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Description

A cataract is a clouding of the natural lens, the part of the eye responsible for focusing light onto the retina (the light-sensing layer at the back of the eye), producing clear, sharp images. This can affect vision by making images appear blurry or fuzzy.

Cataracts can appear in one or both eyes and if left untreated, they may result in blindness. For many people, cataracts develop as a result of natural aging however, they can appear at any age, from babies (congenital) and young children (developmental) to adults. The condition is referred to as childhood cataracts if found in young children and babies and age-related in adults. People with certain inherited retinal degenerations such as Retinitis Pigmentosa are more prone to developing cataracts at a younger age.

Symptoms

Childhood cataracts: In young babies and children, the symptoms of cataracts may vary and in some cases, can be difficult to identify. They may not realise that their vision is being affected but might miss things in their field of vision, or in babies where the cataracts are quite severe, they may not be aware of what is around them.

Age-related cataracts: In the early stages of age-related cataracts, there may not be many visible symptoms.

As time progresses, cataracts can gradually start to affect vision by causing images to appear blurry, misty or fuzzy and colours appear less vibrant. Small patches or spots may appear within the field of vision. The light may start to affect vision, with increased difficulty in seeing in dim light and also potentially in bright light (halos may also appear around bright lights). With advanced cataracts, the lens can start to look yellow or brown in colour and this in turn leads to vision gaining a yellow or brown tint.

Causes

When cataracts are mentioned, people often think of a film that grows on their eyes causing them to see double or blurred images. However, a cataract does not form on the eye, but rather within the eye.

Childhood cataracts: In babies and children, it can be difficult to determine the cause of the condition; however genetics and infections during pregnancy can play a role in the development of cataracts.

Age-related cataracts: In adults, cataracts are caused by proteins which clump together within the lens capsule. Over time, these protein clumps accumulate causing the lens to cloud, making images look blurred or fuzzy.

There are a number of factors which are thought to increase the risk of cataracts. These include having a family history of cataracts, steroid intake, smoking, lifestyle and overexposure to sunlight. Eye injuries, inflammation and diseases such as diabetes and alcoholism have also been known to cause cataracts. People with certain inherited retinal degenerations such as Retinitis Pigmentosa are more prone to developing cataracts at a younger age.

Diagnosis

Cataracts are diagnosed following a thorough examination of the eyes. This examination can be offered by an optometrist at a local optician or by a specialist eye doctor.

Childhood cataracts: Newborn babies will have their eyes checked twice within their first eight weeks, to look for eye conditions including congenital cataracts. In young children, their eyes may be examined by their GP or optometrist.

Childhood and Age-related cataracts: One of the tests the optometrist or GP may use includes looking into the eye using an ophthalmoscope. This instrument produces a larger image of the eye and uses a light which helps with the examination. They will be able to identify if there are any cataracts and establish how much of the lens is affected. If cataracts are present, they may refer the individual for an appointment with an ophthalmologist in a hospital clinic.

At the appointment, the ophthalmologist will ask about a person’s medical history, including any family history of eye conditions. Individuals will receive a clinical eye examination where they may be asked to read letters off a chart (Snellen chart). They will also check intraocular pressure and may examine visual field and visual acuity.

The pupil (central opening in the coloured part of the eye) will be temporarily widened using drops. This will allow the eye doctor to look directly at the lens and assess the type and extent of the cataract.

Treatment

There are treatment options available for cataracts.

Childhood cataracts: For congenital or developmental cataracts, the course of treatment will depend on the nature of the cataracts. For some cases, surgery may provide benefit to the individual and in other cases, glasses or contact lenses may be sufficient to provide benefit. A combination of these options may also be necessary to provide the best benefit.

If cataract surgery is required in young children, this will take place in hospital where the baby or child will have the lens with the cataract removed under general anaesthetic (this will ensure that there is no pain during the operation and that the individual is unconscious). They may be required to stay overnight or longer in hospital for this operation. Where cataracts are present in both eyes of young babies, separate surgeries may be required to remove each lens separately (about one week apart).

Before the procedure, the surgeon will dilate the pupil of the eye(s) with eye drops (to make them wider). During surgery, a small cut is made in the cornea (clear part at the front of the eye) and the lens containing the cataract is removed. A replacement (plastic) lens will then be fitted in many cases. In other cases, the lens may not be replaced and instead a contact lens may be used. Following surgery, a pad may be placed over the child’s eye to protect it from harm and ensure the best possible chances of recovery.

Following this surgery, glasses or contact lenses may be required to help improve vision. In other cases, children may need to undergo occlusion therapy, where the child wears a patch to cover their stronger eye and uses their weaker eye to see. Training the weaker eye strengthens vision overall by teaching the brain to use the visual information received from the weaker eye to see the world around them. Early surgery is recommended for childhood cataract in order to allow normal development of the visual part of the brain.

Age-related cataracts: For age-related cataracts, where the symptoms are absent or very mild, treatment may not be recommended at that stage. Early symptoms may be addressed without surgery and instead providing stronger contact lenses, glasses or bifocals. The ophthalmologist can provide guidance on which treatment option may be best at the time.

Where the symptoms have become more severe, an individual may require surgery to remove and replace the lens with an artificial (plastic) replacement. This surgery should help to restore vision.

