Can hemifacial spasm lead to glaucomatous changes?

Abstract

Purpose: To evaluate the association between hemifacial spasm (HFS) patients and glaucoma as a function of the Botox dosage required. Methods: A retrospective review of clinical documents and procedure records. Results: Information of 76 consecutive patients (58 females) with HFS who received Botox treatment were reviewed. The age at onset of HFS was 66 ± 11 (32–85) years, and all manifested unilaterally. Ten (13%, 95% confidence interval: 6.5–22.9%) patients were diagnosed with glaucoma, including 8 primary open-angle glaucoma (POAG) (4 unilateral and ipsilateral to the HFS), and 2 bilateral chronic angle-closure glaucoma (CACG). Nine of the 10 patients developed glaucoma after the onset of the HFS. The Botox dosage was significantly higher among those diagnosed with glaucoma (31+/8 vs. 26+/7units, P < 0.05). There was a positive relationship between the presenting intraocular pressure (IOP) and the Botox dosage required (R = 0.31, P = 0.0116). However, there was a weak relationship between the Botox dosage required and the vertical cup to disc ratio (R = 0.076, P = 0.525). The presenting IOP of the HFS-affected eyes in those diagnosed with glaucoma was higher than those without glaucoma (19 ± 3.5 vs. 13 ± 3.2 mmHg, P = < 0.05). The presenting IOP between the HFS-affected and unaffected eyes was similar (16 ± 4.8 vs. 15+/4.6 mmHg, P = 0.430). Smoking status, history of diabetes mellitus, hypertension, hyperlipidemia and obstructive sleep apnea were not different between HFS patients with or without glaucoma. Conclusions: Hemifacial spasm patients with glaucoma were associated with a higher Botox dosage. We found a positive relationship between the Botox dosage required and the presenting IOP. Whether hemifacial spasm can result in fluctuation of IOP, eventually causing glaucomatous damage, remains to be studied further.