Document text
Principal Investigator: JONATHAN C HORTON
Organization: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
Fiscal Year: 2024
Award: $209,893
Funding agency: National Eye Institute
Project Summary
Approximately 2% of children in the United States have strabismus, a condition in which the eyes are not
aligned properly. As a consequence, stereovision may be lost and the deviated eye is at risk for reduced vision
from amblyopia. There are many other potential consequences, including reduced eye-hand coordination,
diminished quality of life, employment discrimination, social prejudice, and psychological distress. The goal of
this project is to investigate the most common form of strabismus, intermittent exotropia. A translational
approach is used that combines a prospective, longitudinal observational study of patients with intermittent
exotropia to define its natural history and clinical features along with analysis of data from a parallel set of
laboratory studies in nonhuman primates. Aim 1 will focus on the problem of defining the severity of intermittent
exotropia. Patients wear tracking glasses that record the fixation point of each eye within the visual scene while
they go about their normal daily activities. This technology makes it possible to measure the “occurrence rate”
of exotropia – defined as the percentage of time that an ocular deviation is present. This data will enable eye
doctors to identify which patients have a stable versus a progressive form of intermittent exotropia. The latter
group may need surgery to re-align their eyes, but there is currently no consensus regarding the criteria for
recommending surgery, in part because it has not previously been possible to quantify the occurrence rate. The
project will also stratify patients into the 3 recognized subtypes of intermittent exotropia (basic, convergence
insufficiency, divergence excess) to probe the relationship between fusion loss and vergence demand. Insights
from that correlation could also influence surgical planning. Successful introduction of ambulatory eye tracking
into pediatric eye care would thus have a major impact on the management of intermittent exotropia. Aim 2 will
explore the contingent of retinal ganglion cells that projects to the superior colliculus, a brainstem center
controlling eye movements. Experiments have been performed in monkeys, injecting a retrograde tracer into
the superior colliculus to label these cells. A different retrograde tracer has been injected in the lateral geniculate
nucleus in the same monkeys. The data from these animals will be analyzed to determine the percentage of
ganglion cells which is double-labeled, signifying that the cells send a branching axon to both targets.
Terms: <0-11 years old><Active Follow-up><Adeno-Associated Viruses><Administrative Supplement><Affect><Amblyopia><Ambulatory Monitoring><American><Anterior Quadrigeminal Body><Axon><Brain Stem><Brainstem><Caring><Cell Body><Cells><Child><Child Youth><Childhood><Children (0-21)><Clinical><Cognitive Discrimination><Consensus><Convergence Insufficiency><Data><Data Analyses><Data Analysis><Dependoparvovirus><Dependovirus><Diminished Vision><Diplopia><Discrimination><Divergent Strabismus><Double Vision><Drugs><Employment><Esthesia><Exodeviation><Exotropia><Eye><Eye Movements><Eyeball><Fixation><Genes><Glass><Goals><Injections><Knock-out><Knockout><Knowledge><Label><Laboratory Study><Lateral Geniculate Body><Lentiviral Vector><Lentivirus Vector><Longitudinal observation study><Longitudinal, observational study><Low Vision><Macaca><Macaque><Measurement><Measures><Medication><Mesencephalon><Mid-brain><Midbrain><Midbrain structure><Monitor><Monkeys><Natural History><Operative Procedures><Operative Surgical Procedures><Optic Tectum><Outpatient Monitoring><Partial Sight><Patients><Periodicals><Pharmaceutical Preparations><Phorias><Position><Positioning Attribute><Prejudice><Primary visual cortex><Primates><Primates Mammals><Prognosis><Property><Publishing><QOL><Quality of life><R-Series Research Projects><R01 Mechanism><R01 Program><Recommendation><Reduced Vision><Research><Research Grants><Research Project Grants><Research Projects><Retina><Retinal Ganglion Cells><Risk><Saccades><Saccadic Eye Movements><Saccadic Pursuit><Scotoma><Sensation><Severities><Sight><Squint><Strabismus><Striate Cortex><Striate area><Subnormal Vision><Superior Colliculus><Surgical><Surgical Interventions><Surgical Procedure><System><Technology><Tetracyclines><Time><Toxin><Tracer><United States><Update><Vision><Visual><Visual Field Disorder><Visual Fields><Visual field scotoma><Visual impairment><active followup><adeno associated virus group><animal data><area striata><awake><data interpretation><drug/agent><experiment><experimental research><experimental study><experiments><eye field><eye hand coordination><eye tracking><eye/hand coordination><follow up><follow-up><followed up><followup><gangliocyte><ganglion cell><hand and eye coordination><hand/eye coordination><insight><instrument><kids><lateral geniculate><lateral geniculate nucleus><light weight><lightweight><monocular><neural><neural mechanism><neuromechanism><non-human primate><nonhuman primate><observational cohort study><patient stratification><pediatric><periodic><periodical><prevent><preventing><prospective><psychological distress><receptive field><response><retinal ganglion><retino-tectal><retinotectal><retrograde transport><sample fixation><social><stratified patient><superior colliculus Corpora quadrigemina><surgery><tentoxilysin><tetanospasmin><tetanus neurotoxin><translation strategy><translational approach><translational strategy><vision impairment><visual field defect><visual function><visual tectum><visual tracking><visually impaired><wearable><wearable device><wearable electronics><wearable system><wearable technology><wearable tool><wearables><youngster>