Anomalous Retinal Correspondence (ARC) is a sensory adaptation in which the brain learns to fuse images from two misaligned eyes by remapping the extra-foveal point of the deviated eye to correspond with the fovea of the straight eye. Under normal retinal correspondence (NRC), points in space stimulate corresponding foveal locations in each eye, yielding single vision. In ARC, due to long-standing eye misalignment, the visual cortex adapts so that the fovea of one eye and an eccentric retinal point of the deviated eye still produce a unified image, preventing diplopia despite ocular deviation EyeWiki.
This adaptation involves neuroplastic changes in primary visual cortex (V1), where binocular neurons remap inputs so that disparate retinal points become perceptually corresponding. ARC most often develops in childhood strabismus, when cortical plasticity is high, but can also occur in adults secondary to late-onset retinal pathologies that shift the foveal position, such as epiretinal membranes and subretinal neovascular membranes in age-related macular degeneration EyeWiki.
Types of ARC
Harmonious ARC occurs when the subjective angle of anomaly (sensory misalignment) equals the objective angle of strabismus (motor deviation). In this type, patients experience no residual subjective mislocalization of objects EyeWiki.
Unharmonious ARC is characterized by a subjective angle that is less than the objective angle. The brain partially adapts, but the extra-foveal point does not perfectly map to the foveal axis, leading to subtle misperceptions of object location EyeWiki.
Paradoxical ARC arises when the subjective and objective angles are crossed—uncrossed in an esotrope or crossed in an exotrope—resulting in a reversal of perceived direction relative to the actual deviation EyeWiki.
Causes
Congenital Esotropia: An inward turning of the eye present early in life causes persistent foveal misalignment. The brain develops ARC to avoid diplopia by remapping the deviated eye’s retinal image NCBI.
Intermittent Exotropia: A variable outward deviation leads to alternating periods of alignment and misalignment. Over time, ARC can form to maintain single vision during deviations NCBI.
Microtropia: A small-angle strabismus (<5°) often presents without diplopia because ARC adapts the slight foveal offset, allowing near-normal binocular vision EyeWiki.
Anisometropic Refractive Error: Significant difference in refractive power between eyes disrupts congruent foveal images and can induce strabismus. The visual system adopts ARC to compensate for chronic disparity NCBI.
Craniofacial Anomalies: Orbital malformations (e.g., craniosynostosis) can physically misalign extraocular muscles, leading to strabismus and subsequent ARC PMC.
Oculomotor Nerve Palsies: Paralysis of cranial nerves III, IV, or VI causes acute misalignment; if long-standing, this can trigger ARC as a compensatory sensory adaptation PMC.
Thyroid Eye Disease: Inflammatory enlargement of extraocular muscles restricts movement, producing restrictive strabismus. ARC may develop to maintain single vision despite muscle restrictions PMC.
Retinopathy of Prematurity: Abnormal retinal vascularization in preterm infants can lead to strabismus, with ARC arising as the brain compensates for early foveal misalignment PMC.
Premature Birth: Low birth weight and shortened gestation increase risk for strabismus; prolonged misalignment in infancy fosters ARC development PMC.
Family History: Genetic predisposition to strabismus increases the likelihood of early ocular misalignment and ARC formation PMC.
Maternal Smoking: Smoking during pregnancy is linked to refractive errors and strabismus in offspring, setting the stage for ARC if misalignment persists PMC.
Orbital Trauma: Injury to orbital bones or muscles can cause acquired strabismus; chronic deviation may induce ARC as the visual cortex adapts PMC.
Epiretinal Membrane: Membrane formation on the retinal surface can distort foveal position; if chronic, the brain may remap correspondence points, resulting in ARC EyeWiki.
Subretinal Neovascular Membrane (AMD): Foveal displacement from neovascular membranes leads to eccentric fixation and eventual ARC as the system adapts EyeWiki.
Central Neurological Disorders: Conditions like stroke or cerebral palsy affecting ocular motor centers can lead to persistent misalignment and secondary ARC PMC.
Symptoms
Strabismus Without Diplopia: Patients exhibit a visible eye turn but report no double vision, thanks to ARC’s sensory remapping EyeWiki.
