Interdisciplinary challenge of central retinal artery occlusion: a case report

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BACKGROUND

Central retinal artery (CRA) occlusion is the ocular equivalent of ischemic stroke and is characterized by sudden painless vision loss in one eye [1].

The CRA, a branch of the ophthalmic artery, arises from the ciliary ganglion and enters the dural sheath of the optic nerve about 1 cm behind the eyeball [2]. Then the artery divides into the superior and inferior branches, which supply the optic nerve and inner retina. The ciliary arteries originating from the ocular artery also supply the retina [3]. Compromised blood supply to the CRA leads to ischemia and, if persists, to retinal necrosis. The cilioretinal artery, found in 5%–30% of people, supplies the macula and can preserve central vision in CRA occlusion [4].

The condition incidence is 1 per 100,000 people annually [5], but it is predicted to increase because of population aging [6]. The visual prognosis for CRA occlusion remains poor, as visual function decreases to finger counting or light perception in 61% of patients. Currently, there are no generally accepted, evidence-based treatment guidelines for CRA occlusion [1].

The article presents a clinical case of CRA occlusion and discusses possible approaches to the diagnosis and treatment of the condition.

CASE DESCRIPTION

Patient Information

A 71-year-old male patient was admitted to the regional vascular center of City Clinical Hospital No. 4 (Perm, Russia) on December 20, 2024 with complaints of sudden painless loss of vision in his right eye and numbness in his left arm.

Medical history: The patient had hypertension and smokes. Two weeks before admission, numbness and clumsiness in his left arm occurred. He did not seek medical care. Before admission, he suddenly lost vision in his right eye without pain. A day later, he called an ambulance and was taken with suspected cerebrovascular accident.

Examination Results

At admission, no vision in the right eye and mild left side hemiparesis were observed. Brain computed tomography (CT) showed previous cerebral infarctions of internal and external border zones (Fig. 1, d). CT angiography revealed prolonged stenosis (up to 90%) of the left internal carotid artery caused by a calcified plaque (Fig. 1, c). Intravenous thrombolysis was contraindicated because of prolonged symptoms duration.

 

Fig. 1. Fundus image showing a cherry-red spot (a); OD duplex scan showing a spot sign (b); computed tomography–angiography: prolonged stenosis (up to 90%) of the left internal carotid artery caused by calcified plaque (c); brain computed tomography: previous cerebral infarctions of internal and external border zones (d); brain magnetic resonance imaging: FLAIR-hyperintense lesions (string of pearls sign) in the right-sided deep border zones, isolated foci of restricted diffusion (microinfarcts) (right box), a linear restricted diffusion area within the external border zone (left box) (e); catheter cerebral angiography (f): stenosis of up to 90% in the orifice of the right internal carotid artery (1); after internal carotid artery stenting (2).

 

The patient was admitted to a neurological department for patients with cerebrovascular accidents. Secondary prevention of minor stroke included dual-antiplatelet therapy with acetylsalicylic acid and clopidogrel. Ophthalmology consultation was scheduled.

At ophthalmological examination, OD visual acuity was light perception with light projection; OD corrected visual acuity was 0.2, sph. −1.5 D=0.7. Intraocular pressure was normal (13/14 mmHg). Full range of eye movements was preserved. The OU anterior segments were unremarkable. A relative afferent pupillary defect was observed in the right eye. Nuclear opalescence (early stage age-related cataract) was detected in both eyes.

Bedside fundus photography showed pale pink OD optic disc, blurred optic disc margins, no excavation, narrow and irregular arteries, medium-sized veins, poorly visualized vascular pattern, diffuse macular edema, and a cherry-red spot (Fig. 1, a). OS optic disc was pale pink with clear margins and normal excavation; the arteries were narrow; the veins were moderately filled with blood.

OD ultrasound revealed a retrobulbar spot sign; ocular artery blood flow was not visualized.

The patient was stable. The next day, brain magnetic resonance imaging was performed and showed deep FLAIR-hyperintense lesions, mainly right-sided (string of pearls sign) (Fig. 1, e), single foci of restricted diffusion (microinfarcts) (Fig. 1, e, top right box), and a linear restricted diffusion area within the external border zone (Fig. 1, e, bottom left box).

