Clinical practice is endlessly fascinating. This patient came to us last week via her own research on the Internet. She related having undergone vision therapy as a child through a practice in New York, but was sketch on the details and records were no longer available from over 40 years ago. All she knew was that her baby photos showed her right eye to drift outward, but her high school yearbook and wedding photos showed her eyes appearing aligned. 16 years ago, married but without children, she was diagnosed as having multiple sclerosis. Her neurologist advised her that if she was contemplating having a child, there was some risk involved, but going through childbirth when MS is in its early stages was less risky than when MS has advanced. Conceive she did, and after giving birth to her now 15 year-old son she lost control of her right eye.
In primary gaze our patient had a constant right exotropia at distance and near that measured 60 prism diopters and was comitant. She had developed a right medial rectus palsy which prevented her from adducting the eye inward beyond the midline. This is our patent attempting to look leftward with the right eye, and with face turn restrained she cannot view leftward past the midline.
The patient advised us, and a copy of her records substantiated that previous doctors were reluctant to operate on her because they felt the strabismus was linked with her MS. Although her MS has been well controlled with medication, and she experienced no other ocular manifestations such as optic neuritis, she apparently had experienced unilateral internuclear ophthalmolplegia (INO) of the right eye.
When taking visual acuities through the right eye, which was emmetropic, best visual acuity was only 20/80. This is because the INO left eye with residual exodeviation putting her in the position of someone eccentrically viewing. However, if we left the patient’s head movement unrestrained, she naturally rotated her head leftward which reflexively allowed her to place her right eye in a position where she could view the eye chart with her macula.
In this position, with her head rotated, the patient was able to see between 20/20 and 20/25 with the right eye. So here is our plan. Let’s work on monocular adduction calisthenics followed by a heavy dose of MFBF therapy for the right eye, including adduction under MFBF conditions.
Through neuroplasticity our patient should be able to mitigate the effects of her INO and turn back the clock to where her alignment was 15 years ago. There is no guarantee that she can do this through therapy alone, but once she can attain good visual acuity and visual localization monocularly with the right eye in primary gaze, surgery may be a very useful adjunct to maintaining binocular alignment.