Posterior scleritis is a sight-threatening entity that is defined by inflammation posterior to the ora serrata. It may be difficult to recognize because of lack of inflammatory signs in the anterior part of the sclera unless it is concomitant to anterior scleritis. The rate of association with inflammatory systemic conditions is comparable to that of anterior scleritis. Patients often report severe deep, boring pain and tenderness to palpation, but in 30%–40% of patients, these symptoms may be mild or absent. Decreased vision is often reported, but also depends on the topography of scleral inflammation and involvement of underlying structures. Possible signs include choroidal detachment and folds, subretinal fluid, and optic disc edema (Fig 7-9). Anterior rotation of the ciliary body pars plicata can displace the iridolenticular diaphragm anteriorly, leading to angle closure and acute elevation of intraocular pressure. Involvement of extraocular muscles (myositis) occasionally leads to diplopia.
McCluskey PJ, Watson PG, Lightman S, Haybittle J, Restori M, Branley M. Posterior scleritis: clinical features, systemic associations, and outcome in a large series of patients. Ophthalmology. 1999;106(12):2380–2386.
Excerpted from BCSC 2020-2021 series: Section 9 - Uveitis and Ocular Inflammation. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.