In cases of separation of the retina where this membrane is considerably elevated, a correct estimate of the accuracy with which surface diathermy is applied may prove very difficult, for no mark will then show in the fundus. As failure to achieve a permanent sealing of the existing breaks—either by means of coagulation alone or with the aid of a scleral buckling—could then follow, the importance of proper detection and localization of the affected areas cannot be overemphasized.
Transillumination of the eye with a special electrode has been advocated by Strampelli4 as a valuablé addition to ordinary ophthalmoscopic control. The glowing tip of the instrument is moved on the sclera until a small clear spot is seen to reach the retinal tear; current is then turned on, whereby a brown-gray pilot mark will be left at precisely the right place. A similar instrument has been used by Amenábar,1 in
URRETS-ZAVALIA A. Fixation Pick and Scleral Depressor for Use in Operations of Retinal Detachment. AMA Arch Ophthalmol. 1959;62(1):97-98. doi:10.1001/archopht.1959.04220010101011