Posterior Subcapsular Cataract: What Is It? Causes & Treatment

Posterior subcapsular cataracts (PSC) reduce reading vision, negatively impact bright light vision, and can cause individuals to see glares or halos when around sources of light at night. 

PSCs are caused by protein buildup that forms in front of the posterior lens capsule, right near the back of the lens. 

Posterior subcapsular cataracts are considered complicated cataracts that occur secondary to an intraocular disease. They are generally classified by size (measured in millimeters) ranging from 1+ to 3+ PSC. They can occur individually or in combination with other cataracts. 

What Is a PSC?

Essentially, posterior subcapsular cataracts occur in a specific area of the eye that becomes opaque – at the crystalline lens’s posterior or rear portion. PSCs can cause a significant reduction in vision because of their centralized position and the fact that they occupy the papillary area.

PSCs are different from “normal” cataracts. The most common type of cataract is the nuclear cataract, which entails a gradual hardening and yellowing of the nucleus (the central zone of the lens). 

Posterior subcapsular cataracts differ from other types of cataracts because of the location where they occur as well as the fact that they often develop more rapidly. PSC symptoms can become noticeable in a short period of time, often within months of diagnosis.

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Causes of Posterior Subcapsular Cataracts

Posterior subcapsular cataracts are caused by protein buildup. These formations of protein end up disrupting lens fiber transparency, which causes opacities in the lens. The fact that fewer light rays are reaching the retina results in compromised vision.

This building of protein occurs as a natural part of the aging process and is considered an age-related risk factor. As individuals advance in age, they become more susceptible to getting PSCs. 

Other factors have also been shown to cause or contribute to the development of posterior subcapsular cataracts, including these:

• Medical conditions, especially diabetes
• Trauma, especially blunt force trauma
• Exposure to certain kinds of medication (steroids in particular)
• Inflammation
• UV/radiation exposure
• Smoking
• Skin disorders, such as atopic dermatitis

Symptoms

The most common symptoms of posterior subcapsular cataracts have to do with visual disturbances and vision restrictions. They include the following:

• Decreased vision
• Blurred vision
• Near vision worse than vision at a distance
• Bright light sensitivity
• Seeing halos around bright lights
• Contrast sensitivity reduction
• Difficulty driving at night (due to headlight glare)

Risk Factors

Certain individuals are more at risk for developing posterior subcapsular cataracts than others. Those with diabetes are at a higher risk, as are older individuals.

Other risk factors include steroid use. These medications may have been prescribed by a medical professional to patients with skin disorders, asthma, or certain autoimmune disorders. Steroids are often prescribed for these conditions: 

• Hives
• Eczema
• Hay fever
• Joint pain
• Arthritis
• Sciatica
• Inflammatory bowel disease
• Allergies
• Asthma

PSCs can also develop as complications related to other medical conditions, procedures, and events, such as these:

• Intraocular inflammation (chronic uveitis)
• Vitreoretinal surgery
• Trauma to the eye (especially the lens)

Treatment of PSC

If you believe you have a posterior subcapsular cataract, it’s important to seek medical attention from a vision care specialist as soon as possible. If you currently wear glasses and your prescription fails to result in clear vision, seek medical care to avoid further damage and discomfort.

Cataract surgery is the only way to get rid of posterior subcapsular cataracts, although specialists in the optometry field are researching nonsurgical treatments for PSCs. There is no available medication or eyewear that can fully correct or counteract vision issues related to posterior subcapsular cataracts.

The upside is that PSC treatment involves a common procedure and can be completed in less than 30 minutes. It takes approximately 15 minutes in most cases. 

Cataract surgery is generally low risk and entails removing the cloudy lens and replacing it with an artificial lens (also called an intraocular lens or IOL).

Most intraocular lenses that are used are composed of materials like silicone or acrylics. The intraocular lens is folded and inserted through a small 3-millimeter incision. Many IOLs available today are coated with a protectant that shields the eye from harmful UV rays. Individuals heading into cataract surgery should choose the best IOL option for their specific needs.

For those who do not wish to undergo surgery, an eye doctor may advise annual visits to monitor the cataract. While surgery is recommended promptly after diagnosis, delaying treatment generally does not affect recovery or success rate. Just make sure to see your eye doctor regularly, so you are able to get surgery promptly when it reaches that point.

Diagnosis

Proper diagnosis for PSCs comes after an eye exam administered by a medical professional, most likely performed by an ophthalmologist. Although an optometrist can perform an eye exam and provide preoperative and postoperative care, only an ophthalmologist can perform cataract surgery. 

During an eye exam, a doctor will dilate the eye with eye drops. The doctor will then utilize an ophthalmoscope or a slit lamp to examine the eye for cataracts. The patient will also likely undergo a visual acuity test. In some cases, the doctor may measure fluid pressure in the eye (via a test/process called applanation tonometry). 

Once posterior subcapsular cataracts are diagnosed, a doctor will likely recommend surgical treatment.  

Prevention of Cataracts

Although certain risk factors such as aging are unavoidable, there are certain measures individuals can take to reduce the risk of developing posterior subcapsular cataracts. If you have any sort of medical condition that leads to or aggravates cataracts, it’s important to work with a medical professional to manage your condition in order to avoid developing a PSC or worsening one that has already developed.

Other measures you can take to reduce the chances of developing PSCs include the following:

• Avoid prolonged UV exposure.
• Supplement your diet with vitamins C, D, and E.
• Avoid smoking and/or alcohol consumption.
• Maintain a healthy BMI, as obesity is a risk factor.

Getting into the habit of seeing an eye care professional at least once a year is recommended in order to address any eye issues early. Regular exams put you in the best position to enjoy clear vision for as long as possible, as early diagnosis and treatment are essential to mitigating damage.

References

1. Complicated Cataract. (July 2022). StatPearls.

2. Etiology of Posterior Subcapsular Cataracts Based on a Review of Risk Factors Including Aging, Diabetes, and Ionizing Radiation. (September 2020). International Journal of Radiation Biology.

3. Structural Characteristics of the Lens in Presenile Cataract. (December 2021)). Frontiers in Medicine.

4. Trends in Cataract Surgical Treatment Within the Brazilian National Public Health System Over a 20-Year Period: Implications for Universal Eye Health as a Global Public Health Goal. (June 2022). PLOS Global Public Health.

5. Trends in Cataract Surgical Treatment Within the Brazilian National Public Health System Over a 20-Year Period: Implications for Universal Eye Health as a Global Public Health Goal. (June 2022). PLOS Global Public Health.