In-vitro evaluation of resistance to the development of glistenings between Acrysof SN60WF and eternity natural uni NW-60 intraocular lenses

Session Details

Session Title: Cataract II
Session Date/Time: Saturday 27/02/2016 | 08:30-11:00
Paper Time: 09:00
Venue: Trianti Room
First Author: : E.Philippaki UK
Co Author(s): :    D. O'Brart   C. Hull           

Abstract Details

Purpose:

The aim of this study was to evaluate the difference in incidence and severity of glistenings, generated using laboratory thermal treatment, between the Alcon Acrysof SN60WF and Santen Eternity Natural Uni NW-60 intraocular lenses (IOLs). Both IOLs are made of hydrophobic acrylic material, however, they have a different composition and manufacturing process. In addition, both IOLs are currently among the latest intraocular lenses on the market, considered as glistening-free lenses.

Setting:

Centre for Applied Vision Research, City University London, UK

Methods:

Five Acrysof SN60WF and five Eternity Natural Uni NW-60 were studied. All IOLs were single piece blue blockers with the same dioptric power (20D) and optic diameter (6.0mm), delivered to our labs in October 2013. Laboratory-induced glistenings were developed under 50C for 5 days. Ten images were captured for each IOL, pre and post treatment, for objective quantification of glistenings using our Glistenings Detection Program. The angular distribution of forward light scatter was measured using an optical bench system over ±18 degrees. Forward light scatter was quantified by calculating the volume under the scatter function (>1°) and the straylight parameter.

Results:

There was no statistical difference between the number of glistenings for the two materials pre-treatment (p=0.21) but post treatment there was a statistically significant increase in the number of glistenings for the Acrysof (p=0.01) but not for the Eternity IOLs (p=0.09). The Eternity lenses developed a larger proportion of 20- 40μm size glistenings compared to the Acrysof, which developed a higher proportion of 1-20 μm size glistenings. The volume under the scatter function (VUSF) was higher in all cases for Alcon IOLs. In two cases, both Acysof IOLs, the straylight parameter exceeded the level for a subject with cortical cataract.

Conclusions:

Eternity Natural Uni can be considered as a material that strongly resists the development of glistenings with low VUSF and straylight values. In contrast, the Acrysof NS60WF material developed a significant number of glistenings of less than 20microns following laboratory thermal treatment with high VUSF and straylight values. A variation found between the Acrysof lenses may suggest that, under in vivo conditions, not all Acrysof NS60WF are likely to cause a noticeable impact on visual function. However, in some cases the impact could exceed the light scatter from a cataractous lens.

Financial Disclosure:

One or more of the authors research is funded, fully or partially, by a company producing, developing or supplying the product or procedure presented