Abstract
Purpose: :
Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. Accumulation of A2E, a major fluorophore of lipofuscin in human retinal pigment epithelium is reported to be one of the causative factors in the pathogenesis of AMD. The accumulated a2e acts as photo-sensitizer causing damage and photoreceptor cell death in the macula leading to vision loss. Dietary rich intake of macular xanthophylls is reported to protect macula from blue light induced oxidative damage. Therefore, the present study was undertaken to elucidate the relationship between macular xanthophylls and A2E in normal aging Indian donor eyes.
Methods: :
Donor eyes (above 40 yrs; N=45) obtained after the removal of cornea for transplantation were collected from the Lions' International Eye Bank of our hospital with prior approval from the Standing Institute Human Ethics Committee. Macular portion of neural retina and retinal pigment epithelium was dissected out using 8mm punch. Macular xanthophylls were estimated in neural retina by HPLC and A2E in retinal pigment epithelium using LC/MS/MS.
Results: :
The mean (+/- SEM) macular lutein and zeaxanthin concentration of donors in the age group of 40-60 yrs was found to be 0.39 +/- 0.08 and 0.26 +/- 0.04 ng / mg tissue respectively. The aged donor eyes (60-80 yrs & > 80 yrs) showed significantly high concentration of lutein (60-80 yrs group: 0.65 +/- 0.12 & > 80 yrs group: 0.61+/-0.16 ng /mg) and zeaxanthin (60-80 yrs group: 0.44+/-0.04 & > 80 yrs group: 0.41+/- 0.07 ng / mg) as compared to 40-60 yrs donors group. Interestingly, the older age group donors showed significant accumulation of A2E (85%) as compared to 40-60 yrs age group donors.
Conclusions: :
A positive correlation was observed between the macular lutein and A2E levels in normal aging Indian donor eyes. Considering this observation, further studies are required to evaluate this relationship in the pathogenesis of AMD in our population
Keywords: age-related macular degeneration • carotenoids/carotenoid binding proteins • macular pigment