[History of diaphanoscopy. Pictures from the history of otorhinolaryngology, illustrated by instruments from the collection of the Ingolstadt German Medical History Museum].

BACKGROUND

In 1854 the Spanish singing teacher Manuel Garcia succeeded in inspecting his own larynx. In 1857 the neurologist Ludwig Türck in Vienna, without knowledge of Garcia's achievement, had been experimenting on laryngoscopy with his patients using a small mirror and sunlight. When in the winter of 1857-1858 he had to suspend his experiments for lack of sunlight, he lent his mirror to physiologist Johann Czermak in Budapest. Czermak, using artificial light reflected by a perforated mirror, developed modern laryngoscopy within a few weeks and made it a clinically valuable method. He described it in March 1858 as his own invention. This was the beginning of a an embittered fight with Türck about whose development had priority.

DIAPHANOSCOPY OF THE LARYNX

During his very first studies on laryngoscopy Czermak noticed that the interior of the larynx could be inspected very well when the neck was illuminated by a strong light from without and the mirror was held in the dark pharynx. The tissue would then appear transilluminated in a glowing deep red. When sufficiently bright electric lamps became available in 1889, Rudolph Voltolini in Breslau, Germany, took up the transillumination of the larynx and even carried out some minor intralaryngeal operations using this method. Although suitable diaphanoscopes were soon on the market this technique was not widely adopted. It was ony used once in 1954 (Pellnitz et al.) for diagnosing early stages of laryngeal cancer.

DIAPHANOSCOPY OF THE PARANASAL SINUSES

Voltolini in Breslau and Cozzolino in Naples experimented independently of each other with small electric lamps with the aim of finding new techniques of rhinoscopy. Both of them placed their lamp in the nasopharynx and performed anterior rhinoscopy using an ordinary speculum. However, it was only Voltolini who noticed the transillumination of the maxillary sinuses when the lamp was placed in the oral cavity. On October 29, 1888, in Breslau he demonstrated diaphanoscopy of the maxillary sinus for the first time. Cozzolino claimed that he had introduced this technique prior to Voltolini. Voltolini had died in 1889 and could not comment on this. A careful study of the original publications, however, shows that Cozzolino had only inspected the nasal cavity with retronasal illumination, but had not demonstrated the maxillary sinus by transillumination. The diaphanoscopy of the paranal sinuses was very soon elaborated to perfection: Vohse in 1890 applied it to the frontal sinuses, Gerber in 1900 invented a double diaphanoscope for examining both frontal sinuses simultaneously. Although the shortcomings of diaphanoscopy soon became apparent, the method was widely used for about half a century, but in the end could not compete with modern techniques of radiography and ultrasound. The history is related in detail and illustrated with numerous figures.