Growth of acanthamoeba on human corneal epithelial cells and keratocytes in vitro.

Acanthamoebic keratitis, a potentially devastating infection usually associated with contact lens wear, has been recognized with increasing frequency in recent years. Once the Acanthamoeba organisms gain access to the human cornea, it is not clear which constituents of the corneal milieu provide a substrate for their growth. The growth of Acanthamoeba polyphaga was investigated on cultured monolayers of human corneal epithelial cells, stromal keratocytes, and stromal homogenate suspensions. Growth was determined through organism counts and observation of cytopathic effects on tissue culture dishes. Compared with tissue culture media controls, acanthamoebic growth was supported by cultured epithelial cells and keratocytes but not stromal homogenates. These results suggest that in acanthamoebic keratitis the organisms depend on the cellular components of the cornea as substrates for growth. This in vitro model may also provide further information on the pathogenesis of keratitis and a system for drug sensitivity testing.

Sinus histiocytosis presenting as an epibulbar mass. A clinicopathologic case report.

Sinus histiocytosis is a well-recognized condition that mainly affects children in the first decade of life. Although this usually benign disease often features massive cervical lymphadenopathy, numerous extranodal sites of involvement can be seen. We describe a new presenting manifestation for sinus histiocytosis. A 13-month-old infant developed a rapidly growing unilateral epibulbar tumor that involved the cornea. A complete physical examination revealed only mild inguinal lymphadenopathy. A diagnosis of sinus histiocytosis was made by histologic examination of the lesion after surgical excision.

Indications for keratoepithelioplasty.

Thirteen patients with ocular surface failure were treated by keratoepithelioplasty using allografts of corneal limbal epithelial cells from donor eyes. The ocular surface was stabilized with long-term healing of persistent epithelial defects in five of eight eyes followed up for 4 to 19 months. The procedure was performed on an additional 5 patients with superficial keratopathies. Three of those five procedures resulted in a stable and clear optical surface. These results suggest that epithelial transplantation may be a useful option in the care of chronic ocular surface failure unresponsive to conventional medical management.

Survival of Acanthamoeba in contact lens rinse solutions.

Acanthamoeba may cause a severe keratitis in contact lens wearers. Since most sterilization techniques require rinsing the lenses prior to insertion, contaminated solutions represent a potential vector for transmission of Acanthamoeba. The ability of rinse solutions to sustain an inoculum of Acanthamoeba polyphaga was investigated. A. polyphaga was exposed to 0.1% benzalkonium chloride, 0.001% thimerosal/0.1% edetate disodium, 0.1% edetate disodium, saline, tap water, and distilled water. The status of the organism was evaluated with direct microscopic counts and cultures to confirm viability. Incubation with 0.1% edetate disodium, saline, tap water, and distilled water resulted in the maintenance of reduced populations of viable organisms for 7 days. Benzalkonium chloride preserved saline and solutions containing thimerosal with edetate rendered the Acanthamoeba nonviable.

Atypical cases of sinus histiocytosis (Rosai-Dorfman disease) with ophthalmological manifestations.

Sinus histiocytosis with massive lymphadenopathy is a non-neoplastic disease of unknown cause observed mainly in children with markedly enlarged cervical or other lymph nodes. We have reported two very atypical cases with extranodal manifestations that required ophthalmological consultation. Neither patient had significant lymphadenopathy. One patient, who had tumors of all four eyelids as well as lesions of the nose and larynx, was 68 years old when first examined, and 70 at the time of his last surgical procedure. The other patient, a 13-month-old child, had a unique corneoscleral lesion as his only clinical manifestation. The excised tissues obtained from the eyelids and larynx in case 1 and from the corneoscleral lesion in case 2 revealed characteristic histopathologic features of sinus histiocytosis (Rosai-Dorfman disease), including strongly positive immunoperoxidase staining for S-100 protein in the cytoplasm of most of the histiocytes.

Prolonged recoverability of desiccated adenovirus type 19 from various surfaces.

Epidemic keratoconjunctivitis is a highly contagious disease whose transmission has been linked to the ophthalmologist's office. The authors studied the ability of adenovirus 19 (ADV 19) to survive on surfaces commonly found in the office setting. An initial in vitro laboratory experiment demonstrated that ADV 19 in a desiccated state could be recovered up to 8 days from paper, and up to 10 days from cloth, metal, and plastic. The amount of recovered ADV 19 was significantly greater (analysis of variance, P less than 0.0001) from nonporous surfaces (plastic, metal) compared with porous surfaces (cloth, paper). A second experiment demonstrated that 35 days was the maximum length of time that desiccated ADV 19 could be recovered from a nonporous surface (plastic). The authors conclude that despite drying, ADV 19 is a hearty virus that remains potentially infectious for a long time on various surfaces that may be found in an ophthalmologist's office.