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Biomedical subjects

M I Aswad

Publications and source records attributed to M I Aswad.

9 recordsLinked to original sources
PubMed1995

The effect of cleaning and disinfection of soft contact lenses on corneal infectivity in an animal model.

PURPOSE: Bacterial contamination of previously worn soft contact lenses, especially at sites of lens deposits, might play a role in the pathogenesis of lens-associated bacterial keratitis. We studied the effects of three commercial contact lens cleaners and disinfectants in a rabbit model to determine whether cleaning and disinfection reduced infectivity. METHODS: Duragel 75 soft contact lenses, designed to fit the eyes of rabbits, were worn by rabbits under tarsorrhaphies, then were removed and cleaned in one of three cleaner and disinfectant solutions according to the manufacturers' instructions. The lenses were contaminated by overnight incubation in a suspension of 10(8) Pseudomonas aeruginosa/ml and were placed under tarsorrhaphies on the eyes of fresh rabbits. The rabbits were observed for two weeks for signs of infection. Control rabbits wore new, uncleaned but contaminated lenses or worn, uncleaned but contaminated lenses. RESULTS: The rates of infection with the three commercial cleaner and disinfectant solutions ranged from 18% (two of 11) to 31% (four of 13); these incidences were not significantly different from one another or from the 19% (three of 16) incidence with new, contaminated but uncleaned lenses. By contrast, when worn, uncleaned but contaminated lenses were placed in rabbits' eyes, seven of eight were infected, a rate that is significantly higher than that of the other four groups (P = .0003). CONCLUSIONS: These data indicate that the three commercial lens cleaner and disinfectant solutions were of similar efficacy in reducing the infectivity of contaminated contact lenses to a level similar to that of new, unworn lenses.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Bacterial adherence to extended wear soft contact lenses.

The authors studied the adherence of Pseudomonas aeruginosa and Staphylococcus aureus to extended wear soft contact lenses (EWSCLs) with and without focal deposits using both a radiolabeling technique and electron microscopy. P. aeruginosa showed significant adherence to contact lenses in vitro. In contrast, S. aureus failed to show significant adherence to contact lenses in vitro (i.e., the radioactive uptake was not significantly above background). The extent of adherence of Pseudomonas was proportional to the number of focal deposits on the lenses. Results of electron microscopic examination showed the bacteria to be adherent primarily to large focal deposits (greater than or equal to 150 microns). There was no pseudomonal adherence to the small focal deposits (less than or equal to 50 microns) and little adherence to the areas in between the focal deposits. The authors hypothesize that worn lenses, especially those with large focal deposits, serve as a vehicle for the transport of P. aeruginosa to the cornea. This hypothesis could be a partial explanation for the high incidence of keratitis caused by P. aeruginosa in EWSCL patients.

Bacterial Adhesion↗
PubMed1989

Effect of lid closure on contact lens-associated Pseudomonas keratitis.

New or used extended-wear soft contact lenses, preincubated in suspensions of Pseudomonas aeruginosa, were placed on the corneas of rabbits. The lids were then sutured shut for either 1 or 2 weeks. Bacterial keratitis occurred in 9 of 9 eyes fitted with the used contaminated lenses but in none of 12 eyes fitted with new contaminated or new noncontaminated lenses. Similar experiments were carried out with other lenses specifically designed to fit the cornea of rabbits. Some of these lenses were preworn by rabbits for 1 week (used), whereas others were new. A significantly greater incidence of bacterial keratitis was found in eyes that had undergone lid closure after the placement of used contaminated lenses (4 of 5) than in closed eyes with new contaminated lenses (1 of 8) and in open eyes with used contaminated lenses (0 of 13). These findings suggest that extended eyelid closure is a risk factor in the experimental model and may be a factor in clinical Pseudomonas keratitis associated with the wearing of extended-wear soft contact lenses.

Animals↗
PubMed1988

Plasmapheresis treatment in patients with severe atopic keratoconjunctivitis.

A 19-year-old woman with hyperimmunoglobulinemia E (the hyper-IgE syndrome [HIE]) and a 62-year-old man with atopic dermatitis experienced dramatic improvement in their chronic ocular symptoms and signs of atopic keratoconjunctivitis after plasmapheresis was instituted. Both patients had previously received topical and oral corticosteroids as well as topical cromolyn sodium without significant beneficial effect. The authors recommend a trial of plasmapheresis in selected patients with recalcitrant and debilitating atopic keratoconjunctivitis when standard therapy proves unsuccessful.

Adult↗
PubMed1987

Optimal time for postoperative irradiation of pterygia.

A prospective study of the optimal time for postoperative beta irradiation of pterygia in 54 eyes of 54 patients suggested that immediate postoperative irradiation, given as a single dose of 2000 rad, was associated with a lower rate of recurrence than a similar dose given 4 days postoperatively. The authors suggest that patients with recurrent pterygia, selected to have postoperative beta radiation, receive the radiation as a single dose of 2000 rad at the end of the surgical procedure.

Adult↗
PubMed1987

Ocular findings in mitral valve prolapse syndrome.

Thirty-two patients with mitral valve prolapse (MVP) underwent detailed ophthalmologic examination in order to detect the ocular abnormalities associated with this disorder. Three patients had Marfan's syndrome, and 29 had no associated systemic disorders. Of the latter, 19 (65.5%) were myopic (average, 2.00 diopters), 12 (41.4%) had lenticular opacities, and all had unusually deep anterior-chamber angles with prominent iris processes. None of the 29 patients had subluxated lenses. These findings support the view that MVP syndrome can be considered a generalized connective tissue disorder different from Marfan's syndrome.

Adolescent↗
PubMed1985

Homonymous hemianopia and systemic lupus erythematosus.

The case of a 23-year-old woman with systemic lupus erythematosus and homonymous hemianopia is presented. A calcarine cortical infarct occurred as a result of a postpartal exacerbation of her disease and was demonstrated by CT scanning of the brain. The neuro-ophthalmic manifestations of SLE are reviewed briefly. The authors propose to include collagen vascular disease in the differential diagnosis of homonymous hemianopia in the young age group.

Abortion, Spontaneous↗