Clinical Trial on Blindness, Visual Impairment - Clinical Trials Registry

Study Overview

Status

Enrolling by invitation

Conditions

Detailed Description

BLINDREAM is an observational neuropsychology study purely for scientific purposes, with no diagnostic or therapeutic aims. This study aims to assess the impact of blindness on sleep and dream processes and their relationship with perceptual and spatial memory performance, examining the connection with clinical, psychological/behavioral indices, neurobiological characteristics, and electrophysiological measures. Specifically, the study seeks to test the following hypotheses:

Circadian Rhythm Desynchronization: To determine if visual deprivation leads to circadian rhythm desynchronization in both congenitally blind individuals and those with late-onset blindness after many years of visual deprivation. Specifically, whether greater circadian desynchronization is associated with poorer performance in perceptual and spatial memory tasks in blind subjects.
Sleep Structure: To investigate if circadian desynchronization affects sleep structure in blind individuals and if it is the sole factor influencing sleep structure. We hypothesize that even blind subjects with a normally modulated circadian rhythm due to the light-dark cycle show significant differences from sighted controls, particularly in terms of sleep microstructure (figures) and macrostructure (stages) involved in sensorimotor processing and spatial information consolidation.
Dream Recall and Spatial Abilities: To examine if there is a significant difference in dream recall frequency and specific spatial tasks between the two groups. Specifically, whether a higher presence of visual content in dreams predicts better spatial skills, and whether increased eye movement in dreams correlates with better spatial abilities in blind subjects.

These findings will enable initial assessments that may lead to the development of new tools and rehabilitation protocols for blind individuals.

The study will be conducted in three experimental phases over a total of one week per participant:

Phase 1: Sleep and Dream Assessment: This includes two measures-1A. Questionnaires and 1B. Polysomnography.
Phase 2: Circadian Assessment: This includes three measures-2A. Actigraphy (worn for one week), 2B. Salivary melatonin analysis, and 2C. Dream diary.
Phase 3: Neuropsychological Assessment: This involves evaluating several conditions with two specific configurations-3A. Assessment of spatial perceptual functions and 3B. Assessment of spatial memory.

Each phase involves different sessions: the circadian assessment requires wearing an actigraphic bracelet for a week, during which salivary melatonin will also be measured; the sleep and dream assessment involves wearing a home polysomnograph for one night and completing a verbal dream diary for one week; and the neuropsychological assessment will be conducted in a single session lasting between approximately 30 minutes and 2 hours.

The study will include adult individuals both with and without visual impairments. The visual impairment may be congenital or acquired later in life. Control group participants will be selected to match the experimental group (those with visual impairments) in terms of age and gender. Due to the proof-of-concept nature of the study and the lack of prior estimates of effect sizes, power calculations are not currently possible. The sample size is therefore based on a provisional and conservative estimate of recruitment capacity, informed by previous literature. However, efforts will be made to conduct interim analyses to estimate effect sizes based on the primary outcome and adjust assumptions accordingly. The study currently aims to recruit 20 blind participants and 20 healthy controls.

Therefore, the preliminary data will utilize the Power Analysis method to calculate the minimum sample size required to achieve a correct effect size for a given dimension. The data will be analyzed using both parametric and non-parametric tests, and differences between groups will be assessed with t-tests, ANOVA, TANCOVA, and linear mixed models where appropriate. An appropriate post-hoc test will be conducted if significance is found. The significance level will be considered at p<0.05. Where necessary, parametric techniques will be replaced by non-parametric equivalents. The standard software used will include: Matlab, R, Origin, Statistica, and SPSS, recognized in the research field. For the analysis of electroencephalographic data, EEGlab and/or Fieldtrip toolboxes will be utilized.

Study Type

Observational

Enrollment (Estimated)

40

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Italy
- - Genova, Italy, 16132
    - U.O. Clinica Neurologica Ambul. disturbi del sonno ed epilessia; IRCCS Ospedale Policlinico San Martino

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Adult
Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

The study will include adult individuals both with and without visual impairments. The visual impairment may be congenital or acquired later in life. Control group participants will be selected to match the experimental group (those with visual impairments) in terms of age and gender. Due to the proof-of-concept nature of the study and the lack of prior estimates of effect sizes, power calculations are not currently possible. The sample size is therefore based on a provisional and conservative estimate of recruitment capacity, informed by previous literature. However, efforts will be made to conduct interim analyses to estimate effect sizes based on the primary outcome and adjust assumptions accordingly. The study currently aims to recruit 20 blind participants and 20 healthy controls.

Description

Inclusion Criteria:

Signature of the informed consent;
The participating subjects may have typical or atypical development (i.e., group with visual disability). In the case of visual impairment, the disability should be congenital (from birth) or late onset. Furthermore, the following requirements must be met: subjects with visual disabilities must be classified according to current diagnostic rules, with visual problems present from birth or occurring later, with residual vision lower than 1.3 LogMAR;
Age range required is ≥ 18 years old and ≤ 85 years old;
Any Gender;
Any ethnicity, as long as a good knowledge of the Italian language.

