To recognize the anatomical positions of the superior oblique muscle in enucleated eyes using trypan blue.

Twenty-two surgically-enucleated eyes of 11 bodies were studied. The shortest distance from the nasal insertion of superior rectus to the anterior end of the superior oblique tendon, the distance from the temporal insertion of superior rectus to the anterior end of the superior oblique insertion, and the greatest width of superior oblique tendon insertion were measured by caliper 3 consecutive times. The average values in each of the above 3 points were calculated, and values prior to and after trypan blue staining were compared.

Prior to staining with trypan blue, the average distance from the nasal insertion of superior rectus to the anterior end of the superior oblique tendon was 4.97 mm and the average distance from the temporal insertion of superior rectus to the anterior end of the superior oblique insertion was 7.57 mm; after staining with trypan blue, the average values were 5.09 mm and 7.65 mm, respectively. There was no statistically meaningful difference in values prior to and after staining ( p > 0.05). Prior to staining, the average value of the greatest width of the superior oblique tendon was 10.32 mm, and after staining with trypan blue, the average value increased to 10.76 mm. There was a statistically meaningful difference between the values ( p = 0.02).

Trypan blue staining helped to recognize the location and the width of the superior oblique tendon more precisely.