Influence of Scheimpflug corneal tomography parameters on refractive astigmatism and visual acuity in patients with keratoconus

Session Details

Session Title: Anterior Segment Imaging II

Session Date/Time: Tuesday 25/09/2018 | 08:00-10:30

Paper Time: 09:50

Venue: Room A4

First Author: : M.Sommer AUSTRIA

Co Author(s): :    M. Nitsche-Resch   A. Kollenc   W. Glatz   M. Shajari   G. Steinwender        

Abstract Details

Purpose:

To evaluate the influence of Scheimpflug-derived corneal tomography parameters on refractive astigmatism (RA) and corrected distance visual acuity (CDVA) in treatment-naive keratoconus eyes.

Setting:

Department of Ophthalmology, Medical University Graz, Austria

Methods:

Scheimpflug measurements (Pentacam) and medical records of treatment-naïve eyes of patients who have been diagnosed with keratoconus between 2008 and 2017 were retrospectively analyzed. Eyes were excluded if the obtained Scheimpflug tomography didn’t meet the quality criteria for further evaluation or if there was no sufficient data on refractive error and visual acuity available. Analyzed parameters included CDVA, RA, topographical astigmatism (TA), maximum anterior keratometry value (Kmax), minimum pachymetry (Pachymin), and the Belin-Ambrosio enhanced ectasia display D-value (BAD-D). The coordinates of Kmax and Pachymin were determined to calculate the distance between those points and the corneal vertex.

Results:

289 eyes were included in this study. RA was positively correlated to TA (r=0.525, p<0.001), BAD-D (r=0.442, pp<0.001), Kmax (r=0.435, p<0.001), and negatively correlated to Pachymin (r=0.298, p<0.001). There was no correlation of RA with the distances between the corneal vertex and Kmax and Pachymin, respectively. CDVA was positively correlated to BAD-D (r=0.612, p<0.001) and Kmax (r=0.614, p<0.001), and negatively correlated to Pachymin (r=0.476, p<0.001) and the distances between the corneal vertex and Kmax and Pachymin (r=0.303, r=0.267, p<0.001, respectively).

Conclusions:

While keratoconus severity (BAD-D, Kmax, Pachymin) showed an influence on visual acuity and refractive astigmatism, keratoconus localization (distances between corneal vertex and Kmax and Pachymin, respectively) only affected visual acuity but not refractive astigmatism.

Financial Disclosure:

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