LASIK Singapore
Epi-LASIKThe Safe, Effective, No-Cut, No-Cornea Flap Surface-Based Procedure.By Martin Kwan, Senior Optometrist, Clearvision Eye Clinic & LASIK Centre Epi-LASIK is fast becoming the mainstream choice of laser vision correction. Unlike LASIK, Epi-LASIK does not require a cut into the cornea. In LASIK surgery, a cornea flap is created using either a micro-keratome blade, or Femtosecond laser. However, in Epi-LASIK, only the superficial skin cells are removed. This layer of skin cells is called the Epithelium. There are different ways to remove the epithelium. Currently, the best known way to remove the epithelium is by using an epi-keratome. This device employs a blunt blade that oscillates at a very high frequency to effectively separate the epithelium from the rest of the cornea. Another way to remove the epithelium is by using the excimer laser to vaporize the epithelial tissues before proceeding to sculpt the underlying cornea tissues. This method is also called No Touch Epi-LASIK or Trans-epithelial PRK. Once the epithelium layer is removed, excimer laser is then applied onto the exposed cornea tissue to correct vision. After the laser treatment is completed, a bandage contact lens is placed onto the cornea surface. The lens acts as an artificial cornea skin to help in the healing of the cornea epithelium. After three to four days, the cornea epithelium would have successfully regenerated. The contact lens is then removed. The patient is expected to return to normal activities in around four days, and vision will continue to improve. The human cornea is a strong structure that is primarily made up of collagen fibres and water. This layer is called the Stroma. This thick layer of collagen and water is bounded by the epithelium in front, and the endothelium at the back. Therefore, the stroma is vital to the biomechanical structural strength of the entire cornea. By not cutting into the stroma, Epi-LASIK keeps the cornea biomechanically strong, reducing the chance of developing cornea thinning complications such as cornea ectasia. Without the need to cut and create a cornea tissue flap, the risk profile of the surgery is drastically reduced. This is because, although low, the bulk of LASIK related complications originate from the creation of the cornea tissue flap. During cornea flap creation, complications such as incompletely or irregularly cut flap, loss of cornea flap, folds, shifting or wrinkling of the flap, interface inflammation, infection, epithelial in-growth underneath the flap, instability of the flap requiring cornea sutures could occur and result in permanent loss of best corrected vision. By doing away with the need to create a cornea flap, Epi-LASIK effectively does away the risks of flap related complications. On top of that, Epi-LASIK does not exacerbate dry eyes like what LASIK does. This is because cornea nerves are cut off when a cornea flap is created during LASIK surgery. In Epi-LASIK, these cornea nerves are preserved. The job of the cornea nerves is to inform the brain that the cornea surface is dry. The brain subsequently instructs the tear gland to secrete tears to lubricate the cornea. After LASIK surgery, this feedback system becomes impaired In conclusion, Epi-LASIK is a safe and effective procedure that is suitable for all patients that are already suitable for LASIK. In addition, Epi-LASIK may also be suitable for patients who have been previously rejected from LASIK due to high myopia and/or thing corneas. This is because, Epi-LASIK helps preserves more cornea tissues for vision correction by not wasting it on the cornea flap. Epi-LASIK is also suitable for the avid sportsperson and military personnel, as there are no worries of cornea flap dislodgement due to trauma. Why is Epi-LASIK a better choice?
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