-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.
-26-36% of patients have an associated systemic disorder.
-Collagen vascular diseases (RA most common), Vasculitides, Dermatologic disease, metabolic disease and atopy.
-Vascular congestion occurs in the superficial episcleral plexus.
-The episclera as well as Tenon’s capsule become infiltrated with inflammatory cells.
-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
-RF, ANA, Serum Uric acid, ESR, CBC with differential counts, VDRL/FTA-ABS.
-Conjunctivitis, phlyctenular conjunctivitis, scleritis, pingueculitis
-Reassuring the patient
-Weak topical steroids
Image from Rajan Eye Care Hospital