N

Nanophthalmos is a rare developmental anomaly in which both the anterior and posterior segments of the eye are shortened due to arrested ocular growth during the embryonic period. It is characterized by high hyperopia, shallow anterior chamber, and thickened sclera, and is frequently complicated by glaucoma and uveal effusion.

Explains the causes, classification, diagnosis, and treatment of nasolacrimal duct obstruction (epiphora in adults). Covers indications and outcomes of lacrimal endoscopy, DCR (dacryocystorhinostomy), tube intubation, and management of drug-induced lacrimal duct obstruction.

Necrobiotic xanthogranuloma (NXG) is a type of non-Langerhans cell histiocytosis. It is a rare granulomatous disease characterized by yellow to orange nodules that commonly appear around the orbit, and it has a strong association with paraproteinemia and lymphoproliferative disorders.

Necrotizing fasciitis is a severe infection that affects the superficial fascia and leads to rapid skin necrosis. In periorbital cases, reported mortality is 8–15% and vision loss is 13.8%. Early surgical debridement and antibiotic therapy are the mainstays of treatment.

Rapidly progressive necrotizing retinitis caused by herpes viruses (HSV, VZV, CMV). It is an ophthalmic emergency that presents as acute retinal necrosis (ARN) in immunocompetent individuals and progressive outer retinal necrosis (PORN) in immunocompromised individuals.

Neonatal conjunctivitis is inflammation of the conjunctiva occurring within the first 28 days of life. Chlamydia and gonorrhea are the main causes. Early diagnosis and treatment lead to a good prognosis, but delayed treatment can result in serious complications.

This article explains the etiology (diabetic retinopathy, retinal vein occlusion, ocular ischemic syndrome), staging, diagnosis of iris rubeosis, anti-VEGF therapy, panretinal photocoagulation, trabeculectomy (with MMC), and tube shunt surgery for neovascular glaucoma (NVG).

Neuhauser syndrome (MMR syndrome) is a rare autosomal recessive disorder characterized by the triad of megalocornea, intellectual disability, and hypotonia. This article reviews ocular findings, genetic background, differential diagnosis, and management.

This article describes the symptoms, diagnosis, and treatment of neuro-ophthalmic complications caused by immune checkpoint inhibitors (ICIs), including optic neuropathy, orbital inflammatory disease, thyroid eye disease, giant cell arteritis, and myasthenia gravis.

This article explains the pathophysiology, diagnosis, and treatment of various neuro-ophthalmic signs associated with SARS-CoV-2 infection, including optic neuritis, cranial nerve palsy, eye movement disorders, and pupillary abnormalities.

Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by chronic inflammation of the lacrimal and salivary glands, presenting various neuro-ophthalmic symptoms such as optic neuritis, trigeminal neuropathy, and dry eye.

Explains neuro-ophthalmic signs associated with cryptococcal meningitis (CM), such as papilledema, cranial nerve palsy, optic neuropathy, and endophthalmitis. Covers the two main mechanisms of increased intracranial pressure and direct infiltration, as well as diagnosis, treatment, and pathophysiology.

Explanation of neuro-ophthalmic findings associated with familial dysautonomia (Riley-Day syndrome). Includes alacrima, corneal disorders, optic atrophy, and ocular motor abnormalities due to IKAP gene mutation, and their management.

Ganglioglioma is a rare central nervous system tumor that presents various neuro-ophthalmic signs such as papilledema, abducens nerve palsy, and Parinaud syndrome depending on the tumor location.

Glioblastoma is the most common primary malignant brain tumor in adults, causing various neuro-ophthalmic symptoms through direct involvement, infiltration, compression of the visual pathways, and increased intracranial pressure.

Hypertrophic pachymeningitis (HP) is a rare disease characterized by diffuse or localized thickening and inflammation of the dura mater, presenting various neuro-ophthalmic signs such as visual loss, diplopia, optic disc edema, and cranial nerve palsy. Autoimmune diseases, infections, and tumors are the main causes, and contrast-enhanced MRI and dural biopsy are key to diagnosis.

This article explains the ophthalmic signs of Lambert-Eaton myasthenic syndrome (LEMS), such as ptosis, diplopia, and pupillary dysfunction, as well as the pathophysiology of autoantibodies against VGCC, diagnostic methods, and treatment.

Lymphocytic hypophysitis (LH) is a rare disease in which autoimmune lymphocytic infiltration of the pituitary gland causes various neuro-ophthalmic signs such as visual field defects due to optic chiasm compression, diplopia due to cavernous sinus cranial nerve palsy, and anisocoria.

This article explains neuro-ophthalmic complications associated with obesity hypoventilation syndrome (OHS), such as papilledema, central retinal vein occlusion, and non-arteritic anterior ischemic optic neuropathy.

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis affecting medium-sized arteries. Ocular involvement occurs in 10–20% of cases, presenting various neuro-ophthalmic signs such as choroidal vasculitis, retinal vascular occlusion, ischemic optic neuropathy, and cranial nerve palsy.

