Laser-based refractive surgery
Laser-based refractive surgery techniques offer the possibility of altering the shape of the cornea to correct refractive defects, such as nearsightedness (myopia), farsightedness (hyperopia), and astigmatism.
Three methods in use
1. SMILE (Small incisional Lenticule Extraction)
For management of nearsightedness and/or astigmatism
Using high-frequency femtosecond laser, a lenticule and small incision in the cornea is created. The surgeon then manually loosens and removes the lenticule through the incision, thereby altering the shape of the remaining cornea.
2. FS-LASIK (FemtoSecond LAser in SItu Keratomileusis)
For management of hyperopia and astigmatism.
Using high-frequency femtosecond laser, a flap in the cornea is created.
The surgeon lifts the flap and alters the shape of the remaining cornea using
an excimer laser. Finally, the flap is repositioned back.
3. PRK (Photo Refractive Keratectomy)
Rarely used for all kinds of refractive errors.
After manually removing the top layer of the cornea (epithelium), excimer laser is used to alter the shape of the underlying cornea. The epithelium subsequently grows back.
Prerequisites for laser-based refractive surgery
- The best results and satisfaction are achieved in the following cases:
- Healthy eyes
- Age 21 years or older
- Stable refraction for at least 2 years
- An understanding of the fact, that biological healing processes in the cornea after surgery are not always predictable
- Not pregnant or lactating for at least 6 months.
Results
Millions of surgeries have been performed worldwide over the past decades and the results are generally encouraging.
There is some unpredictability of results owing to the biological variation in
a population. This unpredictability is partly subject to the degree of refractive error corrected. In case the refractive error is higher than -6 diopters, approximately 80% of treated individuals will be able to see as well without glasses/contact lenses, as they could prior to surgery with glasses/contact lenses.
Laser-based refractive surgery cannot provide clearer vision than what can
be achieved with glasses or contact lenses prior to surgery.
Despite undergoing laser-based refractive surgery, you will probably require reading glasses after the age of 45-50 years (presbyopia).
Supplementary surgery may be considered in selected cases where the results of surgery are unsatisfactory.
Before surgery
Contact lenses before preoperative assessment
Do not use soft contact lenses for 48 hours and rigid/hard contact lenses for
1 week prior to your preoperative assessment. This is to ensure correct measurement of the cornea.
Preoperative assessment
After a thorough examination of your eyes, we will determine whether or not
you are eligible for surgery.
If you are not suitable for surgery, we will suggest possible alternatives.
In some cases, it may be necessary to come for more than one preoperative assessment. Please bring along previous prescriptions for glasses/contact lenses.
You will receive eye drops that dilate your pupils. These drops cause blurry vision for about 24 hours. It is, therefore, inadvisable that you drive home by yourself.
Expect to be at the hospital for a duration of about 2 hours.
Prescriptions for eye drops
After surgery, you are required to use eyedrops that prevent inflammation and irritation. The prescriptions are available to you electronically on the pharmacy’s digital server. This means that you can buy the eyedrops from any pharmacy provided that you bring along your ID.
Buy preservative-free lubricating eye drops and painkillers (if required), such
as Tbl. Paracetamol. These may be bought in the pharmacy or supermarkets without prescription.
We recommend that you acquire these medications before the day of surgery.
On the day of surgery
The surgery will be performed on an outpatient basis in local anesthesia.
Follow these instructions:
- Eat breakfast as usual
- Take your usual medications (if any)
- Refrain from using eye make-up for at least 48 hours before surgery
- Refrain from using perfume for at least 24 hours before surgery as the laser may not work optimally when exposed to perfume.
Before surgery you will be offered an anxiety-reducing tablet. Expect to be
at the hospital for about 1-2 hours.
The surgery
The duration of surgery is about 30 minutes.
Your eyes will be anesthetized and disinfected using eye drops. A speculum
will be used to keep them open and prevent blinking.
For SMILE and LASIK, a contact lenses attached to the laser will come in contact with the cornea. Using suction, the cornea is kept attached to the laser for the duration of 10-15 seconds that the laser is working.
In SMILE surgery, the surgeon will loosen and remove the lenticule from inside the cornea using an instrument.
In LASIK surgery, the surgery bed will be moved to a different laser machine. Then the flap will be lifted and laser applied to the cornea. Finally, the flap will
be repositioned back in place.
In PRK surgery, the top layer of the cornea (epithelium) will be removed manually and then laser will be applied to the cornea. A bandage lens will
be placed.
You may go home after a short stay in the waiting room. Due to blurry vision
you cannot drive home by yourself.
After surgery
Eye drops after surgery
In order to prevent inflammation and irritation, you must apply the eye drops
as suggested during the preoperative assessment.
Moreover, it is recommended to use preservative-free lubricating eye drops,
1 drop 4 times daily for at least 2 months.
Wash your hands before applying eye drops.
Pain after surgery
Once the effects of local anesthesia subside (usually after 20 mins.), you will feel slight irritation or pain in your eyes. For pain, you can take pain-killers, such as Tbl. Paracetamol 500 mg 1-2 tablets, max. 4 times daily.
Sunglasses after surgery
It is recommended that you wear sunglasses when you are outside for the first 5 days after surgery.
Do’s after surgery
You may:
- read and watch television, smartphone, tablet or laptop
- shower with closed eyes the day after surgery
- exercise (avoid sweat or dirt in the eyes)
- travel by plain.
Don’t after surgery
For 2 weeks after surgery, you may not:
- bath in a tub or swim in a pool or sea
- perform activities which increase the risk of getting something in the eye.
Vision after surgery
Your vision will be blurry immediately after surgery. It will gradually improve and the next day you will see much better.
After PRK, the surface of the cornea needs to heal before vision improves.
This usually occurs about 2-4 days after surgery. Your vision will vary in the first weeks after surgery.
If you still require correction after surgery
- Buy cheap glasses (as prescription is likely to change during the first few months)
- Ask the ophthalmologist about the need for glasses or contact lenses during the final follow-up after surgery.
Follow-up after surgery
You will be called in for follow-up after surgery at the Department of Ophthalmology.
Sick leave
Depends on occupation. The majority of patients resume work after 4-5 days.
Risks and complications
About 25% experience glare and night vision problems initially. After 1 year,
only 5% still have these complaints.
Eye dryness after surgery is common and is managed with lubricating eye drops. The dryness usually improves within 6 months.
About 2% experience worse vision despite using glasses/contact lenses
as compared to before surgery.
Infection is a rare complication occurring in about 1 out of 200 patients.
Sincerly,
The department of ophthalmology
Rigshospitalet Glostrup