Anal fistula is a chronic abnormal communication between the epithelialised surface of the anal canal and usually the perianal skin. An anal fistula can be described as a narrow tunnel with its internal opening in the anal canal and its external opening in the skin near the anus. Anal fistulae commonly occur in people with a history of anal abscesses. They can form when anal abscesses do not heal properly.Anal fistulae originate from the anal glands, which are located between the internal and external anal sphincter and drain into the anal canal. If the outlet of these glands becomes blocked, an abscess can form which can eventually extend to the skin surface. The tract formed by this process is a fistula.Abscesses can recur if the fistula seals over, allowing the accumulation of pus. It can then extend to the surface again – repeating the process.Anal fistulae per se do not generally harm, but can be very painful, and can be irritating because of the drainage of pus (it is also possible for formed stools to be passed through the fistula). Additionally, recurrent abscesses may lead to significant short term morbidity from pain and, importantly, create a starting point for systemic infection.Treatment, in the form of surgery, is considered essential to allow drainage and prevent infection. Repair of the fistula itself is considered an elective procedure which many patients opt for due to the discomfort and inconvenience associated with an actively draining fistula.
Moorens ulcer is a rare idiopathic ocular disorder that may lead to blindness due to progressive destruction of the peripheral cornea. Although the etiology of Moorens ulcer is poorly understood, recent evidence suggests that the pathogenesis of this disease appears to be the result of an autoimmune process directed against molecules expressed in the corneal stroma.Moorens ulcer is also defined as a special and the most common type of peripheral ulcerative keratitis (PUK). Signs and symptoms
Symptoms of Moorens ulcer can include:
Pain in the affected eye(s)
Redness of the affected eye(s)
Progressive ulceration of the cornea
Blurred vision
Photophobia
TearingSome epidemiological studies have noted that men tend to be affected more than women. Classification
The most commonly used classification was proposed by Watson in 1997. He divided the disease into three types based on the clinical picture:
Unilateral Moorens ulceration is characterized by extremely painful progressive ulceration of the cornea in one eye. This form is more common in elderly patients. Bilateral aggressive Moorens ulceration which is observed more often in young patients and progresses along the entire circumference, then captures the central area of the cornea. Bilateral indolent Moorens ulceration (BIM) usually occurs in middle-aged patients and manifested by a progressive peripheral corneal guttering in both eyes. Risk factors
Several risk factors affecting the development of Moorens ulcer have been suggested. Corneal trauma
Previous ocular trauma or infection can cause disruption of the corneal integrity resulting in the expression of tissue-specific antigens that are normally hidden from the immune system.