Using Steroids to Promote Epithellal Healing
 Use steroids with caution when there is a significant corneal
epithelial defect. In most cases, you want to achieve re-epithelialization
prior to adding a steroid, if in fact one is needed. An exception
to this rule is when there is significant underlying stromal
inflammation that can impede epithelial healing. For example,
it's common to see corneal stromal infiltration where the overlying
epithelium is secondarily broken down and stains with fluorescein.
Conventional teaching says not to use a steroid. A better
approach, however, calls for combination therapy such as TobraDex.
The dexamethasone will suppress the cell-mediated inflammatory
response, commonly a result of corneal hypoxia,  while the tobramycin
prophylaxes against opportunistic bacterial infection. Only
when the underlying stromal inflammation is controlled can
epithelial integrity be restored in many cases.
This underscores an important clinical observation: It's often
impossible for the epithelium to remain intact if the underlying
stroma is sufficiently inflamed. In these cases a steroid must
be instituted in order to facilitate corneal re-epithelialization,
an approach which runs counter to what many of us have been
taught.
In most cases of nodular episcleritis, the conjunctival epithelium
overlying the inflammatory nodule is compromised to such a
degree as to give positive fluorescein staining. Just as with
corneal tissue, if there is sufficient episcleral inflammation
present,overlying conjunctival epithelial function can be compromised,
i.e. epithelial breakdown. How are these tissues restored to
normal? By suppressing the  inflammatory condition with a potent
topical corticosteroid. Furthermore, for nodular episcleritis,
we simply use a pure steroid, not a combination antibiotic-steroid.
Were there a risk of opportunistic bacteria infection, the
expert textbooks would recommend use of a combination drug;
they don't, so we don't. Having been privileged to collectively
treat hundreds of patients with episcleritis, we have found
the textbooks to be true.
In rare circumstances, even following good anti-inflammatory
therapy, an epithelial defect may linger. This could represent
a local toxic effect to one of the components in the drug(s)
being used, or its preservatives. In these circumstances, there
can often be seen an increase in punctate epithelial staining.
Solution: Reduce frequency of instillations, or stop the drug(s)
if deemed clinically appropriate, and lubricate aggressively
with a preservative-free artificial tear solution for several
days.
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