ECLIPSE IOL

A new photochromic IOL has performed very well in initial trials and seems to offer the safety advantages of existing blue-light blocking implants but without compromising mesopic or scotopic vision.

Addressing delegates attending the annual meeting of the French Implant and Refractive Surgery Association (SAFIR) in Paris, Francis Ferrari MD, in private practice in Strasbourg, France, said that the eclipse IOL (Focus Acrylic eclipse by eyePx LLC and distributed by Ophta France) combines retinal protection from harmful blue light with excellent quality of vision in all light conditions.

“There are several studies now showing the harmful effects of blue light to the retina and choroid. It is known to increase oxidative stress and the EUREYE study showed a clinical correlation between cumulative environmental blue light exposure and neovascular AMD in patients with low antioxidants in the blood. Furthermore, the photochromic effects of this IOL means that it will not interfere with patients' sleep patterns
or circadian rhythms in the same way
that a yellow-filter IOL may do,” Dr Ferrari commented.

Describing the implant in more detail, Dr Ferrari said that the eclipse lens is a one-piece hydrophobic acrylic IOL incorporating a pigment with photochromic properties. This pigment is made up of two substructures connected together by a spiro-carbon bond.

Upon exposure to ultraviolet light, the spiro-carbon bond breaks followed by the appearance of a large co-planar molecule that absorbs a part of the blue-coloured rays. As a result, the lens is “activated” and turns yellow, with an absorption curve comparable to that of a 53-year-old human crystalline lens. The aspheric lens can be inserted through a 2.4mm incision, said Dr Ferrari (http://www.ophta-france.com/index.php?alias=eyepx_eclipse&function=display&tplentry=vid&moid=31&template=video.html&oid=T002:g9fgwajde8g&video=1).

In Dr Ferrari’s comparative study carried out at two centres in France between November 2012 and July 2013, 43 patients were implanted with the Eclipse IOL and 48 patients with the Alcon SN60WF incorporating a yellow chromophore. The study was primarily focused on the colour vision of the two groups of patients.

Blue light

There were no statistically significant differences between the performance of the two lenses in terms of postoperative best-corrected visual acuity, postoperative uncorrected visual acuity and preoperative and postoperative pachymetry and IOP.

However, comparisons of blue colour vision using rack 3 of the Farnsworth-Munsell 100 Hue Test showed superior performance for the eclipse lens under both photopic (1,500 lux) and mesopic (40 lux) conditions, said Dr Ferrari.

While filtering out harmful blue light, the eclipse lens still allows sufficient blue light to penetrate the eye in order to prevent changes to patients’ circadian rhythms.

“Just as the basic function of the ear is hearing and maintaining balance, so the eye also has functions that are more than purely visual. This stems from the discovery in 1998 of a new retinal pigment called melanopsin, which is found in the photosensitive ganglion cells. These photoreceptor cells do not provide visual information as such, but are involved in the regulation of circadian rhythms. Since melanopsin photoreceptors reach peak light absorption at blue light wavelengths, they may therefore be less affected by a photochromatic lens than a traditional blue-blocking IOL,” he said.

Francis Ferrari: francisferrari@icloud.com