Types of Cataracts

A cataract is a clouding of the eye’s natural lens caused by proteins in the eye forming clumps which prevent the lens from sending clear images to the retina. The lens inside your eye works much like a camera lens, focusing light onto your retina for clear vision. For people under 50 years the lens also adjusts the eye’s focus which allows us to see things up close and far away.

Symptoms that you may be developing a cataract are cloudy or blurry vision, seeing colours as faded, increased sensitivity to glare, halos surrounding lights, poor night vision and a need for a frequent change in prescription glasses. You may end up with cataracts in both eyes, but they don’t always develop at the same time. It is important to recognise early signs as a prompt to having an eye health check.

Types of Cataracts:

There are three main areas in the eye’s lens where an opacity can develop: the centre portion of the natural lens (nucleus), the outer part of the lens (cortex) and the back surface of the lens (subcapsular). People commonly develop opacity in more than one area of their lens.

Nuclear sclerotic cataract - this is the most common type of age-related cataract. The centre part of the natural lens of the eye, the nucleus, becomes yellow and hardens (sclerosis). There is usually a gradual deterioration in vision. As this type of cataract progresses, it changes the eye’s ability to focus, and people often have a temporary improvement in their near vision. Normally slow changing.

Cortical cataract - this less common cataract is characterised by white opacities that start in the cortex, the outer part of the lens, and work their way to the centre of the eye. Changes in the water content of the lens fibres creates fissures that look like spokes of a wheel. These fissures cause the light that enters the eye to scatter, giving blurred vision, glare, contrast and depth perception problems. Normally slow changing.

Posterior subcapsular cataract - these cataracts form as opacities on the back surface (posterior) of the lens. It is called sub capsular because it forms beneath the lens capsule. Symptoms can become noticeable within months and include difficulty with reading, halo effects and glare around lights. People with diabetes or those taking high doses of steroid medications have a greater risk of developing a subcapsular cataract. Normally fast changing.

Traumatic cataract - can develop in the effected eye after an accident such as following both blunt and penetrating eye injuries.

Metabolic cataracts - can develop in uncontrolled diabetes, people with galactosemia, Wilson disease, and Myotonic dystrophy.

Diabetic snowflake cataracts - appear as grey-white subcapsular opacities and often progress rapidly turning the entire lens white. This rapid onset form of cataract is quite uncommon and may be found in some younger type 1 diabetic patients with very elevated blood sugars.

Congenital cataracts - can occur by themselves or may be associated with a systemic disease.

Risk factors

Apart from ageing, some of the risk factors of developing a cataract are:

       too much UV light exposure

       diabetes

       hypertension

       obesity

       smoking

       prolonged use of steroid medications

       statin medications used to reduce cholesterol

       previous eye injury or inflammation

       previous eye surgery (cornea transplant, glaucoma surgery)

       hormone replacement therapy

       significant alcohol consumption

       high myopia

       family history of cataracts

Prevention

To help reduce your risk of developing cataracts, you can protect your eyes from UVB rays by wearing sunglasses outside, eat fruits and vegetables that contain antioxidants, stop smoking, have a healthy weight and keep any medical conditions managed.

Diagnostic testing

An ophthalmic examination will check if a visually significant lens opacity is present and if it is the cause for the person’s level of vision. Your surgeon can determine if removing the cataract is likely to improve your vision and improve your everyday life, and will discuss with you whether this potential improvement is worth the risk of having the procedure. Your surgeon will talk to you about if you are able to manage with having the surgery and are able to follow the post operative instructions and follow up care.

Treatment

If left untreated, cataracts can lead to blindness. If you are unable or not interested in surgery, your cataracts may be managed with stronger eyeglasses, magnifying lenses, or sunglasses with an anti-glare coating.

Cataract surgery is a very successful procedure to restore vision and is recommended when cataracts prevent you from doing your normal everyday activities, such as reading or driving. During surgery, the surgeon removes the opacified natural lens and replaces it with a new clear artificial intraocular lens (IOL).

 

Contact Bowen Eye Clinic on 0800 69 20 20 if you think you have cataracts and would like them assessed for cataract surgery.