Dr. Chelvin Sng: Can you get early-onset cataracts in your 20s?

What do That 70s Show starlet Mila Kunis, talk show magnate Larry King and local songwriter Dick Lee have in common? Apart from being rich and famous, they’ve all had cataract surgery. 

For us in Singapore, cataracts might seem like part and parcel of ageing – in Singapore, cataract affects¹:

• 78.6% of the elderly
• 63.6% of people aged 60 to 64
• 94.6% of people aged 75 and older 

But did you know that this condition can also affect younger people? We refer to this as early-onset cataracts.

Understanding early-onset cataracts

A cataract is the clouding of a normally clear lens. For those with cataracts, seeing is like looking through a foggy window. Clouded vision caused by cataracts can make it more difficult to read, drive a car (especially when it’s dark), or see the expressions of our loved ones.

There are three common types of cataracts, named for where they are located in relation to the lens:

• Nuclear cataract: Develops in the nucleus, or centre of the lens.
• Cortical cataract: Develops on the outside, or cortex of the lens.
• Posterior subcapsular cataract: Develops in the backmost layer of the cortex, on the lens capsule.

Nuclear and cortical cataracts tend to develop slowly, and usually become more problematic with age. Unlike nuclear and cortical cataracts, posterior subcapsular cataracts are frequently found in younger individuals and can progress more quickly.

Why cataracts develop in young people

There is a perception that cataracts only affect elderly persons; However, young persons, even those in their 20s, can develop cataracts.  

Certain conditions and risk factors can result in the development of cataracts at a younger age. 

These include:

Diabetes 

• In diabetic individuals with poorly controlled blood sugar levels, enzymes convert the high levels of glucose into sorbital, which affect the lens clarity and result in cataracts.
• The risk of cataracts is doubled in diabetics². 
• Singaporeans are becoming diabetic at a younger age. NUS research studies³ have found that 34% of Singaporeans aged 24 to 35 will develop diabetes by age 65. This may result in more Singaporeans developing cataracts at a younger age.

Trauma

• Both blunt and penetrating trauma disrupt lens fibres and result in cataracts.
• Penetrating eye injury may puncture the lens capsule and induce a cataract.
• Blunt eye injury can cause a diffuse cataract with a higher risk of zonular loss, which results in the lens being shaky or unstable. Cataract surgery is much more complex and is associated with higher risks in such cataracts.
• Typically, trauma-related cataracts can progress rapidly. 

Radiation 

• Exposure to high levels of radiation can result in cloudy vision in less than two years
• Exposure can also take over a decade to affect one’s vision.

Drug exposure and reaction

• It’s believed that the chronic use of drugs such as statins and steroids⁴ can contribute to early cataract formation.

Other common risk factors for early cataracts include; 

• Obesity
• Previous eye surgery (eg. retina or glaucoma surgery)
• A family history of early-onset cataracts
• Congenital medical conditions
• Poor nutrition 
• Smoking 
• Excessive alcohol consumption

Many of these factors can be effectively managed. If you want to avoid having cataracts at a young age, focus on maintaining a healthy lifestyle.

What do early cataracts look like? 

In its initial stages, a cataract may only affect a small part of the eye lens, and individuals may be unaware of any vision loss. As cataracts become more advanced, they increasingly impede the passage of light that passes through your lens. This will lead to more symptoms.

Some symptoms of cataracts include:

• Cloudy, blurred or dim vision
• Increasingly poor night vision
• Sensitivity to bright light and glare
• Needing brighter light for reading and other activities
• Frequent changes in your eyeglass or contact lens prescription
• Seeing halos around lights
• Colours appear faded or have a yellowish tinge
• Double vision in one eye

Can children have cataracts?

A child may have a congenital cataract, or they may develop the condition later in life. The following may cause cataracts in children:

• Poisoning
• Steroid use
• Eye injury or trauma
• Inflammation in the eye
• Medical conditions (eg. diabetes, rheumatoid arthritis)
• Complications from other eye diseases (eg. glaucoma)
• Down syndrome

Are childhood cataracts the same as congenital cataracts? 

The short answer is no. A cataract may develop during childhood due to the conditions listed above, but if the cataract is already present at birth, it is a congenital cataract. 

A congenital cataract is a rare birth defect that can cause vision problems or even blindness. A baby may have a cataract in one or both eyes. The most common infections that cause congenital cataracts include toxoplasmosis, rubella, cytomegalovirus and herpes simplex virus.

At what stage should cataracts be removed? 

While most age-related cataracts progress gradually over years, early-onset cataracts may develop rapidly in a short period of time, especially in high-risk individuals.

This is why no matter your age, you should take an eye exam the moment you notice any changes in your vision. Symptoms such as sudden vision changes, seeing flashes of light, and sudden eye pain might all be cause for immediate concern.

There is no medication or eye drop that can treat cataracts. Removing them with surgery is the only way to treat and stop cataracts from progressing. 

But the most important thing to remember is: The earlier visually-significant cataracts are detected, the earlier they can be treated.Patients who wait more than 6 months⁵ for cataract surgery have been known to experience vision loss, reduced quality of life, and an increased rate of falls.

To find out more about cataract surgery in Singapore, please read my cataracts guide, or feel free to drop me a message. 

References

1. Cataract - NUH | National University Hospital. (n.d.). Www.nuh.com.sg. Retrieved April 7, 2022, from https://www.nuh.com.sg/About-NUH/Clinical-Outcomes/Pages/Cataract.aspx#:~:text=In%20Singapore%2C%20the%20percentage%20of
2. Becker, C., Schneider, C., Aballéa, S., Bailey, C., Bourne, R., Jick, S., & Meier, C. (2018). Cataract in patients with diabetes mellitus—incidence rates in the UK and risk factors. Eye, 32(6), 1028–1035. https://doi.org/10.1038/s41433-017-0003-1
3. https://sph.nus.edu.sg/2016/05/young-singaporean-diabetes-on-the-rise/#:~:text=Diabetes%20in%20Singapore%20is%20on,by%20the%20age%20of%2065. 
4. Wise, S. J., Nathoo, N. A., Etminan, M., Mikelberg, F. S., & Mancini, G. B. J. (2014). Statin Use and Risk for Cataract: A Nested Case-Control Study of 2 Populations in Canada and the United States. Canadian Journal of Cardiology, 30(12), 1613–1619. https://doi.org/10.1016/j.cjca.2014.08.020
5. Hodge, W., Horsley, T., Albiani, D., Baryla, J., Belliveau, M., Buhrmann, R., O’Connor, M., Blair, J., & Lowcock, E. (2007). The consequences of waiting for cataract surgery: a systematic review. Canadian Medical Association Journal, 176(9), 1285–1290. https://doi.org/10.1503/cmaj.060962