Atypical cruciform crystals in crystalline keratopathy with vitreous involvement

We report a case of a 69-year-old woman with a history of tamoxifen and anastrozole use, as well as prior retinal detachment, presenting with cruciform crystals in the anterior and posterior chamber. Retrospective case review. Our patient underwent workup including a slit lamp exam, funduscopy, OCT, and cytologic analysis of aqueous aspirate. The patient initially presented with decreased visual acuity in the left eye to 20/40 with an intraocular pressure of 15 mmHg. Examination revealed anterior segment inflammation with white refractile deposits dusting the corneal endothelium, iris, intraocular lens implant, and vitreous skirt. Cytologic analysis of aqueous aspirate revealed non-polarizable, variably sized cruciform crystals. Although retinopathy is associated with tamoxifen and anastrozole usage, such crystals have not been described within the aqueous or vitreous. While the etiology in our patient remains unclear, tamoxifen has been previously detected within intraocular fluids and may have precipitated crystal formation. Deposits from Fuchs uveitis or occult infection-related deposition as seen in crystalline keratopathy are also possible.