Higher oxygen levels in the eyes of African Americans may explain why they develop glaucoma more often than white (Caucasian) people, reports EurekAlert.
Glaucoma is a disease of the optic nerve – if left untreated, it leads to its atrophy and blindness. The most common cause is abnormally high pressure inside the eyeball. Glaucoma develops quickly and usually asymptomatically – it is not painful, and the loss of the visual field is slow, often imperceptible (a healthy eye can compensate for the impaired vision in the affected eye). Some people only see a doctor when they can see only one eye.
By measuring the oxygen level in the eyeball during ophthalmic surgery (for cataracts and / or glaucoma), researchers at Washington University School of Medicine in St. Louis found that African Americans with glaucoma have significantly more oxygen in their eyes than Caucasians. It is likely that more oxygen can damage the drainage system from the inside of the eyeball, which increases the pressure and causes blindness, damaging the optic nerve. The higher oxygen levels appear to be due to a more efficient metabolism.
Compared to whites, African Americans are six times more likely to develop glaucoma, they develop the disease at an earlier age, and they are 16 times more likely to lose their eyesight because of it. Scientists at the Washington University School of Medicine believe the phenomenon may explain the metabolic differences between African Americans and white people. A large amount of oxygen can promote the formation of free radicals that accelerate the aging of tissues. It has also been observed that vitrectomy – that is, removing the jelly-like vitreous body from the eye – increases the level of oxygen in the eye and increases the risk of glaucoma.
Glaucoma detected early can be treated – modern drugs as well as laser and surgical treatment are available. However, early detection is most important – treatment will not restore the patient’s normal vision, it can only stop the development of the disease, and untreated glaucoma will inevitably lead to complete, irreversible blindness (PAP).