The Emmetropia Verifying Optical (EVO) Formula is an advanced intraocular lens (IOL) formula for cataract surgery. It is based on the theory of emmetropization and generates an ‘emmetropia factor’ for each eye. As a thick lens formula, it takes into account the optical dimensions of the eye, and can handle different IOL geometry and powers.
Instructions
- Use ULIB or IOLCon SRK/T A constant for optical biometry
- Select the appropriate IOL model for each specific IOL as calculations will differ
- Select ‘AR40e/E/M’ for J&J Vision AR40e, AR40E, AR40M IOLs
- Select ‘MA60MA’ for Alcon MA60MA, MA60AC, MN60AC IOLs
- Select ‘Tecnis’ for J&J AAB00 and other Tecnis IOLs not in dropdown list
- Select ‘Standard’ for other IOLs (eg. SN60WF, Bausch & Lomb, Hoya, Nidek, Zeiss)
The EVO Toric Formula is a toric IOL formula based on the EVO Formula. It combines theoretical posterior cornea astigmatism prediction, thick lens modelling for different types of toric IOLs, and a dynamically interconnected prediction of IOL power and toricity.
Instructions
- Select the appropriate model depending on the location of the IOL toric surface / IOL type
- Anterior (eg. Nidek Toric, RayOne Toric, RayOne EMV Toric)
- Bitoric (eg. Zeiss)
- Posterior (eg. Alcon, Hoya, Physiol, RayOne Trifocal Toric)
- Tecnis (for all Tecnis models not in dropdown list eg. ZMT)
Note: The EVO IOL calculator is solely intended for use with a pseudophakic IOL during cataract surgery and not for use with a refractive phakic IOL such as Staar Surgical’s EVO Visian ICL
EVO Formula — Disclaimer
The Emmetropia Verifying Optical (EVO) formula intraocular lens (IOL) calculator is to assist in the selection of IOL power for cataract surgery. It should be used in conjunction with comprehensive ophthalmological examination and diagnostic tests. The user must arrive at his or her own decision in IOL power selection and is solely responsible for the treatment of his or her patient. The information provided is without warranty of any kind, expressed or implied. It is not meant to serve as medical or surgical instruction. The user assumes all risks and responsibilities when using the calculator for IOL power selection. Dr Tun Kuan Yeo, or anyone connected to the website is not liable for any damages arising from the use of information provided, and the user assumes the entire costs of any damages, direct or indirect, arising from the use of the calculator. Copyright of all contents of this website is held by Dr Tun Kuan Yeo and its material may not be used, reproduced or copied without prior consent. The EVO formula IOL calculator is based on intellectual property of Dr Tun Kuan Yeo and the user may not copy, reproduce, disassemble or decompile the calculator.
EVO Toric Formula — Disclaimer
The Emmetropia Verifying Optical (EVO) formula toric intraocular lens (IOL) calculator is to assist in the selection of IOL and toric power for cataract surgery. It should be used in conjunction with comprehensive ophthalmological examination and diagnostic tests. The user must arrive at his or her own decision in IOL and toric power selection and is solely responsible for the treatment of his or her patient. The information provided is without warranty of any kind, expressed or implied. It is not meant to serve as medical or surgical instruction. The user assumes all risks and responsibilities when using the calculator for IOL and toric power selection. Dr Tun Kuan Yeo, or anyone connected to the website is not liable for any damages arising from the use of information provided, and the user assumes the entire costs of any damages, direct or indirect, arising from the use of the calculator. Copyright of all contents of this website is held by Dr Tun Kuan Yeo and its material may not be used, reproduced or copied without prior consent. The EVO formula toric IOL calculator is based on intellectual property of Dr Tun Kuan Yeo and the user may not copy, reproduce, disassemble or decompile the calculator.
The EVO formula and EVO toric formula were developed by Dr Tun Kuan Yeo. Dr Yeo is a Senior Consultant Ophthalmologist at Eye & Retina Surgeons and is the former head of the Cataract, Implant and Anterior Segment service at Tan Tock Seng Hospital in Singapore. Dr Yeo is a member of the IOL Power Club and International Intraocular Implant Club. His main research interests are in complex cataract surgery, intraocular lens formula, biometry and lens design.
Dedication
I dedicate my work to my dear wife Li Yanan who is the light of my life, my ever-present pillar of support and my eternal soulmate. I love her completely with all my heart.
Suggestions and feedback can be emailed to: feedback.evoiolcalculator@gmail.com
