Contrast sensitivity function in pseudophakics and aphakics.

PURPOSE: To study the effect of posterior chamber intraocular lenses and aphakic spectacles on contrast sensitivity.

METHODS

Contrast sensitivity was evaluated in 20 patients in each group of pseudophakics with post chamber IOL (group I), aphakics with spectacle correction (group II), and age and sex-matched normal subjects (group III) using the Pelli-Robson chart.

RESULTS

The mean values of log contrast sensitivity in pseudophakics (1.665+/-0.105) and aphakes with spectacle correction (1.5075+/-0.1) were found to be statistically significantly low (t: 5.186, p < 0.001; t: 11.302, p < 0.001, respectively) as compared to the mean value of normal phakic subjects (1.8075+/-0.0576). Further, mean values of log contrast sensitivity in aphakes with spectacles correction were also found to be statistically significantly low (t: 4.727, p < 0.001) when compared to that in pseudophakes.

CONCLUSION

From observations of the present study, it can be concluded that posterior chamber IOL implantation offers an added advantage of higher contrast sensitivity, over and above the well documented advantages of increased field of vision, negligible effect on image size and elimination of prismatic effect and spherical aberration of thick glasses.