Comparing Ultrasound Biometry with Partial Coherence Interferometry for Intraocular Lens Power Calculations: A Randomized Study
Simon Raymond 1,
Ian Favilla 1,
and
Linda Santamaria 2*
1 Department of Surgery, Monash University, Clayton, Victoria, Australia; Ophthalmology Unit, Southern Health, Clayton, Victoria, Australia
2 Department of Surgery, Monash University, Monash Medical Centre, Level 5, Block E, Clayton, Victoria, 3165, Australia; Ophthalmology Unit, Southern Health, Monash Medical Centre, Clayton, Victoria, 3165, Australia
* To whom correspondence should be addressed. E-mail: linda.santamaria{at}med.monash.edu.au.
 |
Abstract |
|---|
PURPOSE. To determine whether intraocular lens (IOL) power calculations for cataract surgery as measured by postoperative refractive error using partial coherence interferometry (PCI) are more accurate in improving postoperative outcomes than ultrasound biometry (AUS).
METHOD. A double-blind randomized controlled trial consisting of 205 patients was undertaken by the Southern Health Ophthalmology Unit, Victoria, Australia. Mean absolute postoperative refractive error (MAE) represented the dependent variable; the biometric technique (PCI; AUS) employed to determine the IOL power to be implanted in the surgical eye represented the independent variable. An intention-to-treat analysis was used to prevent loss of randomization caused by the effects of cross-over and drop-out.
RESULTS. The MAE of patients implanted with PCI-calculated IOLs was 0.40 dioptres (D) ± 0.37 D standard deviation (SD), 95% CI (0.32 D - 0.48 D) compared to 0.45 D ± 0.41 D (SD), 95% CI, (0.36 D - 0.54 D) for patients implanted with AUS-calculated IOLs. There was no statistically significant difference between the MAE of patients implanted with PCI-calculated IOLs compared to patients implanted with AUS-calculated IOLs on analysis of best possible outcomes, t(167) = 1.0, p = 0.315.
CONCLUSION. This trial demonstrated that the calculation of IOL power based on ocular axial length measurement using PCI technology provided no clinical advantage over conventional applanation ultrasound as measured by postoperative refractive outcome.
Key Words:
cataract surgery, clinical trial, ultrasound biometry, partial coherence interferometry, intention-to-treat analysis
