Folate May Lower Glaucoma Risk

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Exfoliation glaucoma (EG), caused by exfoliation syndrome, a condition in which white clumps of fibrillar material form in the eye, is the most common cause of secondary open-angle glaucoma and a leading cause of blindness and visual impairment. Elevated levels of homocysteine, a non-protein a-amino acid, may increase exfoliation material formation. Research studies have demonstrated that high intake of vitamin B6, vitamin B12 and folate is associated with lower homocysteine levels. Most recently, study from Massachusetts Eye and Ear, Brigham and Women’s Hospital (BWH) / Harvard Medical School (HMS), and Harvard School of Public Health (HSPH) set out to evaluate the association between the intake of these vitamins and EG. The results were

The results, published in April 2014 in JAMA Ophthalmology,showed that vitamin B6 and B12 intake was not associated with EG/SEG risk in pooled analyses (P= .52 and P= .99 for linear trend, respectively). However, there was a trend of a reduced risk of EG/SEG with higher total folate intake, with relations being stronger for higher folate intake from supplements than from diet alone.

A release from Massachusetts Eye and Ear Infirmary explains that the researchers designed a prospective cohort study using more than 20 years of follow-up data from the Nurses’ Health Study (all female registered nurses) and the Health Professionals Follow-up Study (all male health professionals) from June 1, 1980 to May 31, 2010 (Nurses’ Health Study) and Jan. 1, 1986 to Dec. 31, 2010 (Health Professionals Follow-up Study). They observed that higher total folate intake was associated with a lower risk for EG/suspected exfoliation glaucoma (SEG), supporting a possible causal role of homocysteine in EG/SEG.  

The release quotes lead author Jae H. Kang, Sc.D., Channing Division of Network Medicine, Department of Medicine, BWH/HMS, as saying, “We included a subset of 78,980 women and 41,221 men who were 40 years or older, free of glaucoma, had completed dietary questionnaires, and reported an eye examination during follow-up. Incident cases of EG/SEG, totaling 339 were first identified with the questionnaires and were subsequently confirmed with medical records. Multivariable relative risks for EG/SEG were calculated in each cohort and then pooled with meta-analysis.”

 “Our conclusions are that higher folate intake is associated with a lower risk for EG/SEG, supporting a possible causal role of homocysteine in EG/SEG,” said senior author Louis Pasquale, M.D., Glaucoma Service Director, Mass. Eye and Ear. “More work needs to be done but these are critical insights that may give us a better understanding of how EG progresses, which helps to bring us closer to developing interventions or treatments that prevent this blinding disease.”