Which medication class is associated with pigment on the corneal endothelium?

• A. Phenothiazines + Phenergan + Promethazine
• B. Tetracyclines
• C. Prostaglandins
• D. Isotretinoin

Answer: (A)

Pigment on the corneal endothelium is classically seen with long-term use of phenothiazines, which include chlorpromazine and related drugs like promethazine. These medications are highly lipophilic and tend to accumulate in ocular tissues, producing slate-gray or brownish deposits on the corneal endothelium (and sometimes the lens). On slit-lamp exam you’d observe fine deposits along the posterior cornea, which reflect the drug’s affinity for pigmented ocular structures. This pattern helps distinguish it from other drug classes.

Tetracyclines can cause various ocular effects but not the characteristic endothelial pigment. Prostaglandin analogs are more associated with iris pigmentation and conjunctival changes rather than corneal endothelium deposits. Isotretinoin mainly causes dry eye and keratopathy without endothelial pigment deposition.