Treatment

Management of the patient was coordinated with a cardiovascular surgeon, and catheter cerebral angiography was recommended to select recanalization technique of the internal carotid artery. The examination dated December 28, 2024 confirmed stenosis of up to 90% in the orifice of the right internal carotid artery extending for 2.5 cm (Fig. 1, f1). Internal carotid artery stenting was performed (Fig. 1, f2).

Follow-up and Outcomes

The patient was discharged on day 10 without neurological deficit; visual acuity remained unchanged. Recommendations included dual-antiplatelet therapy for one month followed by long-term oral administration of acetylsalicylic acid and high-intensity statin therapy (80 mg atorvastatin).

Prognosis

The visual prognosis for CRA occlusion remains poor; however, after internal carotid artery stenting and with the secondary prevention recommendations observed, the life prognosis is quite favorable and the possibility of recurrent vascular events is low in this case.

DISCUSSION

The described clinical case is a clear example of acute contralateral hemiplegia (optic-pyramidal syndrome) caused by arterial embolism. In Russia, E.V. Schmidt provided a detailed description of this condition in 1963 [7]. He pointed out that the clinical presentation of carotid artery occlusion in the neck is characterized by a combination of blindness or decreased vision on the side of the affected artery and contralateral pyramidal disorders. Late blindness is possible with CRA embolism from a clot in the carotid artery, which was the case in the presented patient.

Acute motor dysfunction required transfer to a hospital with a neurological department for patients with cerebrovascular accidents. This transfer is recommended by the procedure for medical care¹; however, if there was only visual impairment, things could have developed differently. In Russia, ischemic stroke typically refers to a clinical syndrome caused by a focal cerebral infarction. Current clinical guidelines state that CRA occlusion is a form of ischemic stroke characterized by compromised blood flow to the CRA or its branches resulting from thromboembolism or vasospasm with or without retinal ischemia.² Notably, back in 2013, experts from the American Heart Association/American Stroke Association (AHA/ASA) updated the classification of strokes to include occlusion of the CRA and its branches [8]. This is explained by similar etiology and pathophysiology of cerebral and retinal infarction, as both conditions are often caused by thromboembolism leading to vascular occlusion. Moreover, treatment strategies of acute CRA occlusion are similar to stroke therapy and include reperfusion and optimization of atherosclerosis control to prevent further ischemic events [1].

In our opinion, optimal strategy is to hospitalize a patient with suspected CRA occlusion to a neurological department for patients with cerebrovascular accidents, where the required examination and treatment can be carried out as soon as possible. Thus, the fundus can be objectively assessed already during the initial examination using a portable fundus camera. There is accumulating evidence that fundus photography without pharmacologically induced mydriasis increases diagnostic accuracy in emergency neurological conditions [9], including monocular blindness [10]. Typically, fundoscopy in patients with CRA occlusion reveals retinal edema (pallor) and a cherry-red spot. The latter refers to the bright red fovea appearance surrounded by pale ischemic retina because of preserved choroidal circulation [1].

Recently, diagnostic methods have significantly advanced so that now they visualize morphological changes and the origin of retinal perfusion in detail and use artificial intelligence to accelerate diagnosis. Conventional diagnosis of CRA occlusion is based on clinical assessment and fluorescein angiography, showing delayed filling of the retinal arteries; however, current imaging methods offer a more detailed and non-invasive assessment. For example, enhanced depth imaging optical coherence tomography (EDI-OCT) provides highly detailed cross-sectional images of the retina and choroid. In acute CRA occlusion, EDI-OCT reveals hyper-reflective foci and edema of the inner retinal layers, whereas chronic condition is characterized by atrophy and thinning of the inner layers. Analysis of these changes provides grading of ischemia and the prognosis. Optical coherence tomography–angiography (OCTA) is a non-invasive method which visualizes the vessels of the retina and choroid without using a contrast material and provides 3D images of microcirculation, critical for assessing perfusion of the retina and choroid and detecting poor circulation. OCTA is more accurate than fluorescein angiography and especially useful for assessing blood flow in deep vascular plexuses, which are poorly visualized by fluorescein angiography [11]. Indocyanine green angiography assesses choroidal circulation in detail, which is of particular importance in ophthalmic artery occlusion without a cherry-red spot because of concomitant choroidal ischemia [12].

Artificial intelligence technologies to analyze medical images are rapidly evolving, speeding up and improving the accuracy of diagnosis. Deep learning algorithms are being developed and tested to automatically detect signs of CRA occlusion in conventional fundus photos. These technologies can be used by neurologists in stroke units for rapid diagnosis and initiation of reperfusion therapy within the therapeutic window [13]. Current methods to diagnose CRA occlusion based on multimodal imaging (OCT, OCTA, and indocyanine green angiography) and artificial intelligence technologies significantly increase the accuracy and speed up the diagnosis, which is crucial for timely initiation of treatment and secondary prevention of ischemic events.

As there are various conditions that can mimic CRA occlusion, early and accurate differential diagnosis is critical for choosing the adequate treatment strategy. Table 1 presents the key criteria for differentiating CRA occlusion from other conditions.

 

Table 1

Differential diagnosis of central retinal artery occlusion

Condition	Clinical presentation	Ophthalmoscopy	Optical coherence tomography	Fluorescein angiography
Central retinal artery occlusion	Sudden, painless loss of vision in one eye	Ischemic retinal edema, a characteristic cherry-red spot in the macular area, and ocular ischemic syndrome	Hyper-reflective foci and thickening of the inner retinal layers	Delayed or no filling of the central artery
Arteritic central retinal artery occlusion	Sudden loss of vision is often combined with symptoms of giant cell arteritis (headache, jaw pain, fever, and pain in the temples)	Ischemic retinal edema, a characteristic cherry-red spot in the macular area, and optic disc edema	Hyper-reflective foci, thickening of the inner retinal layers, and optic disc edema	Delayed filling of the central retinal artery and often of the choroid
Central retinal vein occlusion	Gradual or sudden decrease in vision. Distorted vision may occur	Multiple intraretinal hemorrhages, optic disc edema, dilated and tortuous veins	Cystoid macular edema	Delayed vein filling, dilated capillaries, and dye leakage
Paracentral acute middle maculopathy	Sudden paracentral scotomas (blind spots). Vision may remain high	It may be normal or with small whitish foci in the paramacular area	Hyper-reflective inner nuclear layer	Scans are often normal. Delayed blood flow in the paracentral vessels may be observed
Purtscher retinopathy	Sudden vision loss of varying degree, often after pancreatitis or other systemic diseases	Cotton wool spots (Purtscher spots) in the retina, often around the optic disc. Hemorrhages may be present	Multiple discrete hyper-reflective foci, often around the optic disc	Dye leakage in affected areas
Hypertensive retinopathy	It is usually bilateral. Vision may be reduced in macular edema	Cotton wool spots, hemorrhages, optic disc edema, narrowed arteries	Hyper-reflective inner retinal layers, edema	Dye leakage from the damaged vessels may be present

 

The main cause of CRA occlusion is thromboembolism secondary to atherosclerosis, usually embolism from atheromatous plaques in the carotid artery, which was the case in the presented patient [14]. This allows considering acute painless monocular blindness or contralateral hemiplegia as a marker of carotid artery disease and generally high cardiovascular risk, which requires a structured vascular assessment with visualization of the cerebral and precerebral arteries [15]. Ultrasound is extremely convenient for this purpose, as it not only assesses an atherosclerotic plaque and its embolization, but also visualizes blood flow in the ophthalmic artery. B-scan ultrasound reveals a hyperechoic density on the distal aspect of the optic nerve, the so-called retrobulbar spot sign, in 75% of patients with CRA occlusion. This sign indicates the embolic origin of occlusion (calcified embolus), and when it is absent, arteritis becomes a more likely cause of reduced vision [16]. In the presented clinical case, the spot sign suggested a calcified plaque in the internal carotid artery.

In the discussed clinical case, the patient was admitted outside the therapeutic window for intravenous thrombolysis; however, if a patient is hospitalized within the first 4.5 h after the onset of symptoms, reperfusion therapy is feasible [17]. For example, the randomized THEIA clinical study (France, n=70) showed that intravenous thrombolysis within the first 4.5 h of CRA occlusion is safe and associated with a high rate of vision improvement (66%). However, there were no statistically significant differences in the treatment outcomes between the thrombolysis and standard therapy (acetylsalicylic acid) groups because the study was not sufficiently powered, according to the authors [18]. A meta-analysis of individual data from non-randomized studies (783 patients with CRA occlusion) showed that intravenous thrombolysis within the first 4.5 h is associated with faster recovery from severe vision loss compared with standard treatment (28.8% vs 11.1%; OR 3.3); intra-arterial thrombolysis demonstrated efficacy within the first 6 h (27.2% vs 12.0%; OR 2.7) [19].

