation in retinal arterioles and venules before and after glaucoma filtering surgery. Twenty-five consecutive patients were recruited and 19 had adequate image quality. Fourteen underwent trabeculectomy and 5 glaucoma tube surgery. Twelve had primary open angle glaucoma and 7 had exfoliative glaucoma. IOP decreased from 23±7 to 10±4 mmHg (mean±SD, p=0.0001).
Results: Oxygen saturation increased in retinal arterioles from 97±4% to 99±6% (n=19; p=0.046) and was unchanged in venules (63±5% before surgery and 64±6% after, p=0.76). There were no significant changes in saturation in the fellow eyes (p>0.60). The arteriovenous difference was 34% before surgery and 36% after surgery (p=0.35).
Conclusions: Glaucoma filtering surgery had almost no effect on retinal vessel oxygen saturation.
Key Words:
glaucoma surgery, retinal metabolism, retinal blood flow, hypoxia, image analysis, clinical physiology
