Peripheral Ulcerative Keratitis Secondary to Atypical Hemolytic Uremic Syndrome

Biological properties and surgical applications of the human amniotic membrane

The amniotic membrane (AM) is the inner part of the placenta. It has been used therapeutically for the last century. The biological proprieties of AM include immunomodulatory, anti-scarring, anti-microbial, pro or anti-angiogenic (surface dependent), and tissue growth promotion. Because of these, AM is a functional tissue for the treatment of different pathologies. The AM is today part of the treatment for various conditions such as wounds, ulcers, burns, adhesions, and skin injury, among others, with surgical resolution. This review focuses on the current surgical areas, including gynecology, plastic surgery, gastrointestinal, traumatology, neurosurgery, and ophthalmology, among others, that use AM as a therapeutic option to increase the success rate of surgical procedures. Currently there are articles describing the mechanisms of action of AM, some therapeutic implications and the use in surgeries of specific surgical areas, this prevents knowing the therapeutic response of AM when used in surgeries of different organs or tissues. Therefore, we described the use of AM in various surgical specialties along with the mechanisms of action, helping to improve the understanding of the therapeutic targets and achieving an adequate perspective of the surgical utility of AM with a particular emphasis on regenerative medicine.

Peripheral ulcerative keratitis due to systemic diseases

PURPOSE OF REVIEW

To discuss peripheral ulcerative keratitis, with a focus on the evaluation and management of associated systemic diseases.

RECENT FINDINGS

Peripheral ulcerative keratitis (PUK) is a sight-threatening condition that is often defined by the presence of a crescent-shaped area of peripheral corneal thinning, an epithelial defect, and an inflammatory corneal infiltrate. It is highly associated with rheumatoid arthritis, systemic necrotizing vasculitides like granulomatosis with polyangiitis, and collagen vascular diseases like systemic lupus erythematosus. Undertreated PUK carries a risk of vision loss and premature death.

SUMMARY

Multidisciplinary collaboration between the ophthalmologist, rheumatologist, and other consultants is required. Early and aggressive steroid-sparing therapy should be considered in cases due to noninfectious systemic disease.

Peripheral ulcerative keratitis: A review of aetiology and management

Background: Peripheral ulcerative keratitis (PUK) is a severe inflammatory disease of the peripheral cornea that can be caused by local factors or systemic inflammatory disease.Aim: The purpose of this review is to give an overview of the pathophysiology, aetiology, clinical features, diagnosis, and management of PUK.Method: A PubMed search was conducted using the keywords, ‘peripheral ulcerative keratitis’ and ‘Mooren’s ulcer’.Results: The peripheral cornea has unique characteristics the predispose to the development of PUK. These include fine capillary arcades that allow for deposition of immune complexes and subsequent activation of an inflammatory cascade with corneal melt. Several conditions have been implicated in the aetiology of PUK. The most commonly cited causes are rheumatoid arthritis (RA), granulomatosis with polyangiitis (GPA) and various dermatoses. In patients with RA, PUK usually presents in established disease, whereas in GPA, PUK may be the presenting feature in up to 60% of cases. In RA it heralds the onset of a systemic vasculitis with significant associated morbidity and mortality. The management of PUK follows an individualised stepwise approach. All patients require supportive measures to encourage healing and halt the process of keratolysis. Systemic autoimmune conditions need a systemic corticosteroid as a fast-acting agent to halt the inflammatory process while cytotoxic therapy maintains long term disease control. Failure to achieve disease control with CTT, necessitates the use of a biologic agent.Conclusion: Peripheral ulcerative keratitis is a severe inflammatory disease of the peripheral cornea that needs a thorough diagnostic workup and stepwise management approach.

Update on the application of amniotic membrane in immune-related ocular surface diseases

Immune-related ocular surface diseases, a group of diseases in which immune dysregulation damages the ocular surface, can induce uncontrolled inflammation and persistent epithelial defect, thus leading to the most severe forms of acute keratoconjunctivitis, dry eye disease, epithelial keratitis, stromal ulceration, and corneal perforation. As these diseases are often refractory to treatments, they have a threatening impact on the vision and life quality of patients. This review summarizes the current literature regarding the clinical application of sutured and self-retained cryopreserved amniotic membrane (AM) in treating Stevens-Johnson syndrome/toxic epidermal necrolysis, ocular graft-versus-host disease, Sjögren's syndrome, Mooren's ulcer, and peripheral ulcerative keratitis. Current evidence supports the safety and effectiveness of AM, especially self-retained cryopreserved AM, in decreasing ocular surface inflammation, promoting corneal epithelial and stromal healing, improving visual acuity, and preventing sight-threatening complications. Future studies are still required to validate the above findings and explore the varied application methods of AM to improve the clinical efficacy in maintaining ocular surface health.

Peripheral ulcerative keratitis

Peripheral ulcerative keratitis (PUK) is an inflammatory condition of the peripheral cornea with hallmark features of epithelial defects and stromal destruction as a result of a complex interplay of factors including host autoimmunity and the peculiar anatomic and physiologic features of the peripheral cornea and environmental factors. PUK may be the result of local or systemic causes and infectious or noninfectious causes. Arriving at a specific etiological diagnosis requires a meticulous clinical workup that may include a battery of laboratory and radiological investigations. Management by a team of internists or rheumatologists and ophthalmologists and judicious use of immunosuppressive agents may yield favorable results minimizing adverse effects. We review current clinical knowledge on the diagnosis and management of PUK.