Hyperbaric oxygen therapy is another promising treatment method for CRA occlusion. A large retrospective study (Portugal, n=114) showed that hyperbaric oxygen therapy is safe and improves visual acuity in patients with non-inflammatory CRA occlusion; the treatment efficacy is affected by the number of therapeutic sessions, age of patients, obesity, and a cherry-red spot [20]. As for thrombolysis, hyperbaric oxygen therapy has the therapeutic window of 24 h [21, 22].

Another key aspect in the management of patients with CRA occlusion is secondary prevention of cerebral and ocular embolic events, which includes short-term dual-antiplatelet therapy (if the criteria for minor stroke or high-risk transient ischemic attack are met) and early recanalization of the carotid artery (in case of >50% ipsilateral stenosis) [12], which was performed in the presented case.

The analysis of the presented clinical case and relevant scientific publications suggests the proposed algorithm for management of patients with painless monocular blindness in primary care departments of vascular medicine and regional vascular centers (Fig. 2).

 

Fig. 2. Algorithm for management of patients with painless monocular blindness in primary care departments of vascular medicine and regional stroke response centers. *Unless contraindicated.

 

CONCLUSION

CRA occlusion is a serious interdisciplinary challenge requiring collaboration of ophthalmologists, neurologists, and specialists in cardiovascular prevention. This condition should be considered an emergency, and awareness of the “time is vision” concept should be promoted. A patient with suspected CRA occlusion requires emergency hospitalization to a multidisciplinary unit offering neurovisualization and angiography, thrombolytic therapy, and revascularization.

ADDITIONAL INFORMATION

Author contributions: V.E. Polina, search and analytical work, discussion of research results, writing the text of the article, patient examination; A.A. Kulesh, search and analytical work, discussion of research results, writing the text of the article, supervision of patient treatment; S.A. Mekhryakov, patient examination; T.V. Gavrilova, writing the text of the article. Thereby, all authors provided approval of the version to be published and agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Consent for publication: The authors obtained written informed voluntary consent from the patient for the publication of personal data, including photographs (with the face masked), in a scientific journal and its electronic version (signed on December 25, 2024). The scope of the data to be published has been agreed upon with the patient.

Funding source: The study had no sponsorship.

Disclosure of interests: The authors declare that they have no competing interests.

Statement of originality: The authors did not use previously published information (text, illustrations, data) while conducting this work.

Data availability statement: All data obtained in this study are available in this article.

Generative AI: Generative AI technologies were not used for this article creation.

 

¹ Order of the Ministry of Health of the Russian Federation No. 928n On Approval of Procedure for Medical Care of Patients With Cerebrovascular Accidents, dated November 15, 2012. Available at: https://base.garant.ru/70334856/ Accessed on: February 15, 2026.

² Ischemic Stroke and Transient Ischemic Attack. Clinical guidelines. Age category: adults, pediatric patients. Available at: https://cr.minzdrav.gov.ru/view-cr/814_1 Accessed on: February 15, 2026.

About the authors

Veronika E. Polina

Academician Ye.A. Vagner Perm State Medical University; State Clinical Hospital No. 4, Perm

Author for correspondence.
Email: dr.polina.v.e@gmail.com
ORCID iD: 0009-0009-8485-1729
SPIN-code: 1910-2036
Russian Federation, Perm; Perm

Aleksey A. Kulesh

Academician Ye.A. Vagner Perm State Medical University; State Clinical Hospital No. 4, Perm

Email: aleksey.kulesh@gmail.com
ORCID iD: 0000-0001-6061-8118
SPIN-code: 7132-9487

MD, PhD, Professor

Russian Federation, Perm; Perm

Sergey A. Mekhryakov

Academician Ye.A. Vagner Perm State Medical University; State Clinical Hospital No. 4, Perm

Email: heartolog@gmail.com
ORCID iD: 0000-0001-5679-4100
SPIN-code: 4127-4022

MD, PhD

Russian Federation, Perm; Perm

Tatyana V. Gavrilova

Academician Ye.A. Vagner Perm State Medical University

Email: gavrilova.tv@mail.ru
ORCID iD: 0000-0003-2071-9322
SPIN-code: 5947-8762

MD, PhD, Professor, Corresponding Member of the Russian Academy of Sciences

Russian Federation, Perm

References

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