Decentration measurements using the tangential curvature topography and Scheimpflug tomography pachymetry difference maps after small incision lenticule extraction procedure

Session Details

Session Title: Presented Poster Session: Keratorefractive Surgery Results II

Venue: Poster Village: Pod 2

First Author: : D.Kang SOUTH KOREA

Co Author(s): :    H. Lee   E. Kim   T. Kim   J. Choi   S. Park           

Abstract Details

Purpose:

To investigate the agreement of decentration measurements between tangential curvature topography and pachymetry difference maps following small-incision lenticule extraction (SMILE) procedure

Setting:

Yonsei University College of Medicine and Eyereum Eye Clinic, Seoul, South Korea

Methods:

Decentrations and pupillary offset (angle kappa) were analyzed and compared in 155 eyes(155 patients) using two different methods. A difference map of the tangential curvature was generated with a Keratron Scout and a pachymetry difference map was generated with the Pentacam system for each eye, using preoperative and 3-month postoperative scans. Decentrations were also compared using a vector difference plot for the two maps

Results:

Magnitude of decentration was 0.27 ± 0.17 mm (range: 0.02 to 0.88 mm) with the tangential curvature difference maps and 0.26 ± 0.20 mm (range: 0.00 to 0.91 mm) with the pachymetry difference maps, showing no significant difference in the arithmetic values of decentration (P = 0.124). However, the vector difference in pupillary offset between pre and post-operative measurements from the pachymetry difference map significantly correlated with the magnitude of vector differences of decentration between the two maps (P = .007). The vector difference plot also showed a wide distribution spread to all four quadrants, demonstrating a lack of agreement.

Conclusions:

Although there was no significant difference between the scalar magnitude of decentration with the tangential topography difference maps and pachymetry difference maps, the vector differences do not agree and increasing error is present with increasing differences pupillary offset in the pachymetry difference maps

Financial Disclosure:

... receives consulting fees, retainer, or contract payments from a competing company