While laser eye surgery is one of the main treatments for people with sight problems, many people find the process a scary prospect.
They may therefore welcome the news that a new type of procedure involving phakic intraocular lenses (IOLs) for correcting short-sightedness could be safer than laser eye surgery.
A Cochrane Systematic Review has found that not only is it possibly safer than surgery, it is also preferred by patients, despite there being little difference between the two procedures in terms of improving vision.
Short-sightedness, or myopia, is a condition where the eye focuses images in front of the retina rather than directly on it. The problem affects around a quarter of the population in Western countries and is becoming more common.
In recent years, the preferred corrective procedure undergone by people who want to avoid wearing glasses or contact lenses has been excimer laser refractive surgery. However, a new alternative could be set to overtake this in popularity.
This new procedure involves the insertion of phakic IOLs, which means a synthetic lens is put in front of the natural lens. Both procedures work by changing the path of light entering the eye and therefore bringing images into focus in the right place, but laser surgery does this by removing parts of the cornea.
Until this review, there had been no systematic analysis comparing the accuracy and safety of the two procedures. Insertion of phakic IOLs has also only been practised in more severely short-sighted patients. However, the procedure could be more widely used as a result of this new study.
"Although it"s not currently standard clinical practice, it could be worth considering phakic IOL treatment over the more common laser surgery for patients with moderate short-sightedness," said Allon Barsam of the Moorfields Eye Hospital NHS Foundation Trust in London, who was also the lead author of the study.
The researchers reviewed findings from three trials comparing the two types of surgery, which included operations performed on 228 eyes in 132 patients.
They discovered that a year after the surgery, the percentage of eyes with 20/20 vision without glasses was the same for both procedures, but patients who had undergone phakic IOL treatment had clearer spectacle-corrected vision and better contrast sensitivity.
Patients also scored the procedure more highly in satisfaction questionnaires.
However, phakic IOL treatment does carry a slightly increased risk of cataract and researchers said that further investigation into the potential adverse effects was needed.
"There may be more long-term risks unique to patients with phakic IOLs that are not apparent after one year of follow-up," Mr Barsam said.
Commenting on the research, Mr Larry Benjamin, vice president of the Royal College of Ophthalmologists, said: "The suggestion that these results may be translated to the use of phakic IOLs for lower degrees of myopia is a little worrying as no trials are reported and there is a two per cent cataract formation complication in the phakic IOL group requiring further surgery."
"On balance, it would appear that either method is reasonable for moderate to high myopia with a higher chance of one particular complication in the laser group but we would like to see more research undertaken in this area," he concluded.
by Martin Burns