Cataracts - Symptoms, Causes, and Treatment
Cataracts are a common eye condition that affects the eye's lens, causing it to become cloudy and opaque. The lens is a transparent structure behind the iris and pupil that helps focus light on the retina, sending visual signals to the brain. When the lens becomes cloudy, it can interfere with light transmission and cause vision problems such as blurred vision, difficulty seeing at night, and sensitivity to light. They may also cause colours to appear faded or yellowed, sometimes with a halo effect around lights.
Cataracts are most commonly caused by age-related changes to the lens. However, they can also be caused by injury, radiation exposure, certain medications, and underlying medical conditions such as diabetes. Cataracts may also be present at birth or develop in early childhood, in which case they are called congenital cataracts.
The eye's lens is composed of specialised proteins called crystallins arranged in a specific pattern to allow light to pass through. These proteins are essential for maintaining the lens's transparency and allowing it to function correctly.
As we age, the proteins in the lens can become damaged and break down, causing them to clump together and form opaque areas in the lens. This can make the lens cloudy, making it more difficult for light to pass through and causing vision problems. The breakdown of these proteins can also cause changes in the refractive properties of the lens, leading to changes in the eye's prescription.
In addition to age-related changes, other factors can contribute to the development of cataracts, such as long-term exposure to ultraviolet light, smoking, and certain medical conditions such as diabetes. Cataracts can also be caused by trauma or injury to the eye, certain medications, and radiation exposure.
“At what age do cataracts typically develop? Cataracts can develop at any age but are more common in older adults. It is estimated that more than half of over-65-year-olds have some degree of cataract development.”
This is the most common symptom of cataracts. The cloudiness or blurriness can affect one or both eyes and make it difficult to see clearly.
Cataracts can make it difficult to tolerate bright lights or sunlight, leading to increased sensitivity to glare.
Cataracts can make it harder to see in low light conditions, such as when driving at night.
Cataracts can cause double vision in one eye, which can signify a more advanced cataract.
As cataracts progress, colours may appear less vibrant or take on a yellowish tint.
Cataracts can cause frequent changes in the eyeglass prescription needed to achieve clear vision.
Cataracts can cause halos or rings around lights, particularly at night.
Cataracts can make reading difficult, particularly in small print or low-light conditions.
Not all changes in vision are due to cataracts, and some other eye conditions can cause similar symptoms. It's important to see an ophthalmologist for a comprehensive eye exam to determine the cause of any vision changes and to receive appropriate treatment.
The treatment for cataracts depends on the severity of the cataract and how much it affects the vision. In the early stages of cataracts, changes in eyeglass prescription may be sufficient to improve vision. However, as the cataract progresses and begins to affect daily activities, surgery may be needed to remove the cloudy lens and restore clear vision.
Cataract surgery is a safe and effective procedure that involves removing the clouded lens and replacing it with an artificial lens called an intraocular lens (IOL). The surgery is usually done on an outpatient basis and is typically done under local anaesthesia. The surgeon makes a small incision in the eye, removes the cloudy lens, and inserts the IOL. The procedure usually takes less than an hour to complete, and patients can usually go home the same day.
While surgery is the most effective treatment option for cataracts, other non-surgical options may suit patients with mild cataracts or other medical conditions that make surgery risky:
- Changing your prescription. If the cataract is only causing minor vision impairment, changing your prescription may help improve vision, as well as adding an anti-glare coating to glasses, and using bifocals or progressive lenses.
- Magnifying devices, such as a magnifying glass, to help with close-up tasks like reading.
- Supplements with Lutein & Zeaxanthin. Lutein & Zeaxanthin have been extensively studied (including part of the global AREDS2 study).
As we age, the proteins in the eye's lens may break down or clump together, causing the lens to become cloudy and form cataracts. The exact mechanism by which this happens is not fully understood. Still, it is thought to be due to changes in the chemical structure of the lens proteins over time. Additionally, the accumulation of oxidative damage in the lens over time may also contribute to the development of cataracts. Age-related changes in lens metabolism may also play a role in cataract formation. These changes can result in a buildup of substances in the lens that cause it to become opaque. Overall, the longer a person lives, the more exposure their eyes have to these age-related changes, which can increase their risk of developing cataracts. Age-related cataracts are the most common type and usually develop gradually over many years.
