A description and clinical evaluation of the small-pupil binocular indirect ophthalmoscope is presented. This instrument can be used as an ordinary indirect stereoscopic ophthalmoscope. In addition, it performs better than available instruments in different situations, for instance when the patient's pupil is small (down to 1.5 mm) or partly occupied by opacities, or for the examination of the extreme fundus periphery with any kind of pupil. The principles of construction of the instrument are briefly outlined. This is followed by a description of the recommended technique and a description of clinical situations in which the instrument has been found of advantage.
Hovland KR, Elzeneiny IH, Schepens CL. Clinical Evaluation of the Small-Pupil Binocular Indirect Ophthalmoscope. Arch Ophthalmol. 1969;82(4):466-474. doi:10.1001/archopht.1969.00990020468008