**Core Concept**
Phlyctenular keratoconjunctivitis is a type of ocular inflammatory disorder characterized by the formation of small, nodular lesions on the conjunctiva and sometimes the cornea. It is often associated with an allergic or hypersensitivity reaction to antigens, such as staphylococcal toxins, and is typically seen in children and young adults.

**Why the Correct Answer is Right**
The treatment of choice for phlyctenular keratoconjunctivitis involves addressing the underlying hypersensitivity reaction and reducing inflammation. Topical corticosteroids, such as prednisolone acetate, are the first-line treatment for this condition. They work by reducing inflammation and suppressing the immune response, thereby alleviating symptoms such as redness, itching, and photophobia. In some cases, additional treatments like cyclosporine or antihistamines may be used to manage symptoms, but corticosteroids remain the primary treatment option.

**Why Each Wrong Option is Incorrect**
**Option A:** Antibiotics are not the primary treatment for phlyctenular keratoconjunctivitis, as the condition is not caused by a bacterial infection. While antibiotics may be used to treat secondary infections, they do not address the underlying hypersensitivity reaction.
**Option B:** Cycloplegics, such as atropine, may be used to treat associated symptoms like ciliary spasm or uveitis but are not the primary treatment for phlyctenular keratoconjunctivitis.
**Option C:** Antiviral medications are not indicated for phlyctenular keratoconjunctivitis, as the condition is not caused by a viral infection.

**Clinical Pearl / High-Yield Fact**
Phlyctenular keratoconjunctivitis is often associated with a history of staphylococcal blepharitis or other ocular allergies, and patients may also exhibit symptoms of atopic dermatitis or asthma.

**Correct Answer:** C. Topical corticosteroids, such as prednisolone acetate.