Arlt’s line is seen on: March 2011
Correct Answer: Superior palpebral conjunctiva
Description: Ans. B: Superior palpebral conjunctiva In trachoma, a characteristic white conjunctival scar (Arlt line) is usually formed at the junction between the lower third and upper two-third of the superior tarsus Trachoma/ Granular conjunctivitis/ Egyptian ophthalmia It is an infectious disease causing a characteristic roughening of the inner surface of the eyelids. It is the leading cause of infectious blindness in the world. Trachoma is caused by Chlamydia trachomatis It is spread by direct contact with eye, nose, and throat secretions from affected individuals, or contact with fomites (inanimate objects that carry infectious agents, such as blankets and pillowcases), such as towels and/or washcloths, that have had similar contact with these secretions. Untreated, repeated trachoma infections result in entropion -- a painful form of permanent blindness when the eyelids turn inward, causing the eyelashes to scratch the cornea. Children are the most susceptible to infection due to their tendency to easily get diy The bacterium has an incubation period of 5 to 12 days, after which the affected individual experiences symptoms of conjunctivitis, or irritation similar to "pink eye." Blinding endemic trachoma results from multiple episodes of reinfection that maintains the intense inflammation in the conjunctiva. The conjunctival inflammation is called "active trachoma" and usually is seen in children, especially pre-school children. It is characterized by white lumps in the undersurface of the upper eyelid (conjunctival follicles or lymphoid germinal centres) and by non-specific inflammation and thickening often associated with papillae. Follicles may also appear at the junction of the cornea and the sclera (limbal follicles). Active trachoma will often be irritating and have a watery discharge. Bacterial secondary infection may occur and cause a purulent discharge. The later structural changes of trachoma are referred to as "cicatricial trachoma". These include scarring in the eyelid (tarsal conjunctiva) that leads to distoion of the eyelid with buckling of the lid (tarsus) so the lashes rub on the eye (trichiasis). These lashes will lead to corneal opacities and scarring and then to blindness. Linear scar present in the Sulcus subtarsalis is called ArIt's line (named after Carl Ferdinand von Arlt). In addition, blood vessels and scar tissue can invade the upper cornea (pannus). Resolved limbal follicles may leave small gaps in pannus (Herbe's Pits). The major complication or the most impoant one is corneal ulcer occurring due to rubbing by concentrations, or trichiasis with superimposed bacterial infection Grading of trachoma McCallan's classification-McCallan in 1908 divided the clinical course of trachoma into 4 stages WHO classification-The World Health Organization recommends a simplified grading system for trachoma. The Simplified WHO Grading System is summarized below (FISTO): Trachomatous inflammation, follicular (TF) - Five or more follicles of >0.5 mm on the upper tarsal conjunctiva Trachomatous inflammation, intense (TI) - Papillary hyperophy and inflammatory thickening of the upper tarsal conjunctiva obscuring more than half the deep tarsal vessels Trachomatous scarring (TS) - Presence of scarring in tarsal conjunctiva. Trachomatous trichiasis (TT) - At least one ingrown eyelash touching the globe, or evidence of epilation (eyelash removal) Corneal opacity (CO) - Corneal opacity blurring pa of the pupil margin SAFE strategy National governments in collaboration with numerous non-profit organizations implement trachoma control programs using the WHO-recommended SAFE strategy, which includes: Surgery to correct advanced stages of the disease; Antibiotics to treat active infection, using Zithromax (azithromycin) donated by Pfizer Inc through the International Trachoma Initiative; Facial cleanliness to reduce disease transmission; Environmental change to increase access to clean water and improved sanitation. Surgery For individuals with trichiasis, a bilamellar tarsal rotation procedure is warranted to direct the lashes away from the globe. Early intervention is beneficial as the rate of recurrence is higher in more advanced disease. Antibiotic therapy WHO Guidelines recommend that a region should receive community-based, mass antibiotic treatment when the prevalence of active trachoma among one to nine year-old children is greater than 10 percent. Subsequent annual treatment should be administered for three years, at which time the prevalence should be reassessed. Annual treatment should continue until the prevalence drops below five percent At lower prevalences, antibiotic treatment should be family-based. Antibiotic selection: Azithromycin (single oral dose of 20 mg/kg) or topical tetracycline (one percent eye ointment twice a day for six weeks). Azithromycin is preferred because it is used as a single oral dose. Although it is expensive, it is generally used as pa of the international donation program organized by Pfizer through the International Trachoma Initiative. Azithromycin can be used in children from the age of six months and in pregnancy. Facial cleanliness Children with grossly visible nasal discharge, ocular discharge, or flies on their faces are at least twice as likely to have active trachoma as children with clean faces. Intensive community-based health education programs to promote face-washing can significantly reduce the prevalence of active trachoma, especially intense trachoma (TI). If somebody is already infected washing one's face is strongly encouraged, especially a child, in order to prevent reinfection Environmental improvement Modifications in water use, fly control, latrine use, health education and proximity to domesticated animals have all been proposed to reduce transmission of C. trachomatis.
Category:
Ophthalmology
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