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Biomedical subjects

D J Coster

Publications and source records attributed to D J Coster.

At least 91 records · Page 5Linked to original sources
PubMed1989

Leukocytes in the graft bed associated with corneal graft failure. Analysis by immunohistology and actuarial graft survival.

Immunohistochemical staining analysis using monoclonal antibodies was performed on 107 recipient corneas removed at graft. There were significantly more infiltrating cells bearing one or more of the leukocyte-common antigen, class II major histocompatibility complex antigens, various myeloid-lineage markers, and a peripheral T cell marker, in the graft beds of those recipients who subsequently lost a corneal graft than there were in the graft beds of those for whom the outcome was successful. The hypothesis that large numbers of leukocytes in the recipient graft bed would be correlated with subsequent graft failure was examined by actuarial graft survival analysis. Recipients whose corneas contained fewer than 50 leukocyte-common antigen-positive cells/mm2 of corneal stroma showed a 3-year actuarial graft survival of 83%, compared with 39% in those whose corneas contained more than 50 such cells/mm2. The corneal leukocyte count was a particularly useful prognostic indicator of outcome in those patients judged clinically to be at risk of graft failure.

Actuarial Analysis↗
PubMed1989

The role of the limbus in corneal allograft rejection.

The state of the recipient peripheral cornea and limbus exerts a strong influence on subsequent corneal graft survival. In particular, graft outcome is influenced by the number of dendritic cells (Langerhans cells) that have infiltrated the graft bed from the limbus. The number of dendritic cells present in the donor button also affects subsequent graft survival.

Animals↗
PubMed1989

Mechanisms of corneal graft failure: the erosion of corneal privilege.

Although corneal transplantation is very successful for keratoconus and some other dystrophies, it is not nearly as successful for acquired corneal opacities. The usual cause of failure is allograft rejection. In high-risk cases a number of strategies are required to decrease the risk of rejection. These include suppression of inflammation, MHC matching, and local and systemic immunosuppression. For the results of corneal transplantation to improve, surgeons must be prepared to choose from a range of approaches, those best suited to the individual patient.

Corneal Diseases↗
PubMed1989

Selection of gentamicin-resistant variants of Pseudomonas aeruginosa in the rat cornea.

Pseudomonas aeruginosa often persists in ocular infections despite intensive antimicrobial therapy. In this study, gentamicin-resistant small colony variants (SCV) were selected in vitro from three gentamicin-susceptible Pseudomonas isolates by incubation with antibiotic. In the rat cornea, SCV were selected from two of these strains by administration of gentamicin either topically or intravenously. The selection of resistant variants may be a contributing factor in the persistence and reactivation frequently associated with ocular Pseudomonas infections.

Animals↗
PubMed1989

Keratoconus: diagnosis and management.

Keratoconus is a common condition whose clinical features represent a common effect on the cornea of a number of diverse processes. This review deals with the clinical signs and accompanying histological and biochemical changes within the cornea, evaluates the significance of associated ocular and systemic conditions and assesses the incidence and prevalence of the disorder. The wider ophthalmic community shares in the treatment of keratoconus, so the general principles of contact lens fitting associated with this difficult condition are examined and the specific protocol used at the Flinders Medical Centre is presented. When contact lenses are not tolerated or an adequate improvement in visual acuity is not achieved, surgery is the next option, so a full assessment is made of the risks and benefits of penetrating keratoplasty. Older techniques, such as thermokeratoplasty and lamellar keratoplasty, are examined and the new technique of epikeratophakia is evaluated.

Conjunctivitis↗
PubMed1989

Surgical manoeuvres to reduce the impact of corneal allograft rejection.

Allograft rejection is the major obstacle to successful corneal transplantation in high-risk cases. The risk factors are well recognized. Within the high-risk group, surgeons can influence graft survival by MHC antigen matching, by immunosuppression, by decreasing the number of antigen-presenting cells gaining access to the graft, and by avoiding up-regulation of MHC expression through the suppression of post-operative inflammation.

Animals↗
PubMed1989

Current status of corneal transplantation.

Corneal transplantation offers the cure for those with blinding corneal disease. Sourcing of a shortage of corneas are important. Graft survival depends on a number of factors, the most important of which is the recipient bed. The management of graft failure by rejection includes tissue matching, local and systemic immunosuppression.

Corneal Transplantation↗
PubMed1988

Assessment of the Dutch organ-culture system of corneal preservation within the Eye Bank of South Australia.

