Purpose: We report a case of cavernous sinus meningioma presenting with unilateral pseudo-internuclear ophthalmoplegia.Case summary: A 50-year-old female visited our clinic with a history of insidious onset of horizontal diplopia at primary and left gaze over 3 weeks. The symptom had diurnal variation and was aggravated with fatigue. There was intermittent upper eyelid drooping of the right eye. She had a history of migraines, which had recently worsened. The pupils showed a normal response to light and near stimulation in both eyes. The extraocular examination showed 14 prism diopter (PD) exotropia at primary, and 25 PD exotropia at left gaze, with -1 adduction limitation of the right eye. There was abducting nystagmus of the left eye. Ocular myasthenia gravis was suspected based on the clinical findings. Magnetic resonance imaging of the brain revealed a right cavernous sinus meningioma. The ocular symptoms improved after radiotherapy. At 3 months of follow-up, the ocular motility findings had improved to 4 PD exotropia, without adduction limitation of the right eye. The upper eyelid drooping had improved.Conclusions: A cavernous sinus meningioma can be manifested by various types of ocular motility disorder, including pseudo-internuclear ophthalmoplegia.

Purpose: To evaluate the effects and limitations of lacrimal endoscopy without silicone tube intubation in patients with epiphora.Methods: We conducted a retrospective chart review of 64 eyes in 49 patients who underwent lacrimal endoscopy between May 2021 and May 2022. The clinical characteristics, irrigation test results, lacrimal endoscopic findings, and type of surgery were analyzed.Results: The mean duration of symptoms was 31.2 months, and was significantly longer in the failure group than in the success group (<i>p</i> = 0.043). Irrigation tests showed passage, partial obstruction, and complete obstruction in 20 (31.3%), 16 (25.0%), and 28 (43.7%) eyes, respectively. Lacrimal endoscopy showed narrowing, mucus, fibrosis, granulation, and stones in 41 (64.0%), 12 (18.8%), 6 (9.3%), 3 (4.7%), and 2 (3.1%) eyes, respectively. Following lacrimal endoscopy, 32 (50.0%) eyes each were included in the success and failure groups. Preoperative irrigation test results did not affect the success rate (<i>p</i> = 0.203). Silicone tube intubation and dacryocystorhinostomy were performed in 5 (7.8%) and 8 (12.5%) eyes, respectively, because the symptoms did not improve after lacrimal endoscopy.Conclusions: Lacrimal endoscopy, performed without silicone tube intubation, was effective in improving symptoms and may guide the choice of surgical technique, if required.