Abstract
Abstract: :
Purpose: Axial length (AL) measurement in silicone oil–filled eyes using ultrasound biometry is not always accurate. An alternative to ultrasound applanation, Laser Doppler Interferometry (LDI) is a non contact optical method that uses partial coherent interferometry to measure AL. To assess the accuracy of LDI in measuring axial length in silicone oil–filled eyes and to compare LDI AL–measurements to B–scan AL–measurements after silicone oil removal. Methods: Optical Biometry (IOL Master®, Carl Zeiss Meditec) was performed in 35 consecutive eyes scheduled for silicone oil removal, both before and after the surgical procedure. In addition, B–scan ultrasound biometry was performed 1 to 4 weeks after removal of the silicone oil. Eyes with recurrent retinal detachment at the time of the postoperative biometry were excluded. Results: Axial length was measured in 30 eyes using LDI. The mean AL ±SD of the silicone oil–filled eyes and silicone oil–free eyes were respectively 25.86 ±3.93mm and 25.36 ±3.95mm. The mean difference in LDI axial length measurement between eyes with and without silicone oil tamponade was 0.42 mm. Axial length measurements was slightly longer in the silicone oil–filled state. This difference was not statistically significant. There was also no significant difference between data obtained using B–scan and LDI. Conclusions: Laser Doppler Interferometry is useful to accurately measure axial length in silicone oil–filled eyes, particularly in phakic eyes where silicone oil removal can be combined with phacoemulsification and intraocular lens implantation.
Keywords: imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)