Project Details
Description
ABSTRACT
Strabismus is a common eye alignment disorder found in 3-5% of children and 3-4% of adults. If left untreated
in children, strabismus can lead to loss of stereopsis and amblyopia; the brain silences connections from the
misaligned eye, resulting in poor visual acuity. In strabismus, the ocular motor control of eye alignment is
unbalanced. One potential cause for this imbalance is disruption of the normal two-way neurotrophic factor
communication between the ocular motor system and the extraocular muscles (EOM). Our preliminary and
published data show that we can produce strabismus in infant monkeys or improve eye alignment in adult
strabismic monkeys. With those neurotrophic factors that were effective, the eye alignment was altered by 8 to
14o. We believe improved treatment efficacy for strabismus will require larger angles of correction to eye
misalignment. Gene array and our own data suggest that deficits in neurotrophic factor communication
associated with strabismus may involve multiple neurotrophic factors. Thus, to increase efficacy we predict that
we need to use a combination of neurotrophic factors. We will test two approaches. First, we predict that
combinations of neurotrophic factors that used singly on EOM had a demonstrated ability to alter eye
alignment in non-human primates. We will test efficacy of neurotrophic factor “cocktails” in adult rabbits, and
the most efficacious will be tested for the ability to produce a significant eye misalignment in infant monkeys.
Second, we predict that blocking retrograde signaling of neurotrophic factors will produce a significant eye
misalignment. We will examine efficacy of mixtures of neutralizing antibodies or inhibitory binding peptides to
block binding of endogenously produced neurotrophic factors to their receptors. This will prevent retrograde
signaling by these factors, which we predict are critical for normal eye alignment. The key for success of these
experiments is the use of a sustained delivery approach. One issue that we believe precipitates surgical failure
rates is that the change in eye alignment is larger than the ability of the ocular motor system to adapt. There is
substantial evidence that there is a significant amount of inherent plasticity possible when slow adaptation
strategies are used. Our approach uses a sustained delivery method that releases low doses of neurotrophic
factors for 3 months. Our data show that unilateral treatment is sufficient to produce altered eye alignment . In
addition, the largest change in eye alignment occurs during the final month of treatment, suggesting that ocular
motor system plasticity between brainstem nuclei requires 3 months. This timing agrees with literature showing
that visual deprivation period in infant monkeys needs to approach 3 months to produce a strabismus. We will
test our most efficacious approach for its ability to correct the eye alignment in adult strabismic monkeys. Our
long term goal is to develop effective strategies for modulating neurotrophic factor signaling, whether neuron-
or muscle-derived, based on a combination treatment strategy. This will inform future choices for moving this
strabismus treatment into human patients, with the ultimate goal of preventing loss of visual acuity.
Status | Finished |
---|---|
Effective start/end date | 1/1/04 → 4/30/23 |
Funding
- National Eye Institute: $392,506.00
- National Eye Institute: $376,331.00
- National Eye Institute: $380,131.00
- National Eye Institute: $530,421.00
- National Eye Institute: $372,528.00
- National Eye Institute: $501,845.00
- National Eye Institute: $479,907.00
- National Eye Institute: $501,847.00
- National Eye Institute: $536,729.00
- National Eye Institute: $494,752.00
- National Eye Institute: $479,909.00
- National Eye Institute: $34,385.00
- National Eye Institute: $361,277.00
- National Eye Institute: $357,331.00
- National Eye Institute: $165,482.00
- National Eye Institute: $297,000.00
- National Eye Institute: $494,752.00
- National Eye Institute: $290,021.00
- National Eye Institute: $551,588.00
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