Clinical Findings, Pathogenesis, and Treatment in Non-Infectious Peripheral Ulcerative Keratitis

Peripheral ulcerative keratitis (PUK) is a group of diseases that manifest with ulceration and/or thinning in the peripheral cornea. Although this group of diseases can occur as a result of infection, most cases are of immunological origin and are associated with autoimmune diseases (AID). The most common form of AID associated with PUK is rheumatoid arthritis (RA). However, PUK may also be seen with other AIDs, such as systemic lupus erythematosus and Wegener’s granulomatosis. There are immunological differences between the peripheral and central cornea that may explain the localization of PUK in the peripheral cornea. For example, the proximity to limbal blood vessels and conjunctival lymphatics is different. Both humoral and cellular immunity play a role in the development of PUK. Although the number of CD8+ T cells did not vary significantly in RA patients, the number of CD4+ T cells was significantly greater. As PUK is very serious, early diagnosis and treatment are very important. Local and systemic corticosteroids, immunosuppressants, biological agents, bandage contact lenses, tissue adhesives, and in some cases, surgical treatment can be applied. Adjacent conjunctival excision, patch lamellar grafts, and keratoplasty are options in surgical treatment. It is very important not to forget the possibility of disease progression despite surgery, and the treatment of underlying disease is crucial. Keratoplasty in PUK cases may not be successful as a result of several factors, such as dry eye and the underlying immunological disease.