an interesting trend…
Over the last few years, an interesting trend has developed with some of my adult patients who seem to fit the same profile. All patients are in their early to mid 40’s, developed an eye turn (usually turning in) as Presbyopia sets in, and all had Lasik in their mid 30’s to correct for a high myopia. They all seem to complain of an acute onset of visual confusion, dizziness, vertigo like symptoms, and what might loosely be described as visual shutdown – similar to what patients with TBI’s experience. Not having much knowledge in this are, I began to research the possibilities, trying to better understand if somehow Lasik might exacerbate a fragile Accommodative/Vergence relationship, or perhaps changes the brain’s interpretation of the world causing an increased propensity for de-compensation. Oddly enough, I located this website which is intended as a support group for post-op Lasik patients. On that site, the following information was contributed by a group of Ophthalmologists as part of larger thread :
Unexpected strabismus following refractive surgery may be avoided if susceptible subjects are identified. Methods: A relationship was suspected between prior ocular misalignment or reduced binocularity in 5 cases of strabismus following LASIK. Results: Exotropia following reduction of hyperopia occurred in 1 patient. In 2, exotropia followed overcorrection of myopia to hypermetropia. Two corrected hyperopes had an elimination of esotropia. All 5 had a history of strabismus, 2 developed diplopia. Conclusion: Patients with an ocular misalignment, a history of strabismus, or abnormal results on sensory testing may have an unanticipated change in alignment following LASIK. A useful preoperative evaluation regimen is presented.
In response on the same thread, Clint Hoxie O.D., FCOVD offered this opinion:
I suspect this is a scenario which is under-reported. Most docs do not really understand binocular vision well enough to recognize that some patients, particularly those with past history of strabismus, maintain binocularity only tenuously. A fragile binocular system can experience a ‘break-down’ relatively easily, and a large change in refractive state can definitely be a spoiler. Fortunately, if even ‘fragile’ binocularity exists pre-operatively, it can usually be re-established post-operatively. This may be another reason for under-reporting, as it then becomes, in the minds of some docs, a ‘rare, short-term complication’. I’m glad there are some in the medical community who are taking notice and are publishing.
Dr. Dominic Maino M. Ed., FAAO, FCOVD also offered this input on the topic in 2007 in the Optometry & Vision Development publication, Vol. 38 Issue 4, p185
I also located interesting conversations on the topic here.
It seems that the incidence of post Lasik strabismus is low, in fact, percentage wise it’s probably in the single digits. Doesn’t seem to be an incredible concern, unless you’re the one affected. Most of the patients I’ve met who fall into this category have been to a collection of doctors and a endured a litany of tests. Everything from vestibular specialists, neurologists, optometrists, ophthalmologists, an so on. Many of them benefit from Vision Therapy.
To date, I have been unable to locate any published studies on the topic.