Implantable Contact Lens Surgery
Until recently, patients with extreme refractive errors have posed a problem to the ophthalmologist. Studies conducted on implantable contact lens surgery have shown that this intra-ocular surgical technique may be the solution. In the case of patients who display high degrees of short-sightedness and farsightedness implantable contact lenses are more suitable than laser surgery.
The ICL is made of a collagen polymer called a "collamer". The collamer is extremely hydrophilic, allowing it to float on the crystalline lens without actually touching it. The ICL is implanted behind the iris, in front of the natural lens of the eye. The operation is similar to a cataract operation except that the natural lens of the eye is left in place.
Who is suitable for ICL?
- Individuals who have very high degrees of hyperopia
- Individuals with very high degrees of myopia
- Those who have had previous refractive surgery and did not attain the desired results
- Patients who are free from corneal disease and glaucoma and have healthy eyes.(Cataracts or other visual problems may influence the willingness of the surgeon to perform ICL surgery.)
Certain medical conditions, such as AIDS, uncontrolled diabetes and immune disorders are contra-indications for ICL surgery.
The preliminary examination
Firstly, a thorough eye examination and some specialised tests will have to be performed to determine whether you are indeed a suitable candidate for implantable contact lens surgery. You may not wear any soft contact lenses for at least three days prior to these tests. If you normally wear RGP or hard contact lenses, these may not be worn for three weeks prior to these tests.
Wearing contact lenses causes swelling of the cornea, which will result in inaccurate test results. Contact lenses should also be removed for the same period of time before the day of surgery. This first consultation takes about 90 minutes. Your pupils will be dilated, causing blurry vision for about eight hours, so you must bring someone that can drive you home afterwards.
Before implantable contact lens surgery
YAG laser iridotomy is necessary seven to ten days before lens implantation to prevent rising of intra-ocular pressure after surgery. Two openings will be made in the iris for fluid to drain freely between the front and back of the eye.
If both eyes need surgery, your non-dominant eye will be operated on first, followed by the other eye a week or two later. It is important to have functional vision in the first eye before doing surgery on the second eye.
During the implantable contact lens surgery
You may receive either topical (eye drops) or general anaesthesia. As this is a very sterile procedure you will be thoroughly prepared for surgery.
A clear corneal incision will be made through which surgery takes place. The total time spent in theatre is ± 30 minutes. You will spend some time in the recovery room, during which time you intra-ocular pressure will be monitored. After a few hours you may go home.
After the implantable contact lens surgery
Allow yourself about three day's recuperation after the surgery. You will be given eye drops to use after surgery to prevent infection and to reduce swelling of the cornea. You will receive instructions on how to use these drops on the day of surgery. Although most people don't experience any post-operative pain other than slight discomfort, you will also be given painkillers to use should it be necessary.
The most important thing is not to rub, touch, bump or to have any pressure on the eye after implantable contact lens surgery.
What to expect after the implantable contact lens surgery
- Your vision may be a bit blurry for the first few days and you may experience some difficulty with reading. This is due to your pupils still being dilated; it takes about 48 hours before the effect wears off.
- You may feel that your eyes get tired more quickly during the first week or two, especially after prolonged close-up work like reading or computer work.
- You will experience some light sensitivity and your eyes may tear more than normal.
- You may experience some problems with night glare and halo's around lights.
- Your eyes may feel a bit scratchy and dry during the first few days.
- Your vision may fluctuate during the first few weeks.
- Visual recovery is rapid and relatively painless.
All of the above mentioned symptoms are normal and any discomfort you have will become less each day as the eye heals.
Possible side effects and complications
- Post-operative pain may occur in some individuals. Take the painkillers as prescribed. As with all surgical procedures there is always a possibility of infection, although this is rare. If you should get an infection in the eye, it will be treated with additional eye drops. Severe eye pain may mean the intra-ocular pressure is raised. On this occurrence the surgeon must be contacted immediately.
- With implantable contact lens surgery, as with all other refractive surgery procedures, there is a possibility that the desired refractive outcome is not attained, leaving you with the need for corrective spectacle or contact lenses. In some cases it may be necessary to do laser surgery ± three months after the ICL implantation to treat the remaining refractive error and therefore improve the refractive result. Results thus cannot be guaranteed.
- There is, as declared by the FDA, a 1.45% incidence of cataract formation after implantable contact lens surgery. This can occur within months or years after the surgery and causes progressive blurry vision. In such a case it will be necessary to remove the ICL and the natural crystalline lens of the eye and replace it with a synthetic intra-ocular lens. The power of this lens is determined beforehand to ensure that your uncorrected vision will be good post-operatively.