AIM: To validate Pentacam System and the Optical Quality Analysis System II(OQASII)serve as auxiliary tools to assess lens opacity and help select the optimal time for surgery.

METHODS: The patients with age-related cataract were recruited, patients who had any abnormality with cornea or fundus were excluded. Objective scatter index(OSI)and modulation transfer function(MTF)cut-off were acquired by the Optical Quality Analysis System II(OQASII)with dilated pupil after the best corrected visual acuity(BCVA)was obtained. The pupillary regional density of anterior cortex, lens nucleus, posterior cortex was measured via a Pentacam Scheimpflug System(Oculus, Wetzlar, Germany). Correlation analysis was applied to determine the relationship between these parameters. Multiple linear regression relationships were analyzed between the regional lens densities and OSI, MTF, BCVA.

RESULTS:Sixty-nine patients(108 eyes)were studied. Both nuclear and cortical lens density were significantly correlated with the OSI, MTF cut-off and BCVA. The correlation between lens opacities(anterior cortex and nucleus)and OSI/MTF was stronger than that between lens opacities and BCVA. By analyzing multiple linear regressions, OSI had the largest relevance with all regional opacities while maximum density had larger relevance than average density in every parameter. Maximum nuclear density weighted most in both OSI and MTF equations, whereas average cortex density raised weight in MTF and BCVA equations.

CONCLUSION: Any local opacity in the lens, including anterior cortex, nucleus and posterior cortex, could impact both visual quality(VQ)and visual acuity(VA). Nuclear density had the most influence on OSI and MTF, followed by cortical opacity. OQAS II analyzer ought to be provided as an auxiliary pre-surgery tool for mixed cataract with cortical and nuclear opacities since OSI was discovered to be the most sensitive parameter to lens opacities.