Biomedical subjects

A G Casswell

Publications and source records attributed to A G Casswell.

8 recordsLinked to original sources

PubMed1990

Treatment of diffuse diabetic macular oedema: a comparison between argon and krypton lasers.

We report the results of a randomised treatment trial of macular grid photocoagulation in 91 eyes with diffuse diabetic macular oedema followed up for at least two years comparing Krypton red with Argon blue/green lasers. At two years, macular oedema had improved equally in both groups, and the visual acuity was unchanged or better in 85% of eyes treated with Argon and in 79.5% of eyes treated with Krypton laser. No statistically significant differences were observed between the two groups in terms of visual acuity or the degree of oedema. We conclude that the observed effect of grid laser treatment in diffuse diabetic macular oedema did not depend on the wavelength of the laser light used in this study.

Adult↗

PubMed1989

Choroidal malignant melanoma in an albino.

This is the first report of an amelanotic melanoma arising in the unpigmented choroid of a tyrosinase-positive oculocutaneous albino (TPOCA). Melanosomes within the tumour showed a maturation arrest in the unpigmented type II (premelanosome) phase. Other neural crest derived melanocytes in iris and choroid showed similar limited melanogenesis. The neuroectodermally derived melanocytes of the iris, ciliary body, and retinal pigment epithelium (RPE) contained mature melanosomes, though clinically the RPE was pale. The significance of this tumour arising in an albinotic eye is discussed.

Adult↗

PubMed1987

The surgical management of uveal effusion syndrome.

Vortex vein decompression and/or partial thickness sclerectomies were performed on 6 eyes of 4 patients with uveal effusion syndrome. Vortex vein decompression was undertaken in 3 eyes and was followed by retinal re-attachment in two. Multiple sclerectomies were undertaken in 4 eyes of 3 patients; an initial reduction of sub-retinal fluid occurred in all eyes and retinal re-attachment followed in two. There were no complications following the procedure. The response to surgery in these eyes suggests that the approach is justified and provides further evidence that a scleral abnormality is the underlying cause of uveal effusion syndrome.

Adult↗

PubMed1987

Silicone oil removal. I. The effect on the complications of silicone oil.

The results of a retrospective study of the effects of silicone oil removal from 85 eyes in 85 patients are reported. Pars plana vitrectomy and fluid/silicone oil exchange had been undertaken for retinal detachments associated with giant retinal tears or with proliferative vitreoretinopathy in all cases. Clinically significant cataract developed in 60% of lenses that were clear at the time of oil removal, and 85% of pre-existing lens opacities progressed. Removal of oil from 19 eyes with uncontrollable glaucoma was combined with drainage surgery in 14 eyes. Postoperatively the intraocular pressure was controlled in 13. Corneal decompensation either improved or was unchanged in eight out of nine patients after silicone oil removal, and three patients had penetrating keratoplasty and maintained a clear corneal graft. Patients who did not have glaucoma or keratopathy at the time of silicone oil removal did not develop these complications.

Cataract↗

PubMed1987

Silicone oil removal. II. Operative and postoperative complications.

A retrospective study of the effects of silicone oil removal was carried out on 85 patients who had undergone pars plana vitrectomy and silicone oil exchange for giant retinal tears or proliferative vitreoretinopathy. Silicone oil was removed either as part of the treatment of anterior segment complications such as glaucoma and keratopathy (25 patients) or in order to prevent these complications (60 patients). The major complications of the removal of silicone oil were retinal redetachment (25%), hypotony (16%), and expulsive haemorrhage (1%). The length of time that the oil remained in the eye and the presence of anterior segment complications did not appear to have an effect on the rate of retinal redetachment or hypotony.

Corneal Diseases↗

PubMed1986

Isolated retinal telangiectatic masses.

The clinical findings of 20 patients with an isolated peripheral retinal mass secondary to retinal telangiectasis were reviewed. The important clinical features were subretinal exudation, vitreous haemorrhage and retinal detachment. No associated systemic abnormalities were identified. Early results suggest that cryotherapy is effective for the reduction of subretinal exudation but not for macular oedema. Patients with extensive retinal detachment complicated by vitreous haemorrhage and epiretinal membrane formation were treated with vitreoretinal surgery.

Adult↗

PubMed1986

Paramacular telangiectasis.

Forty six patients with paramacular retinal telangiectasis were reviewed; unilateral telangiectasis was present in 26 and bilateral disease was present in 20. Patients with unilateral macular telangiectasis had the more extensive vascular involvement associated with exudation and were more likely to have peripheral telangiectasis. Bilateral macular telangiectasis was associated with pigment epithelial changes and sub-retinal scars. Visual acuity was mildly reduced in the majority of patients; severe loss of vision was most frequent in patients with bilateral macular disease. The evolution of vascular changes was very slow and only 5 patients lost vision of two lines or more during an average period of 40 months. The high incidence of peripheral changes in unilaterally involved patients implies the possibility of a primary defect of the retinal vessels in these patients. There is evidence to suggest that there may be a primary defect of the retinal pigment epithelium in some patients with bilateral involvement.

Adult↗

PubMed1985

Retinal pigment epithelial detachments in the elderly: classification and outcome.

Sixty-four eyes of 57 elderly patients with pigment epithelial detachments (PEDs) were studied with the aim of describing their morphological features and identifying prognostic factors. They were classified into four groups according to the following characteristics: early fluorescence, late fluorescence, shallow detachment with limited fluorescence ('drusen type'), irregular fluorescence. The following conclusions were drawn: 30% developed demonstrable subretinal new vessels; all groups except the drusen type were susceptible, the irregular group being particularly prone. 10% developed retinal pigment epithelial tears, and these occurred almost exclusively in the slow fluorescent group. Flattening of PEDs was a feature of drusen type and early fluorescent groups. Most patients lost vision. RPE tears occurred within a few months of presentation with immediate loss of vision; likewise rapid loss of vision followed the development of demonstrable new vessels, though not necessarily in those with changes thought to imply the presence of new vessels. Flattening after prolonged detachment was associated with pigment epithelial atrophy and invariable loss of vision. Visual acuity was maintained consistently only in those eyes with persistent detachment.

Aged↗