Which pharmacotherapeutic option is most important to administer to a patient with a corneal abrasion?

In the context of treating a corneal abrasion, the most important pharmacotherapeutic option is Gentamicin ophthalmic. Corneal abrasions are injuries to the outer layer of the cornea, and they can leave the eye vulnerable to infections, especially if the abrasion is large or if there is associated foreign body trauma.

Gentamicin is an antibiotic that can help prevent and treat potential bacterial infections in the cornea. It is effective against a variety of gram-negative and some gram-positive bacteria, making it a suitable choice to ensure that bacterial pathogens do not complicate the healing process of the corneal abrasion.

While the other options may have their uses in ophthalmic treatment, Gentamicin's role in infection prevention is critical in the context of a corneal abrasion. Timolol is primarily used for managing intraocular pressure in conditions like glaucoma, while Cromolyn is an anti-allergic agent not indicated for acute injuries. Olopatadine, being an antihistamine, is also focused on allergic reactions rather than addressing the immediate concern of infection associated with a corneal abrasion. Thus, Gentamicin ophthalmic stands out as the essential choice for protecting the eye from potential bacterial infection after such an injury.