Siegrist streaks and Elschnig spots

Key Points at a Glance

Key Points of This Disease

• Siegrist streaks (1899) and Elschnig spots (1900) are necrosis and pigmentary changes of the retinal pigment epithelium (RPE) due to choroidal ischemia.
• Malignant hypertension, giant cell arteritis (GCA), and preeclampsia are the main causes.
• The main subjective symptom is blurred vision, and serous retinal detachment may occur in the acute phase.
• Fluorescein angiography (FA), indocyanine green angiography (ICG), and OCT-A are useful for diagnosis.
• If giant cell arteritis is suspected, ESR and CRP measurement and immediate corticosteroid administration are necessary¹⁾.
• The basis of treatment is control of the underlying disease (hypertension, GCA).

1. Siegrist streaks and Elschnig spots

Siegrist streaks, described by Siegrist in 1899, and Elschnig spots, described by Elschnig in 1900, are choroidal ischemic lesions. Both are representative fundus findings of hypertensive choroidopathy and appear in association with malignant hypertension.

Siegrist streaks are linear pigment deposits along the choroidal arteries, reflecting atrophy and pigment changes corresponding to occluded choroidal arterioles. They remain as traces of vascular occlusion caused by chronic hypertension or giant cell arteritis (GCA).

Elschnig spots are lesions of RPE necrosis caused by acute choriocapillaris ischemia, observed as small yellow to gray-white spots in the acute phase. Subsequently, pigmentation and atrophy progress, changing to chronic lesions with a central dark area and a surrounding ring of pigmentation.

Siegrist streaks

Mechanism: Long-term occlusion and atrophy of choroidal arteries

Appearance: Linear pigmentation along the course of choroidal arteries

Course: Chronic, scarred lesion

Elschnig spots

Pathogenesis: Acute ischemia of the choriocapillaris → RPE necrosis

Appearance: Yellow small spots in the acute phase, ring-shaped pigment changes in the chronic phase

Course: Morphological changes from acute to chronic

Q Which indicates more severe disease: Siegrist streaks or Elschnig spots?

A

Both reflect the degree of choroidal ischemia, but Elschnig spots indicate acute capillary ischemia and often appear as active lesions with serous retinal detachment. Siegrist streaks are evidence of a chronic course and do not necessarily imply an active phase.

2. Main symptoms and clinical findings

Subjective Symptoms

• Blurred vision: The most common subjective symptom. Reflects RPE dysfunction due to choroidal ischemia.
• Decreased visual acuity: Becomes prominent when serous retinal detachment (SRD) involves the macula.
• Metamorphopsia: May occur when fluid accumulates under the macula.

Clinical Findings

• Linear pigmentation (Siegrist streaks): Observed as linear pigmentation along the choroidal arteries from the posterior pole to the periphery.
• Yellow to gray-white small spots (acute Elschnig spots): Necrosis of the RPE at sites of choriocapillaris occlusion, showing hypofluorescence in the early phase of fluorescein angiography.
• Ring-shaped pigment changes (chronic Elschnig spots): A characteristic chronic finding where a dark RPE proliferation ring surrounds the central atrophic area.
• Serous retinal detachment (SRD): Occurs when RPE pump function fails in acute hypertensive choroidopathy.

3. Causes and Risk Factors

Diseases that cause choroidal ischemia are responsible.

• Malignant hypertension: A rapid rise in systolic blood pressure (usually >180 mmHg) causes fibrinoid necrosis of choroidal arterioles, leading to ischemic RPE necrosis. This is the most common cause.
• Giant cell arteritis (GCA): Occlusion of the posterior ciliary arteries causes choroidal ischemia ¹⁾. Urgent treatment with corticosteroids is required, and it typically occurs in older adults (age 50 and older) ¹⁾.
• Preeclampsia/gestational hypertension: An important cause of hypertensive choroidopathy in pregnant women, often improving after delivery.

Malignant Hypertension

Features: Rapid blood pressure elevation (systolic >180 mmHg)

Mechanism: Fibrinoid necrosis of choroidal arterioles → capillary occlusion

Management: Hospitalization and antihypertensive therapy

Giant Cell Arteritis

Features: Age >50, temporal headache, jaw claudication

Mechanism: Granulomatous inflammation of posterior ciliary arteries → occlusion

Management: Emergency administration of corticosteroids¹⁾

Preeclampsia and Others

Preeclampsia: Hypertensive choroidopathy in pregnant women. Resolves after delivery.

Others: Secondary hypertension such as renal hypertension and pheochromocytoma can also be causes.

Prevention and Daily Care

• If you have hypertension, measure your blood pressure regularly and continue oral medication.
• If you are over 50 and experience headache, jaw pain, and vision loss simultaneously, see an ophthalmologist and internist immediately (possible GCA).
• If your vision changes during pregnancy, consult an obstetrician and an ophthalmologist.

Q Can Elschnig spots due to giant cell arteritis be distinguished from those due to hypertension?

A

Differentiation based solely on clinical findings is difficult. Systemic symptoms (temporal headache, jaw claudication, fever) and elevated ESR/CRP levels suggest giant cell arteritis¹⁾²⁾. Temporal artery biopsy is required for confirmation¹⁾.

4. Diagnosis and Examination Methods

Evaluation using a combination of multiple modalities is standard.

Examination	Main Findings
FA (Fluorescein Angiography)	Early hypofluorescence → late hyperfluorescence (RPE necrosis/leakage)
ICG angiography	Direct visualization of choroidal perfusion deficit
OCT-A	Visualization of avascular areas in the choriocapillaris

• Fluorescein angiography (FA): Acute Elschnig spots show early hypofluorescence and late leakage from surrounding areas. Siegrist streaks may show window-defect-like hyperfluorescence along arterial courses.
• Indocyanine green angiography (ICG): Allows direct evaluation of choroidal circulation better than FA, clearly delineating the extent of ischemic areas.
• Optical Coherence Tomography Angiography (OCT-A): Noninvasively evaluates avascular areas of the choriocapillaris. Also useful for follow-up.
• Fundus Autofluorescence: Used to evaluate RPE atrophy and proliferation patterns in chronic Elschnig spots.

