Cataract surgery: Innovative techniques and what you need to know

What is a cataract?

The natural lens inside the eye is positioned behind the color or iris of the eye. The function of this lens is to focus incoming light on the retina, permitting sharp vision for all distances. To see clearly at near the lens needs to change shape or accommodate. As we age, the lens loses its ability to focus at near, because it loses its elasticity. This is known as presbyopia or dysfunctional lens syndrome, and results in the need for reading glasses. This aging process of the lens is progressive, and the lens also becomes cloudy. This cloudy lens is known as a cataract.

How are cataracts treated?

The cataracts are treated with a surgical procedure, performed with a needle through a 2,2 mm incision. The cloudy center of the natural lens is washed out and replaced with an artificial intra-ocular lens. The artificial lens grows into position in the bag left from the old lens within six weeks and never needs a replacement. 

The procedure is done with local anesthesia of the eye, as well as conscious sedation. The procedure itself is painless, and the patient might experience some grittiness as the feeling returns but should not experience any discomfort. The result of the procedure is permanent as the cataract can not grow again. 

Are there different kinds of artificial lenses?

The primary aim of the procedure is to restore vision, but the secondary aim is to also reduce a patients’ spectacle dependence. Essentially, we need good vision at three distances, namely far, intermediate and near. Intermediate vision is important for activities like computer work, reading the paper and seeing your face in the mirror. 

The power of the lens to be implanted is calculated from measurements taken with a laser instrument of each individual eye. Artificial intelligence is used in software that can accurately establish the correct lens for an individual eye to reduce the spectacle error as much as possible. 

A monofocal lens can only focus at one distance, whether it be distance or near. With monovision one eye focuses sharp for distance, but the other eye focuses a little closer for intermediate, and thus a patient will be less dependent on spectacles but will still need spectacles for reading. 

Extended range of vision lenses provides a longer area that is in focus than a monofocal lens, providing a larger area of overlap between the two eyes with balanced vision. The result is less spectacle dependence and for some patients, complete spectacle independence.

Multifocal intra-ocular lenses provide the best opportunity for complete spectacle independence. 

How does multifocal lenses work?

Multifocal intra-ocular lenses do not have the same side-effects as multifocal spectacle lenses that causes a distorted view at the bottom. The implanted lens works with small rings that focuses for distance as well as intermediate and near, providing complete spectacle independence for most. Approximately 5% of patients might still need spectacle on occasion, mostly for reading small print when the lighting is poor. 

Are there any side-effects to multifocal lenses?

Not all individuals are candidates for multifocal intra-ocular lenses. A patients’ suitability depends on many factors including age, spectacle error, eye health and occupation. It is advisable for every patient to discuss their options with their ophthalmologist. The multifocal intra-ocular lenses are more expensive than standard monofocal lenses, but the price compares well with the cost of multifocal spectacles. The most common observation from patients is a transient awareness of small rings around lights at night, but this improves spontaneously.

Learn more or book a consultation at drfrikkiehartog.co.za