Posters

Pupil shape, size and centroid changes associated with clear-cornea cataract surgery

Poster Details

First Author: C.Roussou GREECE

Co Author(s):    A. Kanellopoulos   I. Kontari           

Abstract Details

Purpose:

To compare postoperative changes in apparent photopic and mesopic pupil size and centration in relation to cornea reflection landmarks following cataract surgery.

Setting:

LaserVision.gr Clinical and Research Eye Institute, Athens, Greece

Methods:

Prospective study of 80 eyes subjected to cataract surgery. Patient age 70.6±10.3 years. Pre-operatively and one-month post-operative pupil imaged by infrared camera auxiliary to corneal topography system (Vario, WaveLight, Germany). Digital analysis implemented on pupil images investigated the Cartesian coordinates (nasal – temporal, horizontal axis, and superior-inferior, vertical axis) of the first Purkinje reflection point, approximating the corneal intersection of the visual axis (corneal vertex), to the pupil geometric center, approximating the corneal intersection of the line of sight (corneal apex). Pupil size changes were investigated and vertex to apex shift changes were associated with postoperative pupil centroid shift.

Results:

XØ was reduced by -0.27±0.22mm (-9.7%), and YØ by -0.32±0.24mm (-11%) (both p<0.05). Eccentricity was reduced by -0.10±0.11 (-39.56%) (p<001). The pupil size (diameter) change corresponded to a relative reduction by -9.8 % for the photopic and to -9.1% for the mesopic pupil, with a statistically significant difference (p 0.045 and 0.011, respectively). Additionally, there was a noted reduction in the centroid shift from an average (all eyes) of 0.12 mm pre-operatively to 0.05 mm post-operatively, as a result of the post-operative less temporal horizontal difference between the corneal vertex and the apex.

Conclusions:

Cataract extraction surgery appears to affect pupil size and centration. Specifically, a smaller pupil size and a less temporal shift was recorded. These data may have clinical reference in targeted intraoperative IOL centration. FINANCIAL DISCLOUSRE: One or more of the authors travel has been funded, fully or partially, by a company producing, developing or supplying the product or procedure presented