Color specular microscopy of disorders involving the corneal epithelium.

Color specular microscopy, a noninvasive, in vivo microscopic technique, was utilized to study the corneal epithelium in 17 patients including eight with keratoconus, seven with bullous keratopathy, and two with Fuchs' corneal dystrophy. Color specular microscopy was also performed on rabbit corneas with experimental surgical trauma. Changes observed by specular microscopy in these diseased states correlated with alterations noted by light microscopy and scanning and transmission electron microscopy. Specular microscopy can provide detailed in vivo cellular morphology of the ocular surface, obviating the need for tissue biopsy. Thus, specular microscopy is a valuable diagnostic technique available for the clinician to monitor changes of the diseased ocular surface.

Gram-negative corneal ulcers in elderly aphakic eyes with extended-wear lenses.

We report 13 cases of corneal ulcers caused by gram-negative bacteria. These cases occurred in aphakic eyes wearing hydrophilic contact lenses on an extended-wear basis. The risks for infection in the elderly aphakic eye with extended-wear hydrophilic lenses are increased by delay in removal of the lens. Caution in the use of these lenses is urged. The ability of either the patient or an attendant to remove the lens as soon as redness, diminished vision, or pain presents itself is essential in minimizing the risks for serious infection.

Acanthamoeba keratitis successfully treated with penetrating keratoplasty: suggested immunogenic mechanisms of action.

A patient with a corneal ulcer caused by Acanthamoeba polyphaga has been successfully treated with a penetrating keratoplasty. The pathologic specimen showed no inflammatory infiltrate surrounding the intact amoeba, whereas necrotic organisms were surrounded by an intense cellular reaction. Indirect immunochemical studies showed that the trophozoite stained profusely, but the cyst form exhibited the antigenic site on the cyst wall.

Ocular surface defense mechanisms.

The outer eye is furnished with a variety of defenses active in protecting against continual exposure to the hazards. These defenses include the bony orbit, the eyelids and cilia, the tear film, corneal and conjunctival epithelium, and a submucosal secretory immunoglobulin system. Compromise of one or more of these components in disease states can lead to ocular infection. Rapid engulfment of foreign material introduced into the tearfilm is demonstrated with the use of polystyrene microspheres.

Cellular hypersensitivity to toxoplasmal and retinal antigens in patients with toxoplasmal retinochoroiditis.

To investigate the possible role of hypersensitivity to toxoplasmal and retinal antigens in patients with toxoplasmal retinochoroiditis, we examined their in vitro lymphoproliferative responses to antigens prepared from Toxoplasma gondii and human retina. The magnitude of patients' responses, determined by incorporation of [3H]-thymidine, was compared to those of Toxoplasma seropositive and seronegative controls. Patients were indistinguishable from seropositive controls in terms of antitoxoplasmal antibody titer (dye test, indirect hemagglutination and enzyme-linked immunosorbent assay) and in vitro lymphoproliferative responses to toxoplasmal antigens. Furthermore, there was no relationship between antibody titer and the magnitude of proliferative responses in seropositive individuals. Four of four patients with active eye disease and six of 13 with inactive disease, but none of the seropositive or seronegative controls, had significant lymphoproliferative responses to human retinal antigens. These observations raise the possibility of an autoimmune component in the pathogenesis of relapses in toxoplasmal retinochoroiditis.

Corneal epithelial lesions in keratosis follicularis (Darier's disease).

The prevalence of eyelid keratotic plaques and unique corneal changes associated with Darier'sdisease, peripheral epithelial nebular opacities associated with irregular surface of the central corneal epithelium, are described. These corneal lesions occurred in 16 of 21 patients. The corneal lesions were asymptomatic, stable, and did not respond to oral retinoid therapy. Histopathology of the peripheral corneal opacities showed epithelial cell edema especially in the basal layer, and decreased desmosomes.

Blepharoconjunctivitis: a side effect of 13-cis-retinoic acid therapy for dermatologic diseases.

Blepharoconjunctivitis developed as a side-effect of treatment of patients with basal cell carcinomas, keratinizing dermatoses, and cystic acne with oral 13-cis-retinoic acid. Forty-two of the 97 dermatologic patients had signs and symptoms of blepharoconjunctivitis that were dose related and abated one week after discontinuation of the medication. About half of the patients had a history of similar symptoms prior to treatment. Staphylococcus aureus was present in eye cultures of 73% to 79% of the patients, whether symptomatic or not. Patients whose clinical appearance was that of staphylococcal blepharoconjunctivitis and whose cultures grew S aureus were successfully treated with topical erythromycin ointment to the lids even while being treated with the 13-cis-retinoic acid.

Clindamycin in chronic toxoplasmosis. Effect of periocular injections on recoverability of organisms from healed lesions in the rabbit eye.

Bilateral toxoplasmic retinochoroiditic scars were induced in 21 rabbits. Eleven rabbits were treated with clindamycin phosphate and ten rabbits received parallel injections of normal saline solution. All injections were made into Tenon's space. Toxoplasma organisms could be recovered from tissue suspensions of retina and choroid of four (18%) of the clindamycin-treated eyes, compared with recovery from 12(60%) of the 20 control eyes. There were significantly fewer Toxoplasma cysts in the hematoxylin-eosin-stained sections of the treated eyes than in similar sections of the untreated control eyes.

Antibiotic susceptibility of Chlamydia trachomatis.

The antibiotic susceptibility of Chlamydia trachomatis isolates was determined in a tissue culture system. Representatives of all currently recognized serotypes of trachoma-inclusion conjunctivitis agents were tested. Tetracycline and erythromycin yielded similar results, with 1.0 mug/ml preventing chlamydial replication. Rifampin was the most active antibiotic, with 0.25 mug/ml completely suppressing inclusion formation of all strains. Fifty percent end points were usually achieved at one-fourth to one-eighth the 100% suppression level. Penicillin was not as effective, and the assays were often irregular. Antibiotic susceptibility of these chlamydiae was essentially the same, regardless of serotype, anatomic site infected, geographic origin, or antibiotic use in the community.