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Elevated Homocysteine Linked to Exfoliative Syndrome and Exfoliative Glaucoma: Presented at ESO

By Cameron Johnston

MADRID, SPAIN -- June 11, 2003 -- Elevated homocysteine could be linked to a form of glaucoma that affects an estimated 75 million people worldwide, and 40% of all patients with glaucoma in Finland.

The findings of a study, presented here at the Annual Meeting of the European Society of Ophthalmology, now suggest that hyperhomcysteinemia could be associated with an increased risk of stroke, heart disease and other atherosclerotic abnormalities.

According to Dr. Hillevi Blomster, an ophthalmologist with the department of ophthalmology at the Kuopio University Hospital, in Finland, elevated homocysteine is, in general, caused by a nutrient-deficient diet, and poor dietary habits could also explain why Finns have one of the highest rates of heart disease in the world. Now, this latest study shows that there could also be a correlation between homocysteine levels and exfoliative syndrome, and exfoliative glaucoma. This condition appears as visible clumps or clusters on the anterior surface of the lens of the eye, and has been described as looking like dandruff under the cornea. It does not cause glaucoma, but instead, makes up one of the specific forms of the disease.

In a small study conducted at the hospital in Kuopio, 36 patients, mean age 77.4 years, with exfoliative syndrome or exfoliative glaucoma who were having routine cataract surgery had their serum homocysteine, as well as serum levels of vitamins B6 and B12 measured. The concentration of homocysteine found in the aqueous humor, and erythrocyte folate were also measured. These results were compared with the concentrations seen in 36 age-matched controls who did not have either of the ocular conditions.

Samples were collected from the patients in a fasting state, immediately before their cataract surgery.

Patients who had any history of heart disease, or any condition known to interfere with homocysteine metabolism were excluded from the study.

It was found that among those who had either of the exfoliative conditions, the mean plasma homocysteine level was 17.8 micromol/Litre compared with 15.8 micromol/Litre in the control group. Median levels were 16.8 micromols/Litre and 13.9 micromols/Litre respectively. Although there a clear definition of "normal" homocysteine does not exist, Dr. Blomster said levels of 5 to 15 micromol/Litre are considered "acceptable".

There were no significant differences in homocysteine levels depending on whether the patients had either exfoliative syndrome, or exfoliative glaucoma.

The reasons elevated homocysteine could be associated with either of the ocular conditions are unclear, but probably stem from the same reasons that hyperhomocysteinemia is associated with heart disease, Dr. Blomster said. High homocysteine is known to impair nitric oxide synthesis and to increase the coagulability of the blood.

Dr. Blomster said these findings suggest that other factors associated with homocysteine levels and exfoliative syndrome or exfoliative glaucoma should be studied in more detail, and perhaps therapeutic trials involving supplements of vitamins B6 and B12 in patients with glaucoma should be considered.


[Study title: Plasma Homocysteine Levels In Exfoliation Syndrome And Exfoliation Glaucom. Abstract FP 36]

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