Episcleritis

Apr 20

Common, benign, self-limited cause of red eye, due to inflammation of the episcleral tissues.
2 forms of this condition: nodular and simple.
Nodular: discrete, elevated area of inflamed episcleral tissue.
Simple: vascular congestion in the absence of an obvious nodule.

WHAT IS THE EPISCLERA?

Fibroelastic structure consisting of 2 layers loosely joined together.
The outer parietal layer, with the vessels of the superficial episcleral capillary plexus, is the more superficial layer.
The superficial vessels appear straight and are arranged in a radial fashion.
The deeper visceral layer contains a highly anastomotic network of vessels.
Both of the vessel networks originate from the anterior ciliary arteries, which stem from the muscular branches of the ophthalmic artery.
The episclera lies between the superficial scleral stroma and Tenon’s capsule.

ETIOLOGY:

Mostly idiopathic.
26-36% of patients have an associated systemic disorder.
Collagen vascular diseases (RA most common), Vasculitides, Dermatologic disease, metabolic disease and atopy.

PATHOLOGY:

Vascular congestion occurs in the superficial episcleral plexus.
The episclera as well as Tenon’s capsule become infiltrated with inflammatory cells.

FEATURES:

20-50yrs
Redness (pain rare)
Nodular: redness noted when patient wakes up in the morning
Area of diffuse or sectoral, bright red or pink bulbar injection
Eyelid edema, conjunctival chemosis may be present
Use a narrow slit beam to differentiate episcleritis from scleritis
Nodular scleritis: inner reflection, which rests on the sclera and visceral layer, will remain undisturbed while the outer reflection will be displaced forward by the episcleral nodule
Scleritis: both of the light beams will be displaced forward
Nodule in episcleritis is freely mobile over the scleral tissue that lies underneath

TESTS: