The History of Ophthalmology – The Monographs volume 18: The Atlas of ophthalmoscopes: Non-electrical or reflecting ophthalmoscopes

The first ophthalmoscope developed by Herman von Helmholtz in 1851 was one of the most significant advances in not just ophthalmology, but in medicine overall in the 19th century. For the first time the interior of a living organ could be directly observed. For ophthalmology this meant that causes of blindness that were not readily apparent by examination of the anterior part of the eye and were previously labeled as “amblyopia” or “amaurosis” for the many cases of blindness or impaired vison due to unknown causes could now be identified. For medicine in general the uptake was slower however the advantages of viewing blood vessels and the retina directly, led to a greater understanding of the effects of hypertension and other vascular and microvascular diseases such as diabetes as well as a wide variety of other inflammatory, infectious, neoplastic and haematological disorders.

The early instruments were very difficult to use and the next couple of decades saw rapid advances in light gathering with the use of initially plane and then shortly after this concave mirrors in place of the initial glass plates that Helmholtz employed. Other advances included the incorporation of lenses to allow the refractive errors of both the examiner and the patient to be corrected. These were initially separate lenses that had to be included in a clip on the observer side of the instrument. These were cumbersome to use and G. Rekoss the machinist at the University of Konigsberg who initially manufactured the Helmholtz ophthalmoscope, developed the Rekoss disc of lenses allowing much greater ease of finding the most appropriate corrective lens. This led to the development of refracting ophthalmoscopes which incorporated a number of lenses often in several overlapping discs allowing a great range of lens powers when used in combination. These “Rekoss discs” in some instruments included both spherical and cylindrical lenses.

Another major advance was the early development of the indirect form of ophthalmoscopy. The Helmholtz instrument was used for the direct method which resulted in greater magnification (15X) and an upright image. Much of the reflected light, however, does not penetrate into the eye and is wasted. The indirect method of ophthalmoscopy was developed by Theodor Ruete in 1852 allowed greater light gathering capacity and a wider field of view, however the image was totally inverted and the magnification less (4X). Most ophthalmoscopes after this time included condensing lenses to allow both forms of ophthalmoscopy to be practiced. Many of these ophthalmoscopes included plane and both short and long focus concave mirrors allowing both retinoscopy (or skiascopy) and both forms of ophthalmoscopy.

With the advances in ophthalmoscope design and improvements in light sources from the initial candles to oil and later gas lamps there was a great uptake by ophthalmologists in the use of this instrument in the latter part of the 19th century.

Many texts and atlases were published in extraordinary scientific and artistic detail illustrating the fundus characteristics of various retinal conditions and diseases. The first and in many ways the most significant was the “Atlas der Ophthalmoskopie” by Richard Liebreich in 1863. A later atlas by Eduard Jaeger “Ophthalmoskopischer Hand-atlas” was published in 1869 (29 colour plates and 128 drawings) and
such was the detail of the drawings each of which required 20-30+ sittings of 2-3 hours each with his large ophthalmoscope that it remained the major atlas for the next 50 years. These plates which were all hand done by the ophthalmologist are still instantly recognizable for the disease they depict even today.

Over the remainder of the 19th century multiple ophthalmologists and manufacturing opticians introduced new models with most claiming some specific benefit of their model compared to previous ones. Some of these innovations were very small or insignificant but others had a major influence on the designs that followed. Overall, they all contributed to the evolution of this instrument which is and remains an
invaluable and indispensable diagnostic tool for medical and optometric practitioners.

This volume, which will be the first in a series of two, details the non-electrical or reflecting ophthalmoscopes. We have identified over 400 such instruments many of which have not been identified or catalogued in previous books on the ophthalmoscope. These instruments are compiled from our respective collections and other major collections worldwide in both private and public museum hands. These start with Helmholtz in 1851 and most ceased with the gradual improvement in electric bulb reliability and batteries in the early 20th century. A very few, because of their portability, robustness and low price of manufacture, were still being produced up until 2000. We are planning the second volume in this series which will depict the development and improvements in electrical ophthalmoscopes over the remainder of the 20th century.

We readily acknowledge that despite our best efforts over a number of years, there will be instruments that we have missed and errors in attribution. We will be most grateful for any suggestions or comments from anyone interested in these instruments.

Introduction
About the authors
Helmholtz and the Development of the Ophthalmoscope
Index of named Ophthalmoscopes

Austria
Denmark
France
Germany
Greece
Italy
Japan
The Netherlands
Norway
Russia
Switzerland
Turkey
Ukraine
United Kingdom
United States of America
Unidentified
Illumination
Glossary
Acknowledgements
Index of names
Index of manufacturers