Giant papillary conjunctivitis is associated with foreign bodies, such as contact lenses, sutures, and prostheses.[
7] Giant upper tarsal conjunctival papillae are arbitrarily defined as greater than 0.3 mm in diameter.[
8] Contact allergic conjunctivitis may be produced by ophthalmic medications, including neomycin, bacitracin, atropine, thimerosal, benzalkonium chloride, and chloramphenical.[
9] Cytologic preparations in all of these allergic disorders may show mast cells, eosinophils, and basophils (Figure 3-4). Eosinophils are not normally present in the conjunctiva; therefore, the presence of any may be significant.[
10] However, eosinophils may be absent in allergic conjunctivitis.[
11]
ADENOVIRUS
Acute conjunctivitis due to adenovirus infection is characterized clinically by the presence of pale nodules (follicles) in the conjunctiva, a red eye, watery discharge, and preauricular lymphadenopathy (Figure 3-5). Cytologic smears may show numerous lymphocytes of varying sizes, occasional macrophages, and epithelial cells may exhibit nuclear enlargement, an increased nuclear-to-cytoplasmic ratio and, rarely, intranuclear inclusions. Certain strains of adenovirus, types 3 and 8, may selectively infect conjunctiva.[
12]
CHLAMYDIA TRACHOMATIS
Trachoma, caused by the bacterial agent Chlamydia trachomatis is a major cause of blindness in the world, in the United States, it manifests as inclusion conjunctivitis characterized by a follicular conjunctivitis (Figure 3-7). Chlamydia is important to diagnose because the disease may require topical systemic therapy. Historically, the diagnosis has been made by cytology of conjunctival scrapings.[13] Chlamydial infection begins when the elementary body, a 300 nanometer (nm) particle enters epithelial cells. This particle is enclosed by the host membrane and enlarges to become the initial body (1000 nm). The initial body divides to form numerous elementary bodies. When the cell ruptures, the cycle is continued. On Giemsa-stained preparations, the initial body is basophilic and helmet shaped (Figure 3-8). The cellular constituents seen on Giemsa-stained preparations from known chlamydia infections include neutrophils (usually predominant), lymphocytes, immunoblasts, plasma cells, and occasional multinucleated cells.[
14] Because cytoplasmic inclusions are only rarely identified in patients with clinically suspected disease, classic cytology has been largely supplanted by direct immunofluorescence with fluorescein-conjugated monoclonal antibody.[
15] However, false positive results may occur with this test; therefore, a combination of techniques (e.g., smear and culture) has been recommended.[16] In-situ hybridization for chlamydia has been 100% sensitive and specific in animal models.[17] However, in human tissues, the specificity and sensitivity have been reported to be only 80% and 91%, respectively.[18] Papanicolaou staining of smears in gynecologic specimens may be as effective for diagnosis as DNA in-situ hybridization.[
19-
20]References:
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Richmond PP et. al Int Opthamol Clin 1981.
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Korb DR et. al Am J Opthalmol 1980.
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Hatinen A. et. al Acta Opthalmol (Copenh) 1985.
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Butrus SI. et. al Int Opthalmol Clin 1988.
11.
Abelson MB et. al Arch Opthalmol 1983.
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Thelmo W. et. al Acta Cytol 1972.
13. Halberstaedter L, Von Prowazek, S. Zur aetiolgie des trachoms. Dtsch Med Wochenschr 1907;16:172-177.
14.
Wilhelmus KR, et. al Arch Opthalmol 1986. 15.
Tam MR, et. al N Eng J Med 1984.
16. Ugland DN, Jones DB, Wilhelmus KR, et. al. Diagnosis of adult chlamydial conjunctivitis and use of fluorsecein-conjugated monoclonal antibody. Invest Opthalmol Vis Sci 1985;26(suppl):272.
17. Horn JE, Kappus EW, Falkow S, Quinn TC. Diagnosis of
Chlamydial trachomatis in biopsied tissue speciemens using in situ DNA hybridization. J Infect Dis 1985; 157:12790-1953.
18. Horn JE, Hammer ML, Falkow S, Quinn TC. Detection of
Chlamydia trachomatis in biopsied tissue soecimens by using DNA hybridization. J Infect Dis 1986; 153:1155-1159.
19.
Gupta PK, et al. Diagn Cytopathol 1988. 20.
Ghiradini C, et al. Diagn Cytopathol 1991.