Systemic Testing When Giant Cell Arteritis Is Suspected

When giant cell arteritis is in the differential diagnosis, perform the following promptly.

• ESR and CRP: In elderly patients, an ESR of 70 mm/h or higher strongly suggests giant cell arteritis²⁾. CRP is also a sensitive indicator¹⁾.
• Temporal Artery Biopsy: Gold standard for definitive diagnosis¹⁾. Positivity is maintained for up to 2 weeks after starting corticosteroids, so treatment should not be delayed while waiting for biopsy results.

Q How do Elschnig spots appear on OCT-A?

A

In the choriocapillaris slab, they are depicted as avascular areas (dark spots) corresponding to ischemia. By comparing with FA/ICG, the extent and activity of the lesion can be assessed non-invasively.

5. Standard Treatment

The cornerstone of treatment is controlling the underlying disease. Local ophthalmic treatment alone is ineffective, and collaboration with internal medicine and obstetrics is essential.

• Blood pressure management (malignant hypertension, preeclampsia): Stepwise blood pressure reduction is performed during hospitalization. Rapid reduction risks worsening choroidal ischemia, so careful adjustment toward the target blood pressure is necessary.
• Corticosteroids (GCA): High-dose prednisolone (usually ≥1 mg/kg/day) is initiated as soon as giant cell arteritis is suspected ¹⁾. If there is a risk of vision loss, intravenous methylprednisolone pulse therapy may be considered ¹⁾. Treatment should not be delayed even before biopsy confirmation.
• Serous retinal detachment: Often resolves spontaneously with treatment of the underlying disease. If it persists after control of the underlying disease, additional treatments such as photocoagulation are considered.

Precautions in treatment

• If giant cell arteritis is suspected, initiation of corticosteroids should not be delayed while waiting for the results of a temporal artery biopsy. Prompt initiation of treatment is essential to prevent irreversible damage to the optic nerve ¹⁾.
• In malignant hypertension, avoid excessively rapid blood pressure reduction. Medical management considering the risk of organ damage to the brain, kidneys, and coronary arteries is prioritized.

6. Pathophysiology and detailed pathogenesis

The stepwise process from choroidal ischemia to RPE necrosis and pigmentary changes is shown below.

Stage	Pathological changes	Corresponding clinical findings
Acute ischemia	Choroidal arteriolar fibrinoid necrosis → capillary occlusion	ICG hypofluorescent area
RPE necrosis	RPE cell necrosis and loss of pump function in ischemic area	Acute Elschnig spots and SRD
Chronic changes	RPE proliferation, pigmentation, and atrophy	Chronic Elschnig spots and Siegrist streaks

In malignant hypertension, when a rapid rise in blood pressure exceeds the autoregulatory capacity of the choroidal arterioles, fibrinoid necrosis of the vessel wall occurs. This necrotic area occludes the precapillary arterioles, causing local non-perfusion of the choriocapillaris. The RPE that loses perfusion undergoes necrosis, and the outer blood-retinal barrier breaks down. As a result, subretinal fluid accumulation (SRD) occurs. In the chronic phase, the necrotic RPE proliferates and becomes pigmented, forming the characteristic ring-shaped appearance of Elschnig spots. When multiple occlusions occur continuously along the course of an artery, they form Siegrist streaks.

In giant cell arteritis, granulomatous inflammation and occlusion of the posterior ciliary arteries are predominant, which tends to lead to more extensive choroidal ischemia and severe visual dysfunction.

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7. Latest Research and Future Perspectives (Research-stage Reports)

For Patients: Please Read

The following content is currently at the research stage or under clinical trial and is not standard treatment available at general hospitals. It is reference information for professionals regarding future medical developments.

Advances in Choroidal Assessment Using OCT-A

OCT-A can noninvasively visualize avascular areas of the choriocapillaris better than FA/ICG. Research is ongoing into its application for quantifying the extent of choroidal ischemia and monitoring treatment effects.

Revising the Classification of Hypertensive Fundus Changes

Classification systems for hypertensive retinopathy, including the Wong-Mitchell classification, have been refined. Studies continue on the association between choroidal lesions, such as Elschnig spots and Siegrist streaks, and systemic cardiovascular risk.

COVID-19 and Hypertensive Choroidopathy

Mollan et al. (Lancet, 2024) reported the impact of the COVID-19 pandemic on the diagnosis and management of giant cell arteritis ³⁾. Delays in seeking care and diagnosis may increase the risk of visual impairment.

Q Do Elschnig spots improve?

A

If the underlying disease (hypertension, GCA) is treated appropriately, acute serous retinal detachment often resolves and vision recovers. However, chronic Elschnig spots (pigment changes, atrophy) may remain irreversible.

Q Do Siegrist streaks and Elschnig spots recur?

A

Recurrence can occur if hypertension worsens again or giant cell arteritis flares. In patients with giant cell arteritis who are tapering corticosteroids, attention to flare-ups is necessary, and regular blood pressure monitoring and inflammatory marker surveillance are important¹⁾³⁾.

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8. References

1. American Academy of Ophthalmology. Retinal and Ophthalmic Artery Occlusions Preferred Practice Pattern. AAO; 2024.
2. Aguiar de Sousa D, et al. Horner syndrome in giant cell arteritis. J Neuroophthalmol. 2024.
3. Mollan SP, et al. Giant cell arteritis. Lancet. 2024.