Search PubMed⌕ Search

Biomedical subjects

F A Billson

Publications and source records attributed to F A Billson.

At least 73 records · Page 4Linked to original sources
PubMed1989

Vogt-Koyanagi-Harada syndrome--isolation of cloned T cells with specificity for melanocytes and melanoma cells.

The pathogenesis of Vogt-Koyanagi-Harada syndrome is poorly understood. A unifying mechanism for its diverse clinical manifestations affecting central nervous system, eye, integument and auditory system has not been found, although many authors have suggested that the features of the disease are the result of autoimmune responses. We performed immunological studies on two patients with Vogt-Koyanagi-Harada syndrome. In one case antibodies to melanoma cells in cytotoxic assay were detected, which it was thought may indicate the presence of antibodies to melanocytes. In the second patient three clones of interleukin-2-dependent T cells were isolated which appeared to have specificity in both cytotoxic and proliferative assays to cultured normal melanocytes and to three allogeneic melanoma cells. These findings further support a role for autoimmunity to pigmented cells in the pathogenesis of Vogt-Koyanagi-Harada syndrome. However, the precise role of autoimmunity in this disease is yet to be established.

Adolescent↗
PubMed1989

The scotopic threshold response in diabetic retinopathy--a preliminary report.

The scotopic threshold response (STR) and the scotopic b-wave of the electroretinogram were recorded in a group of 30 patients with insulin-dependent diabetes mellitus. Retinopathy was assessed using colour stereo fundus photography and an adaptation of the Airlie House classification scheme. Wide-angle fundus fluorescein angiography was also performed and angiograms were graded for the presence of leakage and capillary non-perfusion. The STR was reduced in those eyes with retinopathy of grade 3 or above compared with eyes with retinopathy of grade 2 or below. There was a significant correlation between the amplitude of the STR and: (1) the grade of retinopathy; and (2) fluorescein leakage. There was no correlation between the b-wave amplitude and the severity of retinopathy. The STR may have a role as a screening test for diabetic retinopathy.

Adult↗
PubMed1989

Microbial investigations in keratitis at the Sydney Eye Hospital.

We investigated 107 cases of presumed microbial keratitis amongst patients presenting to the Sydney Eye Hospital between October 1986 and August 1988 to determine the frequency of infection, the common causative organisms and those factors that predispose to corneal infection. We found that 95% of culture-proven cases were caused by bacteria and that Staphylococcus epidermidis and Corynebacterium sp. accounted for 42.5% of these cases. All bacteria (except Staphylococcus epidermidis and Mycobacterium chelonae) were sensitive to gentamicin. In 62.6% of cases, cultures for bacteria and fungi were negative. Retrospective review of the clinical records of these patients showed that herpes simplex virus, contact lens wear, staphylococcal marginal keratitis and recurrent erosion were important causes of keratitis in this group.

Adolescent↗
PubMed1989

Transient corneal changes associated with the use of gold foil electrodes.

The corneas of 50 normal subjects were examined before and after electroretinography performed with gold foil electrodes. Examination included slit-lamp biomicroscopy and staining with sodium fluorescein. All corneas were normal on examination prior to electroretinography. Three types of transient corneal changes were observed--punctate epithelial keratitis, corneal erosions, and stromal thinning. Each cornea was assigned a numerical damage score based on a simple scoring system. Thirty one subjects (62%) had some degree of corneal change, and in three cases (6%) follow-up was required. Multiple regression analysis was performed to discover any risk factors. Both age of the subject and the use of local anaesthetic were strongly associated with corneal changes.

Adult↗
PubMed1989

'In-the-bag' hyphaema--a rare complication of posterior chamber lens implantation.

A 72-year-old woman developed a hyphaema on the first postoperative day after a combined trabeculectomy and extracapsular cataract extraction with posterior chamber intraocular lens implantation. On the second day the blood had redistributed to accumulate 'in the bag' posterior to the intraocular lens and had formed a fluid level. Postural drainage helped to clear the hyphaema from both locations, with no short-term effect on visual function or the filtering bleb.

Aged↗
PubMed1989

The development of a thin stainless steel eye plaque to treat tumours of the eye up to 15 mm in diameter.

The development of a thin stainless steel ophthalmic applicator is described. The features of this device are that it can be assembled with the radioactive sources (I-125) precisely positioned without the use of adhesives or mechanical devices such as clamps or screws in a matter of a few minutes under sterile conditions. Dismantling occurs in seconds after which the applicator is ready for cleaning and re-sterilisation. The radioactive sources are contained in an acrylic button which fits neatly into a stainless steel shell 1 mm thick. Different distributions of sources may be accommodated in the same stainless steel shell by inserting a different acrylic button. The overall thickness of the plaque is 2.6 mm but potentially can be reduced to 2.1 mm. Suture holes are provided on a flange subtending 120 degrees around the circumference of the shell and are exactly matched on a stainless steel template. An analysis of the dosimetry suggests that the treatment of the radioactive I-125 seeds as point sources may lead to only small errors in the determination of dose at the scleral surface and tumour apex. The differences in the dosimetry resulting from the treatment of the seeds as line sources appear to be of little consequence. As a result, point source dosimetry with anisotropy factor removed is quite satisfactory.

Eye Neoplasms↗
PubMed1989

Late development of localized band keratopathy in relation to a Molteno tube.

We report a case in which, 6.5 years postoperatively, localized band keratopathy developed in relation to a Molteno tube. At no stage had direct contact been noted between the tip of the tube and the corneal endothelium. The mechanisms of development of corneal opacities in relation to anterior chamber drainage tubes are discussed and the implications for the placement of such tubes are examined.

Anterior Chamber↗
PubMed1989

Traumatic hyphaema. Outcome and management.

The files of 206 patients who had sustained a hyphaema as a result of a contusion injury and had been admitted to Sydney Eye Hospital between January 1979 and December 1981 were reviewed. Most hyphaemas were small (189 or 91.7 per cent), occupying less than one-third of the volume of the anterior chamber. Fifteen patients had a secondary haemorrhage while in hospital and nine of these had a small hyphaema.

Adolescent↗
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

Morphology of intraretinal new vessels in the PETH rat.

The mature stages of retinal dystrophy in PETH rats are characterised by loss of the photoreceptor layer and invasion of the retinal pigment epithelium by new capillaries derived from the retinal vessels. The new capillaries are fenestrated where they are adjacent to the basement membrane of the retinal pigment epithelium and are surrounded by cells of the disrupted pigment epithelium, which follow the course of the capillaries into the inner retina. Abnormal basement membrane deposits are common within the retinal pigment epithelium.

Animal Husbandry↗
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

Visual failure in allergic aspergillus sinusitis: case report.

We present a case of rapid progressive unilateral visual loss in a 69-year-old woman who presented with facial pain, ipsilateral proptosis and restriction of eye movements, and nasal symptoms suggestive of sinusitis. A diagnosis of allergic aspergillus sinusitis was made on the basis of local histopathology and systemic features. Over a three-week period vision deteriorated to bare perception of light but showed a dramatic improvement to a level of 6/9 central vision on systemic steroid therapy. The mechanism of visual failure in the context of allergic aspergillus sinusitis and the therapeutic implications are discussed.

Aged↗
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↗