Viral conjunctivitis is usually temporary and self-limiting, often resolving within a few weeks.¹ But just because the pink eye itself clears up doesn’t mean patients are completely out of the woods yet. Researchers believe that epidemic keratoconjunctivitis (EKC) can leave behind corneal subepithelial infiltrates (SEIs) that can cause persistent damage to both the eye’s structure and its visual function.² These SEIs can develop and prevail for months or even years.^1-3 The complete extent of this impact is not known, but researchers are now saying that at least one structure—the tear film—is significantly compromised for these patients.³

The researchers looked at 38 patients with EKC and 42 healthy volunteers. The EKC patients were split into two groups: those with SEIs after EKC in one eye only and those for whom the second eye was involved.³ Best-corrected visual acuity (BCVA), corneal subepithelial infiltrate scoring (CSIS), Fantes score of corneal clarity, tear break-up time (TBUT), Schirmer testing and Ocular Surface Disease Index (OSDI) scores were measured. Additionally, the Oxford grading system was used to score corneal staining.³

The study found that SEIs can develop after EKC in up to half of the patients, and about half of those can have unilateral involvement.³ The patients with only unilateral involvement fared worse visually than the patients with bilateral involvement, but they were statistically equal (in terms of BCVA, OSDI scores and Oxford staging) when compared with the healthy eyes.³ TBUT, Schirmer’s and OSDI scores all showed that SEI patients develop worse dry eye issues than the healthy controls.³ This disturbed tear film function and tear film instability may be causing decreased vision in addition to the corneal opacities, the researchers suggest.³

The study also suggests that the cause of dry eye in these patients could be related to a cascading effect the SEIs set into motion, first increasing inflammatory mediators in the tear film, then increasing evaporation due to the ocular surface irregularity and, finally, destroying the lacrimal gland.³ Steroids, they explain, may halt this cascade by decreasing SEIs and, ultimately, preventing the evaporation.³

The investigators support the use of topical steroids as a remedy for SEIs—noting that, when discontinued, SEIs can recur.³ However, since steroids themselves may weaken the tear film, they advocate the use of topical cyclosporine as a steroid-sparing agent to prevent SEI recurrence.³