Refractive index modification of intraocular lenses with femtosecond laser action

Session Details

Session Title: Training and Innovation

Session Date/Time: Tuesday 10/10/2017 | 16:30-18:00

Paper Time: 17:36

Venue: Room 4.4

First Author: : K.Bacharis GREECE

Co Author(s): :    I. Tsilikas   A. Konstantinou   E. Ntoumou   I. Sianoudis   M. Makropoulou   A. Serafetinidis     

Abstract Details

Purpose:

Our goal is to modify non-invasively the refractive power of an already implanted intraocular lens (IOL) in situ with laser. In this work, experimental studies on the effect of ultra-short laser radiation on IOL polymer refractive capacity, as a method to refractive index tuning technique for IOLs customization, will be presented. Also, a possible photo-induced mechanism is discussed.

Setting:

1. National Technical University of Athens (NTUA), School of Applied Mathematical and Physical Sciences, Department of Physics, Zografou Campus, Gr-157780, Athens, Greece. 2. Technological Educational Institute (TEI) of Athens, Department of Optics & Optometry, Egaleo Gr-12210, Athens, Greece.

Methods:

Laser - IOL interaction experiments were performed on commercially available hydrophobic and hydrophilic acrylic IOLs, applying different pulsed laser radiation parameters. The laser source was a Ti:Sapphire laser at λ= 800nm, pulse width tp=48 fs, frequency=85 MHz and mean power P= 360 mW. The morphology of the ablated IOL surface and quantitative measurements of the refractive index were examined at various settings of laser pulses, different focal length and laser fluencies. Quantitative measurements of the refractive index were performed by measuring the IOLs power with a focimeter.

Results:

The experimental results of refractive power value changes after fs laser irradiation show a linear behavior with laser intensity. The effect of IOLs surface morphology after exposure to NIR fs laser radiation was also investigated.

Conclusions:

Our first preliminary results indicate a small modification (~ 0.25 D) of the refractive power at the non-ablative laser parameters used in this work. The exact refractivity photo-induced modification mechanism must be further elucidated. Moreover, the hypothesis that the underlying mechanism is a cross-linking procedure involving a photo-induced photochemical process must be further studied.

Financial Disclosure:

NONE