Are There More Risks Associated With Higher Prescriptions?
Mr Glenn Carp – “In general, there may be a slight increase in the risks profile with very high prescriptions, bearing in mind from the point of view that you are removing a lot more tissue under those conditions, which leaves less tissue to correct for any residual issues and residual issues occur both on the actual residual prescription, your last bit of focusing, allowing you to see the last few lines on the chart or in terms of the quality of the vision, or things like night vision disturbances etc., which may also need to be addressed and nowadays can be addressed. So, in terms of actual risk, yes, there is a slightly increased risk but it is really down to an individual basis.”
Risks And Higher Prescriptions Explained Further…
The two areas where higher risks are associated with higher prescriptions are night vision disturbances (halos and starbursts) and corneal haze.
One of Professor Reinstein’s main research focuses over the last 8 years has been the correction (and prevention) of night vision disturbances. Professor Reinstein has developed protocols for correcting and preventing halo and starburst effects even when treating very high prescriptions and patients with large pupils. Zeiss incorporates many of his findings in the commercially available Carl Zeiss Meditec MEL 80 excimer laser system, in use at the clinic today. It is therefore extremely rare for patients in our practice to end up with night vision disturbances. We confidently believe that we have the most sophisticated systems in place for preventing or treating night vision disturbances.
The risk of haze in PRK / LASEK increases the higher the prescription to be treated, but is also dependent on the smoothness of the surface created by the laser as well as the protocols for postoperative management of the cornea.
Corneal haze is part of the normal healing process in the corneal surface procedures (PRK / LASEK), and gradually subsides with little or no permanent effect on vision.
However, if the haze is excessive or does not go away, the patient may need additional treatment either with medications to reduce the haze or further laser surgery to physically remove the haze or both. Haze is extremely unusual in LASIK.
In about three in every 1,000 cases, patients develop astigmatism after surgery. Contact lenses can usually correct this form of astigmatism (glasses will not). People who have very high prescriptions have a higher risk of this complication. Astigmatism can happen even if the surgery is perfect, but an inexperienced surgeon or one who does not use the best equipment increases this risk.
There is more information about Laser Eye Surgery risks and can be discussed further at your initial screening.