Thirteen per cent of all corneas harvested by the Eye Bank of South Australia during 1986 were discarded because storage time in McCarey-Kaufman medium exceeded four days. We have therefore examined the suitability of the Dutch method of long-term corneal storage for our purposes. Twenty-two human corneas that had been discarded from the Eye Bank were assessed using the trypan blue-sucrose staining technique, and then placed into long-term storage for 15 to 17 days. They were then reassessed by vital dye staining before permanent flat-mounts were prepared for silver staining of the endothelium. A good correlation (albeit subjective) was found between the non-destructive and destructive techniques of endothelial cell assessment. Those corneas that failed to survive organ culture storage were easily detected. The Dutch system of corneal preservation and post-storage assessment seems well-suited to Australian eye-banking.

Cornea↗
PubMed1988

Effectiveness of a decontamination method for donor corneas.

A retrospective study was made of the effectiveness of an eye bank decontamination and storage method. A comparison was made between microbial cultures taken from the limbus at enucleation and from scleral remnants recovered after surgery. Organisms were isolated from the limbus of 73% of donor eyes and from 4% of remnants. Standard eye bank procedures were found to eradicate gut and skin organisms, including candida, from donor tissue.

Cornea↗
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↗
PubMed1987

First report of the Australian Corneal Graft Registry.

In the Australian Corneal Graft Registry's first 18 months of operation, May 1985 to November 1986, data supplied by 53 surgeons relating to 322 graft recipients have been entered and analysed with respect to: the most common presenting diseases (primarily keratoconus, bullous keratopathy and corneal opacities), risk factors (especially prior sensitisation to HLA antigens, corneal vascularisation, past or present anterior segment inflammation and history of raised intraocular pressure [IOP]), donor and recipient sex, cause of donor death, storage procedures for donor eyes, operative procedures accompanying the grafts themselves, and preliminary indications of overall graft survival by actuarial analysis. It is hoped that the establishment of this Registry will not only reinforce the use of actuarial graft survival analysis as the method of choice for transplantation surgeons wishing to monitor the survival of their patients and grafts, but will also provide a useful service for the Australian ophthalmic community in general.

Actuarial Analysis↗
PubMed1987

Endophthalmitis following cataract extraction.

We describe a case of bacterial endophthalmitis complicating routine cataract extraction and intraocular lens implantation in a 91-year-old woman. The ocular and systemic factors that may have predisposed to intraocular infection in this case, and the possibility of predicting these pre-operatively, are discussed.

Adenocarcinoma↗
PubMed1987

Acanthamoebic keratitis diagnosed by paracentesis and biopsy and treated with propamidine.

A previously healthy 53-year-old man had keratitis of the right eye for six months, unresponsive to topical medical therapy. Acanthamoeba was grown from tissue obtained by corneal biopsy and from aqueous from an anterior chamber tap. The patient was treated with propamidine isethionate 0.1% drops and dibromopropamidine isethionate 0.15% ointment, and after two and a half months the ocular inflammation was continuing to resolve. This case supports a role for the diamidines in the treatment of acanthamoebic keratitis.

Acanthamoeba↗
PubMed1987

Host, microbial, and pharmacological factors affecting the outcome of suppurative keratitis.

A review of 87 cases of microbial keratitis in South Australia was made to determine the factors which influence the outcome of the disease. The preceding pathology and the extent of ulceration at presentation were found to be significant, while the presence of hypopyon was less important. Infection with Pseudomonas aeruginosa was most likely to result in a poor outcome. Most patients had a history of traumatic injury, herpes simplex keratitis, or a corneal graft. The choice of gentamicin and a cephalosporin as appropriate initial therapy in Australia was supported. The results are discussed with reference to current research objectives.

Adolescent↗
PubMed1987

Topical steroid, cyclosporin A, and the outcome of rat corneal allografts.

The effects of a combination of topical corticosteroid and cyclosporin A on corneal graft survival were tested in a model of penetrating keratoplasty in the inbred rat. Topical medications were applied four times daily to the graft for 28 days postgraft. Neither topical steroid (1% prednisolone acetate) nor topical cyclosporin (1% in chremophor EL/ethanol) was able to modify the overall incidence of rejection, though all steroid-containing medications delayed the onset of rejection significantly. The combined formulation of steroid plus cyclosporin A caused a reduction in the incidence of rejection which did not reach statistical significance and which did not eliminate the response in all animals. The chremophor/ethanol vehicle was reasonably well tolerated but did cause some periocular dermatitis.

Administration, Topical↗