Abstract
Purpose: :
Removal of the crystalline lens by cataract surgery enhances the exposure of the phototoxic short wavelength blue-light to the retina, and could be a risk factor of the development of age-related macular degeneration (AMD). Recently, yellow tinted intraocular lenses (IOL) that absorb blue-light have been recommended for the protection of the retina from phototoxic blue-light. On the other hand, human retina contains macular pigments that absorb blue-light and contribute to the protection from phototoxic damage. Macular pigment optical density (MPOD) changes with aging and AMD, but the change in pseudophakic eyes has not yet been investigated. We quantified MPOD in patients who had implantation of either a clear IOL or yellow IOL.
Methods: :
Implantation of clear IOL (SA60AT, Alcon) or yellow IOL (SN60AT, Alcon) were performed in 117 and 125 eyes, respectively. MPOD was measured by resonance Raman spectrophotometry at day 1,4,7,14 and month 1,2,3,4, and 6 after surgery under the approval of our hospital IRB. All subjects signed informed consent forms that complied with the tenets of the Declaration of Helsinki. Eyes with poor (<0.8) post-operative visual acuity and any fundus diseases were excluded. The difference in MPOD between both IOL groups was analyzed by repeated-measurement MANOVA, and factors associated with MPOD were analyzed by multiple regression analysis.
Results: :
MPOD in the clear IOL group declined with time (p=0.0003, MANOVA). MPOD was significantly lower in clear IOL group than in yellow IOL group 6 months after surgery (p<0.05). Age and pre-operative myopic refractive error correlated significantly with low MPOD level (p<0.05) in the first month. Diabetes correlated significantly with low MPOD (p<0.05) later than three months after surgery.
Keywords: macular pigment • intraocular lens • oxidation/oxidative or free radical damage