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Cataract caused by exposure to ionizing radiation (X-rays, gamma rays). Characterized by posterior subcapsular cataract. In 2012, ICRP lowered the threshold dose to 0.5 Gy. Prevention with leaded protective glasses is most important, and visual impairment is treated with standard cataract surgery.

A comprehensive explanation of the definition, dose threshold, diagnosis, and treatment including anti-VEGF therapy for radiation-induced ocular disorders (cataract, retinopathy, optic neuropathy).

Delayed optic nerve damage occurring after radiation therapy for head and neck or orbital tumors. The main mechanism is ischemic changes due to vascular endothelial injury. There is no definitive treatment, and the prognosis is often poor.

A chronic progressive occlusive microvasculopathy that develops after radiation therapy to the eye, head and neck, or brain. It is associated with macular edema and neovascularization, leading to severe visual impairment.

Describes the types of radiation therapy used for eye tumors and the radiation doses used for each disease. This overview explains the features and side effects of external beam radiation (30–70 Gy), stereotactic radiotherapy, proton beam therapy (covered by insurance for rhabdomyosarcoma in 2016), heavy ion therapy (adenoid cystic carcinoma and uveal melanoma), and plaque therapy (¹⁰⁶Ru/¹²⁵I).

Raeder syndrome (Raeder paratrigeminal syndrome) is a rare neurological disorder characterized by unilateral postganglionic Horner syndrome accompanied by ipsilateral trigeminal nerve symptoms. Early identification of underlying conditions such as internal carotid artery dissection is important.

A rare syndrome caused by simultaneous ipsilateral impairment of the cervical sympathetic trunk, recurrent laryngeal nerve, and phrenic nerve. It is characterized by the triad of Horner syndrome, vocal cord paralysis, and unilateral diaphragmatic paralysis, with malignant tumors being the most common cause.

Ramsay Hunt syndrome type 2 is a syndrome caused by reactivation of varicella-zoster virus latent in the geniculate ganglion, characterized by the triad of ear pain, auricular vesicles, and facial nerve palsy. Early combination therapy with antiviral drugs and steroids within 72 hours of onset significantly affects prognosis.

A benign cystic lesion arising from anatomical remnants during pituitary development. Often asymptomatic, but enlargement can cause headache, visual field defects, and endocrine dysfunction.

An alternating hemiplegia syndrome caused by a lesion in the medial ventral portion of the mid-pons. It is characterized by ipsilateral abducens nerve palsy and contralateral hemiplegia, and in the classic form, it is accompanied by contralateral central facial palsy.

A condition in which epithelial erosions recur due to abnormal adhesion of the corneal epithelium. Characterized by sudden eye pain upon waking, and managed stepwise from conservative therapy to surgical treatment.

Recurrent painful ophthalmoplegic neuropathy (RPON) is a rare disorder characterized by recurrent episodes of unilateral headache and ipsilateral oculomotor nerve palsy, with an incidence of 0.7 per million. It primarily affects children, and the oculomotor nerve is most frequently involved.

Repeated low-level red light therapy (RLRL) is a myopia progression control treatment that irradiates red light in the 650–670 nm band for 3 minutes twice daily to suppress axial elongation. This article explains the evidence from major RCTs, treatment protocol, safety, and comparison with other therapies.

This article explains the pathways, clinical significance, and examination methods of nine types of reflexes related to the eye (such as the pupillary light reflex, near triad, corneal reflex, and vestibulo-ocular reflex). Abnormal reflexes are important diagnostic indicators for optic nerve diseases, cranial nerve disorders, and autonomic nervous system diseases.

This article explains the causes, classification, prevention, and treatment options such as glasses, laser, and IOL exchange for refractive errors including myopia, hyperopia, and astigmatism that occur after cataract surgery.

A clinical sign detected as a difference in pupillary response between the two eyes when light is shone into each eye separately. It indicates unilateral or asymmetric optic nerve or retinal damage and is useful for early detection of many important diseases, including emergencies.

A rare bilateral inflammatory choroidal disease first reported in 2000. It combines features of APMPPE and serpiginous choroiditis, and is a refractory disease in which new lesions continue to appear over months to years.

Explains the reliability and limitations of intraocular pressure measurement methods (Goldmann applanation tonometer, non-contact tonometer, Tonopen, iCare, DCT). Covers the influence of central corneal thickness (CCT), diurnal variation, and the latest information on continuous IOP monitoring devices.

Renal retinopathy is a retinopathy associated with malignant hypertension and chronic glomerulonephritis, characterized by hypertensive changes combined with uremic toxins and metabolic disturbances, leading to multiple cotton-wool spots and serous retinal detachment. Treatment of the underlying disease and blood pressure control are important.

Yellow-white reticular deposits in the subretinal space on the surface of the retinal pigment epithelium (RPE). They are precursor lesions of age-related macular degeneration and increase the risk of geographic atrophy and choroidal neovascularization.

