Obana Akira, Gohto Yuko, Tanito Masaki, Okazaki Shigetoshi, Gellermann Werner, Bernstein Paul S, Ohira Akihiro
Department of Ophthalmology, Seirei Hamamatsu General Hospital, Sumiyoshi 2-12-12, Naka-ku, Hamamatus City, Sizuoka, 430-8558, Japan,
Graefes Arch Clin Exp Ophthalmol. 2014 Aug;252(8):1221-8. doi: 10.1007/s00417-014-2574-x. Epub 2014 Mar 11.
Macular pigment is a defense system against phototoxic damage of the retina by visible light. It is still under debate whether or not macular pigment optical density (MPOD) levels decline with age, because the age effect varied depending on the technique used to measure MPOD levels. Resonance Raman spectroscopy (RRS) is an objective method to measure MPOD, and studies using RRS showed a drastic age-related decline of MPOD levels; however, since RRS measurements are influenced by cataracts, it has been argued that the age-related decline of RRS measurements is an artifact from lens changes in aged subjects. In the present study, MPOD levels were measured with RRS in pseudophakic eyes, and the effects of age and other factors on MPOD levels were investigated.
The subjects included 144 patients with no fundus disorders who received cataract surgery with untinted intraocular lens implantation. MPOD levels were measured in 144 eyes using integral RRS 1 day post surgery. Factors potentially associated with MPOD levels such as age, gender, smoking habits, body mass index, diabetes, glaucoma, axial length, pupil diameter, spherical equivalent refractive error, and foveal thickness were examined by multiple regression analysis.
The macular pigment RRS levels ranged from 776 to 11,815 Raman counts, with an average level of 4,375 ± 1,917 (standard deviation [SD]) Raman counts. Multiple regression analysis revealed that age and axial length were significantly correlated with low MPOD values (regression coefficient of -59 for age and -404 for axial length, respectively). No significant correlations were observed for other factors.
After removing the potentially confounding effect of age-related lens yellowing on the RRS measurements, age remained a significant patient parameter for lowered MPOD levels. MPOD levels were found to decline by more than 10 % each decade. Axial length was also a negative predictor of MPOD levels. Since the present study included only patients aged 50 years and older, the effects of age and other factors on MPOD levels for younger subjects remain unknown.
黄斑色素是视网膜抵御可见光光毒性损伤的防御系统。黄斑色素光密度（MPOD）水平是否随年龄下降仍存在争议，因为年龄效应因用于测量MPOD水平的技术而异。共振拉曼光谱（RRS）是一种测量MPOD的客观方法，使用RRS的研究表明MPOD水平与年龄相关的急剧下降；然而，由于RRS测量受白内障影响，有人认为RRS测量中与年龄相关的下降是老年受试者晶状体变化导致的假象。在本研究中，使用RRS测量了人工晶状体眼的MPOD水平，并研究了年龄和其他因素对MPOD水平的影响。
受试者包括144例无眼底疾病且接受了无色人工晶状体植入白内障手术的患者。术后1天使用积分RRS测量了144只眼的MPOD水平。通过多元回归分析检查了可能与MPOD水平相关的因素，如年龄、性别、吸烟习惯、体重指数、糖尿病、青光眼、眼轴长度、瞳孔直径、等效球镜屈光不正和黄斑中心凹厚度。
黄斑色素RRS水平在776至11,815拉曼计数之间，平均水平为4,375±1,917（标准差[SD]）拉曼计数。多元回归分析显示，年龄和眼轴长度与低MPOD值显著相关（年龄的回归系数为-59，眼轴长度的回归系数为-404）。未观察到其他因素有显著相关性。
在消除年龄相关晶状体变黄对RRS测量的潜在混杂效应后，年龄仍然是MPOD水平降低的一个重要患者参数。发现MPOD水平每十年下降超过10%。眼轴长度也是MPOD水平的一个负向预测指标。由于本研究仅纳入了50岁及以上的患者，年龄和其他因素对年轻受试者MPOD水平的影响仍不清楚。
