Binocular Indirect Ophthalmoscopy : The Beginner's Guide
The technique of examining the fundus of the eye is called ophthalmoscopy. In direct ophthalmoscopy, a virtual and erect image of the fundus is seen. In indirect ophthalmoscopy, a real and inverted image is formed between the condensing lens and the observer. The advantage of stereopsis (depth perception) and a larger field of view makes indirect ophthalmoscope (IDO) more useful both in retina clinics and during posterior segment surgeries. Inventions and innovations The journey of developing ophthalmoscopy began with an idea by the great physicist, Hermann von Helmholtz, who described the optical principles of direct ophthalmoscopy in 1851 (Fig:1a). This was followed by series of innovations and methods of examination including the indirect method of ophthalmoscopy developed by Reute in 1852 (Fig:1b), binocular model by Marc-Antoine Giraud-Teulon (Fig:1c) and more practical hand-held reflex-free binocular ophthalmoscope by Allvar Gullstrand (Fig:1d). It was Charles Schepens who popula
Dr. Nagesha CK