This article explains the neuro-ophthalmic symptoms and signs of post-concussion syndrome (PCS) after traumatic brain injury (TBI), including findings such as convergence insufficiency, accommodative dysfunction, and traumatic optic neuropathy, as well as diagnostic methods and treatments focusing on visual rehabilitation.

Ophthalmic complications caused by chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). This article explains the pathology, diagnosis, and treatment of ocular muscle palsy, papilledema, optic neuropathy, proptosis, and pupillary abnormalities.

Pneumosinus dilatans (PSD) is a rare condition characterized by abnormal expansion of the paranasal sinuses. PSD of the sphenoid or ethmoid sinuses can compress the optic nerve, leading to compressive optic neuropathy.

Periventricular leukomalacia (PVL) is an ischemic injury to the periventricular white matter in preterm infants, which may be discovered in adulthood as pseudo-glaucomatous optic disc cupping and visual field defects. Clinical differentiation from normal-tension glaucoma is important.

Explanation of neuro-ophthalmologic findings such as pupillary response, eye movements, and fundus findings observed in comatose patients. Covers essential clinical evaluation methods for lesion localization, etiological estimation, and prognosis prediction.

This article describes neuro-ophthalmologic manifestations such as optic neuropathy, ophthalmoplegia, pseudotumor cerebri, and dry eye caused by vitamin deficiency or autoimmune mechanisms associated with celiac disease (gluten-sensitive enteropathy).

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease affecting upper and lower motor neurons, and can present various neuro-ophthalmologic signs such as eye movement abnormalities and anterior visual pathway changes. Although extraocular motor neurons are usually spared until late stages, square-wave jerks, saccadic abnormalities, and retinal changes have been reported.

Chordoma is a rare malignant bone tumor arising from notochordal remnants. When it occurs at the skull base, it presents with neuro-ophthalmologic symptoms such as abducens nerve palsy, diplopia, and visual field defects. This article explains diagnosis, treatment, and prognosis.

Chronic basilar artery occlusion (CBAO) is a condition in which long-term occlusion of the basilar artery leads to the development of collateral circulation, presenting with various neuro-ophthalmologic symptoms such as internuclear ophthalmoplegia, homonymous hemianopia, and cortical blindness.

This article explains neuro-ophthalmologic signs such as papilledema, abducens nerve palsy, and dorsal midbrain syndrome caused by colloid cysts of the third ventricle, as well as imaging diagnosis and treatment.

This article explains neuro-ophthalmologic signs associated with multiple system atrophy (MSA), such as eye movement disorders, pupillary abnormalities, and blepharospasm, including red flag findings that aid diagnosis and treatment options.

Explanation of neuro-ophthalmologic signs of PML, a demyelinating disease of the central nervous system caused by JC virus. Main ocular symptoms include homonymous hemianopia, cortical blindness, nystagmus, and diplopia due to cranial nerve palsy.

This article explains the diverse neuro-ophthalmologic signs caused by thalamic lesions, including vertical gaze palsy, skew deviation, pupillary abnormalities, and nystagmus, as well as the etiology, diagnosis, and treatment including Percheron artery infarction.

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is a hereditary cerebral small vessel disease caused by NOTCH3 gene mutations, presenting various ophthalmic signs such as visual aura, diplopia, and retinal vascular changes.

This article explains the diagnosis, treatment, and pathophysiology of neuro-ophthalmological complications associated with LADA (type 1.5 diabetes), including diabetic retinopathy, ophthalmoplegia, and optic neuropathy.

Myoclonus epilepsy associated with ragged-red fibers (MERRF) is a rare multisystem disorder caused by mitochondrial DNA mutations, presenting with various neuro-ophthalmological findings such as optic atrophy, ophthalmoplegia, and pigmentary retinopathy.

Krabbe disease (globoid cell leukodystrophy) is a lysosomal storage disorder caused by GALC gene mutations, presenting neuro-ophthalmological findings such as optic atrophy, nystagmus, and cranial nerve palsy.

This article describes the characteristics of neuro-ophthalmological symptoms such as papilledema, abducens nerve palsy, and optic neuritis in Mollaret meningitis (recurrent benign lymphocytic meningitis), its association with HSV-2, and diagnosis and treatment.

This article explains the neuro-ophthalmological findings such as papilledema, abducens nerve palsy, and transient visual obscurations associated with increased intracranial pressure due to choroid plexus papilloma (CPP), covering diagnosis, treatment, and pathophysiology.

A comprehensive review of the diagnosis, treatment, and pathophysiology of neuro-ophthalmological findings such as nystagmus, ophthalmoplegia, diplopia, and autoimmune retinopathy associated with anti-GAD antibody syndrome.

Cerebral amyloid angiopathy (CAA) is a disease in which β-amyloid deposition in blood vessel walls causes cerebral hemorrhage, leading to ophthalmic symptoms such as homonymous hemianopia and cortical visual impairment due to damage to the occipital lobe and optic radiation.

This article explains the neuro-ophthalmological aspects of language disorders (bilingual aphasia) that occur after brain injury in bilingual or multilingual individuals. It outlines different patterns of impairment between two languages, associations with visual field defects, and diagnosis, treatment, and rehabilitation.

