Confocal Microscopy of Stellate Stromal Deposits in Two Cornea Grafts Treated with Moxifloxacin and Prednisolone Acetate

Purpose: To describe unusual anterior stromal stellate deposits, imaged by confocal microscopy, appearing in corneal graft stro- ma shortly after penetrating keratoplasty (PK) with postoperative topical moxifloxacin and prednisolone acetate treatment.

Methods: We report two cases and a review of the literature. Corneas were evaluated using the Heidelberg Retinal Tomograph II confocal laser scanning ophthalmoscope with the Rostock Corneal Module.

Results: Two corneal grafts, treated with topical moxifloxacin and prednisolone acetate, developed birefringent stellate deposits at all stromal levels. On confocal microscopy, they appear as blunt- and sharp-ended spikes radiating from a central nexus (rosette form) up to 50 microns in diameter. Morphologically, they resemble fluoroquinolone and (more so) calcium phosphate (blunt-ended needle, rosette form) crystals and do not resemble lipid (spikes with sharp ends), cholesterol (rhomboid, rectan- gular, notched, polychromatic), or prednisolone (birefringent, irregular, branched, and pleomorphic) crystals in solution. How- ever, these deposits do not resemble the typical anterior stromal, epithelial, or surface punctate or plaque deposition of calcium or fluoroquinolones.

Conclusions: This is the first report of stellate intrastromal depos- its following PK and topical moxifloxacin and prednisolone ace- tate, with the deposits morphologically similar to those reported in a single case in a PK graft following gatifloxacin and prednisolone acetate treatment. The cause and composition of these deposits remain unknown, but the etiologic role of fluoroquinolones, pred- nisolone acetate, and calcium must be considered.