Factors in Learning And Plasticity: Macular Degeneration

Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-89
SponsorUniversity of Alabama at Birmingham

About this trial

A greater understanding of plasticity after central vision loss can inform new therapies for treating low vision and has the potential to benefit millions of individuals suffering from low vision. The treatment of low vision is particularly relevant to the mission of the NEI to support research on visual disorders, mechanisms of visual function, and preservation of sight. The comparison of different training and outcome factors is in line with the NIMH RDOC framework and studies in an aging population are consistent with the mission of the NIA.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Aged 18-89

Severely impaired vision in both eyes (20/100 or worse)

diagnosis of Macular Degeneration by an Ophthalmologist

Light sensitivity in the macular retina that is at least 10 dB units worse than in peripheral regions, as demonstrated by a scanning laser ophthalmoscope (MAIA)

Disqualifiers

Pacemaker or any ferromagnetic metal implanted in their body

Metal of any type implanted in their head (limited dental work is acceptable)

Claustrophobia

Being hearing-impaired

Trial design

Design model

Parallel

Treatments tested in this trial

  • Training visual sensitivity

    Behavioral

    Investigators adopt a standard PL approach to train early visual processes of discriminating the orientation of Gabor patches presented at threshold contrast. Across training blocks, Gabors will range in spatial frequency, where contrast is adapted with a 3/1 staircase. Whenever a specific contrast threshold is reached, spatial frequency will increase by 2 cycles per degree and contrast will be reset. Preliminary data from this method in normally seeing and MD participants show both feasibility and tentative evidence that this training gives rise to improvements in acuity.

  • Combination training

    Behavioral

    Daily tasks involve a combination of being sensitive to basic visual features, being able to integrate these features, and directing attention and eye movements to better evaluate the information of potential interest. To address this integrative nature of real-world vision, this condition combines elements of training visual sensitivity, spatial integration, and spatial attention.

Treatment groups

60 Participants
are divided into 2 treatment groups
Group A: Training visual sensitivityExperimental treatment 1 intervention
Group B: Combination trainingExperimental treatment 1 intervention

Trial outcomes

Primary outcomes

1

Change from Baseline Radial Bias from the Crowding Task after completion of Training at approximately 7 weeks

The ratio of the crowding threshold along the axis connected to the fovea vs. along the orthogonal axis.

Time frame
Baseline and Within 3 weeks of training completion, training is complete 7 weeks from baseline on average
2

Change from Baseline Saccadic Precision after Completion of Training at approximately 7 weeks

Consistency across trials in placement of the first saccade calculated by the distribution across trials (bivariate contour ellipse area) of the landing point of the first fixation of each trial.

Time frame
Baseline and Within 3 weeks of training completion, training is complete 7 weeks from baseline on average
3

Change from Baseline Fixation Stability after Completion of Training at approximately 7 weeks

Normalizing fixations in the PRL to the first fixation to that region and calculating the distribution of all fixation locations in this normalized space (measured as a bivariate contour ellipse area).

Time frame
Baseline and Within 3 weeks of training completion, training is complete 7 weeks from baseline on average

Secondary outcomes

Other outcomes

1

Change from Baseline Acuity after Completion of Training at approximately 7 weeks

Acuity threshold from the Landolt C task.

Time frame
Baseline and Within 3 weeks of training completion, training is complete 7 weeks from baseline on average
2

Change from Baseline Contrast Sensitivity after Completion of Training at approximately 7 weeks

Threshold value from contrast sensitivity task.

Time frame
Baseline and Within 3 weeks of training completion, training is complete 7 weeks from baseline on average
3

Change from Baseline Minimal print size from the MNREAD task after Completion of Training at approximately 7 weeks

Minimal print size from the MNREAD task

Time frame
Baseline and Within 3 weeks of training completion, training is complete 7 weeks from baseline on average
4

Change from Baseline Precision of Reconstructed Representation of Stimulus Orientation after Completion of Training at approximately 7 weeks

Precision of reconstructed representation of stimulus orientation (quantified with FWHM)

Time frame
Baseline and Within 3 weeks of training completion, training is complete 7 weeks from baseline on average

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

University of Alabama at Birmingham

Lead sponsor

University of California, Riverside

Collaborator