Which drugs are commonly associated with superficial punctate keratitis (SPK)?

Which drugs are commonly associated with superficial punctate keratitis (SPK)?

• A. Isotretinoin and Tobramycin/Gentamicin
• B. Isotretinoin
• C. Prostaglandins
• D. Platelet inhibitors

Answer: (A)

SPK arises when the corneal epithelium is compromised by dryness or direct drug toxicity, so medications that dry the eye or injure the surface commonly lead to this finding. Isotretinoin can cause significant dry eye by reducing lacrimal gland secretion and altering the meibomian glands, which sets up a vulnerable ocular surface prone to superficial punctate keratitis. Topical aminoglycoside antibiotics such as tobramycin or gentamicin are known to be toxic to the corneal epithelium, especially with preserved formulations, producing epithelial microerosions that stain as SPK. When these two are involved—systemic drying from isotretinoin and local epithelial toxicity from the antibiotic—the risk of SPK is particularly notable. The other agents listed are less characteristically linked to SPK: prostaglandins mainly cause surface redness and conjunctival/surface effects but not SPK as a classic finding, and platelet inhibitors do not typically injure the corneal epithelium.

SPK arises when the corneal epithelium is compromised by dryness or direct drug toxicity, so medications that dry the eye or injure the surface commonly lead to this finding. Isotretinoin can cause significant dry eye by reducing lacrimal gland secretion and altering the meibomian glands, which sets up a vulnerable ocular surface prone to superficial punctate keratitis. Topical aminoglycoside antibiotics such as tobramycin or gentamicin are known to be toxic to the corneal epithelium, especially with preserved formulations, producing epithelial microerosions that stain as SPK. When these two are involved—systemic drying from isotretinoin and local epithelial toxicity from the antibiotic—the risk of SPK is particularly notable. The other agents listed are less characteristically linked to SPK: prostaglandins mainly cause surface redness and conjunctival/surface effects but not SPK as a classic finding, and platelet inhibitors do not typically injure the corneal epithelium.