The concept refractive surgery includes all surgical procedures intended to correct optical (=refractive) defects of the eye: myopia, hyperopia, astigmatism and presbyopia.
Refractive Surgery
Traditionally, people affected by visual defects could only be helped with glasses or contact lenses, on which they had to depend.
Nowadays, the aim of Refractive surgery techniques is to correct these problems, so patients must not rely on glasses and contact lenses.
All Laser techniques aim to remodel the curved shape of the cornea, in order to confer the optical qualities necessary to correct optical errors.
- Excimer Laser treatment: Excimer Laser is a thermal UV-based laser. Its different techniques (LASIK / LASEK / PRK) reshape the cornea by vaporizing tissue (photoablation). Excimer Laser is indicated for young patients with mild to moderate refractive error (up to 6-8 diopters), as well as for the correction of refractive errors after cataract surgery.
- Zeiss® Visumax Relex Smile®: The Zeiss Visumax® is a most modern Femtosecond Laser. It uses ultra-short light pulses of disruptive effect, in order to produce thousends of micro-bubbles at a determined depth inside corneal tissue. Thanks to this principle, it sculpts a lens shaped slice inside the cornea (“lenticle”), after which removal trough a tiny peripheral incision the cornea becomes it’s new curvature, compensating and correcting the pre-existing optical error.
Advantages of Laser treatment:
- Quick procedure and fast visual recovery
- Minimally invasive
- Both eyes can be treated within a session
Disadvantages of Laser treatment:
- Not every case is suitable
- Irreversible
- Doesn’t prevent future cataract formation
More at:
Intraocular lenses are made of highly biocompatible plastic materials, in order o be implanted inside the eye, where they can correct pre-existing optical errors.
Phakic intraocular lenses
Phakic IOLs are clear implantable lenses that are surgically placed inside the eye. These type of lenses are designed to co-exist with the crystalline lens. They go beyond Laser surgery in correcting visual errors, and are therefore indicated for young patients with moderate to high refractive error, who are not eligible for undergoing Laser Surgery.
Phakic lenses enable light to focus properly on the retina for clearer vision without glasses or contacts. Implantable lenses function like contact lenses to correct nearsightedness. The difference is that phakic IOLs work from within your eye instead of sitting on the surface of your eye.
Further info at:
http://youtu.be/kR4HGL01Lbg
http://visianinfo.eu/en-gb/what-is-visian-icl
http://www.amo-inc.com/products/cataract/refractive-iols/verisyse-phakic-iol
Refractive Lens Exchange (RLE)
The aim of this kind of treatment is to exchange the natural lens of the eye for an artificial intraocular lens in order to correct optical errors that go beyond the correcting options of other techniques. If an intraocular lens with multifocal optics (bifocal or trifocal) is chosen, it will provide good vision from far to near without having to use glasses.
This type of treatment, originally developed for treating cataracts, can be considered after careful patient selection, even if there is no significant cataract formation. If indicated, it confers independency of glasses for most activities and daily routine. It also prevents the later formation of cataracts.
It is a particularly suitable technique for :
- People with nearsightedness or farsightedness and advanced presbyopia
- Patients not suitable for surgery with excimer laser or phakic lenses
- Patients aged 50 and more,
- Patients with early signs of incipient cataract or with familiar or other risk factors for developing cataracts
Learn more here:
http://www.allaboutvision.com/visionsurgery/refractive-lens-exchange.htm
