Posters

The optimization of the Haigis formula using IOLMaster

Poster Details

First Author: R.Higa JAPAN

Co Author(s):    H. Uozato   K. Inoue   M. Wakakura        

Abstract Details

Purpose:

To assess the optimization of intraocular lens constants for the Haigis formula using IOLMaster500.

Setting:

Inouye Eye Hospital, Tokyo, Japan

Methods:

Data for SN6CWS (Alcon) implanted 480 eyes of 356 patients (group for optimization : 300 eyes of 226 patients, group for postoperative refractive error analysis : 180 eyes of 130 patients) was analyzed. At first, manufacturer's lens constant for SN6CWS was manually inputted on IOLMaster500 (Ver.7.5.2), and converted automatically to three constants for the Haigis formula (a0=1.110, a1=0.4, a2=0.1). Next, 33 eyes (11 eyes for each short, standard, long axial length) were picked out randomly from the group for optimization, and used for optimization for the Haigis formula（a0, a1, a2）started from the converted constants value. The optimization was executed with each phase of 33, 50, 75, 100 eyes, and every 50 eyes over 100. The post-operative refractive error was analyzed with the group for post-operative analysis based on the estimated post-operative refraction calculated by each phases' optimized lens constants.

Results:

Variation of the amount of three optimized constants was changed smaller over 75 eyes. The post-operative refractive error was observed to be hyperopic in converted value, and the constants optimized with 33 eyes, however the post-operative error produced by the constants optimized with each phase over 50 eyes had no significant difference. The accuracy of calculation by all three constants for post-operative estimation was higher than by the constants optimized only for a0.

Conclusions:

At least over 50 eyes are needed for optimization lens constants using IOLMaster 500 for the Haigis formula to achieve a certain level of post-operative outcome. FINANCIAL INTEREST: NONE