Drawing on previous studies, I explained the association between Alzheimerʼs disease and ocu lar movement disorders, saccadic intrusions, and vestibular impairment. The ocular movement disorders and vestibular impairment associated with dementia, such as Alzheimer's disease, can lead to poor balance, and may affect dementia progression, as well as the patientʼs quality of life (QOL) , due to bone fractures caused by a fall.

　Patients with Alzheimer's disease usually have abnormalities in the saccadic system, smooth pursuit system, and vestibular system. Furthermore, saccadic intrusions, such as microsaccades and square-wave jerks, are often observed in those affected by Alzheimerʼs disease. The hippocampus is important in the pathogenesis of Alzheimerʼs disease. Many studies have investigated vestibular disorder in patients with Alzheimerʼs disease and confirmed the association between the vestibular system and the hippocampus. However, more studies to clarify the usefulness of the oculomotor test for vestibular function as a potential biomarker of Alzheimer's disease are warranted.

　Oculomotor symptoms in Parkinsonʼs disease (PD) include saccadic pursuit, hypometric saccades, reduced pursuit gain, square wave jerks, and fixation deficits. Although relatively mild compared with eye movement abnormalities observed in other parkinsonisms, oculomotor symptoms provide a window into the pathophysiology of the brain in PD by considering the drives converging onto the superior colliculus (SC) , the final common pathway of saccades. Overactivity of the basal ganglia and consequent inhibition suppresses the SC in PD, and inhibitory control of saccades is also impaired secondary to “leaky” suppression. An investigation of saccadic abnormalities in PD may be useful to monitor changes in the pathophysiology of PD over the course of disease progression.

　Spinocerebellar degeneration (SCD) is a neurodegenerative disease, primarily affecting the cerebellum and brainstem. It is classified into hereditary and sporadic type, including various disorders with different clinical features. The cerebellum and brainstem are involved in eye movement components such as saccades, smooth pursuit eye movement, vestibulo-ocular reflex, optokinetic response, vergence, and fixation. Therefore, abnormal eye movements are frequently observed in patients with SCD, often with disease-specific characteristics. Therefore, neuro-ophthalmological examination is important as it can prompt the diagnosis of SCD.

　Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disease characterized by postural instability, vertical supranuclear gaze palsy, axial rigidity, akinesia, and cognitive impairment. Various atypical subtypes have been reported recently. In PSP, ocular motor dysfunction in the vertical direction is usually detected from an early stage; it is characterized by prolonged latency and reduced velocity and amplitude of saccadic movements. Square wave jerks are also recognized early. Smooth pursuit movements and horizontal saccades are initially spared, but are eventually impaired as the disease progresses. The vestibuloocular reflex is relatively preserved until the late stage, whereas the optokinetic nystagmus becomes poorly induced due to depression of the quick phase.

Introduction: Intravenous immunoglobulin (IVIg) therapy for steroid-resistant optic neuritis has been covered by health insurance, but its effectiveness and indications remain unclear. We investigated the outcome and issues of IVIg therapy in our cases.

Method: We retrospectively studied 6 patients (7 eyes) diagnosed with optic neuritis at our Department, who switched to IVIg therapy after 1-2 courses of pulse steroid therapy failed to improve visual acuity (VA) . VA, visual field and critical fusion frequency before and after therapy were analyzed.

Results: Mean age at diagnosis was 44.2 years. Two patients (2 eyes) had neuromyelitis optica spectrum disorders (NMOSD) , 2 patients (3 eyes) had myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) , and 2 patients (2 eyes) had idiopathic optic neuritis. Before treatment, minimum VA was light perception – 0.15. Five eyes had central or paracentral scotoma, and 2 eyes had only peripheral vision. After IVIg treatment, final VA improved to 1.0 or above in 5 eyes; scotoma disappeared in 5 eyes, although central scotoma remained in 1 eye. One patient each with NMOSD and MOGAD required plasmapheresis after IVIg therapy.

Discussion: Although IVIg therapy is generally effective for steroid-resistant optic neuritis, plasmapheresis may be more effective in patients with severe visual field disturbance after pulse steroid therapy.