Ultraviolet (UV) light exposure is a significant risk factor for cataracts, particularly long-term exposure to UV light from sunlight. The harmful UV radiation in sunlight can cause damage to the proteins in the eye's lens and lead to the development of cataracts over time. Wearing protective eyewear and sunscreens that block UV radiation can help reduce the risk of cataracts.
Smoking is also a known risk factor for cataracts. The chemicals in tobacco smoke can cause oxidative damage to the lens proteins, increasing the risk of cataracts. Smoking cessation can help reduce the risk of cataracts and other eye problems.
People with diabetes are at an increased risk of developing cataracts due to changes in the metabolism of the lens proteins and increased oxidative stress in the lens. Poorly controlled blood sugar levels can also contribute to the development of cataracts. Regular eye exams and good diabetes management can help reduce the risk of cataracts in people with diabetes.
Certain medications, such as corticosteroids, chlorpromazine, and amiodarone, have increased the risk of cataracts when used for prolonged periods. Discussing the potential dangers of these medications with your doctor or ophthalmologist is important.
Trauma or injury to the eye can also increase the risk of cataracts. The lens of the eye can be damaged by impact or penetration injuries, causing clouding and other changes that can contribute to the development of cataracts.
Exposure to certain types of radiation, such as X-rays, can increase the risk of cataracts. This is particularly true for people with repeated or prolonged exposure to radiation, such as healthcare workers and people undergoing radiation therapy.
Genetic factors can also increase the risk of developing cataracts. Some genetic disorders, such as Down syndrome and myotonic dystrophy, are associated with an increased risk of cataracts. Additionally, having a family history of cataracts may be a risk factor for developing the condition.
Alcohol use has been linked to an increased risk of cataracts. Alcohol can cause damage to the proteins in the eye's lens by increasing oxidative stress and disrupting protein metabolism, leading to the development of cataracts. Alcohol consumption may also interact with other cataract risk factors, such as smoking and poor nutrition. Heavy alcohol consumption is associated with an increased risk of cataracts and smoking.
Congenital cataracts are cataracts that are present at birth or develop in early childhood. Congenital cataracts can be caused by genetic and environmental factors, including genetic disorders like Down, Lowe, and Marfan. Metabolic disorders like galactosemia, phenylketonuria, and trauma or injury to the eye during development can also contribute to congenital cataracts. Environmental factors such as infections during pregnancy, exposure to toxins or certain medications can increase the risk of congenital cataracts.
Recovery time after cataract surgery varies depending on age, health, and the extent of surgery. Most people can return to normal activities in a few days or weeks.
Eye drops are given to prevent infection and reduce inflammation. A follow-up visit must ensure proper healing within the first week or two. Patients should avoid activities that can put pressure on the eye. Normal activities can usually be resumed within a week, but vision may take several weeks to fully stabilise. Glasses or contact lenses may be needed to correct any remaining vision problems.
Cataracts cannot come back after surgery, but a secondary cataract can sometimes form. A secondary cataract, also known as posterior capsule opacification, is a condition where the back of the lens capsule that holds the artificial lens implant becomes cloudy over time, causing blurry vision.
This condition occurs when the remaining lens capsule cells grow and form a thin membrane behind the implanted lens, which can interfere with vision. The symptoms of a secondary cataract are similar to those of the original cataract, including cloudy or blurred vision, sensitivity to light, and difficulty with night vision.
Fortunately, a laser procedure called YAG capsulotomy can easily treat secondary cataracts - and typically takes only a few minutes. Most patients can resume their normal activities immediately afterwards.
Cataract surgery is generally considered a safe and effective procedure with a high success rate. However, like all surgeries, it carries some risks and potential complications - listed below.
There is a small risk of infection following cataract surgery, which can be serious and require additional treatment.
Some bleeding can occur during or after surgery, which can cause vision loss if it is not controlled.
Swelling of the cornea can occur after surgery, which can cause temporary vision changes.
