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Biomedical subjects

D McLeod

Publications and source records attributed to D McLeod.

At least 199 records · Page 11Linked to original sources
PubMed1984

Retinal pigment epithelial cells in epiretinal membranes: an immunohistochemical study.

Immunohistochemical techniques were used to identify cells containing cytokeratins in sections or tissue-culture monolayers from ocular (reference) tissues and also from 22 epiretinal membranes obtained during closed microsurgery for macular pucker or massive preretinal retraction. Results of cytokeratin immunostaining in reference tissues indicated that this is a valuable means of determining the contribution and distribution of epithelial cells in epiretinal membranes, and that the epithelial cells in the membranes were probably derived from the retinal pigment epithelium. Epithelial cells were identified in 17 of the 22 epiretinal membranes, but they did not usually constitute the predominant cell type. We concluded that the fibroblasts or fibroblast-like cells thought to be responsible for the contraction of epiretinal membranes are seldom of retinal pigment epithelial origin. Biomicroscopic pigmentation of a membrane was shown to be a poor guide to its epithelial cell population.

Animals↗
PubMed1984

Vitrectomy and fluid/silicone-oil exchange for giant retinal tears: results at six months.

The results of vitrectomy combined with fluid/silicone-oil exchange in 73 eyes with giant retinal tears are reported at six months after surgery. Initial anatomical success was achieved in 71 out of 73 eyes (97%) and, prior to removal of silicone-oil, in 66 out of 73 eyes (90%). In 63 eyes (86%) the retina remained attached six months after surgery. Of these visual acuity was 6/60 or better in 44 (70%). The high proportion of eyes with macular detachment before surgery and the frequency of macular abnormalities are thought to account for reduced vision in many of the anatomically successful cases.

Adolescent↗
PubMed1983

Epiretinal membranes in vitro.

Monolayers of cells were grown from epiretinal membranes using standard tissue culture techniques. The growing cells were filmed by time-lapse cinephotomicrography to record their locomotory characteristics and cell-to-cell interactions. The established layers of cells were examined in the scanning electron microscope. In addition, the cultured cells were studied immunohistochemically to identify specific cell types and the distribution of contractile elements (e.g. actin). The locomotory patterns, the topography and the immunohistochemistry of cells from epiretinal membranes were compared to the movement, appearance and staining characteristics of a wide range of normal cells in culture. From the growth characteristics in tissue culture, early membranes appeared more hypercellular than longer standing membranes. Cell outgrowth was established more quickly and was more widespread in the young epiretinal membranes than in older, more fibrous, specimens. The locomotory and immunohistochemical studies demonstrated that a wide variety of cell types may contribute to epiretinal membranes. A remarkably wide range of cell forms were observed in cultures of individual membranes. Epithelial and glial cells were found in many of the monolayers. However, they did not constitute the majority of cells in the cultures. The predominating cell types had the morphological and locomotory characteristics of fibroblasts or macrophages.

Animals↗
PubMed1983

Management of retinal detachment following congenital cataract surgery.

Retinal detachment complicating previous congenital cataract surgery poses problems in management, especially related to difficulties in ophthalmoscopic visualization of breaks. The recent introduction of closed microsurgical techniques has significantly improved the prognosis in such cases.

Adolescent↗
PubMed1982

Management of complex retinal detachments by vitrectomy and fluid/silicone exchange.

The combined procedure of pars plana vitrectomy and liquid silicone exchange has been developed for the management of complex retinal detachment. Complete re-attachment was achieved in 88 per cent of eyes with giant retinal breaks and visual improvement occurred in 71 per cent. Macular re-attachment was obtained in 68 per cent of eyes with massive periretinal proliferation (MPP) and visual improvement occurred in 53 per cent. In contrast, in thirteen cases of severe diabetic traction detachment, only four remained attached with visual improvement in one. In seven eyes with severe perforating trauma and retinal detachment, retinal re-attachment was achieved in four and visual improvement in three. We conclude that this technique is indicated in giant retinal breaks, is encouraging in MPP, has a very limited role in the management of diabetic traction detachment, and requires further evaluation in the management of traumatic detachment.

Diabetic Retinopathy↗
PubMed1982

Posterior non-vascularized proliferative extraretinopathy and peripheral nodular retinal telangiectasis.

Peripheral telangiectatic nodules in the inferotemporal retina were associated with proliferation of posterior fibrocellular epiretinal membranes in seven eyes of five patients. The membranes showed great variation in their extent (localized or widespread), their location (epimacular, paramacular or peripapillary), and their effects (no effect, underlying retinal striation or full-thickness retinal folding). Pars plana vitrectomy and membrane peeling was performed in three eyes.

Adult↗
PubMed1981

Ultrasound.

The application of ultrasonics has been one of the major developments in ophthalmology in the last two decades. Diagnostic ultrasound of the eye and orbit, together with ocular biometry (especially in the field of lens implantation), are now routine investigations, while ultrasonic surgery of the lens (phacoemulsification) has become a well-established part of our surgical armamentarium. The historical development of diagnostic ultrasound is reviewed, its physical basis is recalled, present-day techniques and instrumentation are outlined, and future possibilities considered.

Anthropometry↗
PubMed1981

Closed microsurgery in the management of intraocular foreign bodies.

The instrumentation and techniques of closed intraocular microsurgery offer a valuable approach to the management of selected intraocular foreign bodies. These methods facilitate the removal of retained material and the surgical repair of intraocular damage resulting from penetration. Although guidelines have been proposed, the precise indications and appropriate timing of surgery have not been established. We present the results of closed microsurgery in a consecutive series of patients with posterior segment intraocular foreign bodies or their sequelae. Factors which appear to limit visual recovery are discussed in relation to the timing of surgery.

Adolescent↗
PubMed1980

Role of axoplasmic transport in the pathophysiology of ischaemic disc swelling.

Pathological changes in the optic disc and anterior part of the optic nerve of monkeys were studied 5 hours and several days after occlusion of the temporal short posterior ciliary arteries. Ischaemic vacuolation of neural tissue was observed in some of the animals studied and was restricted to the lamina cribrosa and the immediately retrolaminar portion of the optic nerve. Axonal swelling and organelle aggregation were demonstrated in the prelaminar region, and autoradiography after intravitreal injection of tritiated leucine revealed an associated obstruction of rapid and slow orthograde axoplasmic transport. The experimental findings correlate with those seen clinically in acute ischaemic optic neuropathy. The pale swelling of the optic disc in this condition represents an accumulation of axoplasmic debris in retinal ganglion-cell axons owing to obstruction of axoplasmic transport at the lamina cribrosa; it is thus equivalent to a 'cotton-wool spot' of the disc.

Animals↗