Absence of Double Vision: Despite significant misalignment, ARC prevents perception of two images by aligning disparate retinal points perceptually EyeWiki.
Suppression Scotoma: The brain may suppress certain retinal areas to facilitate ARC, creating localized zones of reduced or absent vision EyeWiki.
Reduced Stereopsis: Depth perception suffers because true foveal fusion is replaced by mapping of non-foveal points, impairing fine stereoscopic vision NCBI.
Amblyopia: Chronic misalignment and suppression can lead to “lazy eye” in the deviated eye, with reduced visual acuity and cortical underdevelopment NCBI.
Abnormal Subjective Visual Direction: Objects may appear shifted from their true location, reflecting the sensory remapping inherent in ARC EyeWiki.
Binocular Triplopia: During shifts in fixation or post-surgical transition, patients may transiently perceive three images as the system toggles between NRC and ARC EyeWiki.
Compensatory Head Posture: Patients often tilt or turn their head to align the adapted correspondence points for more comfortable single vision EyeWiki.
Asthenopia (Eye Strain): Effort to maintain adapted fusion can lead to headaches, eye fatigue, and discomfort, particularly during close work NCBI.
Reading Difficulties: Visual fatigue and unstable correspondence mappings can make reading slow or uncomfortable, with intermittent blurring or fluctuations Wikipedia.
Diagnostic Tests
Physical Examination Tests
Cover-Uncover Test: Reveals manifest tropias by observing refixation movements when one eye is alternately covered and uncovered EyeWiki.
Alternate Cover Test: Detects total deviation (tropia plus phoria) by rapidly shifting a cover between eyes and noting movement, indicating misalignment warranting ARC evaluation EyeWiki.
Hirschberg Test: Estimates ocular deviation by comparing corneal light reflex positions relative to the pupil, useful in non-cooperative patients EyeWiki.
Krimsky Test: Quantifies deviation by placing prisms until corneal reflexes are symmetric, guiding assessment of the objective angle in ARC EyeWiki.
Simultaneous Prism Cover Test: Measures manifest deviation without latent components by using prisms while covering the fellow eye, clarifying the objective angle of strabismus EyeWiki.
Manual Sensory Tests
Worth 4-Dot Test: Assesses peripheral fusion and suppression; in ARC patients, the test can reveal diplopia that is adjustable by prism, indicating anomalous correspondence EyeWiki.
Bagolini Striated Glasses Test: Uses striated lenses to map subjective visual directions; an “X” response in a known strabismus indicates ARC rather than suppression EyeWiki.
Synoptophore (Amblyoscope): Presents separate images to each eye and measures both objective and subjective angles; discrepancy between them confirms the angle of anomaly in ARC EyeWiki.
Red Filter Test: Places a red filter over one eye to differentiate crossed versus uncrossed diplopia; persistent diplopia after neutralization indicates ARC EyeWiki.
After-Image Test: Projects lights separately to each eye; a cross-shaped after-image in a strabismic patient indicates ARC by mapping the extra-foveal point to the foveal axis EyeWiki.
Lab and Pathological Tests
Serum Thyroid Function Tests (TSH, T3, T4): Identify thyroid eye disease as an underlying cause of restrictive strabismus and secondary ARC Wikipedia.
Thyroid Antibody Assays (Anti-TPO, TSH Receptor): Support the diagnosis of Graves’ ophthalmopathy, which can induce chronic ocular misalignment and ARC Wikipedia.
Genetic Testing for Familial Strabismus: Detects hereditary risk factors that predispose to early-onset eye deviation and ARC formation PMC.
Fine-Needle Aspiration Biopsy of Orbital Masses: Pathological evaluation of orbital tumors or inflammatory lesions that can produce incomitant strabismus and ARC PMC.
Electrodiagnostic Tests
Visual Evoked Potential (VEP): Records cortical responses to visual stimuli; in ARC patients, binocular VEP amplitudes can confirm anomalous binocular interaction PubMed.
Pattern Electroretinography (PERG): Assesses retinal ganglion cell function; helps differentiate retinal from cortical contributions in strabismic amblyopia associated with ARC PMC.