Exclusion Criteria:

Participant with a disability/condition/comorbidity that prevents participation and/or does not guarantee the safety of the patient during the execution of the tests and/or does not guarantee the quality/reliability of the data:
- Tactile and/or acoustic hypersensitivity (specifically, the tolerance of the equipment will be assessed);
- Deafness;
- Taking drugs and neuroactive substances and having taken them in the last six months;
- Comorbidity with another clinically significant and uncontrolled pathology;
- Being affected, to the best of their knowledge, by pathologies of the central nervous system, and having suffered from epileptic episodes, even minor ones, and convulsive crises in general;
- Being affected, to the best of their knowledge, by cardio-respiratory pathologies that can influence the macro and microstructure of sleep.
Lack of signature of consent or incomplete consent to acknowledge the incompatibilities for participation in the study;
To the best of their knowledge, IQ values lower than the threshold limit of normality according to one of the recognized international scales.
Pregnant women

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Blind and severely visually impaired (BSI) This group is composed of adults participants (ages of ≥ 18 and ≤ 85 years) with an impairment of the peripheral visual system (i.e., involving pre-chiasmatic structures, such as the retina and optic nerve). The visual deficit can be congenital (from birth) or have a late onset. Participants with visual impairment, classified according to the current diagnostic criteria, must have residual vision lower than 1.0 LogMAR. Participant of any gender and ethnicity are considered, provided they have a good knowledge of the Italian language.
Control Control group is composed of adult participants (without visual deficits) age and gender matched with the BSI group.

Group / Cohort

Blind and severely visually impaired (BSI)

This group is composed of adults participants (ages of ≥ 18 and ≤ 85 years) with an impairment of the peripheral visual system (i.e., involving pre-chiasmatic structures, such as the retina and optic nerve). The visual deficit can be congenital (from birth) or have a late onset. Participants with visual impairment, classified according to the current diagnostic criteria, must have residual vision lower than 1.0 LogMAR. Participant of any gender and ethnicity are considered, provided they have a good knowledge of the Italian language.

Control

Control group is composed of adult participants (without visual deficits) age and gender matched with the BSI group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sleep macrostructure Time Frame: Through study completion, an average of 18 months	Percentage of sleep stages and spectrogram	Through study completion, an average of 18 months
Sleep microstructure Time Frame: Through study completion, an average of 18 months	Analysis of sleep spindles	Through study completion, an average of 18 months
Sleep microstructure Time Frame: Through study completion, an average of 18 months	Analysis of slow waves	Through study completion, an average of 18 months
Sleep quality - PSQI Time Frame: Through study completion, an average of 12 months	Pittsburgh Sleep Quality Index. The seven component scores are then summed to yield a global PSQI score, which has a range of 0-21; higher scores indicate worse sleep quality.	Through study completion, an average of 12 months
Sleep Quality - questionnaire to predict N24HSWD Time Frame: Through study completion, an average of 12 months	Pre-Screening questionnaire to predict Non-24-hours sleep-wake disorders. The questionnaire assesses sleep-wake patterns, focusing on irregularities such as difficulty maintaining a regular sleep schedule and daytime dysfunction. It includes a set of eight key questions. The scoring system can yield final values greater than or less than zero: Values greater than zero suggest that the patient should be evaluated for N24HSWD. Values less than zero indicate the need for assessment for other sleep disorders. This tool serves as an initial filter, guiding whether further diagnostic measures, like actigraphy or melatonin rhythm analysis, are necessary	Through study completion, an average of 12 months
Sleep quality - MEQ Time Frame: Through study completion, an average of 12 months	Morningness -Eveningness Questionnaire. It is a Self-reported assessment of morningness and eveningness preferences with a 19 multiple choice items (4-5 point numerical scale). The sum gives a score ranging from 16 to 86; scores of 41 and below indicate "evening types", scores of 59 and above indicate "morning types", scores between 42-58 indicate "intermediate types".	Through study completion, an average of 12 months
Circadian shift Time Frame: Through study completion, an average of 18 months	Melatonin sample ELISA protocol	Through study completion, an average of 18 months
Circadian shift Time Frame: Through study completion, an average of 18 months	Actigraphy measures	Through study completion, an average of 18 months
Spatial perception ability Time Frame: Through study completion, an average of 12 months	Spatial and temporal bisection	Through study completion, an average of 12 months
Spatial memory ability Time Frame: Through study completion, an average of 12 months	Audiocorsi	Through study completion, an average of 12 months
Dream content evaluation - DRFS Time Frame: Through study completion, an average of 12 months	The Dream Recall Frequency Scale (DRFS) is a useful tool for assessing how often individuals remember their dreams. This scale can help distinguish between high dreamers (those who frequently recall dreams) and low dreamers (those who rarely remember dreams). The scale typically ranges from 0 to 5, where a higher value indicates more frequent recall of dreams.	Through study completion, an average of 12 months
Dream content evaluation - VDAS Time Frame: Through study completion, an average of 12 months	The Van Dream Anxiety Scale (VDAS) is a tool used to assess the severity of nightmares and dream anxiety. The VDAS consists of a set of items that measure the frequency, intensity, and emotional impact of nightmares, as well as their interference with daily functioning. The scale typically provides a range of scores from 0 to 68, where. Higher scores indicate greater severity of nightmares and dream-related anxiety.	Through study completion, an average of 12 months
Dream content evaluation Time Frame: Through study completion, an average of 18 months	Dream Diary	Through study completion, an average of 18 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Istituto Italiano di Tecnologia

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 4, 2024

Primary Completion (Estimated)

October 4, 2025

Study Completion (Estimated)

October 4, 2025

Study Registration Dates

First Submitted

August 31, 2024

First Submitted That Met QC Criteria

October 7, 2024

First Posted (Actual)

October 8, 2024

Study Record Updates

Last Update Posted (Actual)