A special type of age-related macular degeneration characterized by neovascularization originating from the intraretinal capillary plexus (type 3 MNV). It predominantly affects elderly women, has a high rate of bilateral involvement, and tends to be treatment-resistant. Intravitreal anti-VEGF injection is the first-line treatment, and combination with PDT is also an option.

A benign glial tumor arising in the retinal nerve fiber layer. It frequently appears as an ocular manifestation of tuberous sclerosis complex (TSC) and can also occur sporadically. Most cases are asymptomatic, but it may cause complications such as macular edema or branch retinal vein occlusion.

This article explains the definition, clinical findings, diagnosis, treatment, and prognosis of retinal astrocytic hamartoma associated with tuberous sclerosis.

This article explains the diagnosis, treatment, and surveillance of retinal capillary hemangioma (retinal hemangioblastoma) associated with VHL disease, including the latest knowledge such as the VHL Disease Clinical Practice Guidelines (2024 edition).

Retinal capillary hemangioma (RCH) is a benign vascular tumor caused by VHL gene mutations and frequently appears as an ocular manifestation of von Hippel-Lindau (VHL) disease. Early detection and treatment directly affect visual prognosis.

Retinal cavernous hemangioma is a low-flow venous malformation, usually non-progressive. This article discusses clinical findings, differential diagnosis, and management.

General overview of retinal detachment (rhegmatogenous, tractional, exudative, traumatic). A hub article for a group of diseases systematically explaining classification, epidemiology, symptoms, diagnosis, treatment strategy, and prognosis.

A form of traumatic retinal tear in which the retina is detached from the vitreous base at the ora serrata due to blunt ocular trauma. It is common in young individuals and progresses slowly as a shallow retinal detachment, so attention must be paid to delayed diagnosis.

A phenomenon in which the retina shifts relative to the RPE after surgery for rhegmatogenous retinal detachment (RRD). It causes metamorphopsia and aniseikonia, and is diagnosed by a hyperautofluorescent line on fundus autofluorescence imaging.

A general term for retinal vascular events and inflammatory lesions associated with SARS-CoV-2 infection. Reported findings include retinal vein occlusion, retinal artery occlusion, cotton wool spots, and punctate hemorrhages. The main mechanisms are thought to be hypercoagulability and cytokine storm.

A rare fundus finding in which retinal blood vessels change from milky white to cream color due to hypertriglyceridemia. It resolves quickly with normalization of triglyceride levels, but early detection of the underlying metabolic disorder is important.

Explains the principle, algorithm, and glaucoma detection ability of Retinal Nerve Fiber Layer Optical Texture Analysis (ROTA). Covers comparison with conventional OCT RNFL thickness measurement, early detection in ocular hypertension, and ability to differentiate from non-glaucomatous optic neuropathy.

Explains the principles, techniques, and clinical applications of retinal oximetry. Introduces the two-wavelength method based on the Lambert-Beer law, changes in oxygen saturation in various diseases, and prospects as a biomarker for systemic diseases.

Comprehensive explanation of the principles, types, and indications of laser treatment for retinal diseases. Covers various techniques such as panretinal photocoagulation (PRP), focal photocoagulation, and subthreshold micropulse laser, along with the latest evidence.

A condition in which the retinal pigment epithelium (RPE) separates from Bruch's membrane. It is an important associated finding in age-related macular degeneration and central serous chorioretinopathy, and significantly affects visual prognosis.

A retinal pigment epithelial (RPE) tear is a condition in which the RPE abruptly tears in an area with pigment epithelial detachment (PED), exposing Bruch's membrane and the choroid. This article explains its association with age-related macular degeneration and anti-VEGF therapy, imaging diagnostic findings, and visual prognosis based on Sarraf grading.

An implantable device that activates remaining retinal neurons via electrical or chemical stimulation in patients with photoreceptor loss due to retinitis pigmentosa or age-related macular degeneration. It aims to partially restore vision.

Explains retinal tears caused by traction at sites of vitreoretinal adhesion, retinal holes due to atrophy, and lattice degeneration as a peripheral degeneration. Comprehensively describes risk factors, diagnosis, laser treatment, and indications for prophylactic retinal photocoagulation for rhegmatogenous retinal detachment.

Explains the evaluation of retinal and choroidal vessels using OCT-A (optical coherence tomography angiography). Covers the structure of normal vascular plexuses, interpretation of abnormal findings, and precautions regarding artifacts.

A condition characterized by inflammation of retinal blood vessels. It is associated with various underlying diseases such as SLE, Behçet's disease, sarcoidosis, and GPA. Stepwise treatment with steroids, immunosuppressants, and biologics is the standard approach.

Explanation of the definition, classification (BRVO, CRVO), symptoms, diagnosis, and treatment (anti-VEGF therapy, laser photocoagulation) of retinal vein occlusion (RVO).

Retinitis pigmentosa (RP): symptoms, causative genes, tests, treatments, and latest research. Onset with night blindness and visual field constriction; an inherited retinal dystrophy involving over 100 genes.

