The use of trypan blue dye for strabismus reoperations, surgery complications, and especially for the identification and recovery of a "slipped" or "lost" extraocular muscle.

Purpose: To evaluate trypan blue dye in strabismus surgery for tissue identification, to find the lowest optimal concentration, and to describe histological findings. in tissue so stained.

Methods: Trypan Blue dye 0.1% was serially diluted and tested by tissue staining at progressively different concentrations. Fifteen patients were studied using the dye.

Results: Trypan Blue 0.1 percent was the optimal concentration. Muscle, tendon and fibrotic tissues were easily identified and distinguished with the dye at this concentration. Such tissue identification was most useful and enhanced the performance of strabismus surgical operations, and especially in identifying and retrieving slipped or temporarily lost extraocular muscles.Also a thin basement-like membrane surrounding the superior oblique muscle tendons was disclosed with PAS stain, suggesting the presence of glycosaminoglycans.

Conclusions: Trypan Blue 0.1percent contrasts the different tissues, dying the muscle sheath, tendons and fibrotic tissues, but not staining the sclera and muscle fibers per se.