Intermittent Exotropia: Perspectives on Management

Abstract

For the treatment of intermittent exotropia, conventional thinking assigns sensory treatment to the orthoptist and motor treatment to the ophthalmologist. However, upon close examination of this line of thinking as discussed in this paper, one can see that the margins are blurred. It is the orthoptist that provides the measurements that are used by the surgeon to determine the surgical procedure and the amount of surgery. Clearly, the orthoptist is involved in the surgical decision-making process. We therefore have not only an opportunity but an obligation to our patients to expand our involvement by applying measurement strategies that provide the surgeon with the best information about the size of deviation and to do more research in this area. We also must expand our thinking to investigate features that might help predict response to standard surgery, enabling the surgeon to augment the procedure or the amount of surgery to improve surgical outcome when particular features are present pre-operatively. We cannot assume that it is random chance that the exact same surgical procedure for patients with the exact same measurements can result in a cure for some but to overcorrection or under-correction in others. Orthoptic research can help identify reasons for this variation in response to surgery. Orthoptists have been tremendously successful in devising methods for non-surgical management of intermittent exotropia that include techniques for breaking suppression and building fusional convergence. Our role should not be limited, however, to treatment of the sensory anomalies of intermittent exotropia, but rather should include application of our knowledge, skills and research abilities to surgical planning for treatment of the motor component of intermittent exotropia. By expanding the involvement of orthoptists, the orthoptist/ophthalmologist team will be better able to cure intermittent exotropia. In the meantime, however, as we strive toward improving cure rates, we can be encouraged by the knowledge that treatment "failure" does not necessarily equate with patient dissatisfaction. In a review of charts of 69 consecutive patients in my practice that had surgery for intermittent exotropia, some also treated with orthoptics, 39 were not cured and were considered treatment failures at their most recent visit with failure defined as intermittent or constant tropia of any size or a phoria greater than 8? at distance or near. In spite of being categorized as treatment failures, sixty-two percent of those 39 patients were happy with their outcome, unaware of any manifest deviation and asymptomatic. Therefore, obtaining a cure is not necessarily a requirement for patient satisfaction. As orthoptists we can have pride in our past