AA is a 56-year-old man who complained of gradual worsening of his vision. Everything appears blurry to him and he has difficulty driving at night. He is not a known diabetic or hypertensive. Evaluation confirmed that he has cataract.
There are many causes of loss of vision, however, cataract; according to the World Health Organization; remains the leading cause of visual impairment in all areas of the world, except for developed countries.
A cataract is described as the clouding of the lens of the eye. This prevents the passage of light through the affected lens and vision may be impaired. Most cataracts are related to ageing, although, occasionally, children may be born with the condition, or cataract may develop after an injury, inflammation or disease.
What Causes Cataract?
Most cataracts develop in people over age 55, but they occasionally occur in infants and young children. It usually develops in both eyes, but one eye may be worse than the other. Most cataracts are due to increasing age (age-related changes in the lens of the eye that cause it to become cloudy or opaque). However, other factors can contribute to cataract development, including:
- Diabetes mellitus.
- Drugs – These include: Corticosteroids, Chlorpromazine, etc.
- Ultraviolet radiation (excessive sunlight).
- Rarely, cataracts are present at birth or develop shortly after. They may be inherited or develop due to an infection (such as rubella) in the mother during pregnancy.
- A cataract may also develop following an eye injury or surgery for another eye problem.
Clinical features of cataract: How do you know if you or someone you know has cataract?
Normally, the lens focuses light on the retina, which sends the image through the optic nerve to the brain. However, if the lens is clouded by a cataract, light is scattered so that the lens can no longer focus it properly, causing visual problems. Changes in vision can be very gradual. Some people may not initially recognize the visual changes. However, as cataracts worsen, visual symptoms increase.
An individual who has cataract may experience the following:
- Blurred or hazy vision
- Reduced appreciation of colours
- Increased sensitivity to glare from lights, particularly when driving at night
- Increased difficulty seeing at night
- Change in the eye’s ability to see near or far objects.
Diagnosis of Cataract: Cataracts can be diagnosed through a comprehensive eye examination. This examination may include:
- Patient history to determine if visual difficulties are limiting daily activities and other general health concerns affecting vision.
- Visual acuity measurement to determine to what extent a cataract may be limiting near vision and ability to see far distance.
- Other specific examinations are done to determine the need for changes of an eyeglass or contact lens prescription, location of any cataracts, and the pressure within the eye.
- Further testing may be needed to determine whether other eye diseases may limit vision following cataract surgery.
Treatment of Cataract:
Cataract treatment is based on the level of visual impairment they cause. If a cataract minimally affects vision, or not at all, no treatment may be needed. Patients may be advised to monitor for increased visual symptoms and follow a regular check-up schedule.
In some cases, changing the eyeglass prescription may provide temporary visual improvement. In addition, anti-glare coatings on eyeglass lenses can help reduce glare for night driving, and increasing the amount of light used when reading may be beneficial.
The place of surgery: When a cataract progresses to the point that it affects a person’s ability to do normal everyday tasks, surgery may be needed. Cataract surgery involves removing the lens of the eye and replacing it with an artificial lens, in most cases.
How do you prevent cataract?
While there are no clinically proven approaches to preventing cataracts, simple preventive strategies include:
- Reducing exposure to sunlight through UV-blocking lenses
- Decreasing or stopping smoking
- Increasing antioxidant vitamin consumption by eating more leafy green vegetables and taking nutritional supplements
- Researchers have linked eye-friendly nutrients such as lutein and zeaxanthin, vitamin C, vitamin E and zinc to reducing the risk of certain eye diseases, including cataracts.
Key Recommendation: If an individual has blurry vision or the inner part of the eye (the lens) appears cloudy/whitish and vision appears to be worsening, consult a clinician as soon as possible or an ophthalmologist for further evaluation.
Dr Olagoke Ewedairo is a consultant family physician with over a decade experience as a clinician. He obtained his MB: BS degree from the University of Lagos. He completed a post-graduate training in Family Medicine and was awarded the Fellowship in Family Medicine by the National Post-graduate Medical College of Nigeria. He also has a Master of Public Health degree from the Harvard School of Public Health. He is passionate about improving patients’ health outcome as well as patient education. He can be
reached via email at firstname.lastname@example.org.