Abstract
Purpose:
To compare axial length measurements of cataractous eyes between a classic A-scan ultrasound device (DGH 5100E) to two next generation devices, a newer A-scan ultrasound device (DGH 6000) and a partial coherence interferometry device (IOLMaster 500).
Methods:
We performed a retrospective review of axial lengths of cataractous eyes prior to undergoing surgery. Two A-scan ultrasound devices and one partial coherence interferometry (PCI) device were used to measure axial lengths on the same patient with cataractous eye(s) on the same day. The non-contact method, PCI, was used first followed by the two contact methods, classic and newer A-scan ultrasound. Axial lengths for all three devices were recorded and analyzed using paired t-test. Mean, mean difference, standard deviation, and p-values for comparisons of PCI versus classic A-scan ultrasound, and newer A-scan ultrasound versus classic A-scan ultrasound were reported.
Results:
The axial lengths of 79 cataractous eyes (46 patients) were measured with the classic A-scan ultrasound and PCI. A subset of 14 eyes of 13 patients was measured for axial lengths using the newer A-scan ultrasound. The mean axial lengths were 24.14 mm (classic A-scan ultrasound), 24.29 mm (PCI), and 23.85 mm (newer A-scan ultrasound). There was statistical significance between PCI versus classic A-scan ultrasound (mean difference=0.15 mm, standard deviation=0.25 mm, p-value < 0.01). There was no statistical significance between newer A-scan ultrasound versus classic A-scan ultrasound (mean difference=0.09 mm, standard deviation=0.18 mm, p-value =0.07).
Conclusions:
When comparing the classic A-scan ultrasound system, the PCI system provided longer axial length while the newer A-scan ultrasound provided shorter axial length. There was statistical significance between axial lengths provided by PCI and classic A-scan ultrasound. There was no statistical significance between the newer A-scan ultrasound and classic A-scan ultrasound.
Keywords: 445 cataract •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) •
465 clinical (human) or epidemiologic studies: systems/equipment/techniques