Which drug class is associated with crystalline retinopathy and whorl keratopathy?

• A. Estrogen agonists (oral contraceptives)
• B. Ritalin, Dexedrine (ADHD)
• C. Metformin (Glucophage)
• D. Estrogen antagonists (Tamoxifen)

Answer: (D)

Patterns of crystalline retinopathy and whorl keratopathy arise from drug deposition in ocular tissues. Estrogen receptor antagonists, notably tamoxifen, are classically linked to these findings. Tamoxifen is lipophilic and accumulates in ocular tissues, producing refractile crystalline deposits in the retina (often in the macula) and vortex (whorl) keratopathy in the cornea. Clinically, patients may be asymptomatic or report visual changes; examination can reveal intraretinal crystals on fundus exam and a whorled crystalline pattern in the cornea on slit-lamp examination or corneal tomography. The association with tamoxifen helps explain both retinal and corneal crystalline deposits seen with this medication.