The information on this website is not intended for diagnosis or treatment. Please consult your physician for health concerns.

+90 850 321 50 00

Coats Disease — Adult-Onset (Idiopathic Retinal Telangiectasis with Exudation)

Idiopathic non-hereditary retinal vascular disorder characterized by telangiectatic retinal vessels, light-bulb microaneurysms, intraretinal and subretinal exudation, and progressive exudative retinal detachment; predominantly affects males (75 percent) with majority in childhood (Coats disease) but adult-onset variant exists; treated by laser photocoagulation, cryotherapy, intravitreal anti-VEGF, and surgical vitrectomy with retinal detachment repair to prevent neovascular glaucoma and phthisis bulbi.

Written by: Saygı Hospital Health Guide Editorial Board
Last updated:

This content has been compiled by the Saygı Hospital Health Guide Editorial Board and is periodically reviewed by a specialist physician.

This content is for informational purposes only and does not constitute medical advice. You can book an appointment at our Göz Hastalıkları department. Book Appointment →

What is Coats Disease — Adult-Onset (Idiopathic Retinal Telangiectasis with Exudation)?

Coats disease is an idiopathic, non-hereditary, congenital retinal vascular disorder first described by George Coats in 1908, characterized by abnormal telangiectatic and aneurysmal retinal vessels with progressive intraretinal and subretinal lipid exudation. Predominantly affects males (75 percent), unilateral in 95 percent. Classical presentation is in early childhood (mean age 5–8 years) with leukocoria (white pupil), strabismus, or decreased vision, but an adult-onset variant exists presenting in third to sixth decade with milder, often peripheral disease and gradual symptom onset.

Pathogenesis involves somatic mutation in NDP gene (Norrie disease pseudoglioma gene, Xp11.4) encoding norrin, a Wnt pathway ligand essential for retinal vasculogenesis. Loss of norrin-Frizzled-4-LRP5 signaling produces failure of normal retinal vascular development with persistence of immature vessels, telangiectasia, microaneurysm formation, and breakdown of inner blood-retinal barrier with consequent intraretinal and subretinal lipid exudation. Norrie disease (allelic disorder with germline NDP mutation) causes bilateral congenital blindness in males.

Adult-onset Coats differs from pediatric form: typically unilateral peripheral telangiectasis (most commonly inferotemporal), milder exudation, less frequent retinal detachment, slower progression, and better visual prognosis. Symptoms: gradual vision loss (most common), metamorphopsia from macular exudation, paracentral scotoma, vitreous floaters, occasional asymptomatic with incidental discovery during routine examination.

Shields classification (the most widely used clinical staging system): Stage 1 — retinal telangiectasia only without exudation; Stage 2 — telangiectasia plus exudation (2A — extrafoveal exudation, 2B — foveal exudation); Stage 3 — exudative retinal detachment (3A — subtotal: 3A1 extrafoveal, 3A2 foveal; 3B — total retinal detachment); Stage 4 — total retinal detachment with secondary glaucoma; Stage 5 — end-stage advanced disease with phthisis bulbi. Adult Coats most commonly presents at Shields stage 1–2.

Symptoms

Gradual blurred vision in one eye (most common adult presentation)
Metamorphopsia (distortion) when macula is involved
Paracentral scotoma corresponding to area of exudation
Floaters or vitreous hemorrhage (uncommon)
Yellow refractile retinal exudates with light-bulb aneurysms on funduscopy
Macular hard exudates in star or ring pattern
Subretinal fluid with shifting fluid in advanced cases
Leukocoria (white pupil) — uncommon in adult form, more common in pediatric
Strabismus — uncommon in adult form
Asymptomatic with incidental discovery during routine eye examination

Risk Factors

Male sex (75 percent of adult Coats; 95 percent of pediatric Coats)
Unilateral involvement (95 percent)
Childhood history of similar findings (sometimes recognized in adulthood)
Somatic NDP gene mutation (sporadic, not inherited)
No definitive systemic associations (idiopathic)
Differential considerations: retinoblastoma history, FEVR family history, von Hippel-Lindau

When to See a Doctor?

If you experience any of the following symptoms, seek medical attention promptly:

  • Gradual unilateral vision loss in adult — comprehensive eye examination
  • Metamorphopsia or paracentral scotoma
  • Discovery of yellow refractile retinal exudates on routine fundoscopy
  • Light-bulb aneurysms or telangiectatic vessels seen on examination
  • Floaters or vitreous hemorrhage with retinal vascular abnormality
  • Suspected retinal detachment (curtain in vision, photopsias)
  • Need for differential workup of retinoblastoma in pediatric patient
  • Failed initial laser or anti-VEGF therapy with progression

