Refractive eye surgery aims to achieve clearer, sharper vision and today there are more options than ever before.

First performed more than 20 years ago, laser corneal sculpting has afforded millions of people around the world the opportunity to ditch their dependence on glasses or contact lenses and reap the rewards of sharper, clearer vision.

A medical procedure that uses an “excimer” laser to reshape the front surface of the eye, laser eye surgery can correct common vision issues such as myopia (shortsightedness), hypermetropia (long-sightedness) and astigmatism (uneven curvature of the eye’s surface) as well as aid some visual impairment associated with ageing.

The most common procedure is laser-assisted in-situ keratomileusis, or LASIK. Today, however, patients can take advantage of a number of different techniques and technologies their ophthalmologist will discuss with them.

What is laser eye surgery?

It’s estimated that in excess of 161 million people around the world are visually impaired. In Australia, more than half the population suffers some form of eyesight problem as a longterm medical condition. Whilst this includes those suffering long and short-sightedness, a significant proportion comprises those suffering medical visual impairments more commonly associated with age, such as glaucoma, age-related macular degeneration, and diabetic retinopathy.

These medical impairments cannot be treated with laser sculpting, however presbyopia, the visual change that occurs with the natural ageing of the eye, can sometimes be addressed.

Whilst ophthalmologists had understood the principle of reshaping the cornea to improve eyesight for some time, it wasn’t until the 80s that laser was used to reshape the cornea, and so improve visual acuity – the clearness and sharpness of the image that is seen by the eye.

During LASIK surgery, a laser beam is used to remove a certain amount of tissue from the cornea with each pulse. Depending on the visual impairment, the ophthalmologist uses the laser to alter the curve of the cornea, either flattening the arch or making it steeper.

A hinged flap, which can be peeled back, is made in the cornea. The laser is then focused on the underlying layer of the cornea. Once the overall curve of the cornea has been adequately reshaped, this flap will then be placed back on the eye, helping it to heal.

The procedure usually takes less than 30 minutes. The only anaesthesia necessary is local anaesthetic eye drops. There is virtually no post-operative pain, though occasionally patients have slight post-operative discomfort that can be treated with medication.

Most patients record dramatic improvement in vision within 24 hours although some may have a slower improvement, depending on original refractive condition. Typically, most patients can resume normal activities the next day.

Advances in LASIK

Like any surgical procedure, advances in technology and techniques mean LASIK is continually evolving. Developments such as laser eye-tracking systems, faster excimer lasers, improvements in flap-creation techniques and wave-front guided technology can lessen the incidence of some post-LASIK complications such as glare and haloes.

Alternatives to LASIK

Whilst LASIK remains the most popular method of refractive eye surgery, there are a number of alternatives.

Advanced surface laser (ASL)

This is another technique involving the application of a laser to the surface of the eye in order to reshape the cornea. However, because the laser is applied to the surface of the cornea only, it avoids the need for a flap in the cornea to be cut. ASL is commonly used in patients with thinner or more unstable corneas which cannot tolerate a flap being made

Photorefractive keratectomy (PRK)

Photorefractive keratectomy (PRK) was the earliest form of ASL. During this procedure, the outermost ‘epithelium’ layer of the cornea is removed and the deeper corneal layer is treated with laser.

LASEK

Laser assisted subepithelial keratomileusis (LASEK) is an advanced technique, during which the epithelium layer is not removed but lifted for the laser reshaping, before being replaced afterwards.

Whilst ASL surgery avoids some of the complications associated with cutting a flap in the cornea, there is generally more post-operative discomfort and the visual recovery takes longer than the 24-hour recovery time following LASIK.

Implantable contact lenses (ICL)

In cases of very high prescriptions, where reshaping of the cornea is not possible, there are other options. A lens of the appropriate strength, the so-called ‘implantable contact lens’ (ICL), can be inserted into the eye through a small incision.

Clear lens extraction (CLE)

Clear lens extraction (CLE) is similar to a cataract operation. Normally, a cataract is removed when there are opacities in the crystalline lens inside the eye, caused during the ageing process. In clear lens extraction, there is no opacity. In both clear lens extraction and cataract surgery, the lens is removed and replaced by an artificial lens. The patient’s correction is incorporated into the new lens so glasses and contact lenses will (generally) not be required. One advantage of both ICL and CLE procedures is their reversibility, however they are more invasive, especially in the case of clear lens extraction.

For those considering eye surgery, an ophthalmologist will discuss the various options and recommend the best procedure for the patient’s individual needs.