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.

EFFECT OF LUBRICANTS ON CORNEAL THICKNESS AFTER VITRECTOMY.

PURPOSE: This study examines the impact of corneal surface lubricants used during pars plana vitrectomy on corneal edema. METHODS: This prospective, observational, clinical study occurred at an academic institution. Participants were individuals aged 18 years and older who had already consented to undergo pars plana vitrectomy, without pre-existing corneal pathology. A corneal lubricant was chosen by the surgeon. Corneal thickness was measured preoperatively and postoperatively using pachymetry and anterior segment optical coherence tomography (AS-OCT). Main outcome measure was change in corneal thickness as measured by pachymetry. RESULTS: Forty-one patients completed the study protocol. The 23 subjects in the SHCS group had a significantly smaller increase in corneal thickness as measured by pachymetry compared with the 18 subjects in the HPMC group (29.9 µm vs. 58.1 µm, P value 0.02). When measured by anterior segment optical coherence tomography, the SHCS group had a smaller increase in corneal thickness compared with the HPMC group (0.04 mm vs. 0.06 mm, P value 0.09) but did not reach significance. CONCLUSION: SHCS is associated with reduced postoperative increase in corneal pachymetry as compared to HPMC.

Scleral Thinning after Transscleral Biopsy for Uveal Melanoma Using Lamellar Scleral Flap.

PURPOSE: The purpose of the study is to describe the clinical history and histopathologic findings of three cases of scleral thinning after lamellar scleral flap, including one case with confirmed extraocular tumor extension. METHODS: The medical records and pathology specimens of three patients with scleral thinning after biopsy and plaque brachytherapy and lamellar scleral flap performed during a transscleral biopsy were reviewed. RESULTS: The first two patients developed scleral thinning and visible pigmentation, but had tumors that were regressing in size on ultrasound. The two patients were followed by serial observation. The third patient exhibited scleral thinning and evidence of tumor growth on ultrasound, raising the suspicion for extraocular tumor extension. Histopathologic examination of the enucleated eye confirmed extrascleral tumor extension and showed necrotic and intact melanoma with associated pigmented macrophages. CONCLUSIONS: Patients with scleral flaps created for biopsy of uveal melanoma are at risk for scleral thinning and extrascleral extension of tumor recurrence through the flap.