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Comparative analysis of optical biometers based on partial coherence interferometry (PCI) versus optical low-coherence interferometry (OLCI): An office audit

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First Author: H.Bhullar CANADA

Co Author(s):    V. Bhambhwani                    

Abstract Details

Purpose:

To compare biometry measurements of IOLMaster 500 (Carl Zeiss), based on partial coherence interferometry (PCI) versus Aladdin (Topcon), based on optical low-coherence interferometry (OLCI)

Setting:

Retrospective study at a tertiary referral Ophthalmology centre in Ontario, Canada

Methods:

A retrospective analysis of records of patients presenting for cataract surgery at an Ophthalmology practice between October 2019 and March 2020 was done. All patients had biometry measurements on IOLMaster 500 and Aladdin. Data collected included patient demographics, clinical details, axial length (AL), mean keratometry (K), and anterior chamber depth (ACD) measurements. IOLMaster and Aladdin measurements were compared using unpaired t test and chi square test.

Results:

339 eyes (173 patients) were included (77M, 96F). IOLMaster 500 was unable to obtain measurements of AL, K, and ACD in 4, 5, and 14 eyes respectively; and Aladdin in 24, 21, and 15 eyes respectively. The differences for AL (1% vs 7%, p=0.0002) and for K (1.5% vs 6%, p=0.0009) were statistically significant. Advanced and central posterior subcapsular cataracts were most common responsible factors for not obtaining measurements. In eyes measured, mean AL, K, and ACD values for IOLMaster were 23.99±1.23mm, 43.82±1.78D, and 3.15±0.37mm respectively; and for Aladdin were 24.02±1.32mm, 43.85±1.74D, and 3.19±0.36mm respectively (differences not statistically significant).

Conclusions:

The IOLMaster 500 performed better in terms of number of eyes for which measurements were obtained compared to Aladdin, in our practice. This may be related to the high volumes of advanced cataracts that our practice caters to, being a tertiary referral centre. For eyes measured, the AL, K, and ACD values were comparable between the two biometers. The limitations of our retrospective study include possible differences between biometers with respect to order of testing and technician training.

Financial Disclosure:

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