Ophthalmic Decongestants Ophthalmic decongestants reduce ocular congestion thereby relieving the redness and hotness associated with vasodilation. This vasoconstriction can both cause and aggravate angle closure glaucoma and photophobia can occur. The most common effect, however, is rebound vasodilation of ophthalmic vessels in the same manner as rebound nasal congestion occurs. The patient instills more and more of the decongestant seeking relief. Long acting naphazoline is especially troublsome for rebound.
Systemic effects can also occur.
This can be reduced by holding a finger over the tear duct, with the eye closed, for a few minutes after instilling the eye drops.