What is a common adverse effect of prostaglandin analog therapy on the eyelids?

• A. Eyelash growth and potential eyelid skin changes.
• B. Increased tear pH.
• C. Decreased eyelid pigmentation.
• D. Corneal thinning.

Answer: (A)

Prostaglandin analogs used for glaucoma can affect periocular tissues by acting on FP receptors in lash follicles and eyelid skin. The most common eyelid-related side effect is changes in the lashes and surrounding skin: lashes become longer, thicker, and sometimes darker, while the eyelid skin may show increased pigmentation. This reflects stimulation of the hair growth cycle and increased melanin in the skin, and it’s usually cosmetic and often reversible after stopping the medication.

Other options don’t reflect typical eyelid changes from these drugs—tear pH alteration isn’t a noted effect, corneal thinning isn’t a known eyelid adverse effect, and decreased eyelid pigmentation would be the opposite of what’s commonly seen.