Fig. 19. Electro-oculographic recording after location and reinsertion of the superior rectus muscle after unplanned tenotomy. Both upward (U) and downward (D) saccades normally are rapid. Upper tracing: eye position; lower tracing: peak velocity. (Rosenbaum AL, Metz HS: Diagnosis of lost or slipped muscles by saccadic velocity measurements. Am J Ophthalmol 77:215, 1974. Published with permission from the American Journal of Ophthalmology. Copyright by the Ophthalmic Publishing Company)