Imaging Tests
Optical Coherence Tomography (OCT): Visualizes epiretinal membranes and foveal displacement that can lead to adult-onset ARC EyeWiki.
Fundus Photography: Documents foveal and macular topography to detect eccentric fixation points in ARC EyeWiki.
Magnetic Resonance Imaging (MRI) of the Orbits: Assesses extraocular muscle enlargement, nerve pathology, or orbital masses contributing to strabismus and ARC Wikipedia.
B-Scan Ultrasonography: Detects early orbital changes in thyroid eye disease, aiding in diagnosis of restrictive strabismus and ARC Wikipedia.
Non-Pharmacological Treatments
Below are evidence-based, non-drug strategies—grouped by Exercise Therapies, Mind-Body Approaches, and Educational Self-Management—that support proper binocular function in ARC.
Exercise Therapies
Convergence Exercises
Convergence exercises (e.g., pencil push-ups) train the eyes to work together by focusing on a near target and slowly bringing it closer. Purpose: Improve eye teaming and reduce suppression. Mechanism: Stimulates medial rectus muscles and strengthens neural signals for convergence.Divergence Training
Using stereograms or computerized programs, divergence training encourages the eyes to separate focus from a near object to a distant one. Purpose: Balance eye alignment at various distances. Mechanism: Enhances lateral rectus activity and cortical control of divergence.Anti-Suppression Techniques
Introducing brief flashing lights or red/green filters forces the brain to acknowledge input from the deviated eye. Purpose: Breaks down the brain’s habit of ignoring the misaligned eye. Mechanism: High-contrast, alternating stimuli disrupt suppression and reinforce binocular integration.Stereopsis Drills
Using 3D glasses and depth-perception charts, patients practice identifying the relative positions of objects. Purpose: Recover depth perception. Mechanism: Stimulates disparity-sensitive neurons in visual cortex to re-establish stereopsis.Prism Adaptation Exercises
Light prisms temporarily shift images to align visual axes, combined with vergence tasks. Purpose: Retrains eyes to fuse images at a new alignment. Mechanism: Combines optical displacement with active eye movement to recalibrate neural mapping.Computerized Vision Therapy
Interactive software presents controlled stimuli to train fusion and accommodation. Purpose: Offer precise, adjustable exercises in-office or at home. Mechanism: Adapts difficulty based on real-time performance, reinforcing neural pathways.Orthoptic Patching
Patching the stronger eye forces the weaker, deviated eye to fixate and align. Purpose: Enhances control of the poorer eye. Mechanism: Prevents suppression, improves muscle coordination and cortical responsiveness.Thermal Balloon Therapy
Applying gentle heat to periorbital muscles before exercises relaxes tension. Purpose: Prepares extraocular muscles for training. Mechanism: Increases local blood flow and decreases stiffness for more effective exercise performance.
Mind-Body Approaches
- Progressive Muscle Relaxation (PMR)
Systematically tensing and relaxing facial and neck muscles reduces overall tension. Purpose: Lower stress that can worsen eye misalignment. Mechanism: Parasympathetic activation improves ocular blood flow and neural control. Guided Eye-Movement Meditation
Combining mindfulness with deliberate smooth-pursuit eye movements. Purpose: Increase awareness of eye position and reduce aberrant movement. Mechanism: Strengthens feedback loops between vestibular and oculomotor centers.Biofeedback for Ocular Control
Sensors monitor muscle tension around the eyes, giving real-time feedback for relaxation. Purpose: Teach voluntary control of extraocular muscles. Mechanism: Neurofeedback enhances cortical regulation of muscle tone.Visualization Techniques
Patients imagine following moving targets smoothly with both eyes. Purpose: Reinforce correct eye-movement patterns mentally. Mechanism: Activates mirror neurons and motor planning areas to prime physical performance.Stress-Reduction Yoga
Gentle asanas and breathing exercises reduce systemic cortisol. Purpose: Mitigate stress-induced eye muscle spasm. Mechanism: Autonomic balance lowers involuntary muscle tone around the eyes.
