2,701 articles
RESTORE trial (NCT06300268)
RESTORE trial (NCT06300268): prospective multicentre pilot study of the AdvaPro sirolimus-eluting coronary stent in Indian and European populations; 120 patients, not yet recruiting, MACE at 9 months.
Restrictive cardiomyopathy
Restrictive cardiomyopathy is a rare heart muscle disease, about 5% of cardiomyopathies, in which stiff ventricles resist filling, raising filling pressures and enlarging the atria; causes include amyloidosis.
Resuscitative endovascular balloon occlusion of the aorta
REBOA (resuscitative endovascular balloon occlusion of the aorta) is a temporary hemorrhage-control procedure using a balloon catheter inflated in aortic Zone 1 or 3 for non-compressible torso hemorrhage; first used by Hughes in 1954, limited by ischemia time, with conflicting trial evidence including UK-REBOA.
Reticular dystrophy of the retinal pigment epithelium
Reticular dystrophy of the retinal pigment epithelium (dystrophia reticularis laminae pigmentosae retinae, Sjögren 1950) is a rare inherited pattern macular dystrophy with a bilateral fishnet RPE pigment pattern, adult onset, good visual prognosis, PRPH2 linkage.
Reticular formation
Reticular formation (formatio reticularis): brainstem neuron network from midbrain to medulla regulating arousal, consciousness, sleep-wake cycles, and autonomic functions; source of the ascending reticular activating system (RAS) identified by Moruzzi and Magoun in 1949.
Reticular pseudodrusen
Reticular pseudodrusen, or subretinal drusenoid deposits, are yellowish subretinal lesions above the retinal pigment epithelium in age-related macular degeneration, strongly predicting progression to geographic atrophy and detectable only with multimodal imaging.
Reticulocyte
Reticulocyte: an immature anucleate red blood cell that matures in about 1-2 days; also called proerythrocyte. Its count (normal ~0.8-0.9%, ARC 25,000-75,000/µL) gauges marrow erythropoietic activity in anemia, with IRF and CHr parameters.
Retina
The retina is the light-sensitive neural tissue lining the back of the eye, containing rods and cones plus bipolar, horizontal, amacrine, and ganglion cells; the fovea is rod-free with peak cone density, and OCT imaging and AAV gene therapy are central clinical advances.
Retina bipolar cell
Retinal bipolar cells are retinal interneurons relaying photoreceptor input to ganglion cells; about 12 primate and 13+ mouse types, split into ON (mGluR6) and OFF pathways.
Retina horizontal cell
Retina horizontal cells are inhibitory interneurons in the inner nuclear layer that feed back to photoreceptors and forward to bipolar cells, creating center-surround receptive fields; primates have H1 and H2 types, mice one, zebrafish four.
Retinal
Retinal (11-cis-retinal), the aldehyde of vitamin A, is the universal light-absorbing chromophore of rhodopsin and cone pigments; photoisomerized to all-trans and regenerated by the RPE65 visual cycle and a Müller-cell cone cycle.
Retinal artery occlusions
Retinal artery occlusions (CRAO, BRAO, ophthalmic artery occlusion) are embolic blockages of retinal arteries causing sudden painless vision loss; treated as acute stroke with urgent stroke-center referral, though no proven vision-restoring therapy exists.
Retinal cell
Retinal cell: any of the neuron and glia types of the retina, including rods, cones, horizontal, bipolar, amacrine, and ganglion cells; over 130 cell types, with rods outnumbering cones 20-30 to 1 in humans.
Retinal detachment with retinal break
Retinal detachment with retinal break (rhegmatogenous retinal detachment, RRD): retina separates from the retinal pigment epithelium because a tear lets vitreous fluid pass under it. Treated by pneumatic retinopexy, scleral buckling, or vitrectomy; modern reattachment success exceeds 90%.
Retinal gene therapy using lentiviral vectors
Retinal gene therapy using lentiviral vectors: EIAV- and HIV-1-derived integrating retroviral vectors carrying genes up to ~8 kb, targeting RPE and photoreceptors via subretinal injection; used in Stargardt (SAR422459) and Usher 1B (UshStat) trials, distinct from non-integrating AAV.
