Typical features of scleritis
Patients typically present with severe, boring, and persistent pain (except with scleromalacia perforans), with associated erythema, photophobia, and tearing. Less commonly, there can be a reduction in visual acuity. It affects women in two-thirds of cases. Bilateral disease develops in 30% to 70% of cases, with recurrence rates of up to 70%. Most patients (∼95%) maintain the same clinical subtype. It is associated with a systemic disease in ∼50%, with frequency depending on the subtype (see later). Scleritis does not fully blanch with topical phenylephrine. Complications include keratitis, uveitis, glaucoma, cystoid macular edema, and exudative retinal detachment.
| Subtypes of Scleritis | |
| Diffuse | Most benign form, with ocular complications occurring in 50%, but only 18% experiencing a decrease in visual acuity. 60% of patients have an associated systemic disease, with RA being the most common. |
| Nodular | Characterized by local inflammation with a tender immobile nodule. Nodules may have a dark red or violaceous hue. Ocular complications occur in 50%, with <10% experiencing decreased visual acuity. 45% have an associated systemic disorder such as RA. |
| Necrotizing | Most destructive form and can progress rapidly to scleral necrosis; ocular complications common. Up to 95% have an associated systemic disorder . Its presence may indicate increased activity of systemic vasculitis; 45% of untreated patients will die from vasculitis complications within 5 years. Scleromalacia perforans is a subtype of necrotizing scleritis where the sclera becomes necrotic and thin without pain or redness . As a result, the disease presents with an insidious onset and poses a major challenge when attempting to gauge response to therapy. |
| Posterior | May be difficult to diagnose because redness may be absent (unless anterior involvement is also present) and pain and visual disturbance may be minimal. A clue on history and exam may be pain with eye accommodation. Orbital ultrasonography may demonstrate scleral thickening and magnetic resonance imaging (MRI) and computed tomography (CT) scan can also be helpful. Ocular complications occur in 85%, with retinal pathology (cystoid macular edema, exudative retinal detachment) being the most common. Associated with systemic disease in less than one-third when posterior involvement is isolated |
