Oftalmoscopio de Paxton / Paxton's Ophthalmoscope

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First look into the eye.

PURPOSE: Until Helmholtz's discovery of the ophthalmoscope, it was not possible to visualize the posterior pole of the eye in a living subject. The aim of this work is to emphasize the importance of the invention of the ophthalmoscope because the new era in ophthalmology began with it. METHODS: Available literature concerning this topic was studied, especially by getting in contact with institutes for history of medicine as well as medico-historians in Germany and other countries. RESULTS: Hermann von Helmholtz, German physician and physicist, presented and published his invention of the ophthalmoscope in 1851. Albrecht von Graefe was the first to use ophthalmoscope routinely. He said: 'Helmholtz has opened a new world to us'. The first ophthalmoscope was not easy to use. Some ophthalmologists even thought that ophthalmoscopy is harmful for the eye, particularly for a diseased eye. First, it was used in Germany (A von Graefe), Austria (E Jäger), and Netherlands (FC Donders). In England, it was used only at Moorfields till 1855 (W Bowman). At the First International Congress of Ophthalmology in Brussels 1857, the importance of ophthalmoscopy was stressed. FC Donders said that every view with the ophthalmoscope into the living eye was a new discovery. Among retinal diseases, first were discovered pigment retinopathy (FC Donders) and retinal detachment (A Coccius) in 1853. CONCLUSION: Helmholtz inaugurated modern era in ophthalmology with his magnificant instrument which revolutionized the development of ophthalmology. Von Graefe popularized it. Because of the new findings, ophthalmology was definitely separated from surgery in the middle of 19th century.

Schultz-Crock binocular ophthalmoscope.

The ophthalmoscope, which is an indispensable tool of our profession, is now taken for granted. It is often forgotten that it was only just over 150 years ago that the first binocular ophthalmoscope was invented. The early instruments were not popular for a variety of reasons. Australians Donald Schultz and Gerald Crock played a major role in improving this instrument and developing the modifications that turned it into an everyday tool of all ophthalmologists.

The ophthalmoscope: Helmholtz's Augenspiegel.

The origins of Helmholtz's invention of the ophthalmoscope are found in the ancient observation that the back of the eye appeared black. In 1703, Jean Méry reported that the luminosity of the cat's eye could be seen when the animal was held under water, and Mariotte observed that a dog's eye was luminous but erroneously thought this was because its choroid was white. Prévost made a breakthrough when he deduced it was incident light and not light coming out of the eye. Purkinje and von Brucke used lenses to attempt to see the fundus and almost succeeded. However, it was Helmholtz who created the first useable ophthalmoscope, whose development and clinical application are traced in this paper. One of the greatest physical scientists in many spheres of learning, his biography is briefly sketched.

On the evolution of binocular ophthalmoscopy.

The need for stereopsis arose soon after the discovery of the ophthalmoscope, not least because the glaucomatous cup was mistaken for a swelling. At that time, Brewster's popular stereoscope was already in use, and its theory and method were then applied to ophthalmoscopy by Giraud-Teulon. His was the first binocular instrument, subsequently much improved by Zachariah Laurence. Binocular indirect ophthalmoscopy was abandoned toward the end of the 19th century in favor of direct monocular ophthalmoscopy, until it was revived in the 1950s by Schepens.

A history of the optic nerve and its diseases.

We will trace the history of ideas about optic nerve anatomy and function in the Western world from the ancient Greeks to the early 20th century and show how these influenced causal theories of optic nerve diseases. Greek and Roman humoral physiology needed a hollow optic nerve, the obstruction of which prevented the flow of visual spirit to and from the brain and resulted in blindness. Medieval physicians understood that the presence of a fixed dilated pupil indicated optic nerve obstruction, preventing the passage of visual spirit, and that cataract surgery in such cases would not restore sight. During the Renaissance, the organ of vision was transferred from the lens to the optic nerve, which was generally believed to be on the axis of the eye. The acuity of central vision (at the optic disc) was explained by the concentration of visual spirit where the optic nerve met the retina. The growth of anatomy and influence of mechanical philosophy from the 17th century led to visual spirit being replaced with the concept of nerve force, which later became associated with electricity travelling along nerve fibres. This coincided with discourse about the nature of the nervous system and a shift in orientation from understanding illness holistically in terms of an individual's humoral imbalance to the concept of organ-based diseases. Both the microscope and the ophthalmoscope allowed visualisation of the optic nerve, but problems of interpretation persisted until conceptual transformations in medical science were made.