Posters

IOL optic power calculation in patients with eye axial length 24-28 mm without preceding refractive surgery

Poster Details

First Author: A. Tsygankov RUSSIAN FEDERATION

Co Author(s):    A. Tsygankov   N. Pashinova   S. Legkih              

Abstract Details

Purpose:

Analysis of effectiveness of IOL calculating formulas and frequency of intra- and postoperative complications of phacoemulsification in patients with eye axial length 24.0-28.0 mm.

Setting:

109147, Moscow, Marksistskaya str. 3/1, Excimer Eye Centre, kpershin@mail.ru

Methods:

The study included 39 patients (62 eyes) with varying degrees of myopia and axial length of the eye 24.0-28.0 mm. All patients carried out phaco (85.5%) or refractive clear lens exchange (14.5%) with IOL implantation after a comprehensive survey. Average follow-up was 15.1 ± 3.8 months. Patients are divided into two groups - with axial length 24.0-25.9 mm (n=38, group I) and 26.0-27.9 mm (n=24, group II). Calculation of IOL was performed according to the formula SRK/T, retrospective comparison - Hoffer-Q, Holladay II, Haigis and Barrett. Amount of surgically induced astigmatism was determined by the program SIA Calculator v.2.1.

Results:

The study analyzed functional results, mean numerical error and median absolute error of refraction (MAE) after phaco with IOL implantation. In Group I target postoperative refraction (±1.0 diopters in 95% of cases) met all the studied formulas. Refraction ±0,5 diopters using formulas SRK/T achieved in 92.3% of cases, Hoffer-Q – 84.1%, Holladay II – 91.,3%, Haigis – 86.5% and Barrett – 94.2% . In Group II formulas SRK/T, Haigis and Barrett corresponded to refraction ±1.0, with target refraction of ±0,5 diopters in 90% of cases, achieved only by using Barrett formula (91.5%). The value of SIA and frequency of intra- and postoperative complications were not significantly different.

Conclusions:

IOL power calculation in patients with eye axial length 24.0-25.9 mm is possible by using each of five formulas. For eyes with axial length 26.0-27.9 mm a significantly lower MAE when applying formulas Haigis (0.72±0.45) and Barrett (0.33±0.28) formulas is received, which indicates the high efficiency of these formulas, with the target refraction ±0,5 diopters in 90% of cases, achieved only by using Barrett formula.

Financial Disclosure:

NONE