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NCT Number: NCT07830745

Effects of Optokinetic Stimulation Without a Reading Task in Patients With Hemianopic Alexia

The goal of this clinical trial is to investigate whether optokinetic stimulation delivered without a reading task can improve reading performance in adults with post-stroke hemianopic alexia. The main question it aims to answer is: does optokinetic stimulation without a reading task improve reading speed more than optokinetic stimulation with a reading task? Optokinetic stimlation with a reading task is considered the standard rehabilitation. These two conditions will be administered according to a randomized crossover design to determine wether the presence or absence of a reading task influences reading outcomes.

Participants will

* receive 4 weeks of optokinetic stimulation without a reading task and 4 weeks of optokinétic stimulation with a reading task, with the order of these two interventions determined by randomization, * undergo assesments of reading performance, oculomotor behavior, visual field and rehabilitation tolerability before and after each intervention period, * undergo a follow-up assesment 1 month after completion of the interventions.

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Key information

Conditions

Hemianopia Homonymous Blindness Brain Diseases Cardiovascular Diseases Central Nervous System Diseases Cerebrovascular Disorders Eye Diseases Hemianopsia Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms Stroke Vascular Diseases Vision Disorders

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Clinique Les Trois Soleils

Boissise-le-Roi, Île-de-France Region, 77310, France

Location contact

Catherine Maulny

CONTACT

[email protected]

+33164718000

Christophe Duret

PRINCIPAL_INVESTIGATOR

About this study

Stroke can cause a visual field defect known as homonymous hemianopia (HH). When this visual field loss involves the macula, the central area of vision, it may result in reading difficulties known as hemianopic alexia (HA).

The literature reports improved reading performance in these patients after repeated induction of horizontal optokinetic nystagmus (i.e., an oculomotor reflex consisting of horizontal saccades). To induce this nystagmus, previous studies have used a reading task involving text scrolling from right to left.

However, this type of exercise, which relies on reading, is cognitively demanding and may lead to frustration due to reading difficulties, fatigue, and reduced motivation and potentially the impact of rehabilitation. Therefore, the use of a non-reading task could help overcome these limitations.

The present study aims to compare the efficacy of optokinetic stimulation with reading to optokinetic stimulation without reading in patients with HA.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Time since lesion > 1 month
  • Diagnosis of homonymous hemianopia post-stroke without macular sparing
  • Reading complaint and/or reading impairment
  • Proficiency in reading French
  • Agreed to give informed consent
  • Afiliated with national health insurance

Exclusion criteria

  • History of neurological or psychiatric disorders
  • Visual impairment of peripheral origin (i.e., related to damage to the structures of the eye or the optic nerve)
  • Uncorrected visual acuity deficit
  • Reading disorder prior to the stroke (dyslexia)
  • Instability of reading impairment
  • Instability of homonymous hemianopia
  • Major cognitive that would limit the ability of the patient to participate in the study (unilateral spatial neglect, simultanagnosia, comprehension disorder, oral expression disorder)

Treatment and study plan

Optokinetic stimulation without reading task

Other

Participants are exposed to a horizontally moving optokinetic visual stimulus on a computer screen for 40 minutes per session. The task consists of viewing random sequences of letters scrolling from right to left. The sessions are spread out over 4 weeks, with 3 or 4 sessions per week, to achieve 10 hours (15 sessions) of optokinetic rehabilitation.

Optokinetic stimulation with reading task

Other

Participants are exposed to a horizontally moving optokinetic visual stimulus on a computer screen for 40 minutes per session. The task consists of reading aloud sentences scrolling from right to left. The sessions are spread out over 4 weeks, with 3 or 4 sessions per week, to achieve 10 hours (15 sessions) of optokinetic rehabilitation. The scrolling speed ranges from 85 to 275 words per minute, depending on the participant's reading accuracy.

Primary outcomes

  1. Change in reading speed on paper

    Time frame: Baseline and end of each 4-week rehabilitation period: Week 0, Week 4, and Week 8

    Change in the number of correctly read words per minute, assessed using the International Reading Speed Texts (IReST). For each participant, the change in reading speed will be calculated separately for the optokinetic rehabilitation condition with a reading task and for the optokinetic rehabilitation condition without a reading task. The within-participant changes obtained after each 4-week period will be pooled across the two randomized sequences and compared between conditions. A higher reading speed indicates better reading performance.

Secondary outcomes

  1. Change in reading accuracy on paper

    Time frame: Baseline and end of each 4-week rehabilitation period: Week 0, Week 4, and Week 8

    Change in the number and type of errors (paralexias, omissions) assessed using the International Reading Speed Texts (IReST).

  2. Change in reading speed on screen

    Time frame: Baseline and end of each 4-week rehabilitation period: Week 0, Week 4, and Week 8

    Change in the number of correctly read words per minute, assessed using a screen-based reading task

  3. Change in reading accuracy on screen

    Time frame: Baseline and end of each 4-week rehabilitation period: Week 0, Week 4, and Week 8

    Change in the number and type of errors (paralexias, omissions), assessed during a screen-based reading task

  4. Change in subjective reading abilities

    Time frame: Baseline and end of each 4-week rehabilitation period: Week 0, Week 4, and Week 8

    Change in the score on the Hemianopia Reading Questionnaire (HRQ)

  5. Change in ocular fixations during reading

    Time frame: Baseline and end of each 4-week rehabilitation period: Week 0, Week 4, and Week 8

    Change in the number of fixations and in the mean fixation duration (in ms) during the screen-based reading task, assessed with an eyetracker

  6. Change in ocular saccades during reading

    Time frame: Baseline and end of each 4-week rehabilitation period: Week 0, Week 4, and Week 8

    Change in the number and in the mean amplitude of saccades (in degrees) during the screen-based reading task, assessed with an eyetracker

  7. Change in optokinetic nystagmus

    Time frame: Baseline and at the end of both rehabilitation: Week 0 and Week 8

    Change of saccade amplitude and frequency during optokinetic stimulation

  8. Change in visual detection during standard perimetry

    Time frame: Baseline and end of each 4-week rehabilitation period: Week 0, Week 4, and Week 8

    Change in visual sensitivity (in dB) at each tested visual field location on automated static perimetry (Humphrey or Octopus)

  9. Change in visual detection during screen-based perimetry

    Time frame: Baseline and end of each 4-week rehabilitation period: Week 0, Week 4, and Week 8

    Change in number of correctly detected targets and mean reaction time (in ms) at each tested visual field location on screen-based perimetry

  10. Tolerability of rehabilitation

    Time frame: Before and after each rehabilitation session

    Score of fatigue, stress, and mood induced by the treatment, self-assessed using a numbered visual analogue scale

  11. Motivation for rehabilitation

    Time frame: End of each 4-week rehabilitation period: Week 4 and Week 8

    Score obtained on the Situational Motivation Scale

Study contacts

Contact information is provided by the study sponsor or research team.

Anne-Gaëlle Grosmaire

CONTACT

[email protected]

+33164715200

Clotilde Guillerot

CONTACT

[email protected]

Sponsors and collaborators

Lead sponsor

Clinique Les Trois Soleils

Other

Collaborators

  • Laboratoire Mémoire Cerveau et Cognition, Boulogne-Billancourt, France

Registry information

Acronym: OPTO

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Sep 21, 2026
Registry last updated
Sep 21, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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