Posters

Partial coherence laser interferometry and immersion ultrasonography in IOL optic power calculation in myopia patients

Poster Details

First Author: A.Tsygankov RUSSIA

Co Author(s):    K. Pershin   N. Pashinova   S. Legkih   Z. Afaunova           

Abstract Details

Purpose:

Evaluation of axial length and anterior chamber depth measurements accuracy with optical coherence biometry and immersion ultrasound, their impact on IOL calculation accuracy in patients with myopia.

Setting:

Eximer Eye Center, Moscow, Russian Federation

Methods:

An open prospective study included 34 patients (64 eyes) with myopia of varying degrees (the average AL 25.75 �Â�± 1.74 mm according to the immersion scanning and 25.85 �Â�± 1.76 mm over the PCI data) who underwent cataract phacoemulsification (n=42; 65.6%) or lensectomy (n=22; 34.4%) with IOL implantation. Group I includes cases with AL 24.1-25.9 mm (n=34) and group II - AL 26.0-30.6 mm (n = 30).

Results:

In Group I's AL mean value, determined by A-scan (24.98�Â�±1.15 mm) was not significantly different from that according to IOL-Master (25.02�Â�±1.20 mm). In the group with the axial length more than 26 mm mean value according to the A-scan (27.97�Â�±2.14 mm) was significantly lower than that of the IOL-Master (28.16�Â�±2.15 mm; p=0.042). No differences were observed when measuring the anterior chamber depth. Prediction error for the three planned refraction ranges (�Â�±0.5 �Â�±1.0 and �Â�± 1.5 diopters) was not significantly different between the groups (p>0,1).

Conclusions:

Ultrasound A-scan and optical biometry remain methods of choice for measuring the axial length and anterior chamber depth before cataract phacoemulsification. IOL-Master is characterized by high reproducibility and accuracy of AL measurements, despite comparable efficacy with A-scan in patients with myopia. Present study shows a greater precision of optical biometry with IOL optic power calculating formulas Barrett and Haigis compared with Hoffer-Q and Holladay II, but the differences were not statistically significant.

Financial Disclosure:

NONE