Review of bupivacaine use in treatment of strabismus
Reviewed by Fiona Rowe

This review aimed to assess the applications of bupivacaine (B) in the non-surgical treatment of strabismus in human and animal studies. Animal studies show that singly-innervated fibres with low concentrations of mitochondria and developed sarcoplasmic reticulum are more affected by B and are noted in the global muscle layer. Satellite cells are preserved and activate and proliferate during muscle regeneration. On this basis, B acts to increase muscle strength. Human studies show initial weakness in muscle function after injection followed by improvement in eye movement and consequent reduction in deviation of prior treated strabismus cases. Muscle size increases in volume on imaging. It has been used in conjunction with botulinum toxin (BT) with a correction rate about twice of B alone. There is no effect difference for exotropia vs esotropia but better success for deviations <25PD. Injection has been done with and without EMG guidance. Muscle weakness starts within minutes of injection and lasts up to one week. Muscle regeneration is over 34 weeks. If used with BT, often no change is seen in the first two weeks. Correction rate is 5-8PD with B alone and about 15PD when combined with BT. This is a promising treatment but with considerable limitations such as the need for direct infusion of relatively large volumes of B.

Applications of bupivacaine in the non-surgical treatments of strabismus: a review.
Kiarudi MY, Shahri SHG, Es’hahi A, et al.
STRABISMUS
2022;30(3):204-8.