Cataracts affect over half a million Australians every year. Though many people may dread the day they might be told they have a cataract, eye cataracts are actually a very normal part of ageing, much like wrinkles and grey hairs. Because of this, we expect the number of cataract diagnoses to increase as our population ages and subsequently, the number of eye cataract treatments performed every year to also rise – cataract surgery is already one of the most common surgical procedures done in the Western world.
What is a cataract?
A cataract refers to any opacity of the crystalline lens inside the eye. The purpose of this lens is to provide some control over the bending and refraction of light as it enters the eye so that it focuses to a sharp point on the sensory retina at the back of the eyeball to provide clear vision.
A normal, healthy lens is perfectly clear at birth but as we get older, the ageing process results in this lens gradually losing its transparency. As this haziness of the lens progresses, light entering the eye becomes blocked or scattered, which degrades the image reaching the retina and you start to notice your vision is less clear than it may have been several years ago.
There are many different types of eye cataract, but treatment ultimately is largely the same when the time comes to do something about it. The most common type of cataracts arises from age but even under this umbrella term of “age-related cataract” there can be a few different forms of cataract depending on where exactly within the lens the opacity or haze is located.
Although cataracts are often quoted as one of the leading causes of blindness in the world, this statement is not based on cataracts causing permanent damage to the eye. Cataract treatment is not readily accessible in many developing countries worldwide, meaning that an individual with a dense cataract is effectively blind only due to the lack of adequate access to eyecare. Though our healthcare systems are far from perfect, we are fortunate in Western society to have many available eyecare providers in the form of optometrists and ophthalmologists.
What are the symptoms of cataract?
Because a cataract is basically an opacity in the light-transmitting lens of the eye, cataract symptoms are based around the scattering and impeding of light through to the retina. This being said, many patients will experience the effects of cataract without realising the source of them. Here are some common eye cataract symptoms to look out for:
- Blurry vision – some patients will also describe their vision as filmy or hazy, like looking through a dirty window.
- Glare sensitivity – as light is scattered and bounced off the opacities in a lens with cataract, your eye may perceive this as increased glare and associated discomfort.
- Difficulty driving at night or in low contrast road conditions – our pupils dilate and open further in dim lighting conditions. Although the purpose of this is to permit more light into the eye and so improve your night vision, it also means there is more area exposed of the lens and cataract sitting behind the pupil, which then has a greater potential to scatter light entering the eye. This can make people feel unsafe when driving in darker conditions, especially because of glare from street lights and oncoming car headlights.
- Difficulty reading – the process of reading is complex and involves much more than just the eyes, however, the ability of the eyes to discern the fine detail of text plays a big part. Patients with cataract will often report that they now need much better lighting to be able to read comfortably and this is due to the degradation of contrast vision from cataract. Conversely, when reading off a digital device such as a tablet or phone, if the screen is too bright the cataract may cause discomfort from glare.
What is the best treatment for cataract?
Currently, the only option considered to be a real eye cataract treatment with our existing modern medicine is surgical extraction of the cataract. Researchers are working on a steroid-based eye drop to reverse the effects of cataract, but this is still being developed.
Success rates for cataract surgery are excellent, quoted as around 98%. An anaesthetic is applied around the eye for comfort while an incision is made through the cornea to allow access to the cataract. The incision can be performed with either a femtosecond laser or a manual scalpel. The femtosecond laser can also be used to open the capsular bag which contains the cataract, otherwise a second handheld tool can be used for this step. The cataract is then broken up into small pieces using an ultrasound tool and suctioned from the eye. After the cataract has been removed, the surgeon will insert a clear lens implant into the capsular bag, which can often be calculated to correct your refractive error, reducing your dependency on glasses and contact lenses. The prescription of this lens implant is discussed with you prior to surgery.
Within a day or two after the procedure is performed on the eye, cataract symptoms are expected to be almost completely resolved. You may experience some decreasing mild blurriness as the eye heals over the following weeks but the clarity of your vision will be significantly improved. Depending on the type of lens implant decided between you and your surgeon, you may need an updated prescription in your spectacles but with certain types of implants some patients find they no longer need glasses at all, whether for near or distance vision.
If you think you may be developing a cataract, speak to your eye care practitioner. If the cataracts are not having any significant visual impact you may be advised to simply wait and monitor them, or else your optometrist can refer you to a suitable eye surgeon: 1300 297 583