Prediction of Pseudophakodonesis After Uneventful Cataract Surgery

Cataract surgery ist the most often performed surgery worldwide and with increasing number of patients undergoing surgery, patients' expectations concerning postoperative optical outcomes are growing. In order to achieve an optimal outcome after cataract surgery an adequate intraocular lens (IOL) centration is essential, especially when premium IOLs like aspheric, toric or multifocal IOls are being implanted. This fact has to be kept in mind especially in patients with pseudoexfoliation syndrome (PXF) or with history of blunt ocular trauma, where decentration and subluxation of the IOL is more likely due to a higher incidence of zonular weakness and zonular dialysis.

Additionally, pseudophacodonesis - dangling of the IOL with eye movement - can occur. Decentration, tilt and dangling of the IOL may decrease visual acuity and contrast sensitivity and induce glare and subjective perception of image flickering. Because of the large amount of pseudophakic patients worldwide, decentered and dislocated IOLs may cause a relatively large public health care burden.

Additionally, IOL implantation in eyes with zonular pathology may be technically challenging. Several devices to improve IOL stability in demanding eyes have been developed and may be used in cases lacking sufficient zonular support, such as different capsular tension rings. Another option would be to use special surgical techniques like scleral fixation of the IOL.

In pseudophakic eyes, IOL tilt and decentration may be measured as an indicator for zonular stability. Several techniques have been used to measure IOL decentration and tilt, such as slitlamp examination, retroillumination photography, Scheimpflug imaging and the analysis of purkinje reflexes. Slitlamp examination is a subjective method that allows approximate decentration measurements, but no quantitative tilt measurements. For this measurement the pupil has to be dilated. Scheimpflug imaging also needs a sufficiently dilated pupil to make the optic edge and the posterior surface of the IOL visible. A recently developed purkinje meter was shown to be highly reproducible to assess IOL tilt and decentration. A new version of this purkinje meter can additionally acquire videos of eye movements. Analysis of these dynamic images can detect dangling or "wobbling" of the lens capsule and the IOL.

Patients within this study will be examined on two occasions. Only one additional visit will be necessary as the first examination will take place on the day of the routine pre-operative visit and all measurements will be non invasive. The results will lead to a better understanding of the long-term outcome after implanting IOLs in eyes with pseudoexfoliation syndrome or a ocular trauma.