Eyeworld

EW NEWS & OPINION 18 October 2015 MTI'S NEW 440 MOBILE QUAD BATTERY-POWERED STRETCHER BED is ideal for the safe, rapid and stable transportation of patients from pre- op to surgery and recovery. With this model you will also get superior patient accessibility, a revolutionary lightweight lithium ion battery and the thinnest backrest on the market. sales@mti.net | mti.net/stretcherbed | (800) 924.4655 Taking a closer look continued from page 16 Delving into vitamin D, eye health studies T he number of studies focusing on vitamin D and eye conditions ranging from AMD to dry eye to glaucoma is still small. Here are details on 3 recently published studies in the ophthalmic literature to provide a flavor of what's been reported so far. Vitamin D, AMD, and genetic risk In a study published online in August, researchers, led by Amy E. Millen, PhD, University at Buffalo, Buffalo, N.Y., worked with the premise that vitamin D deficiency has been associated with increased odds of AMD. 1 They then analyzed if the association is modified by a genetic risk for AMD and what association there may be between AMD and single-nucleotide polymorphisms of genes associated with vitamin D transport, metabolism, and genomic function. Researchers included 913 postmenopausal women who were part of the Carotenoids in Age- Related Eye Disease Study and had available vitamin D concentrations. The women were also evaluated for AMD signs via fundus photographs. "A 6.7-fold increased odds of AMD was observed among women with deficient vitamin D status," the researchers wrote. These women also had 2 risk alleles for the CFH and CFI genotypes. Vitamin D and IOP In a study published last year and led by Dr. Krefting, researchers examined associations between vitamin D levels and intraocular pressure (IOP). 2 Healthy Caucasians with high or low vitamin D levels were recruited from a population-based study and had their IOP measured. Subjects with low D levels were randomized to receive vitamin D3 capsules of 20,000 IU twice a week or a placebo. The IOP was measured 6 months later. The IOP in 87 participants with low D levels did not differ from the IOP in the 42 participants with high D levels. Based on the results, the researchers said that vitamin D did not appear to play a role in the regulation of IOP. However, Dr. Krefting believes it would be of interest to explore these findings further. "One idea is to investigate if there is a relationship between IOP and levels of vitamin D among those persons with an elevated IOP. It also would be of great interest to do a randomized controlled study to see if there is a link between vitamin D levels and the rate of progression among patients with glaucoma," he said. Dry eye, vitamin D, and a Mediterranean diet Researchers at the Miami VAMC and Bascom Palmer Eye Institute, led by Dr. Galor, examined in a May 2014 study if a Mediterranean diet and vitamin D levels affected dry eye syndrome. 3 The Mediterranean diet focuses for the most part on plant-based, healthy eating. Nearly 250 male patients (mean age, 69 years) from the Miami Veterans Affairs eye clinic with normal eye health participated in the study and filled out a food frequency questionnaire as well as a Dry Eye Questionnaire. Researchers also measured levels of 25-hydroxy vitamin D and various dry eye parameters. Adherence to a Mediterranean diet was positively associated with a risk for dry eye syndrome. Vitamin D levels had a small but favorable effect on the presence of dry eye symptoms. "We didn't find anything that exciting," Dr. Galor said. She and her fellow researchers were considering the need for a clinical trial but decided not to pursue it. She thinks omega-3 supplementation may be more of a superstar within ocular surface disease health going forward. EW References 1. Millen AE, Meyers KJ, Liu Z, et al. Association between vitamin D status and age-related macular degeneration by genetic risk. JAMA Ophthalmology. 2015 Aug 27. [Epub ahead of print] 2. Krefting EA, Jorde R, Christoffersen T, Grimnes G. Vitamin D and intraocular pressure—results from a case-control and an intervention study. Acta Ophthalmol. 2014;92:345–349. 3. Galor A, Gardener H, Pouyeh B, Feuer W, Florez H. Effect of a Mediterranean dietary pattern and vitamin D levels on dry eye syndrome. Cornea. 2014;33:437–441.

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