Evaluation of intraocular lens position and retinal shape in negative dysphotopsia using high resolution MRI

PURPOSE Assessment of potential relationships of intraocular lens (IOL) position and retinal shape in Negative Dysphotopsia. SETTING Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands. DESIGN Case-control study. METHODS High-resolution ocular MRI scans were performed in thirty-seven patients with negative dysphotopsia (ND) and twenty-six pseudophakic controls and used to determine the displacement and tilt of the in-the-bag IOL with respect to the pupil and iris. Additionally, anterior segment tomography was used to assess the iris-IOL distance. Furthermore, the retinal shape was quantified from the MRI-scans by fitting an ellipse to the segmented inner boundary of the retina. Both the IOL position and retinal shape were compared between groups to assess their potential role in the etiology of ND. RESULTS The average displacement and tilt of the IOL were below 0.1 mm and 0.5 degrees, respectively, in both groups and all directions. The corresponding average iris-IOL distance was 1.1 mm in both groups. Neither of these values differed significantly between groups (all p-values > 0.6). The retinal shape showed large variations but was not significantly different between the groups in both the left-right (p=0.10) and the anterior-posterior (p=0.56) direction. CONCLUSIONS In this study, we showed that the in-the-bag IOL position and retinal shape are not significantly different between patients with ND and the general pseudophakic population. Given the large variation in retinal shape between subjects, however, it could still be an important factor in a multifactorial origin of ND.