Intraocular Lens Implants
The intraocular lens (IOL) allows the light entering the eye to be focussed on the retina ("image capturing tissue") at the back of the eye. Prior to surgery detailed measurements are made of the eye shape and length ("A-scan biometry") in order to establish the intraocular lens options. There have been significant advances in intraocular lens design over the past few years such that it is now possible to select different intraocular lens types in order to achieve the optimum outcome for a particular individual. Traditionally a "one focus" (monofocal) intraocular lens implant is used to replace the patient's cloudy natural lens after cataract surgery. In the majority of cases a monofocal lens will provide clear vision at one distance with spectacles being required for other distances eg: good distance vision without spectacles but reading glasses necessary for near tasks. This remains the lens of choice for many people having cataract surgery.
Some patients have a "rugby ball shaped" eyeball (astigmatism) which can result in blurred unaided vision ie without glasses post-surgery using a monofocal IOL. This can be addressed either by:
- 1 - Improving the shape of the cornea (window at the front) by performing relaxing corneal incisions during the cataract procedure (LRI's = "limbal relaxing incisions"), or
- 2 - The astigmatism can be neutralised using an oval Toric lens implant eg AcrySof IQ Toric (Alcon), MicroSil MS (Human Optics). These implants require very accurate positioning in order that the astigmatic lens implant counter acts the "rugby ball shaped" cornea. Reducing any astigmatism present allows for better unaided vision, thereby reducing the need for using spectacles.
Some people are keen not to wear any spectacles at all after cataract surgery. This can sometimes be achieved using monofocal lens implants by aiming to have the focussing of one eye for distance vision and the other for near work (this is called "monovision"). Alternatively there is now the option of using the latest generation of multifocal intraocular lens implants that offer the possibility of providing both clear distance and near unaided vision post-operatively. One such lens is the ReSTOR that is based on Alcon's market-leading AcrySof design, the most frequently used lens implant in the world. It has sophisticated optics which allows over 80% of selected patients to become independent of spectacles after cataract surgery. Even people with astigmatism have a chance of leaving their glasses behind forever with one of the latest advancements in cataract surgery technology - the innovative AcrySof IQ ReSTOR Multifocal Toric IOL (www.alconsurgical.com).
With so many changes over the last few years it is now possible to offer a “bespoke” refractive cataract service and there are many "state of the art" options available. Patients require a complete ophthalmological assessment and appropriate counselling prior to deciding on a tailored surgical treatment plan.