What is the danger of using a steroid on a herpetic corneal ulcer?

Topical corticosteroids suppress immune cell function, which the body normally uses to control viral spread. When applied to a herpetic (HSV) ulcer without concurrent antiviral coverage, the steroid allows the virus to replicate more aggressively, potentially causing the dendritic ulcer to enlarge rapidly into a geographic ulcer, penetrate deeper into the stroma (disciform keratitis), or even perforate the cornea.

What are steroid responders and why are they important?

Steroid responders are individuals whose IOP rises significantly (often 10 mmHg or more from baseline) in response to topical or systemic corticosteroids. This is thought to be a genetic predisposition affecting trabecular meshwork cell function. Any patient on long-term topical steroids needs periodic IOP monitoring to detect this response early and switch to a less IOP-elevating agent (such as loteprednol) or adjust therapy accordingly.

When would you use an NSAID instead of a steroid post-operatively?

NSAIDs are preferred when IOP elevation is a concern (in glaucoma patients), when cataract risk needs to be minimized, or when the primary goal is pain relief and prevention of cystoid macular edema rather than suppression of significant inflammation. Many post-cataract surgery protocols combine both a steroid and an NSAID to get the anti-inflammatory power of the steroid with the analgesic and anti-CME benefit of the NSAID.

What makes fluoroquinolone antibiotics preferred for bacterial keratitis?

Fluoroquinolones (moxifloxacin, ciprofloxacin, ofloxacin) are preferred for bacterial keratitis because they have broad-spectrum activity against gram-positive and gram-negative bacteria (including Pseudomonas), achieve high concentrations in corneal tissue, and penetrate the intact epithelium well. They are bactericidal (kill bacteria rather than just inhibiting growth), which is important for aggressive infections like corneal ulcers.

Anti-Inflammatory & Antibiotic Eye Drops: A CPO Guide

Overview of Ocular Pharmacotherapy Categories

Managing eye infections and inflammation requires matching the right type of medication to the underlying problem. An antibiotic treats bacterial infection; a steroid suppresses inflammation; an NSAID manages pain and mild inflammation; an antiviral targets viral pathogens. Using the wrong drug category not only fails to help but can actively harm the patient (for example, treating a viral ulcer with a steroid alone can cause it to spread rapidly).

As a CPO, you will regularly instill these medications in the office, educate patients on their post-visit drop schedules, and need to recognize when a patient's reported side effects warrant prompt clinician attention.

Corticosteroids (Steroids)

Topical corticosteroids are the most potent anti-inflammatory agents available for the eye. Common examples include prednisolone acetate (the most widely used), dexamethasone, and loteprednol. They work by inhibiting phospholipase A2, reducing the production of prostaglandins and leukotrienes, and broadly suppressing the inflammatory cascade.

Clinical uses:

Uveitis (anterior chamber inflammation): High-frequency dosing, often hourly initially.
Post-surgical inflammation: After cataract surgery, strabismus repair, or other procedures.
Allergic conjunctivitis: Short course for severe cases not responding to antihistamines.
Severe corneal inflammation: Keratitis with significant stromal involvement.

Important side effects:

Steroid-induced ocular hypertension: Chronic use can raise IOP, sometimes dramatically, in susceptible individuals (steroid responders). All patients on long-term topical steroids need IOP monitoring.
Posterior subcapsular cataracts: Chronic systemic or topical steroid use promotes PSC formation.
Masking infection: Steroids suppress symptoms of infection, potentially allowing a bacterial or viral infection to worsen while appearing clinically improved.

Never apply a steroid to a red eye without a confirmed diagnosis. A herpetic corneal ulcer treated with a topical steroid alone can rapidly perforate the cornea because the steroid promotes viral replication and suppresses the immune defense.

NSAIDs (Non-Steroidal Anti-Inflammatory Drugs)

Topical NSAIDs inhibit cyclooxygenase (COX) enzymes, blocking the production of prostaglandins without the systemic or ocular risks of steroids. Common agents include ketorolac (Acular), bromfenac, and nepafenac.

Clinical uses:

Post-operative pain: After cataract surgery or refractive surgery (PRK), where steroids alone may not adequately control pain.
Allergic conjunctivitis: Managing itching and irritation.
Prevention of cystoid macular edema (CME): After cataract surgery.
Corneal pain: After corneal abrasion or refractive surgery.

NSAIDs do not raise IOP and do not promote infection, making them useful in situations where steroid side effects are a concern. However, they can cause epithelial toxicity with overuse and carry a small risk of corneal melt (stromal ulceration) with chronic use in susceptible patients.

Steroids are more potent anti-inflammatories than NSAIDs for intraocular inflammation (uveitis). NSAIDs are preferred for surface pain, post-surgical analgesia, and situations where steroid side effects (IOP elevation, cataract) need to be avoided.

Antibiotics

Topical antibiotics are used to treat or prevent bacterial infections of the eye. The choice of antibiotic depends on the suspected or confirmed pathogen and the severity of the condition.

Common classes and examples:

Fluoroquinolones: Moxifloxacin (Vigamox), ciprofloxacin, ofloxacin. Broad-spectrum, excellent corneal penetration, first-line for bacterial keratitis and prophylaxis after intraocular surgery.
Aminoglycosides: Tobramycin, gentamicin. Effective against gram-negative organisms including Pseudomonas.
Macrolides: Azithromycin (AzaSite). Good conjunctival penetration; useful for blepharitis-related conjunctivitis and chlamydial infection.
Polymyxin B combinations: Polymyxin B/trimethoprim (Polytrim). Common for bacterial conjunctivitis, especially in pediatric patients.

Antivirals

Topical antiviral agents are used specifically against viral pathogens. The most common indication is herpes simplex keratitis:

Trifluridine (Viroptic): Inhibits thymidylate synthetase, preventing viral DNA synthesis. Given frequently (up to 9 times daily) for active herpes keratitis.
Ganciclovir gel (Zirgan): Inhibits viral DNA polymerase. More comfortable and less toxic than trifluridine, now often preferred.
Acyclovir: Available in oral form (systemic treatment of herpes zoster ophthalmicus) and topical ointment in some countries.

Key Takeaways

Steroids (prednisolone) are the most potent anti-inflammatories but carry risks of IOP elevation and cataract with chronic use.
NSAIDs (ketorolac, bromfenac) block prostaglandins without steroid risks; used for post-op pain and allergy.
Fluoroquinolones (moxifloxacin) are first-line topical antibiotics for bacterial keratitis and post-surgical prophylaxis.
Antivirals (trifluridine, ganciclovir gel) are used for herpes simplex keratitis and should not be replaced with steroids alone.