　A 37-year-old man experienced blurry vision in his left eye. His corrected visual acuity was 1.2 OD and 0.6 OS. The relative afferent pupillary defect was negative. Humphrey visual field test indicated bitemporal hemianopia within 10º of visual field and diminished sensitivity in the central nasal field of the left eye. Brain gadolinium-enhanced magnetic resonance imaging (MRI) revealed an enhanced small lesion slightly to the left posterior part within the center of the optic chiasma. The patientʼs visual acuity recovered to 1.0 without treatment, and his visual field defect disappeared. A repeated brain MRI showed no enhanced lesion in the optic chiasma. We speculate that this patient had inflammation, specifically of the crossed macular fibers and uncrossed fibers towards the left of the chiasma. Consequently, this case supports the anatomical evidence indicating the existence of macular fiber chiasma within the optic chiasm. Moreover, such cases could be misdiagnosed as a nonorganized visual disturbance, especially without appropriate selection of the visual field program.

　We presented a patient with gastric cancer that was preceded by rapidly progressing visual acuity and field disturbances, who had no intracranial hypertensive symptoms such as headache or papilledema, and who had an enhancement effect on the optic nerve sheath on magnetic resonance imaging (MRI) . The patient was diagnosed with meningeal carcinomatosis to the optic nerve by direct infiltration of cancer cells.

　The patient was a woman in her 50s who underwent laparoscopic pyloric gastrectomy for gastric cancer 2 years previously. She received postoperative adjuvant chemotherapy; however, peritoneal dissemination was observed afterward. She became aware of blurred vision during chemotherapy. At the time of her initial visit, she had corrected visual acuity of 20/50 in the right eye and 10/50 in the left eye, and the kinetic perimetry test showed a cecocentral scotoma in both eyes. No remarkable findings were observed during slit lamp or ophthalmoscopic examination. However, MRI showed contrast effects on the bilateral optic nerve sheath and other multiple cranial nerves, leading us to suspect meningeal carcinomatosis. On cerebrospinal fluid cytology, Class V positive adenocarcinoma cells were detected, and the patient was diagnosed with meningeal carcinomatosis.

　When a patient with a tumor-bearing cancer presents rapid loss of vision and visual field impairment, meningeal dissemination of the cancer cells to the optic nerve should be considerd.

　Herpes zoster ophthalmicus (HZO) can cause ocular complications and usually occurs after the development of a rash. This report describes a case of HZO with acute dacryoadenitis preceding a skin rash. An 87-year-old man with a history of diabetes mellitus developed conjunctivitis of the right eye 5 days before the rash onset. Conjunctivitis did not improve, and he visited our clinic. In addition to having conjunctivitis, he had swelling of the right eyelid. Orbital computed tomography showed an enlarged lacrimal gland in the right eye. The patient was treated with oral antibiotics for suspected bacterial dacryoadenitis. The next day, erythema with vesicles was observed on the skin around the first branch of the trigeminal nerve around the right eye, HZO was diagnosed, and intravenous acyclovir infusion and eye drops were started. There was little improvement; thus, oral prednisolone (20 mg/day) was added. Intravenous acyclovir infusion was administered for 7 days, and prednisolone was gradually tapered. The dacryoadenitis and other symptoms improved 2 months after disease onset. When unilateral lacrimal gland inflammation is observed in older or immunocompromised patients, HZO should be considered a differ ential diagnosis.

Purpose: To describe the spatial correspondence of hypoperfusion detected using optical coherence tomography angiography (OCTA) with visual field defects, which portrays the link between hypoperfusion and decreased visual function in the eyes with nonarteritic anterior ischemic optic neuropathy (NAION) .

Case Description: This case series included ten eyes with NAION that portrayed the spatial correspondence between reduced perfusion measured by OCTA and visual field defects. The reduced perfusion area found by OCTA matched well with the corresponding area with structural changes. This correlation shows the connection between structural and functional damage in NAION.

Conclusion: This case series shows that OCTA is a useful modality for assessing perfusion to the optic nerve head in eyes with NAION; moreover, it can also be used to monitor disease progression in patients with NAION.