Effects of intraocular lens malposition on binocular single vision in bilaterally pseudophakic patients

To investigate the relationship between intraocular lens (IOL) malposition and quality of binocular single vision following uncomplicated extracapsular cataract extraction and posterior chamber IOL implantation.

Fifty-two bilaterally pseudophakic patients were included. The main outcome measures were visual acuity, stereoscopic acuity, horizontal and vertical amplitudes of fusion and heterophoria, tilting angle and decentration amount of the pseudophacos and summation of these values in somewhat vectorial manner to define the total decentration and tilt of IOLS.

The mean total horizontal decentration was 0.19 mm and vertical decentration was 0.90 mm, mean total horizontal tilt being 1.55 degrees and vertical tilt 7.52 degrees. The mean stereoscopic acuity was found to be 1020 seconds of arc. Although the stereoscopic acuity threshold increased as decentration and tilt of IOLS increased, only the horizontal tilt was found to be statistically significantly correlated with stereoscopic acuity (pc0.01).

The quality of binocular single vision may be affected by IOL malposition in pseudophakic patients. Therefore, when an IOL implantation is planned, the most appropriate IOL design and surgical technique causing least decentration and tilt should be preferred.