Abstract
BACKGROUND: Miller Fisher syndrome (MFS) is a rare triad of ophthalmoplegia, ataxia, and areflexia. There have been few reports of acute angle-closure glaucoma induced by MFS in the literature. However, acute elevation of intraocular pressure in open angle glaucoma induced by MFS has not been reported. CASE PRESENTATION: A 55-year-old male patient with open-angle glaucoma was admitted to the ophthalmology department due to ocular pain, moderate dilation of the pupils, and an acute increase in intraocular pressure. During diagnosis and treatment, neurofunctional deficits such as ophthalmoplegia, ataxia, and areflexia were presented. The blood ganglioside antibody panel was positive for anti-GQ1b IgG, and Miller Fisher syndrome was diagnosed. The symptoms gradually improved after intravenous immunoglobulin treatment. After 3 months of follow-up, ophthalmoplegia, ataxia and areflexia completely resolved, the patient's intraocular pressure stabilized at baseline, and his pupils returned to normal bilaterally. CONCLUSION: This is the first case report of open-angle glaucoma with acute IOP elevation as the first symptom of Miller Fisher syndrome. The mechanism may be due to damage to the trabecular meshwork or maintenance of intraocular pressure, which results in acute intraocular pressure elevation in patients with preexisting open-angle glaucoma when the pupil dilates. Clinicians should be aware of the autonomic dysfunction caused by MFS, dilated pupils, and sudden increases in intraocular pressure, regardless of angle status.