Safety Considerations

How safe is laser eye surgery?

Laser eye surgery in the right hands, with the right technology and aftercare, is extremely safe.

The National Institute for Health and Clinical Excellence (NICE) is the official body that produces guidance for UK doctors on the effectiveness of medical treatments.

In 2006, NICE completed a two-year, in-depth study of laser eye surgery. It concluded that laser eye surgery “is safe and efficacious for use in appropriately selected patients.”

Numerous review articles of the published literature on laser eye surgery have demonstrated excellent patient satisfaction, clinical outcomes, and safety.

All surgery carries some risk of complications (a complication is defined as an unexpected occurrence).

In laser eye surgery, complications are very rare, and advances in technology and surgical expertise mean that almost all complications can now be corrected.

In fact, the chance of an expert being faced with a situation of marked permanently reduced vision or quality of vision that he or she could not correct satisfactorily is about 1 in 30,000.

How is safety measured?

Measures of safety take into account any risk of ‘compromise’ to your vision.

Visual compromise is defined as blurring, doubling or other distortion that cannot be corrected by glasses to achieve the same level of vision you had before surgery with glasses (your CDVA).

This is different from a situation in which vision is improved after surgery but there is some blurring, which can be corrected with glasses. In this case the vision is not compromised, it is simply not fully focused (and can be corrected by glasses or, more usually, by a simple enhancement procedure).

In terms of measuring the extent of visual compromise, the standard method is to measure blurring by the number of lines on the eye chart that the patient is no longer able to read. For example, if before surgery you were able to see the 20/16 line with glasses, and after surgery, your vision – even with glasses – is 20/25, this would be classified as a loss of two lines of CDVA.

The 2006 NICE report looked at the results of studies published in medical journals and found that, on average, less than 1% of LASIK patients lost more than two lines of best-corrected vision after laser eye surgery.

However, for expert surgeons, the likelihood of an eye losing two lines of best-corrected vision is even less.

The level of risk varies slightly depending on your prescription, but on average the risk of an eye losing two lines of best-corrected vision is around 1 in 1,000.

For those with higher prescriptions, the risk may be higher, and this will be indicated at your screening appointment if it applies to you.

The best way to ensure that your treatment is as safe as possible is to have treatment with an expert surgeon, who chooses to operate with the best technology and insists upon very thorough testing before surgery and regular follow-up appointments after surgery.