Ocular Anti-inflammatories and Anti-infectives

Core Concepts

The red eye: matching drug to cause

Before any drug, the cause matters. Bacterial conjunctivitis typically presents with purulent discharge; viral conjunctivitis is watery, often bilateral, follows an upper respiratory infection, and may include a tender preauricular node; allergic conjunctivitis is bilateral, itchy, and watery; herpes simplex keratitis causes pain, redness, and blurred vision and can show a branching corneal lesion — the classic situation where steroids make things worse. Nurses don't diagnose, but this history drives the drug choice.

Corticosteroids: potent anti-inflammatories with real risks

Ophthalmic corticosteroids — prednisolone acetate, dexamethasone, loteprednol, fluorometholone — bind the glucocorticoid receptor and suppress inflammatory mediators (prostaglandins, leukotrienes) at their source. They are used for post-operative inflammation, uveitis, and severe allergic disease. The price is well-known risks: elevated intraocular pressure (monitored during use), cataracts with long-term use, delayed healing, and masking of infection. Steroids are avoided or used with great caution in epithelial herpes simplex keratitis — which is why steroid use in a red eye is a prescriber's decision with a known diagnosis, never a "try some drops and see" choice.

NSAIDs: without the steroid risks

Ophthalmic NSAIDs — diclofenac, ketorolac, flurbiprofen, nepafenac — inhibit cyclooxygenase (COX), cutting prostaglandin synthesis. They treat allergic conjunctivitis and post-operative inflammation, including cystoid macular edema prophylaxis around cataract surgery. They carry less intraocular-pressure and cataract risk than steroids, making them useful when a steroid is undesirable. Downsides: stinging or burning and, rarely with prolonged use, corneal problems. They don't treat infection, so they're appropriate only with a supporting diagnosis.

Allergy medications

Allergic conjunctivitis is driven by histamine release from mast cells. Antihistamine drops (olopatadine, ketotifen, azelastine) block histamine at the H1 receptor, rapidly reducing itching and redness; many also stabilize mast cells. Mast cell stabilizers (cromolyn) prevent degranulation, so they work best preventively rather than after symptoms peak. The hallmark of this class is itching — the most specific symptom of ocular allergy.

Antibacterials: spectrum, penetration, and resistance

Bacterial eye infections are treated with topical antibacterials chosen for spectrum and penetration. The major classes: fluoroquinolones (moxifloxacin, ciprofloxacin, levofloxacin) — broad spectrum, excellent corneal penetration, workhorses for bacterial keratitis and post-op prophylaxis; aminoglycosides (tobramycin, gentamicin) — strong gram-negative coverage but poor corneal penetration; macrolides (erythromycin) — good gram-positive coverage, often an ointment, including newborn prophylaxis; and sulfonamides (sulfacetamide) plus combination products (e.g., with polymyxin) for common conjunctival pathogens. The resistance principles of systemic antibiotics apply: narrowest appropriate agent, complete course, no antibacterials for viral or allergic eyes.

Antivirals and antifungals

Antivirals target herpes simplex keratitis — topical (trifluridine, ganciclovir gel) and, in some cases, systemic (acyclovir). This is where steroid use is most dangerous, so any dendritic (branching) corneal lesion is an immediate red flag. Antifungals (e.g., natamycin, amphotericin B) treat fungal keratitis, linked to contact lens wear and corneal trauma. Both are typically managed with ophthalmology involvement.

Nursing implications

Administration follows the previous topic's technique: hand hygiene, no tip contact, lower sac, spacing between drops, ointment last. Disease-specific teaching: finish the full antibacterial course even if the eye looks better; strict hand hygiene — no shared towels or bottles; remove contact lenses for most products; and understand that pressure checks with steroids are part of the treatment, not optional. Teach patients to call for worsening pain or redness, vision loss, or no improvement — and never to use leftover drops. Nurses administer under prescriber orders and facility policy; verify products, concentrations, and monitoring against references, formulary, and orders.

Common Confusions