Early Steroids Do Not Prevent Subepithelial Infiltrates in Adenoviral Conjunctivitis
The evidence does not support that early steroid use in adenoviral conjunctivitis prevents the development of subepithelial infiltrates (SEIs). Current guidelines reserve steroids for severe acute presentations or symptomatic SEIs after they develop, not for prophylaxis 1.
Evidence Against Prophylactic Steroid Use
Lack of Preventive Effect
A prospective randomized trial found no difference in the incidence of subepithelial corneal infiltrates between patients treated with dexamethasone/povidone-iodine versus artificial tears during the acute phase 2. While the steroid combination shortened disease duration by approximately 2.4 days, it did not prevent SEI formation 2.
An epidemic study of 150 patients with adenovirus type 8 infection found that topical corticosteroids combined with antibiotics during the acute phase did not influence the incidence of subepithelial keratitis or reduce the number of corneal infiltrates 3. In fact, the mean duration of acute keratoconjunctivitis was longer with this therapy compared to controls 3.
One study showed promise with povidone-iodine/steroid combination reducing MSI incidence at day 15 (0% vs 35.7%), but this was a small study with only 19 patients and limited generalizability 4.
Current Guideline Recommendations
The American Academy of Ophthalmology (2024) recommends topical corticosteroids only for severe acute cases with marked chemosis, eyelid swelling, epithelial sloughing, or membranous conjunctivitis—not for routine prophylaxis of SEIs 1.
SEIs typically occur 1 or more weeks after conjunctivitis onset, and guidelines recommend treating them only when symptomatic (causing blurring, photophobia, decreased vision) 1, 5.
When to Actually Use Steroids
Acute Phase Indications (Limited)
- Severe presentations with marked chemosis or lid swelling 1
- Epithelial sloughing 1
- Membranous conjunctivitis (consider membrane debridement as well) 1
Subepithelial Infiltrate Phase (After Development)
- Observation alone is sufficient for asymptomatic SEIs 1, 5
- Initiate topical corticosteroids at minimum effective dose only when SEIs cause visual symptoms (blurring, photophobia, decreased vision) 1, 5
- Prefer low-penetration agents (loteprednol, fluorometholone, rimexolone) to minimize IOP elevation and cataract risk 1, 5
Critical Pitfalls to Avoid
Prolonged Viral Shedding Risk
- Animal studies demonstrate that topical corticosteroids prolong viral shedding in adenoviral conjunctivitis, though human data is lacking 1, 5. This theoretical concern supports limiting steroid use to truly necessary cases.
Monitoring Requirements
- All patients on topical corticosteroids require regular follow-up including visual acuity, IOP measurement, slit-lamp examination, and periodic pupillary dilation to evaluate for cataract 1, 5
- Avoid premature discontinuation—taper slowly to minimum effective dose as abrupt cessation commonly causes SEI recurrence 5
Differential Diagnosis Confusion
- Do not confuse SEIs with HSV epithelial keratitis, where corticosteroids are absolutely contraindicated and will potentiate infection 1, 5
- SEIs occur ≥1 week after adenoviral conjunctivitis onset, whereas HSV presents differently 5
Alternative Steroid-Sparing Options
- Cyclosporine drops (0.05% to 1% compounded) have been found helpful for reducing SEIs as an alternative to prolonged steroid use 1
- Topical tacrolimus 0.03% showed effectiveness as a corticosteroid-sparing agent for steroid-resistant SEIs in a small case series 6
Follow-Up Timing
- Patients not treated with steroids should return if symptoms persist beyond 2-3 weeks 1, 5
- Patients with severe disease (corneal epithelial ulceration or membranous conjunctivitis) require re-evaluation within 1 week 1
- Those on corticosteroids need more frequent monitoring based on treatment response 5