In rare cases, the retina may detach after cataract surgery, which can cause vision loss and require additional surgery.
Cataract surgery can sometimes lead to increased eye pressure, which can cause or worsen glaucoma.
The artificial lens implanted during cataract surgery can sometimes become dislocated, requiring additional surgery to reposition or replace it.
In some cases, a new cataract can form on the lens capsule that holds the intraocular lens (IOL), which can cause vision changes and require additional surgery to remove.
It is recommended to avoid bending over or lifting heavy objects for at least the first few days following cataract surgery to allow for proper healing of the eye. The timeline for resuming normal activities will vary and depend on your circumstances and the surgical technique. However, it is best to follow your surgeon's specific instructions.
It is recommended to wait at least 24 hours after cataract surgery before driving - to allow the effects of the anaesthesia or sedation to wear off and to ensure your vision is stable and clear. However, this may vary depending on your circumstances - such as the type of surgery performed and any other underlying eye conditions. As mentioned above, following your surgeon's instructions is best.
The timing between cataract surgery on each eye may vary depending on your circumstances and the surgeon's recommendation. In general, waiting at least a few weeks or longer before undergoing surgery on the second eye is recommended - to allow the first eye to heal and for any initial visual changes to stabilise. The surgeon may also consider factors such as the severity of cataracts, your overall health and medical history, and the potential risks and benefits of surgery for each eye.
Cataract surgery typically takes 15-30 minutes to perform. However, the exact duration will depend on the complexity of the cataract and any other underlying eye conditions. The procedure is usually performed on an outpatient basis, meaning you can go home the same day. The surgery is performed under local anaesthetic, numbing the eye and surrounding area while awake. After the surgery, you're monitored for a short period to ensure no complications or adverse effects and then allowed to return home.
Recovery time after cataract surgery varies depending on your age, health, and the extent of the surgery. Most people can return to normal activities in a few days or weeks.
Eye drops are given to prevent infection and reduce inflammation. A follow-up visit must ensure proper healing within the first week or two. You should avoid activities that can put pressure on the eye. Normal activities can usually be resumed within a week, but vision may take several weeks to fully stabilise. Glasses or contact lenses may be needed to correct any remaining vision problems.
Lutein and Zeaxanthin are antioxidants that have been shown to protect the eyes from damage caused by oxidative stress and UV light, which are factors that can contribute to the development of cataracts.
Studies have shown that higher levels of Lutein and Zeaxanthin in the diet are associated with a reduced risk of cataracts. However, more research is needed to fully understand the role of these nutrients in preventing cataracts.
Cataracts can be diagnosed through a comprehensive eye exam, which includes several tests to evaluate the eyes' health and the quality of vision.
- Visual acuity test: measures how well a person can see at various distances. The patient is asked to read letters or numbers from a chart, and the doctor evaluates the clarity of vision.
- Slit-lamp examination: This is an exam where the doctor uses a specialized microscope called a slit-lamp to examine the structures of the eye, including the lens. The doctor can see the cloudiness or opacities in the lens that may indicate the presence of a cataract.
- Dilated eye exam: eye drops are used to dilate the pupils, allowing for a more thorough examination of the lens and other structures in the eye.
- Tonometry: This is a test to measure the pressure inside the eye. High eye pressure can signify other eye conditions, such as glaucoma, that can affect vision.
- Other tests: In some cases, additional tests may be needed to evaluate the extent of the cataract and how it affects the vision. These tests may include a contrast sensitivity test, colour vision test, and visual field test.
“While some medications claim to dissolve or prevent cataracts, no scientific evidence supports their effectiveness. They are not approved by the NHS or the FDA as a treatment for cataracts.”
While there is no surefire way to prevent cataracts, there are steps you can take to reduce your risk of developing them. Some of these steps include:
- Protecting your eyes from UV light: Long-term exposure to UV light from the sun can increase the risk of cataracts. Wear sunglasses with UV protection when you're outdoors to protect your eyes and wear a hat to shade your eyes from the sun.
- Quitting smoking: Smoking has been linked to an increased risk of cataracts, so quitting smoking or avoiding exposure to secondhand smoke can help reduce the risk.
