Author: Dr Val Phua MBBS, MMed (Ophth), FRCOphth, FAMS
Photo by: MontyLov
In Singapore, LASIK (Laser-Assisted In Situ Keratomileusis) is a popular procedure to achieve freedom from glasses and contact lenses. It has success rates exceeding 98% and safety rate exceeding 99%. Those who have undergone LASIK often describe it as life-changing. Many people think that LASIK is for the young and don’t realise that LASIK is a treatment option for presbyopia. Here are 5 important things to know before getting LASIK for presbyopia.
1. Presbyopia is not the same as long-sightedness
Many people tend to use the terms presbyopia (lau hua yan) and long-sightedness interchangeably. While there are similarities, the concept behind each of them is quite different. In a patient with long-sightedness, the eyeball is generally smaller. This results in light being focused behind the retina rather than on the retina where it should be to allow for clear vision. Long-sightedness conceptually is the opposite of short-sightedness and it occurs in children as well. Presbyopia (lau hua yan) on the other hand, is due to aging and a decreased ability of the eyes to focus on near objects. It begins about 40 years old and progresses over the years to a certain peak. Patients will find if increasingly difficult to focus on near tasks and often have to compensate by pushing the object further away from the eyes to keep it in focus. Presbyopia affects everyone and unfortunately there is no escape from it.
2. Understanding monovision and eye dominance
LASIK is able to help with presbyopia by utilizing the concept of monovision. Monovision is when one eye is used to focus on distant objects and the fellow eye is used to focus on near objects. How do you know which eye is for which distance? Generally, the dominant eye is used for distant objects and the non-dominant eye is for near objects. In this way, LASIK can be used to address presbyopia, allowing freedom from glasses for distant objects and reading glasses for near tasks. There is a small trade off in terms of stereoscopic vision but by and large most patients are very functional and appreciate the convenience of being glasses free.
3. There are no blades involved
The LASIK procedure involves several steps. One of the key steps in creating a corneal flap and then lifting it to expose the underlying layers to allow for the laser correction. In the early days of LASIK surgery, a blade was used to create this flap and this resulted in potential complications like an incomplete flap and a free flap. WIth the advent of the femto-second laser, this key step of flap creation during LASIK is now replaced by the use of a femto-second laser machine to create a smooth and predictable flap. If you have in your mind an image of a knife splitting your cornea into layers, don’t worry because that method of doing things is now obsolete. Modern day LASIK is now blade-free with the use of lasers for this key step instead.
4. It is painless
Some people have the misconception that LASIK is a painful procedure. It is in fact a painless procedure. The eye is well numbed with topical anesthetic eye drops before the procedure begins and this ensures that the entire process, from the creation of the corneal flap using the femto-second laser to the application of the corrective laser, is painless. Some may experience a mild discomfort during the part where the machine applies a vacuum to keep the eye steady during the corneal flap creation. This pressure sensation is common and usually mild. After this is done, the rest of the surgery proceeds pain-free. Some may also have concerns about pain after surgery. This is usually minimal especially with LASIK surgery. There may be some mild discomfort in the first couple of days but this quickly resolves, allowing a painless recovery.
5. Recovery is quick
One of the many benefits of LASIK surgery is the minimal down time. In general, patients are able to see fairly well by the next day. Eye drops are given after the surgery to prevent infection and aid healing. These are instilled for about a week and thereafter, lubricant eye drops will suffice. Many are back to their normal activities like running and gymming in a week. Swimming is generally avoided for a month while the eye continues to heal and stabilise. The main challenge during this early recovery phase is the avoiding of eye rubbing. Aggressive eye rubbing can result in issues like the corneal flap being dislodged and can affect vision.