Inverse relationship between macular pigment optical density and axial length in Chinese subjects with myopia

Macular pigment (MP) has been the focus of much attention in recent years, due to its protective effect against macular degenerations. In this study, we investigated the association between macular pigment optical density (MPOD) and axial length (AL) in Chinese subjects with myopia. In total, 173 myopes (mean spherical equivalent [MSE] a parts per thousand currency signaEuro parts per thousand-1.00D) were recruited for this prospective observational study. MPOD was measured in both eyes of each subject using a macular metrics densitometer. AL was measured in eyes using an IOL-Master. A raw coefficient of correlation analysis and a partial correlation analysis were used to investigate the relationship between MPOD and AL. The age of the subjects ranged from 18 to 67 years. The overall mean MPOD for the cohort was 0.412 +/- 0.119 (range, 0.105-0.812). The mean AL was 25.18 +/- 1.08 mm (range, 23.14-28.19 mm). Using a raw coefficient of correlation, a significant inverse correlation was found between MPOD and AL (r = -0.134, p = 0.012). When using a partial correlation analysis to eliminate the impact of covariant, a significant inverse correlation was also found between MPOD and AL (r = -0.142, p = 0.008). Furthermore, when AL was divided into two groups: AL > 26 mm and AL a parts per thousand currency signaEuro parts per thousand 26 mm, a significant inverse correlation was observed between MPOD and AL in the former (r = -0.253, p = 0.029), but no significant relationship was observed between these in the latter (r = 0.104, p = 0.067). MPOD correlated inversely with AL in this sample of Chinese subjects with myopia.