Biomedical subjects
Publications and source records attributed to D McLeod.
Ultrasonic examination helps the surgeon to select patients for vitrectomy and enables him to plan the operative procedure. A film demonstrated the advantages of rapid B-scanning over other ultrasonic techniques of previtrectomy assessment.
The three indications for vitrectomy are opacity causing severe visual deficit, vitreo-retinal traction causing or threatening retinal detachment, and displacement of the vitreous from its normal position. The types of pathology which cause opacity and/or traction and which are amenable to treatment by closed vitrectomy are lens changes or lens/iris remnants, opaque vitreous gel, ochre membranes, transgel traction bands, posterior hyaloid membranes, and epiretinal membranes. Closed vitrectomy has superseded the open sky method because the integrity of the cornea is preserved, the crystalline lens can be preserved, the intraocular pressure can be regulated, and the visualization and access to the posterior segment are good. More than 200 closed vitrectomies have been carried out at this hospital since 1974, using the Machemer VISC VII, the Douvas Rotoextractor, and the Peyman Vitrophage. The techniques which have been evolved as a result of experience with these instruments are demonstrated in a film.
The results of 101 closed vitrectomy operations are reported. The cases were classified on morphological grounds, and analysis showed that eyes with anterior segment or pure gel pathology responded favourably to surgery, while those with associated retinal disease had a poorer prognosis.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The vitreous cavity may be invaded by cells penetrating through dehiscences in the inner limiting lamina of the retina, and exaggerated vitreo-retinal adhesions may also develop at such sites. The vitreous often separates from the inner limiting lamina except at these anomalous adhesions, and retinal traction thus results from excessive movement of the otherwise detached gel; traction on the retina may also follow proliferation and contraction of invading cells on the retinal surface, along the posterior hyaloid interface, or traversing the gel. Traction complications are liable to occur at sites of vitreo-retinal adhesion during surgical removal of opaque gel, while division of transgel strands and epiretinal or posterior hyaloid membranes may be necessary in order to relieve retinal traction.
When axoplasmic transport in ganglion-cell axons is interrupted by ischaemia organelles accumulate in distended axon terminals at the edges of the infarct. This report illustrates the localized opaque swelling of nerve fibres shich develops at or near the optic disc after occlusion of the central retinal or posterior ciliary arteries. No such swelling occurs in patients who have a combined occlusion of these vessels.
Explore the source record for details and available documents.
Orthograde and retrograde axoplasmic transport in retinal ganglion-cell axons can be interrupted by axonal ischaemia. This report is believed to be the first to illustrate how this phenomenon can be obserbed clinically in man in cases of retinal vascular disease. The intense retinal "whiteness" of small cottonwool spots and at the periphery of larger areas of retinal ischaemia represents gross localised axonal distension secondary to the cessation axoplasmic flow.
The hypothesis that an occlusion of the central retinal artery is an essential prerequisite for haemorrhage formation after central retinal vein obstruction has been investigated by examining the fundus changes in patients with a cilio-retinal arterial circulation; the findings are at variance with the 'combined occlusion hypothesis'. Comparisons were made between the pathological features in two retinal capillary beds with independent sources of arterial supply--namely, the central retinal and cilio-retinal arteries--but with an obstructed venous drainage channel common to both--namely, the central retinal vein. The importance of intraluminal pressure changes (as distinct from perfusion changes) in the causation of haemorrhages and oedema after venous occlusion is stressed, and the role of arterial disease in the pathogenesis of venous occlusions is distinguished from its role in determining the sequelae of such occlusions.
In conjunction with the development of a computerized goal-oriented record system at Forest Hospital Des Plaines, Illinois, research staff developed a psychiatric goal list from goal statements most frequently used at the hospital. Treatment methods written by hospital staff were also reviewed and classified under the goal statement for which they were most frequently written. The result is the Treatment Methods Index, which currently contains more than 500 goal statements and 1500 treatment method statements, and also lists all drugs and activity therapies used in the hospital. The index is stored in a computer, and a comprehensive treatment plan can be generated by entering the numbers of selected goals and treatment methods. The authors emphasize the advantages of the system in writing and updating treatment plans and its importance in peer review and other medical-care evaluations.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
INTRODUCTION: Rapid innovations and improvements in communication technologies have opened many new channels for health education and delivery, as well as disaster management. Theme 2 examined the role and applicability of these technologies to Disaster Medicine and Management and the various issues involved in their use. METHODS: Details of the methods used are provided in the introductory paper. The chairs moderated all presentations and produced a summary that was presented to an assembly of all of the delegates. The chairs then presided over a workshop that resulted in the generation of a set Action Plans that then were reported to the collective group of all delegates. RESULTS: Main points developed during the presentations and discussion included harnessing convergence, seeking interoperability, building partnerships and making it appropriate. This group identified four Principles of Action underlying its plan: (1) investigate possibilities, (2) identify stakeholders, (3) invite participation, and (4) involve discussants in activities. DISCUSSION: Action plans were categorized into three areas that included "thinking globally, acting regionally", forming a telehealth advisory group, and increasing corporate partnerships. CONCLUSIONS: Technology is opening many opportunities that have applications in disaster management. To optimize benefits, goals and standards must be agreed upon and implemented.
Explore the source record for details and available documents.
Diabetic retinopathy is the leading cause of blindness in the industrialized world. Hyperglycaemia induces retinal hypoxia that upregulates a range of vasoactive factors which may lead to macular oedema and/or angiogenesis and hence potentially sight threatening retinopathy. In this study, we have focused on the association of CD105 and vascular endothelial growth factor (VEGF) with the development and progression of diabetic retinopathy by means of quantifying their expression in the plasma and vitreous of diabetic patients. CD105 levels were quantified in the plasma of 38 type I diabetic patients at various stages of retinopathy and 15 non-diabetic controls. In an additional cohort of 11 patients with advanced proliferative retinopathy and 23 control subjects, CD105 and VEGF were measured in the vitreous. The values were expressed as median (range) and statistical analysis was carried out using the non-parametric Mann-Whitney U test. Plasma CD105 levels were significantly increased in diabetic patients [1.8 (1.1-2.4) ng/ml] compared with non-diabetic controls [0.7 (0.3-1.8) ng/ml] (p<0.01). Plasma CD105 levels were elevated in diabetic patients with all stages of retinopathy, the highest level was observed in background retinopathy [2.3 (2.1-2.5) ng/ml] followed by proliferative retinopathy [2.1 (0.9-2.8) ng/ml] and advanced proliferative retinopathy [1.4 (0.6-1.8) ng/ml]. Vitreous contents of CD105 did not differ between controls and patients with advanced proliferative retinopathy, but vitreous levels of VEGF were elevated by approximately 3-fold in patients with advanced proliferative retinopathy [7.2 (1.90-15.60) ng/ml] compared with the control subjects [1.80 (1.10-2.210)] (p<0.01). These observations indicate that plasma levels of CD105 and vitreous levels of VEGF are associated with diabetic retinopathy, suggesting that CD105 and the angiogenic factor VEGF may play a critical role in the development and progression of diabetic retinopathy. Further studies are required to determine whether circulating CD105 levels could serve as a surrogate marker for early stage retinopathy and for monitoring disease progression.