Posters

Accuracy of toric IOL calculation depending on different keratometry values

Poster Details

First Author: M.Ramsauer GERMANY

Co Author(s):    M. Shajari   N. Luft   S. Vounotrypidis   S. Priglinger   W. Mayer        

Abstract Details

Purpose:

To compare different corneal parameters in the calculation of toric intraocular lenses: Total keratometry (TK) and standard K values obtained by a swept-source assisted biometry system (IOL Master 700, Zeiss, Germany) as well as Total Corneal Refractive Power (TCRP) obtained by a Scheimpflug device (Pentacam, Oculus, Germany).

Setting:

University Eye Hospital Munich, Germany

Methods:

Thirty-two eyes of 24 subjects who underwent toric intraocular lens implantation (Zeiss Torbi-709 or LISA tritoric-939) were included. Lens exchange was standardized performed with Zeiss CALLISTO eye tracking in patients with preoperative regular corneal astigmatism of at least 1.00 D. The expected postoperative residual refraction with the implanted lens was calculated depending on three different corneal parameters (K and TK using IOL Master 700 and TCRP using Pentacam). For all calculations, the Haigis-T formula was used using the EQ Workplace platform (Zeiss). The results were compared statistically with the postoperative refraction calculated according to the Harris dioptric power matrix.

Results:

The most accurate IOL calculation with the lowest prediction error yielded those based on the TK values of the IOL Master 700. By contrast, the prediction error in the IOL calculation with Pentacam’s TCRP was statistically significantly greater (Fig. 1). There was no statistically significant difference in the prediction error between standard K and TK values. The actual surgery significantly reduced the mean preoperative astigmatism of all patients from 2.35 cyl-D to 0.49 cyl-D.

Conclusions:

The most accurate refractive outcomes in toric IOL implantation are achieved by IOL calculations based on the TK values of the IOL Master 700. The IOL calculations based on the standard K and on the TCRP of the Pentacam resulted in a larger prediction error, although there is no statistically significant difference between the standard K and the TK values.

Financial Disclosure:

None