Abstract
Abstract: :
Purpose:The aim of the study is to determine the correlation between apparent accommodation in pseudophakes after implantation of posterior chamber intraocular lens and factors such as pupillary diameter, corrected visual acuity, refractive error and corneal astigmatism. The study also compared horizontal vergence in bilateral pseudophakes and age matched phakic subjects for distance and near. Methods:: the study group comprised of 30 bilateral pseudophakic subjects with posterior chamber intraocular lens implants in the age range of 40- 55 years (Mean = 52.3 years) and control group comprising of 15 phakic subjects in the age group of 40-55 years (Mean = 52.8 years). The amplitude of accommodation was measured monocularly by the push-up method in all the subjects.Beren's prism bar was used to assess the positive fusional vergence and negative fusional vergence for both distance and near. Results:The mean accommodative power in 15 phakic subjects was 2.37+/-1.48D.The mean apparent accommodation was 1.98+/-0.81D .The smaller the pupil size ,the greater the apparent accommodation(p<0.005).There was no significant correlation between apparent accommodation and corrected visual acuity ,refractive error and corneal astigmatism.The mean Base Out vergence findings in psuedophakes was less than that of the control group.The vergence findings was also less than Morgan's standards in all directions except for distance Base In findings. Conclusion:From this study it is seen that Apparent accommodation in psuedophakes is less than that in phakics.Thus it can be concluded that improper prescription of add can therefore hinder near vision as the working distance is affected. Since the Base Out findings for distance and near is less than that of the control group,for comfortable binocular vision in psuedophakes ,it is essential for the practitioner to consider the vergence components also.
Keywords: 304 accommodation • 617 vergence • 310 aging: visual performance