Posterior infectious crystalline keratopathy with Staphylococcus epidermidis

Area of Science:

• Ophthalmology
• Microbiology
• Corneal Surgery

Background:

• Infectious crystalline keratopathy (ICK) is a rare microbial keratitis.
• It typically presents with characteristic crystalline infiltrates in the corneal stroma.
• Cases occurring exclusively in the posterior stroma after penetrating keratoplasty are exceptionally uncommon.

Observation:

• Two cases of ICK exclusively in the posterior stroma after penetrating keratoplasty are detailed.
• One case presented with anterior chamber inflammation, while the other exhibited deep ulceration, hypopyon, and vitreitis.
• Gram-positive cocci were identified in vitreous aspirate in the second case.

Findings:

• Staphylococcus epidermidis, sensitive to vancomycin, was isolated from corneal tissue in both cases.
• Microscopy revealed bacteria anterior to Descemet's membrane and within stromal keratocytes.
• Despite initial antibiotic and steroid treatments, corneal ulceration and ICK persisted.

Implications:

• ICK can manifest solely in deeper corneal layers, posing diagnostic challenges.
• Therapeutic penetrating keratoplasty and vancomycin treatment were effective in resolving the cases.
• This highlights the importance of considering deep-seated infections in post-keratoplasty complications.