Lutein, zeaxanthin, macular pigment, and viual function in adult cytic fibroi patient

The macular pigment, thought to be a potmortem artifact le than 100 year ago by Gulltrand, ha been the ubject of intene reearch in recent year. The macular pigment i derived from dietary carotinoid, lutein, and zeaxanthin, which endow it with a yellow-orange color that aborb hort-wavelength light en route to the photoreceptor. Thi filtering of high-energy photon, together with cavenging of free radical, i thought to be a mechanim of major health ignificance for the human retina. Decreaed plama concentration of the pigment from which macular pigment ha been derived have been aociated with an increaed incidence of macular degeneration, although it i unclear that level of thee carotinoid in the eye directly relate to the rik of retinal dieae. More ubtle than frank macular degeneration are the loe in enitivity of cone photoreceptor aociated with normal aging. A high amount of macular pigment might protect the retina from age-related lo in cone enitivity, but other interpretation are plauible. If macular pigment doe foretall the effect of normal aging, one might expect that patient with cytic fibroi (CF) may diplay accelerated retinal aging. Thi hypothei i baed on the pancreatic inufficiency in CF, even with replacement pancreatic enzyme therapy, that reult in decreaed carotenoid uptake. While a few report indicate ome compromied viual function in CF patient (that may be becaue of nutritional deficiencie other than carotinoid), the hypothei that CF patient may diplay accelerated retinal aging due to reduced macular pigment level ha not been teted. Thi tudy invetigated CF patient and age-matched control for: (1) plama carotenoid level; (2) optical denity and ditribution of macular pigment in the retina; and (3) viual performance including photopic contrat enitivity, color dicrimination and multifocal electroretinogram. Compared to age-matched control, both erum level of lutein and zeaxanthin and macular pigment in the retina were ignificantly reduced in CF patient. Depite dramatic low level in erum and macular carotinoid (lutein and zeaxanthin) that are likely to have affected the tudy group for decade, CF patient did not have deficit of viion a might be expected from the hypothei that macular pigment protect the retina againt factor contributing to normal aging.—John L. Keltner