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Hashemi Eye Care - Neuroscience Institute and Research Center

Posterior Subcapsular Cataract (PSC)

A cataract at the back of the lens causing reading difficulty and glare, often progressing faster than other types. Common with steroid use and diabetes.

4 min read

A posterior subcapsular cataract (PSC) develops at the back surface of the lens, just in front of the lens capsule. Unlike nuclear cataracts, which mainly affect distance vision, PSCs cause early difficulty with reading and significant glare. They often progress faster than other cataract types and are associated with steroid use, diabetes, and younger age of onset.

Key Takeaways

  • Located at the back of the lens—directly in the visual pathway
  • Causes reading difficulty early—affects near vision prominently
  • Significant glare in bright light
  • Faster progression than other cataract types
  • Associations: steroid use, diabetes, trauma, radiation, uveitis
  • May occur in younger patients (unlike most age-related cataracts)

What Is a Posterior Subcapsular Cataract?

Location and Structure

  • Forms on the back (posterior) surface of the lens
  • Just beneath the lens capsule
  • Located centrally (in the visual axis)
  • Appears as a plaque or granular opacity

Why PSCs Cause More Symptoms

Because PSCs are central and located where light converges, they cause disproportionate symptoms for their size.

Symptoms

Early Reading Difficulty

PSCs affect near vision early.

Unlike nuclear cataracts that blur distance vision first, PSCs often cause reading difficulty as an early symptom. When reading, the pupil constricts, directing light through the central opacity.

Glare

  • Significant glare in bright light
  • Difficulty with oncoming headlights at night
  • Halos around lights

Other Symptoms

  • Monocular double vision or ghosting
  • Reduced contrast sensitivity
  • Faster progression than other types

Causes and Associations

Steroid Use

Steroid medications are strongly associated with PSC formation.

Both systemic and topical steroids can cause PSCs with prolonged use. Risk increases with dose and duration.

Other Associations

Diagnosis

Slit Lamp Examination

  • Central, plaque-like opacity
  • Located just in front of posterior capsule
  • May have granular or vacuolar appearance

Glare Testing

  • Often shows more impairment than standard acuity
  • Helps justify surgery when standard acuity is good

Treatment

Cataract Surgery

Surgery is often needed earlier for PSC than other cataract types.

Due to central location and faster progression, PSCs frequently cause significant symptoms at smaller sizes. Patients often need surgery relatively early.

Cataract surgery removes the clouded lens with excellent results.

Special Considerations

Steroid Users

  • Discuss with your doctor about lowest effective dose
  • Regular eye exams to monitor for PSC
  • Consider steroid-sparing alternatives when possible

Posterior Capsular Opacification (PCO)

After cataract surgery, the capsule can become cloudy. This is treatable with a quick YAG laser procedure.

Frequently Asked Questions

Why did I get a cataract at my age?

PSCs can develop in younger patients, especially with risk factors like steroid use, diabetes, or chronic eye inflammation.

Will stopping steroids reverse my cataract?

No. Once a PSC has formed, it won't reverse. However, stopping may slow progression. Never stop steroids abruptly—discuss with your prescribing doctor.

Why is my reading so much worse than my distance vision?

PSCs are located centrally. When you read, your pupil constricts, directing light right through the opacity.

References

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