IN DIFFICULT cases of disease involving the ocular fundus the use of several methods of examination may at times be of value in arriving at a reasonably exact diagnosis. The following procedures have been found to be of value in such instances, particularly in those of retinal detachment and of fundus tumor.
USE OF CONTACT LENS OF TRONCOSO WITH DIRECT OPHTHALMOSCOPY FOR OBSERVATION OF PERIPHERAL FUNDUS
In the examination by direct ophthalmoscopy of the fundus of an eye with little astigmatism and with clear media, the clear, sharp image of the posterior pole gives way peripherally to an increasingly blurred and distorted picture. The most peripheral portion of the observable fundus shows merely as a reddish-orange blur, in which only very large or very prominent lesions, if present, can be seen. Schepens1 has recently commented on this
ROSS MG. SOME AIDS IN OPHTHALMOSCOPYContact Glass; Transilluminating Procedures; Headlight Employed as Ophthalmoscope. AMA Arch Ophthalmol. 1951;46(6):637-646. doi:10.1001/archopht.1951.01700020651004