Commentaires sur : Trifocal IOL – Cataract implant

Par : JC Kim

JC Kim — Tue, 24 Dec 2024 01:06:00 +0000

Hello Dr Gatinel. I am a South Korean opthalomolgist who is a big fan of your works.
Starting from this page, I have tried to understand the mathematical principles behind diffractive bifocal IOLs. However, combining two bifocal diffractive designs to achieve trifocality remains still elusive to me.
Specifically, in the above image titled « TRIFOCAL IOL DESIGN, » the lower trifocal design, if we ignore apodization, appears similar to a bifocal design. In this design, each triangle seems to have the same width corresponding to +3.5D. The only difference is the alternating heights, controlling the light distribution.
As shown in the image, if the initially wider triangle for +1.75D is cut in half and the base half is removed to incorporate the narrower +3.5D triangle, how can the remaining apex half still function to provide a +1.75D power with only half the original width?
Thank you.

Par : Dr Damien Gatinel

Dr Damien Gatinel — Fri, 16 Mar 2018 23:48:45 +0000

En réponse à Mahmoud Ebadi. Thanks, it appears to me that Kappa angle and pupil size do not really affect the performance of trifocal IOLs. It is important to perform an uneventful surgery, and control for astigmatism. If the cornea is irregular (trefoil and coma like aberration), the indication can be reconsidered. But otherwise the precautions and recommendations of these IOLs are the usual ones when it deals with cataract surgery and premimum multifocal implantation.

Par : Mahmoud Ebadi

Mahmoud Ebadi — Fri, 09 Mar 2018 13:52:01 +0000

Congratulations Dr. Gatinel on a very comprehensive and detailed presentation. I was wondering if you could comment on your recommendations for pupil size, Coma, Angle Kappa and any other parameters that you feel are necessary to consider in chosing the pts. for this trifocal IOL.
Thank you,