A 45-year-old man with POAG is prescribed a topical prostaglandin analogue. Which of the following is a recognised ocular side effect specific to this class of drugs?
- A Iris pigmentation darkening (prostaglandin-associated periorbitopathy) ✓
- B Corneal epithelial toxicity and superficial punctate keratopathy
- C Anterior subcapsular cataract formation
- D Band-shaped keratopathy
Correct answer: A. Iris pigmentation darkening (prostaglandin-associated periorbitopathy)
Explanation
Prostaglandin analogues (latanoprost, bimatoprost, travoprost) can cause irreversible darkening of iris color due to increased melanin content in stromal melanocytes, particularly in hazel or mixed-color irides. They also cause periorbital fat atrophy (prostaglandin-associated periorbitopathy), eyelash lengthening and darkening, and eyelid skin hyperpigmentation. These pigment changes are specific to this drug class and are not a class effect of beta-blockers or carbonic anhydrase inhibitors.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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