| Cataracts | |||||
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- What are cataracts?
- Symptoms of cataracts
- Causes of cataracts
- Treatment of cataracts
- Important cataracts facts
Cataracts are cloudy, opaque areas on the lens of the eye which interfere with proper vision, which eventually can cause blindness as they cover the lens.
The lens of the eye needs to be clear to enable vision. The lens focuses light (or an image) onto the retina, when nerve signals are sent to the brain to receive a sharp image.
The lens of the eye consists of three layers:
- Outer layer (capsule) - this consists of a thin, clear membrane
- Middle layer (cortex) - this is the soft, middle layer
- Inner layer (nucleus) - this is the hard centre of the lens
There are three types of cataracts depending on which part of the lens is affected:
- Subcapsular - affects the outer layer (capsule) and causes a small cloudy area just under the capsule of the lens preventing light from entering correctly and it causes problems with reading and vision at night
- Cortical - affects the middle layer (cortex) and causes cloudy streak formations on the outer edge of the cortex which then migrate to the centre of the lens and severely cloud vision so that both distant and near objects appear blurry or distorted
- Nuclear - affects the inner layer (nucleus) and causes a change in the way that light is focused, the lens eventually becoming more yellowed and cloudy affecting driving and inability to distinguish between certain colours (blue and purple)
Cataract formation can start as early as the 40's, but it is people who are over 65 that have a higher risk of developing this condition, with mor ethan half of all people in Australia estimated to have cataracts by age 80.
- Cloudy or blurry vision
- Double vision
- Frequent prescriptions to change lens of glasses (as eyesight gets increasingly worse)
- Halo around lights
- Perception of colours looking faded
- Perception of looking through a veil or cloud
- Sensitivity to glare from lights, which may appear to be too bright
While it is still not known why cataracts develop, scientists do know that certain groups of people and specific activities give people a higher risk for developing cataracts:
- Certain medications - some drugs (such as cortisone drugs) may give people a higher risk of developing cataracts
- Diabetes - metabolic disorders such as diabeteincrease the risk of cataracts due to the improper functioning of several systems in the body
- Drinking heavily - this is a risk factor for cataracts as the nutritional levels of antioxidants may be very low
- Eye injuries - people who injury their eyes in any type of accidents are more prone to developing cataracts
- Genetics - cataract development seems to run in families, which may be caused by defective genes
- People over 65 - as the eye ages, it is more prone to damage and development of cataracts as it becomes thicker and less flexible, not working as well as it does in younger years
- Pregnant women - if a woman develops rubella (German measles) when she is pregnant, there is a possibility of passing on cataract development to the baby (this is termed congenital cataracts)
- Prolonged exposure to sunlight - long term exposure to ultraviolet light is a risk factor for developing cataracts
- Smoking - smoking is another risk factor for developing eye conditions and especially cataracts as levels of certain antioxidants may be depleted by smoking which may lead to development of cataracts
Diagnosis and testing
Cataracts are disagnosed through complete eye exams including:
- Eye chart testing - to determine how well you can view the letters in the eye chart from each eye and at different distances; this test shows how clear vision is and at which distance vision becomes distorted
- Eye exam - special eye drops will be administered to each eye (which do not normally cause any pain) which widen the pupil to allow the eye specialist to view your eyes through a magnifying lens machine for signs of cataracts; vision may stay blurry after the eye exam, due to the effects of the eye drops, but this effect is temporary (it is recommended to have someone take you home after the test)
Conventional treatment
The best way to treat cataracts is to have surgery to remove them and restore proper vision by replacing the damaged lens with a clear lens implant.
Today cataract surgery is simple and effective and is performed without the need for over-night stay in an eye hospital.
A comprehensive examination will be performed by the eye specialist to determine exactly where the cataract is, how advanced it is and which part of the lens it affects. The examination will also determine if the patient is a good candidate for laser eye surgery.
Surgery usually involves the following:
- Anaesthetic to the eye only
- The eye area is cleaned with antiseptic
- There are 3 types of procedures used to remove the cataract and insert the artificial lens in Australia, with the eye specialist (opthalmologist)
viewing the eye and operating through a special miscroscope device to enable precise surgery
- Phacoemulsification - in this procedure, a small cut is made in the eye and a small probe is inserted into the cataract to break it up into small pieces and suction it up (the lens is also removed), after which the artificial lens is positioned; stitches are usually not required and this procedure usually last 1 hour
- Extracapsular Extraction - this procedure is not commonly used except on those patients whose lens is difficult to remove with the normal surgery (phacoemulsification), where the front of the capsule is cut to enable removal of the lens; this procedures requires stitches and post-operative care
- Intracapsular Extraction - this is a rare surgery, not normally performed, where the entire lens and capsule are removed and replaced with an artificial one; stitiches and more post-operative care may be required
Sometimes the cataracts can be corrected through non-surgical means (if they are mild to prevent further deterioration), through the use of special prescription glasses or contact lenses.
Alternative / complementary treatment
Always ensure that you notify your medical practitioner of any supplements that you want to take - it may interfere with other medication or conditions you have. Confirm with your doctor it is safe to take BEFORE you try it.