This article explains neuro-ophthalmic findings associated with dementia with Lewy bodies (LBD), including visual hallucinations, oculomotor disturbances, color vision abnormalities, and eyelid abnormalities, as well as their diagnosis and management.

Neuroblastoma is the most common extracranial solid tumor in children, originating from the neural crest. It may present initially with proptosis and periorbital ecchymosis due to orbital metastasis. This article explains the pathology, diagnosis, and treatment.

Neurofibromatosis (NF) is an autosomal dominant neurocutaneous syndrome, broadly classified into NF1 and NF2. It causes various lesions in the skin, nerves, bones, and eyes. Ophthalmologically important manifestations include Lisch nodules, optic gliomas, retinal hamartomas, and glaucoma.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system mediated by aquaporin-4 antibodies, characterized primarily by optic neuritis and myelitis.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system mediated by aquaporin-4 antibodies, characterized primarily by optic neuritis and myelitis.

Explains neuroprotective strategies in glaucoma. Covers clinical evidence for brimonidine, citicoline, nicotinamide, and neurotrophic factors, mechanisms of RGC death, and latest research trends in combination therapy, gene therapy, and NAD+ therapy.

A disease characterized by inflammation of the optic disc with stellate hard exudates in the macula. Cat scratch disease is the most common cause, and most cases have a good visual prognosis.

A condition in which sarcoidosis affects the central and peripheral nervous systems. It presents with various neurological symptoms such as cranial nerve palsy, uveitis, meningitis, spinal cord disorders, and hypopituitarism.

Neurotrophic keratitis (NK) is a degenerative disease in which corneal epithelial homeostasis is disrupted due to impaired corneal sensory innervation from the trigeminal nerve. This article explains stage-specific management according to the Mackie classification, treatment with cenegermin (rhNGF), and corneal nerve regeneration surgery.

Explains the mechanism of action, clinical trial results, and side effects of nitric oxide (NO)-donating prostaglandin analogs (latanoprostene bunod, NCX 470). Covers differences from conventional PGAs and evidence from VOYAGER, APOLLO, and LUNAR trials.

Nocardia keratitis is a rare corneal infection caused by the actinomycete Nocardia, which inhabits soil. It is characterized by wreath-like infiltrates, and differentiation from fungal keratitis is important. This article explains treatment with amikacin eye drops, as well as diagnosis and management.

This article explains the measurement principle of non-contact tonometers (NCT), the procedure of the air-puff method, accuracy comparison with Goldmann applanation tonometry, the effect of central corneal thickness, and how to interpret test results.

Anatomy, physiology, and regulatory mechanisms of the unconventional aqueous humor outflow pathway (uveoscleral outflow pathway). Covers comparison with the conventional pathway, mechanism of prostaglandin analogs, pressure insensitivity, elastic sponge model, and relevance to MIGS.

An imaging method that photographs the back of the eye without using dilating drops. Widely used for screening diabetic retinopathy, glaucoma, and age-related macular degeneration. Explains the imaging procedure, key points for reading the images, and criteria for deciding on dilation.

This article explains the etiology (hemifield slide phenomenon, foveal traction diplopia syndrome, convergence insufficiency, divergence insufficiency, fusion fear), diagnosis, and treatment of binocular diplopia without extraocular muscle palsy.

A rare autoimmune retinal disease in which anti-retinal antibodies destroy photoreceptors without associated malignancy. Characterized by bilateral progressive vision loss, night blindness, and photopsia, with diagnosis of exclusion and immunosuppressive therapy as mainstays.

Explanation of indications, contraindications, surgical technique (superficial flap, deep flap, Schlemm's canal opening, TDM dissection), implants, goniopuncture, treatment outcomes, and complications of non-penetrating deep sclerectomy (NPDS). Also details the latest techniques such as XEN-DS.

Noonan syndrome is a genetic disorder caused by mutations in the RAS-MAPK pathway, characterized by distinctive facial features, short stature, and congenital heart disease as the three main features, and may be associated with ocular abnormalities such as optic nerve hypoplasia and coloboma.

Definition of normal-tension glaucoma (NTG), epidemiology based on the Tajimi Study, ocular perfusion pressure and vascular factors, diagnosis and differential diagnosis, evidence from CNTGS/LoGTS, first-line medication, and target intraocular pressure setting.

An X-linked recessive genetic disorder caused by mutations in the NDP gene. It presents with bilateral retinal dysplasia and blindness from birth, and may be accompanied by progressive sensorineural hearing loss and cognitive impairment.

A congenital macular dysplasia with autosomal dominant inheritance. It is non-progressive and often maintains stable vision throughout life, but vision loss may occur due to complications of choroidal neovascularization.

A disease in which the optic nerves in both eyes are damaged due to deficiencies of nutrients such as B vitamins and copper. Risk factors include bariatric surgery, vegan diet, and alcoholism.

A comprehensive explanation of the definition, classification, diagnosis, and treatment of congenital nystagmus (jerky nystagmus, pendular nystagmus), nystagmus blockage syndrome, latent nystagmus, spasmus nutans, and periodic alternating nystagmus. Includes indications for refractive correction, prism therapy, and surgical procedures such as the Kestenbaum procedure.