When should cataract surgery be performed?
The timing of surgery is dependent on several factors.
- When vision is reduced and cannot be improved by an adjustment to glasses AND the reduction in vision causes difficulties, such as with reading, needle work, computer work and workshop activities, cataract surgery can be appropriate.
- In some cases, after surgery on one eye, a spectacle imbalance may result if the second eye is not also operated on.
- In some cases, cataract surgery is indicated in order to maintain driving privileges.
- Some people have coexistent cataracts and retinal abnormalities. Cataract surgery can sometimes be necessary in order to improve the ability to assess and monitor the retinal abnormalities.
- Some people may require cataract surgery as a means of improving control of intraocular pressure associated with certain types of glaucoma.
What preoperative measurements are required before cataract surgery?
Several measurements will be taken at your preoperative consultation to assist your surgeon plan the most appropriate operation for you. These include the following:
- Measurement of your current distance and reading glasses.
- Calculation of the curvature of your cornea and the length of your eye (ocular biometry).
- A scan of your retina and optic disc for evidence of coexistent retinal pathology (OCT scan).
- A comprehensive eye assessment, whenever possible involving pupil dilation.
What are the goals of surgery?
In most cases, the primary goal is improved central vision to assist with activities of daily living, such as cooking, reading, driving, playing sport and watching television. A secondary goal is usually to reduce reliance on spectacles or contact lenses.
For some people with retinal or other disorders, however, these may be unrealistic goals. In these cases, a more realistic goal may be improved navigational vision to allow safe movement around the home and when out of doors.
What methods exist to reduce your reliance on spectacles after surgery?
Most people who undergo cataract surgery are already reliant on glasses for some or all of their usual activities. While the prospect of continued post-operative spectacle dependence does not bother some people, for others the need for glasses is a significant burden. Reducing your reliance on glasses after surgery is a key surgical objective. We do this by implanting an intraocular lens of appropriate optical power at the time of cataract surgery.
Several designs of intraocular lenses are available at Tamara Private Hospital. Only monofocal lenses are available in the public hospital system.
Monofocal Lenses
Monofocal Intraocular Lenses
Monofocal lenses produce a sharp image at a given viewing distance. These are normally implanted to target good long distance vision or good reading vision. See below for additional information.
Multifocal Intraocular Lenses
Multifocal intraocular lenses are designed to produce a sharp image at any viewing distance. These lenses are made with a series of concentric rings cut into one surface. They simultaneously produce a series of images, one of which will be optimal for a given viewing distance.
Patients may be aware of some ghosting or halos around images. As a result of the multiple images, it generally takes a few weeks for the brain to become accustomed to and able to ignore the halos. These lenses are associated with a high rate of spectacle independence and it is unusual that a lens would need to be removed and replaced with a monofocal lens because of glare intolerance.
Multifocal intraocular lenses are not a good choice for people who do a lot of night driving because of glare and starbursts around headlights and street lights. This solution is available at Tamara Private Hospital but not in the public hospital system.
Toric Intraocular Lenses
Some people have astigmatism, an irregular shape to the anterior surface of the eye (the cornea). Without contact lens or spectacle correction, their eyes cannot produce a sharply focused image of the world in front of them.
At the time of cataract surgery, a specially designed intraocular lens (a toric intraocular lens) may be available to improve image quality. This solution is available at Tamara Private Hospital but not in the public hospital system.
Toric Multifocal Intraocular Lenses
These are suitable for people with astigmatism and a desire for multifocal intraocular lenses who elect to receive treatment at Tamara Private Hospital. Reduced post-operative spectacle dependence can be achieved in a number of ways.
Many people opt for good distance vision with each eye, knowing that reading and/or computer glasses may be required for some close visual tasks.
Modified Monovision
In some cases, the dominant eye can be made to have good unaided distance vision, while the non-dominant eye is better for close visual tasks, using monofocal lenses.
Within a short time after surgery, the patient typically is able to function at a high level of spectacle independence, particularly with close activities under good lighting conditions and where objects with high contrast are viewed. (This approach is often also utilised by contact lenses wearers to achieve spectacle Independence.)
People who have been short sighted (myopic) often prefer to still be able to read without the need for glasses. In these cases, aiming for a low level of myopia is a good solution, with low powered glasses required for some distance activities such as driving.
Prior to your surgery, you will have the opportunity to discuss with Dr Hinchcliffe, the most appropriate solution to achieve your refractive goals.
We'd Love to Help You
We'd love to assist you! Please get in touch with our team via the Contact page.
If you are a GP or Optometrist, please review our Referral Information page.
