Acute Ocular Effects of Sphenopalatine Ganglion Nerve Block

AIM AND OBJECTIVE: The goal of this study was to measure acute ocular effects in patients undergoing routine sphenopalatine ganglion (SPG) nerve block for headache. Projections from the SPG influence blood flow to the eye which may influence intraocular pressure (IOP). There are limited animal and human studies investigating the relationship between the SPG and its effect on the eye. MATERIALS AND METHODS: This was a single-site, investigator-initiated, single-visit, prospective study. Participants were aged 18–85 years old who had consented to SPG nerve block for headache. The primary outcome measures were change in near visual acuity (NVA) and IOP pre-procedure to immediately post-procedure. Additional data collected included pupil diameter and presence of any ocular or visual complaints. RESULTS: A total of 13 patients were enrolled in the study. Average pre-procedure IOP was 14.2 mm Hg [standard deviation (SD) 3.8] in the right eye and 13.7 mm Hg (SD 3.2) in the left eye. Average post-procedure IOP was 14.8 mm Hg (SD 3.8) in the right eye and 14.2 mm Hg (SD 2.9) in the left eye. Neither the right nor left eye experienced a statistically significant change in IOP after SPG block. There were no statistically significant changes in average NVA or pupil diameter in either eye. There were no adverse events. CONCLUSION AND CLINICAL SIGNIFICANCE: This pilot study suggests no significant acute changes in IOP or other ocular parameters after SPG block for headache disorders and supports the fact that the procedure is safe as it relates to ocular health. The ocular effects of SPG blockade merit further study in a larger cohort of patients. HOW TO CITE THIS ARTICLE: Siegel DT, Ertel MK, Patnaik JL, et al. Acute Ocular Effects of Sphenopalatine Ganglion Nerve Block. J Curr Glaucoma Pract 2020;14(2):57–60.