Bright Sight

Oliver Backhouse, Consultant Eye Surgeon www.cataract.org.uk

Presbyopia

Presbyopia is a natural process and is the most common refractive error. The ability to see objects in the distance and then at near is called Accommodation. This ability to Accommodate reduces with age so that by the age of 40 - 50 it is reduced enough to give you symptoms of blurred near vision. Presbyopia symptoms, due to this reduced accommodation, are usually corrected with reading glasses (bifocal or varifocal) or contact lenses. Modern lifestyles often make glasses or contact lenses inconvenient but it is now possible to correct the symptoms of Presbyopia surgically in certain people. There are many different techniques and the correct procedure for you will be discussed according to your needs, lifestyle and anatomy of the eye. Some techniques involve Laser treatment but there are possible advantages for the increasingly popular non-laser options as the results are more permanent.

The procedure I favour is using a multifocal lens. This lens works on the principle of restoring younger vision by being able to see in the distance, intermediate and at near unaided. This type of surgery is called PRELEX (Presbyopic Lens Exchange) which replaces the ageing natural lens of the eye with a new intra-ocular lens. This surgery is very similar to Cataract Surgery. The implanted lens is designed for life and will also correct long and short sight as well as astigmatism. Because the Lens of the eye is being replaced it removes the chance of developing a cataract later.

Other techniques used to correct Presbyopia are Conductive Keratoplasty (controlled heat shrinkage of the cornea to change the refraction of the eye); Phakic Intraocular Lens (similar to a contact lens placed inside the eye); Corneal Laser monofocal or multifocal; Scleral expansion bands (they change the shape of the eye to allow the accommodating muscles to work more effectively); Intracorneal Inlays (like a special artificial pupil). Many of these techniques are still experimental and results are varied. Others rely on the concept of Monovision. This is where one eye is deliberately adjusted for far vision and the other eye for near. This is tolerated in approximately 70% of individuals. The downside is that both far and near vision is reduced a little because one is not using both eyes together. A trial of contact lenses must be used to see if one can tolerate the concept of Monovision.

Technological advances have made lens surgery an exciting treatment option for Presbyopia and the demand for this type of surgery is increasing and especially with a multifocal lens. Surgery is undertaken as a day-case procedure under needle free eye drop anaesthesia. This allows for faster visual rehabilitation and avoids the obvious risks of needles around the eye.