There are many different types of laser eye surgery, some just a subtle variation of other methods. Not all are commonly available, and some laser eye surgery techniques are much more popular than others. Here are the various types of laser eye surgery procedures to be aware of.
LASIK (Laser-Assisted in Situ Keratomileusis)
LASIK is one of the most well-known and popular laser vision correction methods. During this procedure, a femtosecond laser tool is used to create a flap of corneal tissue out of its uppermost layers. By moving this flap aside, the excimer laser can then vaporise the deeper layers to reshape the cornea. After photoablation is complete, the flap is then replaced and usually left to self-seal. LASIK can be used to treat high degrees of myopia (short-sightedness) and moderate degrees of hyperopia (long-sightedness) and astigmatism.
Laser Blended Vision
PresByond, or laser blended vision, is designed for people who have reached presbyopia. Presbyopia is a natural part of ageing when your ability to focus on near objects starts to decline. The PresByond laser eye surgery technique is a variation of LASIK. Instead of correcting each eye entirely for perfect long-distance sight, laser blended vision aims to incorporate some near sight into each eye as well. Through a computer algorithm, your eye surgeon can apply the LASIK technique to give your dominant eye more distance sight with some near vision ability, while your other eye is predominantly made clear for reading with some distance sight. Your brain then learns to adapt around this new visual experience.
PRK (Photorefractive Keratectomy)
PRK was the original laser eye surgery technique. Although many newer laser vision correction methods have since emerged, PRK remains a valuable option. One of its important advantages is that people with thin corneas who may be ineligible with LASIK may still be suitable to undergo PRK. The reason for this is that only the superficial layer of corneal epithelium is removed rather than a thicker flap. This leaves more tissue available for photoablation. Another advantage is that it eliminates all of the flap-related complications associated with LASIK, making it more suitable for people in high-risk occupations such as the military or athletes in contact sports. PRK may also be known as advanced surface laser ablation (ASLA). PRK is available for patients with myopia, hyperopia, and astigmatism.
LASEK (Laser-Assisted Sub-Epithelial Keratomileusis)
In a way, LASEK is a mix of the LASIK and PRK laser eye surgery procedures. Like LASIK, a flap of tissue is created; however, more like PRK, this flap is comprised only of the epithelial layers. The epithelial flap is kept to the side during photoablation and later replaced on the eye. The advantages of LASEK is that it avoids flap-related complications; however, it may be associated with a slower recovery and more discomfort during the healing process compared to LASIK.
People with hyperopia, myopia, and astigmatism may be eligible for LASEK.
SMILE (Small Incision Lenticule Extraction)
SMILE laser eye surgery is one of the newest methods and the only one that doesn’t involve the excimer laser. During this procedure, your eye surgeon uses another laser tool, known as a femtosecond laser. Instead of lifting the upper parts of the cornea to access the deeper tissues, SMILE laser eye surgery uses the femtosecond laser to create a disc-shaped sliver of tissue within the cornea without disturbing the outer cells. This sliver (lenticule) is then extracted through a keyhole incision, which alters the overall curvature of the cornea. At this time, SMILE is not appropriate for hyperopia but can be used to correct myopia and astigmatism. As it is a minimally invasive procedure, the stability and integrity of the cornea are less disrupted. There are also fewer incidences of complications post-surgery compared to LASIK, such as dry eye.
Each laser eye surgery technique has its own eligibility criteria. After conducting a comprehensive exam, your eye surgeon will be able to discuss the most appropriate options with you. If corneal-modifying refractive surgery techniques are not suitable for you, other methods such as refractive lens exchange may be more appropriate.