Differentiating a scleritis from an episcleritis is important because both entities can be associated with significant systemic diseases, such as arthritis, lupus, herpes zoster or psoriatic arthritis.

The “hallmark” symptom that distinguishes Scleritis from Episcleritis is tenderness to touch.

The “hallmark” sign is Scleral Edema visualized under the episcleral venous plexus on Slit Lamp Examination (sometimes best seen with the red free light) that distinguishes Scleritis from Episcleritis.

It is important to note that scleritis is almost alwaysassociated with a systemic condition. So, if you make a positive diagnosis of scleritis, lab work for systemic diseases is imperative. (Keep in mind that episcleritis also has a systemic disease association in about 36% of cases.¹)

In addition to determining the presence of an underlying systemic disease, there are three key signs to look for when differentiating scleritis from episclertitis. Presentations of scleritis:

·    Cause greater levels of pain and discomfort.

·    Will not blanch with the application of neosynephrine.

·    Will appear much deeper in color (almost a purple hue).

1. Akpek, EK, Uy HS, Chisten W, et al. Severity of episcleritis and systemic disease association. Ophthalmology. 1999 Apr;106(4):729-31.