Case Study: September 2016


A 25 year old female, who is otherwise fit and well presents with photophobia.

Examination shows crystals in the cornea and conjunctiva (Fig 1). A conjunctival biopsy is undertaken and sent for ophthalmic pathology analysis. Fig 2 shows the pathology using transmission electron microscopy.


1. What is the differential diagnosis for the clinical appearance in Fig 1.

2. Describe what the transmission electron microscopy photos shows.

3. What is the diagnosis?

4. How should the conjunctival biopsy be fixed for light microscopy?

5. How should the conjunctival biopsy be fixed for tranmission electron microscopy?


Click to show answers


1. This is a crystalline keratopathy. The diferential includes Infectious (numerous organisms); Non-infectious-Schnyder crystalline corneal dystrophy, Bietti crystalline corneoretinal dystrophy, Cystinosis, Paraprotein, Drugs (topical fluoroquinolone)

2. Membrane bound, intra-lysosomal, geometric crystals.

3. Ocular cystinosis

4. Absolute alcohol

5. 2% gluteraldehyde.