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Inter-patient comparison of angle kappa in pseudophakic eyes
Session Title: IOL Technology
Session Date/Time: Sunday 06/10/2013 | 16:30-18:30
Paper Time: 17:58
Venue: Auditorium (First Floor)
First Author: : L.Bogdan AUSTRIA
Co Author(s): : N. Hirnschall M. Weber P. Draschl J. Wiesinger O. Findl
Epidemiological analysis of angle kappa (angle between line of sight and pupillary axis) in pseudophakic patients and its prediction.
Vienna Institute for Research in Ocular Surgery,Department of Ophthalmology,Hanush Hospital,Vienna, Austria
n this continuous cohort study, patients were included, who underwent cataract surgery 3 months prior to recruitment. In all patients Purkinje meter measurements were performed using a novel modified Purkinje meter. This device is based on capturing and recording Purkinje images of a semicircular ring of LEDs. The distance from the center of the pupil to each Purkinje image was obtained. These data were used to measure the angle between the line of sight and the pupillary axis. Additionally, Hartmann Shack sensor measurements (WASCA, Carl Zeiss Meditec AG, Germany) were performed.
In total, data of 350 eyes of 350 pseudophakic patients were included. Mean age of all patients was 68.2 years (SD: 8.7). Mean angle kappa was 5.6° (SD: 2.4). In general an angle kappa between 0.3° and 12.7° was observed. Mean tilt and decentration of the IOLs was 3.8° (SD: 2.1) and 0.4 mm (SD: 0.2), respectively. A partial least squares regression model to predict angle kappa using conventional optical biometry will be presented. Additionally, the influence of angle kappa on the post-operative higher order aberrations will be presented.
Typically, we measure tilt and decentration only relative to the pupillary axis, assuming that kappa is similar for all patients. But, as this study shows, inter-patient deviation of angle kappa is large.