Retinal haemorrhage
Retinal haemorrhage (retinal hemorrhage) is bleeding into the retina, classified by layer (flame, dot-and-blot, preretinal, subretinal, vitreous). Causes include diabetes, hypertension, vein occlusion, trauma, and abusive head trauma in infants; diagnosis uses OCT and angiography.
Retinal pigment epithelium
Retinal pigment epithelium (RPE): pigmented monolayer behind the retina supporting photoreceptors via phagocytosis, the visual cycle, and the outer blood-retinal barrier; its degeneration drives AMD, and stem cell-derived RPE transplants are in early trials.
Retinal vascular occlusions
Retinal vascular occlusions (ICD-11 9B74) are blockages of retinal arteries or veins, mainly RVO (CRVO, BRVO) and RAO. Prevalence 0.77% ages 30–89; anti-VEGF is first-line for RVO macular edema; acute RAO requires stroke-center referral.
Retinex
Retinex is a theory of human color vision and a family of image-enhancement algorithms, proposed by Edwin H. Land and John J. McCann in 1971.
Retinitis
Retinitis: inflammation primarily of the retina, usually infectious and necrotizing (CMV, HSV/VZV, Toxoplasma, syphilis). CMV retinitis affects AIDS patients with CD4 <50 cells/µL; HAART cut incidence over 80%.
Retinitis pigmentosa
Retinitis pigmentosa (RP), hereditary retinal dystrophy, is a group of inherited retinal diseases causing progressive photoreceptor degeneration, night blindness, tunnel vision, and legal blindness; over 130 genes involved, no cure, vitamin A and emerging gene therapies studied.
Retinitis punctata albescens
Retinitis punctata albescens (RPA, OMIM 136880) is a rare progressive inherited retinal dystrophy with white fundus dots and childhood night blindness, usually caused by RLBP1 mutations and related to retinitis pigmentosa.
Retinoblast
Retinoblast: multipotent embryonic retinal progenitor cell of the optic cup that generates all retinal neurons and Müller glia; distinct from retinoblastoma, the Rb-gene childhood tumor.
Retinoblastoma
Retinoblastoma is a childhood cancer of the retina, caused by RB1 tumor suppressor inactivation (Knudson two-hit hypothesis) or rarely MYCN amplification. Key sign is leukocoria; survival ranges from 99.5% in high-income to 57.3% in low-income countries.
Retinopathy
Retinopathy is a general term for disease-related damage to the retina, the light-sensitive tissue at the back of the eye, most often from diabetes or high blood pressure.
Retinopathy of prematurity
Retinopathy of prematurity (ROP), formerly retrolental fibroplasia, is abnormal retinal blood vessel growth in babies born before 30 weeks or under about 3 pounds; staged 1 to 5, screened by dilated exam, treated with laser, anti-VEGF injections, or surgery.
Retrograde amnesia
Retrograde amnesia is loss of memories formed before the causative event, unlike anterograde amnesia. Key features: Ribot's law temporal gradient, medial temporal lobe damage, consolidation versus retrieval theories, and functional (dissociative) forms.
Retroperitoneal space
Retroperitoneal space (retroperitoneum): abdominal space behind the parietal peritoneum, from diaphragm to pelvis, holding kidneys, aorta, IVC, pancreas, duodenum, and colon, divided into three fascial compartments and interfascial planes.
Revakinagene taroretcel lwey
Revakinagene taroretcel-lwey (ENCELTO, NT-501) is a Neurotech Pharmaceuticals encapsulated cell gene therapy implant releasing CNTF, FDA-approved March 5, 2025 as the first treatment for adults with idiopathic macular telangiectasia type 2.
Reversible cerebral vasoconstriction syndrome
Reversible cerebral vasoconstriction syndrome (RCVS), also called Call-Fleming syndrome, causes recurrent thunderclap headaches with multifocal cerebral artery narrowing that reverses within 3 months; triggered by postpartum state and vasoactive drugs, mainly affecting women.