Abstract
Purpose: :
To determine macular pigment optical density (MPOD) using heterochromatic flicker photometry in young healthy Asian Indian eyes and to investigate its correlation with foveal threshold sensitivity and objectively measured optical quality.
Methods: :
We determined MPOD using the Tinsley macular pigment densitometer (Tinsley Ophthalmic, Surrey, UK) which measures macular pigment absorption density using the log sensitivity to 460nm light for the fovea and parafovea after normalizing with respect to 540nm. Foveal threshold sensitivity was measured using the macular integrity assessment (MAIA) microperimeter (CenterVue, Padova, Italy) using the central 10 degree (37 stimuli) field of testing centered at the fovea. Optical quality indices [Modulation transfer function (MTF), Strehl ratio (SR) and Optical scatter index (OSI)] were obtained from the optical quality assessment system (Visiometrics, Terrassa, Spain) based on the double-pass technique that provides an objective measurement of the optical quality of the eye.
Results: :
50 eyes (25 subjects) were analyzed (15 males and 10 females); mean age was 26.28 ±5.8 (range, 20-35) years. The mean MPOD was 0.42 ± 0.10 and the mean foveal threshold sensitivity was 30.72 ±1.56. The mean MTF was 42.61±11.2, mean strehl ratio was 0.24±0.06 and mean OSI was 0.42 ± 0.24. MPOD correlated poorly with foveal threshold (r=0.179, p=0.21). MPOD also showed poor correlation with the optical quality indices [MTF(r=0.2, p=0.160; SR(r=0.09, p=0.51); OSI(r=-0.140, p=0.33)].
Conclusions: :
MPOD appears to have poor correlation with foveal threshold sensitivity and optical quality measures.
Keywords: macular pigment • optical properties • perimetry