Educational Self-Management
- Home Vision-Therapy Logs
Keeping a daily record of exercise duration and symptom changes. Purpose: Encourage adherence and track progress. Mechanism: Self-monitoring boosts motivation and allows therapists to fine-tune programs. Tele-Orthoptic Sessions
Remote video consultations guide exercises and adjustments at home. Purpose: Increase access and consistency. Mechanism: Ensures correct technique and immediate feedback, reinforcing learning.Eye-Health Education Materials
Illustrated guides explain ARC and exercise rationale. Purpose: Empower patients with knowledge. Mechanism: Understanding promotes compliance and active participation.Digital Reminders & Apps
Smartphone apps prompt scheduled vision-therapy tasks. Purpose: Improve adherence. Mechanism: Timed notifications reduce forgetfulness and foster routine.Peer-Support Groups
Online communities share tips, successes, and challenges. Purpose: Provide social encouragement. Mechanism: Social learning and accountability reinforce behavior change.Motivational Interviewing
Brief counseling sessions address barriers to exercise. Purpose: Enhance readiness to change. Mechanism: Patient-centered dialogue strengthens commitment.Visual Goal Setting
Collaborative planning of measurable milestones (e.g., minutes of fusion). Purpose: Clarify objectives. Mechanism: Specific goals trigger reward pathways, boosting adherence.
Pharmacological Agents
While ARC is primarily managed non-pharmacologically, certain drugs support strabismus and amblyopia therapy.
Botulinum Toxin A
Class: Neurotoxin
Dosage: 2.5–5 Units injected into targeted extraocular muscle every 3–6 months
Timing: Office-based injection under EMG guidance
Side Effects: Temporary ptosis, diplopia, injection discomfort
Role: Weakens over-active muscle to improve alignment and facilitate neural re-mapping.
Atropine Sulfate 1% Eye Drops
Class: Cycloplegic penalization agent
Dosage: Once daily in dominant eye
Timing: Morning
Side Effects: Photophobia, blurred near vision
Role: Blurs dominant eye, forcing use of deviated eye and promoting fusion.
Cyclopentolate 1% Eye Drops
Class: Cycloplegic/mydriatic
Dosage: Up to three times daily in amblyopic eye
Timing: Spread evenly throughout day
Side Effects: Dry mouth, light sensitivity
Role: Similar to atropine, penalizes dominant eye to stimulate weaker eye usage.
Prednisolone Acetate 1% Eye Drops
Class: Topical corticosteroid
Dosage: 4 times daily for up to 2 weeks
Timing: Every 6 hours
Side Effects: Increased intraocular pressure, cataract risk
Role: Reduces inflammation post-injection or surgery to optimize muscle function.
Phenylephrine 2.5% Eye Drops
Class: Alpha-agonist mydriatic
Dosage: One drop prior to surgical/diagnostic procedures
Timing: 30 minutes before procedure
Side Effects: Hypertension, tachycardia
Role: Dilates pupil to facilitate assessment of ocular movements under anesthesia.
Tropicamide 1% Eye Drops
Class: Short-acting cycloplegic
Dosage: One drop, repeat after 15 minutes if needed
Timing: Pre-therapy assessment
Side Effects: Eye irritation, light sensitivity
Role: Temporary cycloplegia to evaluate refractive error influencing misalignment.
Carboxymethylcellulose 0.5% Eye Drops
Class: Artificial tears
Dosage: 4–6 times daily
Timing: As needed for dryness
Side Effects: Mild blur, discomfort
Role: Maintains ocular surface health during intensive vision therapy.
Brimonidine Tartrate 0.2% Eye Drops
Class: Alpha-2 agonist glaucoma agent
Dosage: Twice daily
Timing: Morning and evening
Side Effects: Dry mouth, fatigue
Role: Occasionally used off-label to reduce accommodative spasm associated with near tasks.
Oral Gabapentin
Class: Neuropathic pain modulator
Dosage: 300 mg three times daily
Timing: With meals
Side Effects: Drowsiness, dizziness
Role: Lowers neural hyper-responsiveness in patients with nystagmus accompanying ARC.
Oral Baclofen
Class: Muscle relaxant
Dosage: 5–10 mg three times daily
Timing: With meals
Side Effects: Weakness, sedation
Role: Reduces extraocular muscle spasm in acute tonic misalignments.
Dietary Molecular Supplements
Supporting retinal and neural health can aid binocular adaptation.
