Performance of Conventional Biometry vs. Integrated Laser Interferometry with Keratometry Device in Intraocular Lens Measurement
Sabong Srivannaboon MD*, Morakot Tanehsakdi OD**
Affiliation : * Department of Ophthalmology, Siriraj Hospital, Mahidol University, Bangkok ** TRSC international LASIK Center, Bangkok
Objective : To compare the performance of the Conventional Biometry (CB) (Applanation Ultrasound and
Keratometry) and the Integrated Laser Interferometry with Keratometry Device (LI) in the measurement of
Intraocular Lens (IOL).
Materials and Methods : A prospective study of 100 eyes in 50 cataract patients was conducted. The IOL
measurement using the LI followed by the CB was done on all eyes. The keratometry (K), axial length (AL), IOL
power, and time required for both methods were compared in the same subject by ANOVA with repeated
measurement.
Results : The LI could not obtain the AL in 14%. There were 21% that the signal to noise ratio was below 1.6.
The AL obtained by the LI was significant higher compared to the CB by mean of 0.28 mm (p < 0.05). The K
showed no statistically significant difference (p = 0.05). There was statistically significantly higher IOL
power calculated by the LI compared to the CB by mean of 0.63 D (p < 0.05). The time required for the LI was
2.77 + 1.44 min and the CB was 9.63 + 3.82 min (p < 0.05).
Conclusion : The LI required less time than the CB in measurement of the IOL but could not measure the AL in
the group of patients with dense cataracts. The LI give a higher IOL power compared to the CB.
Keywords : Laser interferometry, Conventional biometry, IOL power
