Most With Orbital Pain Improve Using Peripheral Trigeminal Nerve Blockers

Researchers from the department of Ophthalmology and Visual Sciences at University of Iowa Health Care presented a poster on indications for, and therapeutic responses to, peripheral trigeminal nerve blocking agents at the 2021 Annual Meeting of the American Society of Ophthalmic Plastic and Reconstructive Surgery in New Orleans, held November 11-12. 

Recent studies suggest that the peripheral branches of the trigeminal nerve play key roles in headache and ocular pain. Peripheral nerve blocks have already demonstrated effectiveness in the management of primary trochlear headaches, ocular surface pain, and both supraorbital and trigeminal neuralgias. However, the benefit of nerve blocks in patients with chronic orbital pain has yet to be fully understood, given that orbital pain frequently persists even after resolution of the causative condition. Moreover, the etiology of chronic orbital pain is unclear and typically not elucidated by brain and orbital imaging. 

The researchers in this study, aimed to determine whether peripheral nerve blocks can effectively treat chronic orbital pain. They conducted a retrospective review of patients with chronic orbital pain who underwent periocular and retrobulbar peripheral trigeminal nerve blocks between November 2016 and May 2021. These patients had received injections consisting of lidocaine, bupivacaine, and sometimes dexamethasone. 

Results showed that 55% of patients had a moderate injection response, 38% had a high response, and 8% had no efficacy response. Regarding duration of injection effectiveness, 51% had an effect lasting more than 6 weeks, 9% had a 2- to 6-week effect, 26% had an effect lasting 2 weeks or less, and 14% experienced no treatment effect. 

Overall treatment efficacy findings suggested that 26% of patients had complete or near-complete improvement of symptoms, 58% had partial improvement, and 16% did not experience improvement. The investigators noted that addition of dexamethasone did not improve treatment outcome.

Because most patients suffering from chronic orbital pain achieved partial or complete improvement following nerve block treatment, with about half of total injections producing a response lasting more than 6 weeks, the researchers concluded that their results support the use of trigeminal nerve blocks in the management of chronic orbital pain. 

Reference

Shriver EM, Lee G. Peripheral trigeminal nerve blocks: Indications and therapeutic responses. Poster presented at: American Society of Ophthalmic Plastic and Reconstructive Surgery 2021 Annual Meeting. November 11-12, 2021; New Orleans.