Ocular surface squamous neoplasia
What is it?
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| Ocular surface squamous neoplasia |
Ocular surface squamous neoplasia (OSSN) is an uncommon malignancy of the conjunctiva and cornea. It can be thought of as a 'skin cancer' of the eye.
Clinical features
Typical features of OSSN include:
- Arises near the limbus (junction of cornea and sclera)
- Most commonly found at the 3 or 9 o'clock position
- Fleshy, gelatinous appearance
- Round or oval shape
- Irregular blood vessel pattern
- Minimal symptoms
- Slow growing
Who gets OSSN?
OSSN is more common in patients who are:
- Older
- Have had significant sunlight exposure
- Are taking immune system supressing drugs
Differences between OSSN and pterygia
OSSN can mimic a pterygium. In general pterygia:
- Occur at a younger age
- Are more triangular in shape
- Appear flatter rather than gelatinous
- Have more linear blood vessels
- Cause more symptoms