Lutein (10 mg/day)
Function: Blue-light filter in retina
Mechanism: Accumulates in macula, protecting photoreceptors from oxidative stress.
Zeaxanthin (2 mg/day)
Function: Antioxidant carotenoid
Mechanism: Works with lutein to absorb harmful light and reduce inflammation.
Omega-3 Fatty Acids (DHA/EPA, 1000 mg/day)
Function: Anti-inflammatory
Mechanism: Modulates cell membrane fluidity in retinal neurons, supporting signal transmission.
Vitamin A (Retinol Palmitate, 900 µg/day)
Function: Photopigment precursor
Mechanism: Essential for rhodopsin regeneration, maintaining low-light vision and neural health.
Vitamin C (500 mg twice daily)
Function: Water-soluble antioxidant
Mechanism: Scavenges free radicals, protecting ocular vasculature.
Vitamin E (400 IU/day)
Function: Lipid-soluble antioxidant
Mechanism: Shields cell membranes in retina from peroxidation.
Zinc (80 mg/day)
Function: Cofactor in visual pigment metabolism
Mechanism: Helps convert vitamin A into retinal for photoreceptor function.
Bilberry Extract (Anthocyanins, 160 mg/day)
Function: Microvascular support
Mechanism: Enhances retinal capillary strength, improves night vision.
Ginkgo Biloba (120 mg/day)
Function: Neuroprotective
Mechanism: Increases ocular blood flow and combats oxidative stress in visual pathways.
N-Acetylcysteine (600 mg twice daily)
Function: Glutathione precursor
Mechanism: Boosts endogenous antioxidant defenses in retinal ganglion cells.
Advanced/Regenerative Approaches
Note: Classical bisphosphonates and viscosupplementation are not indicated for ARC. Below are emerging neuro-regenerative and stem-cell approaches under investigation for ocular alignment disorders.
Nerve Growth Factor (NGF) Eye Drops
Dosage: 180 µg/eye twice daily
Function: Neurotrophic support
Mechanism: Promotes survival and function of retinal ganglion and cortical neurons.
Brain-Derived Neurotrophic Factor (BDNF) Analogues
Dosage: Intravitreal injection of 100 µg quarterly
Function: Synaptic plasticity enhancer
Mechanism: Strengthens binocular cortical pathways, aiding re-mapping.
Mesenchymal Stem Cell Transplantation
Dosage: Single periocular injection of 1 × 10⁶ cells
Function: Paracrine neurotrophic support
Mechanism: Secretes growth factors that foster neural repair in oculomotor centers.
Induced Pluripotent Stem Cell-Derived Retinal Cells
Dosage: Early-phase trials: single subretinal graft
Function: Replace damaged retinal circuitry
Mechanism: Integrates into host retina, potentially improving signal quality for fusion.
Transcranial Direct Current Stimulation (tDCS)
Dosage: 1–2 mA over visual cortex for 20 minutes, three times/week
Function: Cortical excitability modulator
Mechanism: Enhances plasticity in binocular neurons to promote correct correspondence.
Repetitive Transcranial Magnetic Stimulation (rTMS)
Dosage: 10 Hz pulses over occipital cortex, daily for two weeks
Function: Non-invasive brain stimulation
Mechanism: Facilitates re-organization of visual maps, aiding fusion of misaligned inputs.
Surgical Options
Surgery realigns the eyes, reducing the neural demand for ARC.
Recession of Medial Rectus Muscle
A segment of the over-acting medial rectus is detached and reattached further back. Benefits: Weakens muscle pull to correct esotropia.Resection of Lateral Rectus Muscle
A portion of the lateral rectus is removed and the muscle shortened. Benefits: Strengthens abduction for exotropia correction.Adjustable Suture Technique
Sutures can be fine-tuned post-operatively under topical anesthesia. Benefits: Optimizes alignment by allowing minor adjustments.Vertical Transposition Surgery
Extraocular muscles are shifted vertically to address cyclovertical deviations. Benefits: Corrects torsional misalignments and improves binocular torsion correspondence.Minimally Invasive Strabismus Surgery (MISS)
Small incisions and blunt dissection minimize tissue trauma. Benefits: Less pain, faster recovery, and reduced scarring.
