The term “corneal ulcer” is often used interchangeably with “bacterial keratitis,” although, in practice, these are two different entities. Bacterial keratitis denotes a bacterial infection of the eye that causes inflammation and, potentially, ulceration of the cornea, whereas corneal ulcer describes a loss of corneal tissue due to many possible causes. Although acute corneal ulcers in emergency settings are most likely infectious in etiology, other sterile causes of ulceration exist.
This article specifically addresses sterile corneal ulcers associated with autoinflammatory diseases.
The most common autoimmune pathologies with ocular manifestations include rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), connective-tissue disorders (Sjögren syndrome, scleroderma, relapsing polychondritis), and vasculitis (granulomatosis with polyangiitis [GPA], polyarteritis nodosa, and, rarely, Behcet disease). Patients with ocular manifestations of autoinflammatory diseases often have keratoconjunctivitis sicca (dry eye syndrome), which can cause corneal ulceration. Less frequently, the autoinflammatory process can also directly attack the cornea, causing peripheral ulcerative keratitis (PUK), a condition that demands aggressive treatment.
Some cases of corneal ulcer may also be idiopathic; these are referred to as Mooren ulcers. These noninfectious ulcerations touch the peripheral cornea and have been classified into two clinical types. One is a milder, unilateral, less progressive form of the disease generally seen in elderly patients that responds well to therapy. The second type is a much more aggressive, frequently bilateral, relentless disease usually seen in younger patients that is poorly responsive to any therapy and often leads to corneal destruction. Increasing evidence has shown an autoimmune basis for this pathology.
Of note, patients with a poor corneal surface especially those with systemic diseases in whom keratoconjunctivitis sicca (dry eye syndrome) often is also present, are at increased risk for corneal infection.