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Biomedical subjects

K A McClellan

Publications and source records attributed to K A McClellan.

28 records · Page 2Linked to original sources
PubMed1989

Nonabsorbable suture material in corneoscleral sections--a comparison of novafil and nylon.

We compared a newly available nonabsorbable monofilament ophthalmic suture, 9/0 Novafil (Davis & Geck), with 10/0 nylon (Alcon), currently the most popular suture for closure of corneoscleral sections. Surgery was performed on nine rats and ten rabbits. In each case a 120 degrees corneoscleral section was made in each eye and closed with interrupted sutures of 9/0 Novafil in one eye and 10/0 nylon in the other. We compared their handling qualities during surgery, as well as their effect on postoperative wound inflammation. In addition we examined the suture material from each eye of the rats by scanning electron microscopy (SEM) after 3 months, and we compared the surgically induced astigmatism in the rabbits in the two suture groups. Both suture materials were easy to handle and well tolerated. Nylon sutures from six of the eight rat eyes studied showed SEM evidence of surface disintegration after 3 months, whereas all the Novafil sutures remained intact.

Absorption↗
PubMed1988

Suppression of viral replication by guanidine: a comparison of human adenoviruses and enteroviruses.

A comparison was made between the relative sensitivities of laboratory strain human adenoviruses and enteroviruses, and recently isolated human enteroviruses, to the presence of guanidine hydrochloride in cell culture media. The concentration of guanidine hydrochloride used was 100 micrograms per ml. Representatives of all six human Adenovirus subgenera were unaffected in their replication at this concentration of guanidine. The different human Enterovirus types examined varied in their sensitivity, with suppression ranging from less than 1 to 3 log10 units for laboratory strains, and from 2 to 7 log10 units for recently isolated viruses. The findings suggest a novel role for antiviral drugs; serving as an adjunct in facilitating selective isolation of specific virus groups which may be present as part of mixed viral populations.

Adenoviruses, Human↗
PubMed1988

Suppurative keratitis: a late complication of radial keratotomy.

A 21-year-old man who had radial keratotomy performed two years previously presented with a painful, red right eye. Suppurative keratitis was found in one of the eight radial incisions and Staphylococcus epidermidis was isolated by culture. Lack of stromal healing of the infected incision and the presence of epithelial cysts in four other incisions in the same eye suggest that the cause of the corneal infection was loss of the epithelial barrier function because of epithelial breakdown.

Adult↗
PubMed1988

Microbiological and histopathological confirmation of acanthamebic keratitis.

A healthy 42 yr-old woman presented with a left keratitis which she had had for 3 months. No organisms could be grown by culture of corneal scrapings for bacteria and fungi, and the condition failed to respond to topical therapy. Amebic keratitis was diagnosed following corneal biopsy and cultures which grew Acanthamoeba of a species similar to, but not identical with, Acanthamoeba polyphaga. Medical treatment was continued for 6 mth. During this time the corneal infiltrate became less prominent but visual acuity remained impaired by both corneal opacity and cataract.

Acanthamoeba↗
PubMed1987

Delayed onset sympathetic ophthalmia.

Three cases of sympathetic ophthalmia that occurred up to 62 years after an ocular injury are reported. Sympathetic ophthalmia occurred spontaneously in the first case, 62 years after a shot-gun pellet had penetrated one eye. In the other two cases, further surgery had been performed on previously-injured eyes. This was followed by a bilateral granulomatous panuveitis that developed within a week in one case and after seven years in the other case. The risk of elective surgery in eyes that are already at risk of sympathetic ophthalmia and the practical aspects of patient counselling are discussed.

Aged↗
PubMed1987

Uveitis: a strategy for diagnosis.

Uveitis may be the first presentation of a wide variety of underlying ocular and systemic diseases. It is important for the ophthalmologist to make a specific diagnosis in order to instigate specific therapy and give an accurate prognosis. The ability to recognise the clinical patterns of uveitis and to initiate appropriate investigations should form the basis of the ophthalmologist's management of the condition. To this end, we have considered uveitis under four major patterns of presentation--anterior uveitis, intermediate uveitis, posterior uveitis, and panuveitis--with subclasses within each of these four groups. We have outlined both the investigations which facilitate diagnosis of the possible underlying causes of inflammation and the interpretation of the results of such investigations.

Capillaries↗
PubMedDate not supplied

Mucosal defense of the outer eye.

A combination of mechanical, anatomical, immunological, and microbiological factors prevent infection of the outer eye. Mechanical and anatomical factors include the intact epithelium of the conjunctiva and cornea and the constant blinking action of the eyelids. Tear components that play a role in eye defense include lysozyme, immunoglobulins, lactoferrin, and betalysin. The normal bacterial flora of the conjunctiva may also have an inhibitory effect on the survival of more pathogenic species. The eye is linked to the common mucosal immune system, thus gaining the benefits of a system of microbial defense which is primed in the gastrointestinal tract, where a continuing large antigen load is capable of stimulating ongoing immune protection. The relative roles of the various factors contributing to prevention of eye infection remain to be fully defined.

Animals↗
PubMedDate not supplied

Diagnosis and management of chronic blepharokeratoconjunctivitis in children.

PURPOSE: To describe the history, symptoms, and clinical signs and discuss the treatment of blepharokeratoconjunctivitis. METHODS: Eight children (five girls and three boys), ranging in age from 3.5-13 years, were clinically diagnosed with blepharokeratoconjunctivitis. Microbiology studies were performed in four of the eight children. Treatment consisted of lid hygiene, oral erythromycin suspension, and preservative-free steroids. Duration of therapy was directed by clinical improvement. RESULTS: Average age at onset was 3.2 years (range: 0.5-8 years). Lid disease, conjunctival redness, and inferior superficial corneal vascularization were consistent features (100%). Other signs were punctate corneal epithelial staining, inferior subepithelial vascularization and infiltrate, conjunctival phlyctenules, corneal phlyctenules, and circumferential pannus. Microbiology testing demonstrated coagulase-negative staphylococcus and Propionibacterium acnes. Average follow-up was 8.3 months (range: 2-23 months). All patients had relief of symptoms within 2-3 weeks. Clinical signs took more time to regress but all had progressive improvement of the ocular surface by 2 months. Blepharokeratoconjunctivitis reactivated in all patients during follow-up, and repeat therapy was administered. CONCLUSION: Blepharokeratoconjunctivitis in childhood is a chronic inflammatory process that can have different presentations. It can be successfully treated with oral erythromycin and topical steroids.

Administration, Topical↗