- Herbs - certain herbs have known beneficial properties to help reduce symptoms or prevent cataracts happening in the first place
- Bilberry - British air force pilots who ate bilberry jam before night raids, found their night vision was better than if they didnt eat it; bilberries contain the antioxidant compound anthocyanidins which have known beneficial effects on eye health and cataracts prevention
- Ginkgo biloba - this herb increase vascular blood activity to the eye, ensuring there is a proper blood supply, plus it contains high levels of flavonoid and terpenoid compounds which are potent antioxidants that neutralise or prevent freee radical damage that can potentially cause cataracts
- Lifestyle - certain lifestyle factors are recommended to reduce risk of developing cataracts
- Stop drinking - heavy drinking is a known risk factor for developing cataracts
- Stop smoking - smoking is a known risk factor for developing cataracts
- Wear a hat - always wear a hat with a brim when outside to avoid prolongd sun exposure to the eyes as this is a known risk factor for cataracts
- Wear sunglasses - always wear sunglasses when outside as prolongd sun exposure to the eyes is a known risk factor for cataracts
- Minerals - there are two main minerals which have potent antioxidant activity
that may reduce risk of cataracts from developing in the first place or reducing symptoms in existing condition
- Selenium - studies have shown that this mineral works to prevent free radical damage which is thought the damage the cells and allow cataracts to develop in the first place
- Zinc - numerous studies show that this mineral is very important for eye health as it prevent free radical damage which can cause cataracts
- Other nutrients - various other nutrients have been shown to have a benefical effect
on cataracts by increasing antioxidant activity and reducing risk of damage to the delicate lens by free radicals
- Alpha-lipoid acid - this is a really potent antioxidant which greatly impedes or reduces oxidation damage especially to the cells of the eye
- Glutathione - this amino acid is a potent antioxidant which removes toxins and neutralises / prevents free radical damage that can lead to cataract formation
- Lutein - this antioxidant found in fruits and vegetables lowers the risk for cataracts and naturally exists in the retina; lutein is one of the natural pigments that colours the eye
- N-acetyl-cysteine (NAC) - this substance is a powerful antioxidant which removes toxins and neutralises / prevents free radical damage that can lead to cataract formation
- Zeaxanthin - this antioxidant found in fruits and vegetables lowers the risk for cataracts and naturally exists in the retina; zeaxanthin is one of the natural pigments that colours the eye
- Vitamins - it is thought that the antioxidant properties of many vitamins are responsible for reducing the severeity of symptoms of cataracts (if the condition is already present) or preventing it from developing altogether
- Betacarotene - this is the precursor to vitamin A and is often used instead of vitamin A, as it has less toxicity when used in higher doses; this is a potent antioxidant which acts
- Bioflavonoids - the antioxidant activity of bioflavonoids are shown to reduce risk for developing cataracts or alleviating symptoms in an existing condition
- Vitamin A - this vitamin is a major antioxidant which acts to prevent free radical damage to the eye and lowers risk of cataracts and reduces symptoms in an existing condition
- Vitamin C - this vitamin (together with bioflavonoids) is a major antioxidant which acts to prevent free radical damage to the eye and lowers risk of cataracts and reduces symptoms in an existing condition
- Vitamin E - this vitamin is a potent antioxidant which acts to prevent free radical damage to the eye and lowers the risk of cataracts developing, but also reduces the symptoms in an existing condition
- Cataracts are one of the leading causes of blindness in the world
- Most types of cataracts are due to ageing
- While symptoms of cataracts can start in the 40's and 50's, it is not until the 60's that they cause vision loss
- The length of time it takes for cataracts to cause vision loss can take anywhere from many months to many years
- Cataract surgery is quite safe and very effective in removing cataracts and improving eyesight
- Cataracts can develop in one eye or in both eyes
- A diet high in fresh vegetables and fruits (rich in antioxidants) may help to prevent cataracts from developing in the first place
Last reviewed: 14 January 2007 || Last updated: 2 September 2007
Related Articles
references
- Jacques PF, Chylack Jr LT . Epidemiologic evidence of a role for the antioxidant vitamins and carotenoids in cataract prevention. American Journal of Clinical Nutrition, 1991; Vol 53, 352S-355S
- Maitra I, Serbinova E, Trischler H, Packer L. Alpha-lipoic acid prevents buthionine sulfoximine-induced cataract formation in newborn rats. Free Radical Biology and Medicine, Volume 18(4), 1995:823-829(7)
- Mares, JA. High-dose Antioxidant Supplementation and Cataract Risk. Nutrition Reviews, Volume 62(1),2004:28-32(5)
- Moeller SM, JacquesPF, Blumberg JB. The Potential Role of Dietary Xanthophylls in Cataract and Age-Related Macular Degeneration. Journal of the American College of Nutrition, Vol. 19, No. 90005, 522S-527S (2000)
- Varma SD, Hegde KR, Kovtun S. Attenuation and Delay of Diabetic Cataracts by Antioxidants: Effectiveness of Pyruvate after Onset of Cataract. Ophthalmologica 2005;219:309-315
- Yeum K-J, Shang F, Schalch W, Russell RM, Taylor A. Fat-soluble nutrient concentrations in different layers of human cataractous lens. Current Eye Research, Volume 19(6), December 1999; 502-505
To learn more, go to the National Eye Institute (USA) web site
NOTE: Mega doses of any type of vitamin, mineral, amino acid or herbal supplement cannot cure illnesses and in fact can be very dangerous and produce toxic side effects and interfere with medicine you are taking. Always ensure you consult your doctor before taking any type of complementary supplements.
Disclaimer: This guide is not intended to be used for diagnostic or prescriptive purposes. For any treatment or diagnosis of illness, please see your doctor.