- Maintaining a healthy diet: Eating a diet rich in fruits and vegetables, especially those with high levels of antioxidants such as vitamin C and beta-carotene, may help reduce the risk of cataracts.
- Managing other health conditions: Certain health conditions, such as diabetes, can increase the risk of cataracts. Managing these conditions through a healthy lifestyle and medical treatment can help reduce the risk.
- Protecting your eyes from injury: Trauma to the eye can increase the risk of cataracts. Wear protective eyewear when playing sports or working in environments with a risk of eye injury to protect your eyes.
Flying is generally safe for individuals with Cataracts, as cabin pressure and altitude changes do not typically worsen the condition. However, if you have recently undergone cataract surgery, ask your surgeon when it is safe to fly, as your eyes may still be healing and vulnerable to complications.
Additionally, cabin pressure changes could affect the healing process or cause discomfort in the operated eye. Following your surgeon's post-operative care instructions and attending all scheduled follow-up appointments is essential to successful recovery.
Cataracts - Resources & References
- National Eye Institute. (2019). Facts About Cataract. Retrieved from https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/cataracts
- American Academy of Ophthalmology. (2020). What Are Cataracts? Retrieved from https://www.aao.org/eye-health/diseases/what-are-cataracts
- Mayo Clinic. (2020). Cataracts. Retrieved from https://www.mayoclinic.org/diseases-conditions/cataracts/symptoms-causes/syc-20353790
- WebMD. (2020). Cataracts. Retrieved from https://www.webmd.com/eye-health/cataracts/default.htm
- American Optometric Association. (n.d.). Cataract. Retrieved from https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/cataract?sso=y
- Cleveland Clinic. (2020). Cataracts: Management and Treatment. Retrieved from https://my.clevelandclinic.org/health/diseases/8589-cataracts/management-and-treatment
- American Academy of Ophthalmology (AAO). (2021). What Are Cataracts? Retrieved from https://www.aao.org/eye-health/diseases/what-are-cataracts
- National Eye Institute (NEI). (2019). Cataracts. Retrieved from https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/cataracts
- Mayo Clinic. (2020). Cataracts: Overview. Retrieved from https://www.mayoclinic.org/diseases-conditions/cataracts/symptoms-causes/syc-20353790
- American Optometric Association (AOA). (n.d.). Cataract. Retrieved from https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/cataract?sso=y
- WebMD. (2020). Cataracts: Causes, Symptoms, and Treatment. Retrieved from https://www.webmd.com/eye-health/cataracts/default.htm
- Cleveland Clinic. (2018). Cataracts: Management and Treatment.
- National Health Service (NHS). (2018). Cataracts: Overview. Retrieved from https://www.nhs.uk/conditions/cataracts/
- American Society of Cataract and Refractive Surgery (ASCRS). (n.d.). Cataract Surgery. Retrieved from https://ascrs.org/patients/eye-conditions/cataract-surgery
- World Health Organization (WHO). (2019). Cataract.
- Lim, R. R., Wollensak, G., & Lapid-Gortzak, R. (2016). Cataract. In: Schachat, A. P., Sadda, S. R., Hinton, D. R., Sadda, S., & Wilkinson, C. P. (eds.). Ryan's Retina (6th ed.). Elsevier. ISBN: 978-0-323-29559-7
- Trattler, W. B., Kaiser, P. K., & Friedman, N. J. (2018). Cataract. In: Review of Ophthalmology (3rd ed.). Elsevier. ISBN: 978-0-323-44338-1
- Steinert, R. F., & Hersh, P. S. (2010). Cataract Surgery and Its Complications (7th ed.). Elsevier. ISBN: 978-0-323-06385-4
- Pascolini, D., & Mariotti, S. P. (2012). Global estimates of visual impairment: 2010. British Journal of Ophthalmology, 96(5), 614-618. https://doi.org/10.1136/bjophthalmol-2011-300539
- Asbell, P. A., Dualan, I., Mindel, J., Brocks, D., Ahmad, M., & Epstein, S. (2005). Age-related cataract. The Lancet, 365(9459), 599-609. https://doi.org/10.1016/S0140-6736(05)70803-5