Before having the surgery, the individual will have a pre-operative assessment, where their health is assessed and their eyes will be examined and measured for the replacement lens. There are many types of replacement lenses available. The ophthalmologist will discuss with the individual which lens will best suit them. Replacement lenses include; fixed strength lenses (monofocal; designed for one level of vision, usually distance vision), multifocal lenses (allow for two levels of vision, near and distance vision) and accommodating lenses (allows for various levels of vision similar to the human lens).

In the operation, eye drops will be administered into the eyes to widen the pupils (black section at the middle of the eye) and a local anaesthetic will be given which ensures that there is no pain during surgery. Individuals may see a bright light during the procedure but will not be able to see or feel anything. The procedure is performed using keyhole surgery, where a very small cut is made in the eye to remove the cloudy cataract and replace it with the artificial lens. This procedure can be completed in a day, with most individuals admitted to hospital as a day-case, meaning no overnight stay at the hospital.

Following surgery, some individuals may notice improvements in their vision quite quickly; however it may take some time to completely recover. To ensure the best chances of recovery, individuals will be asked to protect their eyes as much as possible. This includes trying not to rub their eyes or allow their eyes to come into contact with chemicals such as soaps or lotions. Individuals are also advised to cover their eye(s) with a pad to protect them after surgery.

Depending on the replacement lens a person receives, some individuals may still need to wear glasses to allow them to see objects which are near or far to them. Following surgery, individuals may need to receive a new prescription for their glasses as their vision may have changed. Pre-existing optical errors (short-sightedness, long-sightedness, astigmatism) may be corrected by choosing an appropriate lens implant. As a result, some patients might end up free of the necessity to wear glasses following cataract surgery.

People with cataracts associated with an inherited retinal degeneration can notice significant improvement in vision following cataract surgery. Due to the compromised function of the retina it may be difficult for the surgeon to confidently predict the outcome of surgery.

While cataract surgery is one of the most commonly performed operations, with a high success rate and low rate of complications, like all operations, cataract surgery is not without risk. Cataract surgery puts the eye at risk of bacterial infection. While this is very uncommon in this day and age, severe bacterial infection within the eye after cataract surgery may result in loss of the eye. The implanted plastic lens generally rests of the back membrane of the patient’s original lens. This membrane (called the ‘posterior capsule’) may frost over some time after the surgery and have the same effect as the original cataract.

This frosting can be dealt with by opening a hole in the membrane using a YAG laser. Uncommonly, the macula, the area of the retina which gives us our finest vision, may become soggy (macular oedema). This will degrade the patient’s quality of vision. There are medications available to treat this. Uncommonly, detachment of the retina may occur following cataract surgery. The surgeon will always discuss these, and other, possible complications with the patient so that the patient can make an informed decision regarding cataract surgery.

General eye check-ups are important for people living with Cataracts, as these individuals may still be at risk of developing other kinds of eye problems that affect the general population, some of which may be treatable.

No matter what level of vision a person may have, it is important to look after the eyes. To find out more about what can be done to take care of the eyes on a daily basis, please visit our Tips for Good Eye Health.

Research

Research continues to advance, with many clinical trials now underway to improve the quality of care and identify new and improved treatment options for cataracts.

In the case of childhood cataracts, early detection is important to ensure the best possible outcomes. Newer diagnostic tools are being developed and investigated which aim to provide earlier detection in such cases.

Clinical trials continue to evaluate new and improved replacement lenses, which will aim to be as similar as possible to the function of the human lens. There are many different lenses being investigated, demonstrating the promise for greater choice and potentially more advanced treatment options in the near future.

Investigators are also investigating ways to improve lens replacement surgery, with focus placed on achieving the best outcomes whilst ensuring the most optimum recovery possible. Newer surgical techniques are being investigated which aim to be as minimally invasive as possible (surgery which is as kind to the eye as it can be), with fewer adverse effects after the procedure. Eye infection and inflammation can occur following surgery and clinical trials are ongoing to investigate the therapeutic strategies which will best minimise such risks.

Information about clinical trials can be found on their website  and can be searched by condition and trial location.

For further information, please contact the Research Department on 01 6789004.

Support

Receiving a diagnosis can be overwhelming for anyone, but this is not a journey that you have to make alone. There are many groups and resources available to provide support for people living with Cataracts.

Fighting Blindness offers a free and confidential counselling service (Insight Counselling). For further information please contact insight@fightingblindness.ie or call 01 6746496.

A mindfulness group is also available on every Wednesday at the Fighting Blindness office at 11am.

For technology support and guidance, the Dublin-based Technology Exchange Club meets every Monday at the Fighting Blindness office at 11am. Another Technology Exchange Club, based in Cork, meet every Saturday in the Cork City Library, Grand Parade, Cork City at 11am. The Cork-based club do not meet on Bank Holiday weekends or on the second Saturday of the month. For further information please contact insight@fightingblindness.ie or call 01 6746496.

Resources

Féach provides support for parents of children living with sight loss in Ireland.

ChildVision is the national education centre for children with sight loss in Ireland.

NCBI (National Council for the Blind in Ireland) provides support and services for people living with sight loss in Ireland.

Irish Guide Dogs for the blind helps individuals and their families to achieve improved mobility and independence.

 

 

Last Updated: 4th March 2019