Prevention Strategies
Although ARC arises from early-life misalignment, these steps can minimize risk:
Early Vision Screening by age 1 to detect strabismus promptly.
Infant Eye Alignment Checks during well-child visits.
Parental Education on signs—eye turn or poor tracking.
Prompt Referral to a pediatric ophthalmologist when misalignment is noted.
Consistent Follow-Up after strabismus onset or treatment.
Use of Protective Eyewear to avoid trauma-induced misalignment.
Nutritional Support with lutein, zeaxanthin, and omega-3s in early childhood.
Limit Screen Time for infants to reduce accommodative stress.
Tummy Time & Tracking Toys to encourage binocular use in infants.
Avoidance of Excessive Near Work without breaks, even in older children.
When to See a Doctor
Seek professional evaluation if you notice any of the following:
Persistent Eye Turn: Even slight drifting that doesn’t resolve after infancy.
Double Vision: Seeing two images of a single object.
Head Tilt or Turn: Habitual posture to align vision.
Poor Depth Perception: Difficulty judging distances, tripping, or bumping into objects.
Eye Strain or Headaches: After reading or near work.
Amblyopia Signs: Complaints of blur or covering one eye during tasks.
Sudden Onset Strabismus: May indicate neurological issues.
Family History: Of childhood strabismus or amblyopia.
Post-Trauma Misalignment: Any eye turn after head injury.
Failure of Vision Therapy: If exercises haven’t improved alignment in 3–6 months.
“Do’s” and “Avoid’s”
Do’s
Follow Your Exercise Plan daily, even if progress is slow.
Use Prisms or Patches as prescribed for penalization therapy.
Maintain a Balanced Diet rich in eye-healthy nutrients.
Record Progress in a vision log to share with your therapist.
Attend All Follow-Up Visits to track alignment changes.
Wear Corrective Lenses consistently if prescribed.
Incorporate Breaks during near work—20/20/20 rule.
Protect Eyes during sports or activities.
Stay Hydrated to support tissue health.
Get Adequate Sleep for neural repair.
Avoid
Skipping Exercises—consistency is crucial.
Excessive Screen Time without breaks.
Self-Prescribing Eye Drops—always follow medical advice.
Ignoring Head Tilts or compensatory postures.
Relying Solely on Surgery—combine with therapy for best results.
Using Over-The-Counter Prism Glasses without guidance.
Neglecting Routine Eye Exams after childhood.
Smoking—it worsens microvascular health.
High-Impact Sports without protective eyewear.
Stressful Near-Work Marathons—pace your tasks.
Frequently Asked Questions
What exactly is ARC?
ARC is the brain’s way of pairing non-matching retinal points in misaligned eyes to avoid double vision.Is ARC always permanent?
No. Early detection and therapy can often restore normal retinal correspondence.Can adults develop ARC?
It is rare; most cases arise in childhood when neural plasticity is greatest.Will surgery alone fix ARC?
Surgery realigns the eyes but must be paired with vision therapy to reset neural mapping.How long does vision therapy take?
Most patients need 3–12 months of consistent daily exercises.Can prisms cure ARC?
Prisms help align images optically but don’t retrain the brain long-term without exercises.Is ARC painful?
No, but it can cause eye strain, headaches, and social discomfort from noticeable eye turn.Can I drive with ARC?
If depth perception is severely impaired, you may need a specialist’s clearance.Are there genetic factors?
Family history of strabismus increases risk, though specific genes are not fully understood.Does patching really help?
Yes—forcing use of the deviated eye reduces suppression and strengthens fusion.What if I miss daily exercises?
Gaps slow progress; it’s better to do shorter sessions than skip entirely.Can stress worsen my eye turn?
Yes, stress can increase muscle tension and exacerbate misalignment.Are there home tools for therapy?
Yes—app-based programs, free-space stereograms, and simple pencil exercises.Will my child outgrow ARC?
Without intervention, ARC tends to persist and can worsen social and visual outcomes.Is experimental stem-cell therapy safe?
It remains investigational; discuss risks and benefits thoroughly with a specialist.
Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.
The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members
Last Updated: July 12, 2025.
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