32014Jun

Advancements in Laser Eye Surgery

If you thought LASIK was all there is to Laser Eye Surgery, you would be surprised to see the variety that there is. It’s something like roses. For us laymen, a rose is a rose. Only a rose aficionado can tell you the difference between Musk, Hybrid Tea and Knock out varieties of roses.

Laser Eye Surgery involves the use of lasers to reshape your cornea (outer clear surface of your eye) and correct errors in vision like nearsightedness, farsightedness astigmatism and in the near future presbyopia too. In nearsighted people, the steep cornea is flattened using laser while a steeper cornea is created. In astigmatism, the irregular surface of your cornea is smoothened out.

Photorefractive Keratectomy (PRK) was the first Laser Eye Surgery, having been invented in the 1980s. In PRK, an excimer laser (a type of UV laser) is directly used to remove bits of tissue from your cornea to reshape it. Though PRK is better suited for thin corneas and people with risk of corneal flap dislocation than LASIK, it involves more healing period.

Laser Assisted In situ Keratomileusis (LASIK) is the most popular of all laser eye surgeries, having almost become synonymous with the words laser eye surgery. In LASIK, a microkeratome or a surgical blade is used to cut a flap in your cornea and then an excimer laser is used to reshape your cornea as required. In LASIK, the discomfort after the procedure is greatly minimized.

LASEK (Laser Epithelial Keratomileusis) or E-LASIK is a modification of LASIK in which a very thin flap is created before laser is used on your cornea. This was created for those corneas that were too steep or too thin for LASIK and to reduce the risk of complications arising from an improper thickness flap.

Epi-LASIK is another variation of LASIK where a plastic blade known as an epithelial separator is used to remove part of the epithelial layer. After this, an excimer laser is used to sculpt the cornea as required.

Bladeless / All laser / Blade free LASIK (Commercially available as the systems iLASIK / zLASIK/ Femtec/ Visumax) is a technique which does away with the use of a mechanical cutting tool for creation of a flap. Here, two different types of lasers are used. First a femtosecond laser is used to create a flap after which an excimer laser is used to reshape the cornea. This is more precise but may be associated with more discomfort after surgery.

Wavefront LASIK or Wavefront PRK also called Custom LASIK/PRK uses technology to bounce light into your eyes and catch it on its way out to create a three dimensional map of your eye. A corneal flap is first created followed by removal of corneal tissue as guided by the wavefront map.

Refractive Lenticule Extraction (RELEX) is a new technique in which a femtosecond laser creates a disc shaped piece of cornea which is removed to correct the refractive error. This technique is flapless, precise and the most minimally invasive of its predecessors.
IntraCor and SupraCor are two new laser techniques that have not yet received approval from the FDA, but are the latest advancements for treatment of presbyopia using lasers. These treat presbyopia (impaired vision after the age of 40 years) by creating concentric rings in your cornea using lasers.