A malignant tumor that develops in the retina of infants and young children. Caused by mutations in the RB1 gene, with 70-80 new cases per year in Japan. The most common initial symptom is leukocoria (white pupil). The 5-year survival rate in developed countries is over 95%. Hereditary cases carry a risk of secondary cancers.

A disease involving fundus degeneration in high myopia (≥ -6D or axial length ≥ 26.5 mm). Comprehensive explanation of myopic maculopathy (choroidal atrophy, MNV, MTM). It is the second leading cause of adult blindness in Japan. Anti-VEGF drugs and vitrectomy are the main treatments.

An ocular fundus disease that occurs in association with hypertensive disorders of pregnancy (preeclampsia/eclampsia). It is primarily caused by choroidal and retinal circulatory disturbances due to hypertension, leading to serous retinal detachment and visual impairment. Most cases resolve spontaneously after delivery.

A proliferative vascular disease affecting the immature retinal vessels of preterm infants. The lower the gestational age and birth weight, the more severe the disease tends to be, accounting for approximately 30% of childhood blindness. It is classified by zone, stage, and plus disease based on ICROP3, and laser photocoagulation or anti-VEGF therapy is performed for type 1 ROP according to ETROP criteria.

Explains the symptoms, causes, diagnosis, and treatment of three types of retinoschisis (age-related, X-linked, and myopic). Details differential diagnosis by OCT, ERG findings, and the latest research on gene therapy.

An objective refraction method that uses a retinoscope to measure refractive errors of the eye. It is essential for evaluating patients who cannot undergo subjective testing, such as infants and individuals with developmental delays.

This article describes the technique, drugs, complications, and management of serious systemic complications such as brainstem anesthesia for retrobulbar anesthesia (posterior intraocular injection) used in ophthalmic surgery.

Retrobulbar hemorrhage is an emergency condition in which blood accumulates in the orbit. It causes proptosis, increased intraocular pressure, and vision loss, and prompt decompression is essential.

Explains the structure, surgical technique, clinical outcomes, and mechanism of action of the retrobulbar shunt. Covers the characteristics of this new glaucoma drainage device that guides aqueous humor from the anterior chamber to the retrobulbar space, comparison with conventional GDDs, and its usefulness in refractory glaucoma.

The reverse RAPD test is a procedure to detect an afferent pupillary defect (RAPD) by observing the healthy eye when the other eye has an efferent pupillary defect. This allows evaluation of RAPD even in patients with combined efferent and afferent defects.

A disease in which a tear in the retina allows liquefied vitreous to flow beneath the retina, separating the neurosensory retina from the retinal pigment epithelium. It occurs in 1 to 1.5 per 10,000 people annually and generally requires emergency surgical treatment. Initial surgery achieves reattachment in over 90% of cases, but visual prognosis depends largely on the presence or absence of macular detachment.

Explains eye diseases associated with rheumatoid arthritis. Dry keratoconjunctivitis (dry eye) is the most common, while scleritis and peripheral corneal ulcers are important complications affecting visual prognosis.

A rapidly progressive, fatal fungal infection caused by Mucorales fungi that spreads from the paranasal sinuses to the orbit and brain. It commonly occurs in patients with diabetes or immunodeficiency, and without treatment, the mortality rate reaches 79%.

This article explains the ocular findings, diagnosis, and treatment of rhinosporidiosis, a chronic granulomatous disease caused by Rhinosporidium seeberi. It focuses on its predilection for the conjunctiva and lacrimal sac, histopathological diagnosis, and treatment with surgical excision plus electrocautery.

A honeycomb-like corneal epithelial edema that occurs with the use of ROCK inhibitors (netarsudil, ripasudil), which are glaucoma medications. It is reversible upon discontinuation of the drug.

This article explains the mechanism of action, pharmacological properties, and clinical applications of Rho kinase inhibitors (ROCK inhibitors) for corneal diseases. It focuses on the promotion of corneal endothelial regeneration after Fuchs endothelial corneal dystrophy and Descemet membrane detachment surgery, and describes the indications and safety of ripasudil and netarsudil.

Rituximab, an anti-CD20 monoclonal antibody, is a biologic agent targeting B cells and is used for refractory non-infectious uveitis. It is internationally positioned as a third-line option after adalimumab and infliximab.

Advanced technology that utilizes robotic techniques to enhance the precision of vitreoretinal surgery. It supports delicate procedures such as ILM peeling, subretinal injection, and retinal vein cannulation through tremor filtering and motion scaling.

A rare disorder of the peripheral autonomic nervous system characterized by the triad of tonic pupil, loss of deep tendon reflexes, and anhidrosis. There is no curative treatment, and management is mainly symptomatic.

Explanation of causes, symptoms, diagnosis, and treatment of Roth spots. Detailed description of pathophysiology of retinal hemorrhage with white center, and association with infective endocarditis, anemia, and leukemia.

Uveitis associated with rubella virus infection. This article discusses acquired uveitis occurring during the course of adult rubella, ocular complications of congenital rubella syndrome (cataract, salt-and-pepper retinopathy), and its association with Fuchs heterochromic iridocyclitis.