Secondary Cataracts

Introduction

In a typical eye, the light enters and travels through the lens. The lens concentrates the light into a sharp image on the retina, which sends messages to the brain via the optic nerve. Different eye disorders can affect our vision. For instance, eye cataracts ‘cloud’ the lens and blur our vision. Other eye disorders, such as myopia, can also cause fuzzy vision, but cataracts have their own symptoms.

Cataracts

What are cataracts?

A cataract develops when the usually clear lens in your eye becomes hazy. 

Normally, the light flows through a transparent lens to reach your eye. The lens obscures your iris (the coloured part of your eye). The lens concentrates light so your brain and sight can collaborate to turn visual data into an image.

When a cataract forms on the lens, your eye loses the ability to  focus light properly. As a result, you may experience hazy vision or other visual problems. In addition, the location and size of the cataract will affect your eyesight. ^1,2

Causes

Water and proteins make up the majority of your eye's lens. Proteins and fibres linger in your eye as they degrade over time. These proteins can fog your lenses, making it difficult to see clearly. This is a normal — albeit unpleasant - part of growing older, but when accelerated by other factors, it can lead to cataract formation. ²

Cataract formation can be accelerated by a variety of factors, including:

• Diabetes.
• Steroids that are commonly used to treat illnesses such as arthritis and lupus.
• Chlorpromazine (Thorazine®) is a phenothiazine medication used to treat a range of disorders including schizophrenia and bipolar disorder.
• Eye surgery or injury to the eyes.
• Radiation therapy for the upper body.
• Spending a lot of time in the sun without sunglasses or other eye protection.

Symptoms

Cataracts are a common feature of the ageing eye. They may eventually result in:

• Cloudy, fuzzy, foggy, or filmy vision.
• Bright sunlight, lighting, or headlights cause sensitivity.
• Glare (the appearance of a halo around lights), which is most noticeable when driving at night with incoming headlights.
• Changes in prescription glasses, including unexpected nearsightedness.
• Double vision is a common occurrence.
• Brighter light is required when reading.
• Night vision is challenging (poor night vision).
• Changes in your perception of colour.

Treatments

Your doctor will most likely offer cataract surgery at some point. During cataract surgery, the clouded lens is removed and replaced with an artificial lens implant. The new lens is clear, customised to your vision demands, and tailored to fit your eye.

It takes around an hour to remove a cataract. The surgery is performed under local anaesthetic (medication to numb a specific area). Your doctor will use eye drops or a shot to numb your eye. You will be awake but not feel or see anything during the treatment.

Secondary Cataracts

What Can Cause Cataracts to Come Back?

If you have had cataract surgery to remove cataracts, there is a chance that you will develop secondary cataracts, often known as after-cataracts. Posterior capsular opacification is the medical term for this ailment (PCO). When the membrane around the lens capsule, which was not removed during cataract surgery and now surrounds the artificial lens or intraocular lens (IOL), becomes clouded, it impairs vision in a similar way to the cataract. Proteins mutate, and new cells sprout on the capsule's back, obstructing your field of vision. ^3,4,5

Who is at risk?

• Younger people are more vulnerable.
• People with diabetes had a greater rate of PCO development at a one-year follow-up.
• Uveitis: The uvea, which is located in the centre of the eye, is inflamed, red, and itchy. After cataract surgery, people with this syndrome are more prone to develop secondary cataracts.
• Myotonic dystrophy is an inherited muscular dystrophy illness that usually manifests in adulthood. It causes muscle contractions to last longer and makes it difficult to relax certain muscle groups. Cataracts are another indication of myotonic dystrophy, and sufferers with the disease commonly need additional capsulectomies after their initial cataract surgery.

Can Anything be Done to Prevent Them?

Modern surgical procedures, extensive epithelial capsule cell polishing during cataract surgery, and a variety of more advanced intraocular lenses all help to avoid or delay subsequent cataracts.

Treatments

A YAG laser is used to create an aperture or window in the centre of the posterior capsule (capsulotomy) to restore vision. The YAG laser capsulotomy method is a painless and quick outpatient surgery. It takes only a few minutes after anaesthetic drops are used to dilate the pupil. With eyedrop therapy, the patient can go home right away.

Visual recovery is full (assuming there are no other eye problems involving the retina, optic nerve, or cornea) and rapid, with noticeable improvement in just a few hours. After a few days, we conduct a check-up to track development and an exam to determine whether glasses are required (or not). In any event, a capsulotomy will help you see better in the long run. ^4,5

Complications

Despite being a fairly safe treatment, some patients report seeing "floaters" in the days following the procedure. This is likely due to small remaining capsule fragments that are usually reabsorbed and dissipate in a few days; however, this sensation may last longer in rare circumstances. ^3,4

It is a single-session therapy that is permanent, albeit in rare cases, the opacity recurs, necessitating a repeat procedure.

Summary

It's common to get cataracts and eyesight difficulties as you become older. However, you don't have to put up with it. Cataract surgery is one of the safest and most effective procedures available. It's a quick and painless procedure. It restores vision to 90% of persons and is rarely associated with problems. Sometimes, people may develop secondary cataracts following cataract surgery which can be safely and quickly removed with YAG laser capsulotomy.