Comparison of Ultrasound Biometry with Optical Biometry for Measurement of Axial Length and Calculation of Intraocular Lens Power in Patients Undergoing Routine Cataract Surgery

Abstract

Background

The most common cause of visual impairment in adults is Cataract all over the world. Ultrasound biometry and optical biometry are two methods used to calculate the power of intraocular lens by measuring the axial length. To get good refractive results after surgery the exact estimation of intraocular lens power is very important.

Objective

To compare the axial length and intraocular lens power calculated by using ultrasound biometry and optical biometry in patients with cataract

Material & Methods

It was prospective, randomized control study comprising of 50 patients undergoing contract surgery in Eye Department of PIMS using non-probability consecutive sampling. Patients having traumatic or juvenile cataract, glaucoma, macular or retinal diseases, high myopes, corneal opacities or diseases, vitreal hemorrhages and uveitis were excluded. After taking informed written consent from patients biometry was performed using optical scan and ultrasound biometry (with appalation probe). Axial length and intraocular power calculated by both methods was recorded. SPSS 22 was used to analyze and enter the data.

Results

The mean axial length measurement by ultrasound of the patients’ eyes was 22.72±0.85 mm and by optical biometry was 22.67±0.86 mm. Similarly the mean intraocular lens power calculated by ultrasound was 20.60±1.56D and by optical was 20.51±1.51D. Optical and ultrasound method showed strong positive correlation in measurements of intraocular lens power and axial length of eyes, i.e. r=0.965 & 0.939 respectively.

Conclusion

The findings of this study suggested that optical biometry is good alternate of ultrasound in measurement of axial length and intraocular lens power of patients, as strong correlation exist between both techniques.