Necrotizing scleritis with inflammation

Necrotizing scleritis with inflammation is characterized by overt signs and symptoms of scleral inflammation. It may be subdivided into 3 types: (1) vaso-occlusive, (2) granulomatous (Fig 7-5), and (3) postsurgical.

The vaso-occlusive type progressively displays plaques of nonperfusion of episclera/conjunctiva, associated with scleral edema/infiltration and severe congestion of adjacent episcleral/conjunctival vessels (Fig 7-6). The limbal area and peripheral cornea are often spared. These cases are usually associated with infection or with an underlying systemic immune-mediated disease.

The granulomatous type typically starts with necrotizing inflammation of the limbal area, further extending anteriorly to the cornea and posteriorly to the sclera. The inflamed area assumes a “lumpy” aspect, associated with inflammatory infiltration and edema. Subsequently, necrosis and ulceration of the affected tissues (cornea, conjunctiva, episclera, and sclera) develop. This granulomatous type is frequently associated with systemic vasculitides, particularly granulomatosis with polyangiitis and polyarteritis nodosa. It is important to note that other subtypes of necrotizing scleritis may also display granulomatous inflammation on histopathology.

Figure 7-5 Necrotizing scleritis of the granulomatous subtype in a patient with granulomatosis with polyangiitis, with concomitant lung and kidney disease. Infiltration of the sclera and peripheral cornea is seen, with formation of multiple necrotic/avascular plaques (A). Chest radiograph (D) shows infiltrates in the right lung (bottom left). Simultaneous fluorescein angiography (FA) (B, E) and indocyanine-green angiography (ICGA) (C, F) delineate areas of necrosis (with absence of episcleral and of conjunctival vessels) and of predominantly peripheral corneal neovascularization.

(Courtesy of Daniel V. Vasconcelos-Santos, MD, PhD.)

Figure 7-6 Necrotizing scleritis of the vaso-occlusive type, showing a large avascular area adjacent to the limbus.

(Courtesy of Daniel V. Vasconcelos-Santos, MD, PhD.)

The postsurgical type is rare but frequently arises a few months to several years after surgical trauma to the sclera. It may be infectious or noninfectious. Procedures associated with postsurgical scleritis include cataract, strabismus or retinal surgery, trabeculectomy, cryotherapy, and pterygium excision, the last especially with use of mitomycin C or beta radiation. Recalcitrant inflammation, with progressive necrosis of the sclera, develops commonly at the site of the surgical insult (Fig 7-7), or sometimes more distant to the surgical incision. Many of these patients have an underlying autoimmune disease, with scleral surgical injury being the possible trigger for the local inflammatory process. It is important to exclude infection in these cases.

• Watson PG, Hazleman BL, McCluskey P, Pavésio CE. The Sclera and Systemic Disorders. 3rd ed. London: JP Medical; 2012.

Necrotizing scleritis without (overt) inflammation

Necrotizing scleritis without (overt) inflammation, also called scleromalacia perforans, is characterized by lack of significant symptoms and apparent signs of clinical scleral inflammation. On histopathology, however, there is inflammatory cell infiltration in the sclera. The necrotizing granulomatous response leads to progressive (and “silent”) destruction of the scleral tissue, which may extend circumferentially, eventually leaving a staphyloma. This entity has been historically misnamed scleritis without inflammation. Patients with scleromalacia perforans are often elderly women with long-standing rheumatoid arthritis. They typically present with yellowish or white necrotic scleral plaques involving the sclera and episclera (sequestrum) of both eyes. These plaques are surrounded by mildly dilated episcleral vessels. Associated staphylomata are covered by conjunctiva and a thin translucent layer of fibrous tissue (Fig 7-8). Despite the term “perforans,” these lesions do not usually perforate spontaneously.

Figure 7-7 Necrotizing scleritis of the postsurgical type (following extracapsular cataract surgery), displaying multiple foci of scleral necrosis.

(Courtesy of Daniel V. Vasconcelos-Santos, MD, PhD.)

Figure 7-8 Scleromalacia perforans, showing profuse loss of scleral tissue, covered by conjunctiva. No overt inflammatory signs are seen.

(Courtesy of Daniel V. Vasconcelos-Santos, MD, PhD.)

Figure 7-9 Posterior scleritis. A, Submacular exudation is seen on fundus photography. B, B-scan discloses accumulation of sub-Tenon fluid continuous to the optic nerve shadow (T-sign). C, D, Spectral-domain optical coherence tomography shows marked choroidal infiltration leading to serous detachment of the neurosensory retina and of the underlying retinal pigment epithelium. Fibrin deposition can also be seen in the subretinal space.

(Courtesy of Daniel V. Vasconcelos-Santos, MD, PhD.)

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.