To investigate the results using the OQAS and the Pentacam in cataract patients classified according to the type of lens opacity.

The present study included 124 eyes of 92 patients who had cataract surgery at Seoul St. Mary's Hospital from December 2011 to January 2012 and were classified into nuclear, cortical, and posterior subcapsular cataract patients. The lens opacity was determined with OSI, MTF, Strehl ratio, width 10%, width 50% and the opacity of Scheimpflug image by the OQAS and the Pentacam. Additionally, the correlation between subjective cataract classification and objective opacity value was analyzed.

The nuclear cataract group showed a 6.40 ± 2.41 OSI value and had high opacity. The cortical cataract group showed the highest MTF cut-off value (12.02 ± 6.19 C/deg). When evaluating Pentacam results, the posterior subcapsular cataract group had the lowest average level of lens opacity (9.12 ± 1.08) followed by in increasing order, the cortical cataract group (9.79 ± 1.67) and the nuclear cataract group (11.08 ± 1.84). The results were statistically significant ( p < 0.001). The OSI value of the OQAS was significantly correlated with nuclear and posterior opacity ( p = 0.049, p = 0.039, respectively) except cortical opacity ( p = 0.781). MTF and nuclear opacity showed statistically significant correlation and the lens opacity of Pentacam was correlated with nuclear and posterior opacities. In cortical cataract with severe peripheral opacity, the cortical opacity showed significant correlation with Maximum.

The OQAS and Pentacam results showed high correlation with the nuclear and posterior opacities which can be useful for cataract surgery.