Patient Selection of laser eye surgery
Laser treatment is best for short sighted (myopic) patients whose prescriptions fall between -6.00 to -1.00 Dioptres and long-sighted from +1.50 to + 5.00 Dioptres. Higher prescription levels for the short sighted are possible but the success rate falls the higher the prescription outside the norm.
Remember if you are approaching the age of Presbyopia around 40+ you will still need a reading pair of specs after laser treatment just as contact lens wearers need to do, so the benefit is reduced as it is often when we are out reading menus or shopping etc that we need to revert to reading specs, and the value of perfect distance vision is diluted.
Other problems associated with eyes will affect the type of laser treatment offered or may mean you are rejected, e.g. dry eyes, lid inflammation, skin conditions, and binocular problems such as an old squint of lazy eye or a difficulty in head control.
If you got this far and still in the pack then you should be aware that 4% of those treated are dissatisfied with the result, or put another way 96% are very happy. However this group is likely to report back a higher satisfaction level even if they suffer from long term ghosting and flare from lights at night, just because anything to them is better than groping for specs as they get out of bed each morning.
So what are some of the drawbacks?
According to NICE (National Institute for Health & Clinical Excellence) around 6 people in every 1000 surgical procedures will have worse visual acuity than before the Op.
The greater degree of short sightedness the higher your risk will be of being within that group. More seriously 1 in every 1000 patients will suffer more serious complications.
There have been reports of up to 1 in 10 patients suffering long term glare problems at night and ghosting around images some for only months but some for life. Some will also develop infections although this number is very small and less than that seen in contact wearers.
The level of success does not only involve good patient selection by the pre-consulting staff and more importantly by the surgeon before gaining your consent, but also depends on the quality and competency of the surgeon. It also depends on the level of sophistication of the devices used, which will eventually dictate the cost of the procedure.
What types of laser eye surgery are available?
Lasik (laser assisted in situ keratomileusis)
The cornea is cut by a mechanical blade or laser (often an Intralase laser) to create a flap. The cornea underneath is then sculptured using a laser to re-design the contour of the eye producing a near normal focusing surface, and then the flap is replaced.
This type of treatment is used in around 95% of laser eye surgery procedures; it causes the least pain or discomfort and because vision recovers quickly both eyes can be treated on the same day.
Wavefront guided Lasik for moderate myopia
This newest laser technology, using a femtosecond laser which is customised to treat the specific shape of a person’s eye, The personalisation of the corneal sculpting and the expensive upgrade in machinery needed increases the cost of the procedure considerably. But for those who have a greater risk of after effects, and for dry eye sufferers it is thought to provide a better result.
We are also privy to a medical paper which has been peer reviewed that shows that this procedure is more likely to enhance night vision whilst ordinary Lasik surgery has a greater likelihood of reduction in clear night vision.
Lasek (laser epithelial keratomileusis)
This method is rarely used but because less corneal material is supposedly disturbed it is thought to be good for those at risk in work or sport from corneal assault and for those with thin corneas. Although we would question their suitability in the first place.
A thin flap of the cornea’s outermost layer is created; the flap is lifted out of the way during the laser treatment, then replaced and held in place by a special soft contact lens which acts as a corneal bandage while the eye heals.