Enhancement is the fine-tuning of a previously performed LASIK procedure. It corrects the patient’s residual refractive error. It is like playing golf. The first hit of the ball is to get it as close as possible to the hole. Some golfers get a hole-in-one and do not have to putt again. The second hit of the ball is to get it into the hole. The same applies to LASIK and enhancement.
Unfortunately, LASIK cannot always guarantee optimal results. There will be a few patients with under-correction and over-correction after LASIK. This happens because everyone has a different healing response. Under-correction indicates that a patient’s eye has under-responded to treatment, and that the myopia or hypermetropia may still exist but in a much smaller degree. In the case of over-correction, a patient’s eye has over-responded to treatment. A patient suffering from hypermetropia may become slightly myopic and vice versa.
In spite of this, LASIK is still a superb procedure. Unlike PRK, LASEK and epi-LASIK, fine-tuning or enhancing a patient’s results in LASIK is accurate, relatively easy, and only mildly inconvenient to the patient.
In enhancement, the surgeon will lift the flap open with the aid of special instrumentation to further correct patients whose eyes are under-corrected, over-corrected or have residual astigmatism. The excimer laser is again used. After, the flap is replaced and the eye is allowed to heal. The patient will undergo a similar follow-up as the first procedure.
Enhancement is usually more accurate because the residual myopia, hypermetropia or astigmatism is low. If a patient’s residual power is more than 1.00 dioptre (100 degrees), enhancement will be required for patients with high visual needs. However, for presbyopes (above 40 years of age), residual myopia may be desired for the improvement of their reading vision.
Enhancement is not without risk as infection can still occur and, rarely, surface cells can grow underneath the flap, causing complications. Enhancement is best decided between the patient and the eye surgeon concerned. It also depends on the patient’s wants and visual needs. Enhancement can be done for residual myopia as low as 0.50 dioptres (50 degrees of short-sightedness). The best time for an enhancement is between 3 to 6 months after LASIK surgery. This is because during this time, the patient’s vision and his residual refractive error would normally have stabilised.
Between 3 months to many years, the flap can still be opened with specialised instruments and technique by an experienced ophthalmologist. In rare cases, opening the flap after 6 months is much more difficult and may not possible. In this instance, a full repeat LASIK will be required for further enhancements i.e. a repeat cut must be made. For patients who have under- or over-corrections with residual astigmatism, LASIK offers an additional benefit of allowing enhancements of astigmatism as well.
Advanced LASIK Enhancement for Complicated Cases
Patients with problems from previous radial keratotomy, PRK, epi-LASIK, LASEK and LASIK can be helped with LASIK enhancements. A new flap can be created or the old flap re-lifted to add and adjust the previous correction. Night glare, halos, poor night vision and poor quality of visual contrast can all be alleviated with Advanced LASIK enhancement. These include topography-guided and wavefront-guided enhancements. However, a very experienced surgeon who is used to taking care of complex and complicated cases is essential, especially when the cornea is already thin.