1 Fuchs Endothelial Dystrophy

126 Herpes Simplex Keratitis and Related Syndromes
7
Fig. 7.4 Geographic ulcer. Note large corneal ulcer stained with fluorescein that is
geographic in shape (Reprinted with permission from [80])
Patientswithmarginalorlimbalherpeticulcers
are often more symptomatic and less responsive to
treatment [139, 206]. Although epithelial disease
usually resolves, sequelae may ensue such as a
punctate epithelial keratopathy, recurrent corneal
erosions or epithelial granularity. Some degree of
anterior stromal reaction is common underlying
the epithelial lesions and probably represents
an immune response to the epithelial disease
rather than stromal viral invasion. Herpetic
ulcers may become secondarily infected with
bacteria with associated features. A decrease
in corneal sensation is more common than
has previously been realized and neurotrophic
keratopathy may occur as a result of impaired
corneal innervation. This may manifest as loss
of corneal luster and irregularity of the corneal
surface. Punctate epithelial erosions may develop
and progress to a persistent epithelial or
metaherpetic ulcer, also known as an indolent
or trophic ulcer. The ulcer is oval, shallow,
with smooth borders of grey, elevated, thickened
and rolled epithelium [17, 69, 100].
7.5.7 Stromal Keratitis
Herpetic stromal disease accounts for 2% of initial
presentations and 20–48% of recurrent her-
petic disease [42, 99, 128]. It results from viral
invasion of the stroma, either from reactivation
of latent virus in the supplying sensory nerves or
from within the cornea itself.
The associated immune response contributes
to the type of stromal disease seen. There may be
no history of previous infectious epithelial keratitis
and the epithelium is usually intact. The main
characteristic is stromal inflammation, which
may be focal, multifocal or diffuse and may be associated
with anterior uveitis [205]. The inflammation
may be chronic, recurrent or recrudescent
leading to stromal scarring, thinning, neovascularization,
and lipid deposition (Fig. 7.5).
Occasionally, a partial or complete immune
ring, similar to a Wessely ring, is seen in the central
or paracentral mid-stroma [115]. As with
epithelial disease, marginal keratitis or limbitis
tends to be associated with a greater inflammatory
or immune response. Stromal neovascularization
can be sectoral or diffuse and frequently
occurs in several layers of the cornea, a condition
described as “interstitial stromal HSV keratitis”
[100]. Necrotizing stromal keratitis may occur.
There is necrosis, ulceration, and dense infiltration
of the stroma, usually with an overlying
epithelial defect. Grayish white homogeneous
abscesses with edema, keratic precipitates, and
iridocyclitis are seen.