What are deep ulcers?
Deep ulcers are those which involve the deeper layers of the cornea beneath the epithelium, known as the corneal stroma.
What causes deep ulcers?
A previously ‘simple’ ulcer caused by dry eye, eyelid abnormalities or trauma for example can become deep if the underlying cause remains untreated or if it becomes infected.
How are they diagnosed?
Specialised equipment such as a slit-lamp microscope can be used to assess the depth of the ulcer along with fluorescent dye which highlights the exposed stroma. Swabs of the surrounding cornea can be taken to send for culture to identify and appropriately treat any infectious organisms.
How are they treated?
Medically
- Antibiotics – broad spectrum cover is advised whilst awaiting swab results, then the most appropriate medication can be continued. Initially drops may need to be applied every 1-2 hours for the first 24 – 48 hours of treatment.
- Protease inhibitors – certain bacteria that are often involved in deep ulcers secrete enzymes (collagenases) which contribute to ongoing stromal loss. Serum eye drops derived from blood are used to provide anti-protease activity and promote ulcer healing and are applied at the same frequency as antibiotics above.
Surgically
In ulcers that are more than 50% of the cornea in depth, surgical treatment is required in order to stabilise the fragile cornea. Surgery involves placing grafts into the defect which are usually harvested from the surrounding cornea and conjunctiva. Medical management is required as above alongside an Elizabethan collar to prevent patient-induced trauma post-operatively.
