Vision Therapy for Adults: Neuroplasticity Unilateral Small Angle Esotropia
The ability to use both eyes together (binocularity) is deficient in adults with Small Angle Esotropia. This is due to the brain turning an eye to prevent double vision. While this makes it easier to “suppress” or ignore information coming from that eye, it also typically leads to amblyopia (reduced vision in one eye) and other vision problems such as lack of depth perception.
Esotropia is a term used to describe an eye that turns inward toward the nose while the other looks straight ahead. Many may know esotropia as “cross-eyed”. An eye turn can develop very early in life or at any time after. Some eye turns are less obvious than others, and sometimes aren’t noticeable at all without examination by an eye doctor. This less obvious eye turn is known as Unilateral Small Angle Esotropia.
No matter the size of the angle, vision therapy can help treat any eye turn because of neuroplasticity present in the brain – even in adults!
Many people think that the brain can only change itself and adapt to new information and stimuli during the critical period for development of stereopsis (3D vision) from 3 mo to 3 years of age. This misconception of critical period success may deter professionals and individuals from pursuing care for adults. This is not fair and needs to be corrected! Neuroplasticity is the brain and nervous system’s ability to change itself. We were all born with a nervous system that is not only capable of change, it was designed to change, even as adults (though the process is different for adults). We can see proof of this in the progression of developing vision skills.
There is growing evidence that neuroplasticity is possible in adults past the critical period of visual development. This is evident by improved binocularity in adults with strabismus after surgery, improved amblyopic eye visual acuity in adults with patching and binocular therapy, and improved oculomotor skills in adults with vision therapy adult neuroplasticity.
The brain does not stop being plastic as we mature. As we develop and learn, our brain develops more intricate brain maps. Brain maps are different regions in the brain which have specific functions. Some brain map systems are not known to be plastic – these include digestion, breathing, and heart rate. That being said, the evidence above shows parts of the visual brain certainly can change! This is how adults with esotropia improve new ways of processing vision through creating new pathways from the brain to the eye. There is a common saying in neuroscience: Cells that fire together, wire together – and then opposite is also true – brain maps that aren’t used are trimmed away. The strategy in vision therapy is to achieve binocular vision pathways firing at the same time as support systems – like visual motor pathways. This creates new alternatives for the brain to use, “firing” binocular brain maps by default by integrating existing sensory-motor pathways, and discouraging the use of existing maps that prevent binocular vision. Research shows that disruption of visual input can affect the development of binocularity, specifically stereopsis, in individuals with strabismus. A recently published article provides several cases of adults improving with treatment.
Strabismus is often untreated in adults due to the lack of understanding about the availability and success of available treatments like office-based optometric vision therapy. The goal of vision therapy is to eliminate sensory anomalies and improve sensory and motor fusion to improve binocularity and gain depth perception. At Brighter Outlook Vision, Dr. Jesse designs patients’ individualized treatment plans based on the emerging science of neuroplasticity and the proven methods of optometric vision therapy to help create new possibilities for all patients.
There have been several case studies beyond the article referenced here that show the real world benefits of office-based optometric vision therapy. During a typical vision therapy session at our office, our vision therapists will go through different activities planned alongside Dr. Jesse that provide the patient with new experiences to increase the function and ability of the nervous system and brain to adapt and change in response to the new visual stimuli. Research shows that the brain is still adaptable after the critical period in childhood. Adults still have processes in the brain that can allow for new pathways for visual information.
