Accuracy of IOL power calculation using ultrasound immersion

1. Sharita Siregar
2. Yudisianil
3. Johan Hutauruk

Cipto Mangunkusumo Hospital, Jakarta, Indonesia

Purpose
To increase the accuracy for ultrasound immersion biometry through A constant personalization

Methods
48 consecutive cataract operations were included in retrospective study with acrylic hydrophilic lens (US IOL) implantation. Intraocular lens power was calculated using ultrasound immersion (Axis II). The predictions were calculated using SRK-T method. All calculations were optimized in retrospect to account for systemic errors.Target refraction, intended refraction, and differences between both were measured.

Results
The difference between target and intended refraction in this study was -0.30. The number of predictions within ± 0.25 D, ± 0.50 D and ± 1.00 D of the expected outcomes was 29.16%, 56.25% and 85.41% using ultrasound.

Conclusions
The accuracy of IOL power calculation can be significantly improved using calibrated axial lentg readings and personalized A-constant. The recommend A constant for physiological eye in Indonesia is 117.3 using US IOL.