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Improvements to Phakometry Using Bessel Beams
Marwan Suheimat1, Dipesh Bhattarai, Hannah K Maher
11School of Optometry & Vision Science and Institute of Health & Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia 2School of Engineering and Information Technology, University of New South Wales, Canberra, Australian Capital Territory, Australia.*d.atchison@qut.edu.au.
A new Bessel beam phakometer improves Purkinje image brightness and interobserver repeatability for more accurate lens measurements. This advanced optical instrument enhances phakometry for better eye care insights.
Area of Science:
- Ophthalmology
- Optical Engineering
- Biomedical Optics
Background:
- Phakometry, crucial for assessing lens parameters, traditionally suffers from low visibility of the third Purkinje image.
- Bessel beams offer unique properties like diffraction resistance and self-reconstruction, making them promising for optical instrumentation.
Purpose of the Study:
- To evaluate a novel Bessel beam phakometer.
- To compare its performance against a conventional phakometer regarding Purkinje image brightness, accuracy, and repeatability.
Main Methods:
- Developed a phakometer utilizing Bessel beams with a telecentric imaging system.
- Captured anterior cornea, anterior lens (PIII), and posterior lens (PIV) Purkinje images.
- Assessed accuracy using a model eye and repeatability with human participants.
Main Results:
- The Bessel phakometer demonstrated comparable accuracy to manufacturer specifications for a model eye.
- Interobserver repeatability for key lens parameters (Ra, Rp, RI) was significantly improved (two times better) with the Bessel phakometer.
- Purkinje images (PIII and PIV) were approximately three times brighter using the Bessel beam approach.
Conclusions:
- The Bessel beam phakometer offers enhanced Purkinje image brightness and superior interobserver repeatability.
- It provides accurate lens parameter estimations, outperforming conventional methods in specific aspects.
- This technology holds potential for advancing ophthalmic diagnostics and research.
