A cataract is a fairly common finding during routine eye examinations. In fact, as early and even moderate cataracts cause no noticeable vision problems, it is possible to have one without realising. Fortunately, if you have an undiagnosed cataract with no accompanying vision problems, there’s no need to rush into cataract surgery. While tens of thousands of cataract surgery procedures are performed around the world each day, cataract surgery is typically considered necessary only when your cataracts progress to a level that bothers you and hinders your daily tasks. So, exactly what is a cataract?
What is a Cataract?
Cataracts are a haze or opacity of the crystalline lens of the eye. At birth, a normally developed lens is transparent, allowing light to pass through to form vision. However, as we age, this lens gradually loses its clarity and transparency, resulting in an age-related cataract. While this process is still not fully understood, doctors believe that oxidative stress, which accumulates with age, changes the structure of the fibres of the lens such that light can no longer pass through as easily.
There are three types of age-related cataracts, which are also known as senile cataracts:
- Nuclear sclerosis. The nucleus of the lens refers to its central area. As nuclear sclerosis develops, this core becomes cloudy and turns a brownish-yellow colour. Nuclear sclerotic cataracts can result in vision problems such as a decrease in clarity or foggy vision, altered colour perception, decreased contrast sensitivity, and your prescription becoming more short-sighted (myopic).
- Cortical cataracts. The cortex is the layer of lens fibres that surround the nucleus. During the development of a cortical cataract, the opacities in this area appear like opaque white or grey spokes, radiating from the edge of the lens inward. Cortical cataracts are often responsible for an increase in glare sensitivity, which many people find impacts their comfort when driving at night-time. Depending on how close toward the centre of your lens the spokes extend, they may impair the clarity of your sight. Cortical cataracts may also be responsible for causing your prescription to become more long-sighted (hyperopic).
- Posterior subcapsular cataracts. The outer layer of the lens enclosing the lens cortex is known as the capsule. Posterior subcapsular cataracts form beneath this capsule at the back surface of the lens, appearing like a dense plaque. Often this type of cataract can cause the most debilitating vision problems due to its location.
Early to moderate cataracts may be adequately managed with a change in prescription to your glasses or contact lenses. However, some people may find frequently updating their glasses to be financially unviable, and instead, opt to undergo cataract surgery sooner rather than later.
Cataract surgery is indicated when the symptoms of your cataracts reach the point where you can no longer comfortably participate in whatever activities you need to accomplish and your sight cannot be sufficiently improved with an updated prescription. This may look different for different individuals.
For example, a taxi driver who works a night shift will likely seek cataract surgery earlier than a driver who only works during daylight conditions, even if their cataracts are at exactly the same stage. An interior designer who relies on accurate colour vision may be more bothered by subtle changes to their colour perception compared to an accountant, leading them to undergo cataract surgery even if their sight is otherwise still sharp.
What is a Cataract Caused By?
In addition to increasing age, there are other potential causes of a cataract, which may necessitate treatment with cataract surgery. These include:
- Corticosteroid medications, whether taken orally through inhalers or tablets or administered directly to the eye through topical drops or injections
- Smoking, which has been linked with earlier development of cataract and an increased likelihood of requiring cataract surgery
- Certain systemic diseases, such as diabetes
- Congenital health conditions, including a metabolic disease called galactosaemia
- Trauma, which may involve physical trauma or electrocution
- A history of inflammatory eye diseases, such as uveitis.
- As a side effect of certain eye procedures, such as retinal detachment surgery
- Excessive UV exposure, which can accelerate the development of cataracts
While some of these factors are unavoidable, there are steps you can take to reduce your risk of developing a cataract or at least delay its growth.
- Cease smoking
- If you are prescribed steroid medications, your doctor should advise you to monitor your vision with an eye care professional. If you feel your vision deteriorating, speak to your prescribing doctor about changing your dosage or to an alternative medication
- Use UV protection in the form of a hat and sunglasses when you’re outdoors, particularly if you live in high UV exposure areas, such as Australia. If you work in an industry that involves UV exposure, such as welding, you should always wear your protective equipment.
- Manage any systemic health conditions as well as possible. Keeping your blood glucose levels low if you have diabetes can help to reduce your risk of developing a diabetic cataract.
Cataract surgery is considered a safe and effective procedure and is the only definitive way of treating a visually significant cataract. Most uncomplicated cataract operations take as little as 15 to 20 minutes in a day surgery theatre. You will go home soon after your operation with a list of cataract aftercare instructions.
If you have further questions about what is a cataract or need guidance regarding cataract treatment, the best person to talk to is your optometrist or ophthalmologist.
Call us now on (03) 9070 3580 for a consultation.
Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.