Ocular neovascularisation.

London : University of London Audio-Visual Centre, 1976.

1 encoded moving image (26 min.) : sound, black and white.

00:26:09

University of London

Open

CC-BY-NC

In English

Presented by Dr Alec Garner, Department of Pathology, Institute of Ophthalmology. Made by University of London Audio-Visual Centre for the British Postgraduate Medical Federation. Produced by Michael Clarke.

This video is one of around 310 titles, originally broadcast on Channel 7 of the ILEA closed-circuit television network, given to Wellcome Trust from the University of London Audio-Visual Centre shortly after it closed in the late 1980s. Although some of these programmes might now seem rather out-dated, they probably represent the largest and most diversified body of medical video produced in any British university at this time, and give a comprehensive and fascinating view of the state of medical and surgical research and practice in the 1970s and 1980s, thus constituting a contemporary medical-historical archive of great interest. The lectures mostly take place in a small and intimate studio setting and are often face-to-face. The lecturers use a wide variety of resources to illustrate their points, including film clips, slides, graphs, animated diagrams, charts and tables as well as 3-dimensional models and display boards with movable pieces. Some of the lecturers are telegenic while some are clearly less comfortable about being recorded; all are experts in their field and show great enthusiasm to share both the latest research and the historical context of their specialist areas.

Segment 1 Dr Garner begins the lecture by discussing blood vessels and the structure of the eye. Blood vessels are not normally found on the cornea or iris. Photographs of eyes with lesions due to a damaged cornea are seen. A photomicrograph of a damaged retina is seen, and Garner points out the abnormal growth of blood vessels. He also talks about the clinical problem of dealing with the growth of blood vessels in the eye due to lack of understanding of this process. A table lists medical conditions that give rise to new vessels, including sickle cell retinopathy and diabetic retinopathy. Time start: 00:00:00:00 Time end: 00:05:06:13 Length: 00:05:06:13

Segment 2 Garner discusses the exposure of premature babies to excessive amounts of oxygen and the effect of this on the retina. A series of slides of an experiment on a kitten are shown. The newborn kitten is kept in an oxygen enriched atmosphere for three days, making the vessels undergo widespread and irreversible closure. Then the kitten is returned to normal air. Garner discusses the effects of the experiment and the conclusions that he has drawn from it. Some diagrams show what his hypothesis regarding a vasoformative factor looks like. He also mentions an American team's work on the 'tumour angiogenetic factor' using cancer cells to investigate vascular activity. Time start: 00:05:06:13 Time end: 00:10:04:24 Length: 00:04:58:11

Segment 3 Garner continues to discuss the 'tumour angiogenetic factor'. He also talks about another US study involving exposing neonate animals to toxic amounts of oxygen. Diagrams show anaerobic processes in a retina with reduced vascular perfusion, and Garner discusses whether products of anaerobic glycolysis affect vessel growth. He talks about another experiment on kittens' retinae exposed to vasotoxic amounts of oxygen. The experiment is described using diagrams. Time start: 00:10:04:24 Time end: 00:14:56:11 Length: 00:04:51:12

Segment 4 Garner wonders how important his experiments have been but says that his team will continue them. A photomicrograph of an iris with new vessels on the surface is seen, as well as a table listing medical causes for it, including diabetic retinopathy and retinal detachment. Garner discusses this condition and the research that has gone into it. Next, he discusses corneal neovascularisation and its possible causes. These are listed in a table. Again, he mentions US studies into this condition, including experiments involving subjecting animals to massive doses of radiation to knock out the circulating leukocytes. Time start: 00:14:56:11 Time end: 00:20:19:12 Length: 00:05:23:01

Segment 5 Next, Garner talks about how amino acid and nutritional deficiencies can also affect corneal vessels. He also talks about how difficult it is to construct a unifying hypothesis for corneal vascularisation and about how a stimulus may not be the cause but rather the removal of a substance. Garner summarises the lecture saying that ophthalmologists, pathologista and biochemists need to work together to solve the problem of untoward vascularisation in the eye. Time start: 00:20:19:12 Time end: 00:26:09:18 Length: 00:05:50:06