Transient extremely shallow anterior chamber caused by ciliochoroidal detachment in a patient with Mycobacterium chelonae keratitis

PURPOSE: To report a case of Mycobacterium chelonae keratitis that resulted in a transient reduction of anterior chamber depth. OBSERVATIONS: A 46-year-old man with keratoconus and reduced visual acuity (20/286) in his left eye presented with ciliary injection 16 months after femtosecond laser-assisted penetrating keratoplasty (PK). A slit-lamp examination showed a corneal ulcer with infiltrates and edema in both the host and graft between the 3 o'clock and 6 o'clock positions. Microbiologic tests confirmed the presence of M. chelonae. Topical arbekacin and moxifloxacin, erythromycin/colistin ointment, and oral clarithromycin were prescribed. We monitored anterior chamber depth by anterior segment optical coherence tomography (AS-OCT) throughout the recovery period. The anterior chamber depth was normal before treatment, with an intraocular pressure (IOP) of 7 mmHg. Although ciliary injection and infiltrates were gradually resolved, slit-lamp examination and AS-OCT revealed an extreme reduction of anterior chamber depth without corneal perforation, 1 month after beginning treatment. The IOP was 5 mmHg, and ciliochoroidal detachment (CCD) was present. The anterior chamber increased with the resolution of CCD and keratitis. Although hypotony continued despite the resolution of CCD and keratitis, the IOP eventually recovered to ≥10 mmHg at 1 month after remission. Onset and resolution of transient reduction of anterior chamber depth presumably occurred by anterior rotation and recovery of the ciliary body, respectively. Subsequent PK triple surgery enabled visual recovery to 20/100. CONCLUSIONS AND IMPORTANCE: severe anterior segment inflammation due to infectious keratitis may cause CCD and subsequent reduction of anterior chamber depth due to anterior rotation. AS-OCT is a non-invasive and efficient tool for the evaluation of iridociliary structure and the anterior chamber in patients with infectious keratitis.