Partial pressure of oxygen is significantly higher in African American patients

Ocular oxygen levels are higher in African American patients than in Caucasians, according to a study in the Archives of Ophthalmology.

Dr Carla J. Siegfried et al., Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, USA, used an optical oxygen sensor inserted into the anterior chamber through a peripheral corneal paracentesis to measure partial pressure of oxygen before intraocular cataract/glaucoma surgery.

The flexible fiberoptic probe was used to measure the oxygen pressure in the central corneal endothelium, the mid-anterior chamber and the anterior chamber angle in both glaucoma and cataract patients. Oxygen pressure was measured at the anterior lens and in the posterior chamber situated behind the iris in the cataract patients.

The findings suggest there may be differences in systemic physiologic function. The partial pressure of oxygen was higher in all ocular locations in African American patients compared with Caucasians.

The results indicate an integral difference in oxidative metabolism in the lens and cornea. Oxidative stress, cell damage, intraocular pressure and glaucoma risk may be increased by oxygen or oxygen metabolites.