Treatment Methods

01
Diagnostic workup: dilated fundus examination (telangiectatic vessels, light-bulb microaneurysms, lipid exudates with refractile yellow crystalline appearance, subretinal fluid), wide-field fluorescein angiography (gold standard — defines extent of telangiectasis, aneurysms, capillary nonperfusion, leakage; differentiates from retinoblastoma — Coats has lacy abnormal vessels rather than mass with calcification), OCT (intraretinal cysts, subretinal fluid, exudates, foveal involvement), B-scan ultrasound if media opacity (retinal detachment, distinguish from retinoblastoma calcification — calcification highly specific for retinoblastoma), wide-field OCT-A (emerging — non-invasive vascular imaging), MRI in pediatric to exclude retinoblastoma (Coats lacks calcification on imaging unlike retinoblastoma)
02
Differential diagnosis (especially pediatric): retinoblastoma (calcification on B-scan, mass on imaging — Coats lacks both), familial exudative vitreoretinopathy (FEVR — bilateral, peripheral avascularity, often family history), persistent fetal vasculature, von Hippel-Lindau (retinal capillary hemangioma — discrete vascular mass with feeding artery and draining vein), retinal arterial macroaneurysm, idiopathic juxtafoveal telangiectasis (MacTel)
03
Stage 1 (telangiectasia only): close observation with serial wide-field FA every 3–6 months; selective laser photocoagulation to clearly leaking telangiectatic vessels if progression
04
Stage 2 (telangiectasia plus exudation): laser photocoagulation (preferred for posterior telangiectasis) — thermal photocoagulation of telangiectatic vessels and adjacent capillary nonperfusion zones, often multiple sessions over 4–8 weeks; intravitreal anti-VEGF (bevacizumab 1.25 mg, ranibizumab 0.5 mg, or aflibercept 2 mg) as adjunct to reduce exudation before laser or for macular edema; cryotherapy for anterior peripheral telangiectasis with subretinal fluid
05
Stage 3 (exudative retinal detachment): combination of cryotherapy or laser for telangiectasis, anti-VEGF for exudation control, scleral buckle for retinal reattachment in selected cases, pars plana vitrectomy with subretinal fluid drainage and silicone oil tamponade for total exudative detachment with persistent fluid
06
Stage 4 (total detachment with neovascular glaucoma): often poor visual prognosis; pars plana vitrectomy with silicone oil, panretinal photocoagulation for neovascularization, anti-VEGF for neovascular glaucoma, glaucoma surgery (Ahmed valve, cyclophotocoagulation) for intraocular pressure control; consider enucleation for blind painful eye
07
Stage 5 (phthisis bulbi or blind painful eye): symptomatic management; consider enucleation for cosmesis or pain control if intractable; histopathologic confirmation may be obtained at enucleation
08
Adjunctive therapy: photodynamic therapy (PDT) with verteporfin (rare modern use), focal laser for macular edema, intravitreal triamcinolone (limited role given side effects)
09
Long-term management: lifelong follow-up with serial dilated examinations and wide-field FA; careful monitoring for recurrence (10–20 percent), new telangiectasis, secondary complications (cataract, glaucoma, neovascular glaucoma, vitreous hemorrhage); refraction and amblyopia management in pediatric patients; vision rehabilitation for residual visual impairment
10
Prognosis: adult-onset Coats generally has better visual prognosis than pediatric form due to milder disease, peripheral involvement, and earlier symptom recognition; early detection and treatment of stage 1–2 disease produces best outcomes; advanced stages 3–5 carry poor visual prognosis; key to preventing progression is identification of early disease with prompt laser photocoagulation

Which Department to Visit?

You can visit our Göz Hastalıkları department for these complaints. Our specialist physicians will create the most suitable treatment plan for you.

Learn About Göz Hastalıkları Department

Let us help you

You can make an appointment with our specialists or contact us for your concerns.

Book AppointmentContact Us

Related Health Topics

Other articles from the same department you may want to explore.

Anaemia

Dahiliye (İç Hastalıkları)

Anaemia is a low haemoglobin level that reduces oxygen delivery, causing fatigue, pallor, and shortness of breath. It is not a disease itself but a sign of many underlying conditions. Most cases are correctable with appropriate diagnosis and treatment.

Iron Deficiency Anaemia

Dahiliye (İç Hastalıkları)

Iron deficiency anaemia develops when dietary intake, absorption, or losses create an iron shortfall, most often affecting women and children. Identifying the underlying cause is the core of management, alongside iron replacement.

Vitamin B12 Deficiency

Dahiliye (İç Hastalıkları)

Vitamin B12 deficiency can cause megaloblastic anaemia, neurological symptoms, and cognitive impairment. Early treatment with intramuscular or oral B12 largely prevents irreversible complications.

Hypertension (High Blood Pressure) Management

Dahiliye (İç Hastalıkları)

Hypertension is often called the silent killer because it progresses symptom-free for years and can damage the heart, brain, kidneys, and eyes. Regular monitoring, lifestyle change, and evidence-based drug therapy dramatically reduce cardiovascular risk.

Chronic Kidney Disease

Dahiliye (İç Hastalıkları)

Chronic kidney disease is one of the most common complications of chronic conditions such as diabetes and hypertension, and can be silent in its early stages.

Hepatitis B (HBV)

Dahiliye (İç Hastalıkları)

Hepatitis B is a DNA virus infection causing acute and chronic hepatitis with risk of cirrhosis and hepatocellular carcinoma; diagnosis integrates HBsAg, HBeAg, anti-HBc, and HBV DNA with management based on disease phase using nucleos(t)ide analogues (entecavir, tenofovir) and universal infant vaccination.

Hepatitis C (HCV)

Dahiliye (İç Hastalıkları)

Hepatitis C is an RNA virus causing chronic hepatitis that may progress to cirrhosis and hepatocellular carcinoma; modern direct-acting antiviral (DAA) pangenotypic regimens (sofosbuvir/velpatasvir, glecaprevir/pibrentasvir) achieve sustained virologic response over 95% in 8–12 weeks with universal adult screening and cure for nearly all patients.

Fatty Liver Disease

Dahiliye (İç Hastalıkları)

Non-alcoholic fatty liver disease (NAFLD) is closely related to obesity and metabolic syndrome and is largely reversible with early treatment.

Health Disclaimer: The information on this page is prepared for general informational purposes only. It does not replace medical diagnosis and treatment. Please consult your physician for your complaints. Saygı Hospital does not accept responsibility for actions taken based on the information on this page.