Results of fusional vergence therapy in managing consecutive esotropia: A case series

Purpose: To analyze the efficacy of fusional vergence therapy (FVT) in management of consecutive esotropia with diplopia after intermittent exotropia (IXT) surgery. The current study is carried on how FVT affects the duration of treatment, sensory fusion, and exotropic drift. Methods: This was a retrospective study for the medical record of 11 patients with consecutive esotropia after IXT surgery of 543 patients over the period of 5 year, with mean surgery age of 9.5 (range: 4–33 y). FVT was planned after minimum 6 weeks of surgery and was considered for maximum 24 weeks. Patients underwent a combination of office-based and home-based FVT. Successful outcome of therapy was considered where diplopia resolves in free space and achieves sensory fusion, stereopsis with no manifest deviation. Results: Record of 543 patients who had horizontal muscle surgery for IXT were identified and reviewed. Records of 11 patients who showed consecutive esotropia of 10 prism diopter (PD) or more with normal retinal correspondence, with or without diplopia complaint, after 6 week of surgery and had undergone vision therapy management were reviewed. A successful outcome of binocular single vision with good sensory and motor fusion with no manifest deviation or prism requirement was achieved with in the mean duration of 4.8 month of therapy. With a mean duration of 4 weeks of therapy, the mean angle of deviation reduced by 53% for distance (17 PD to 8 PD) and 27% for near (11 PD to 8 PD) and mean stereopsis improvement by 80% with 94% patients demonstrating sensory fusion on Bagolini test and 94% of patients having no symptoms of diplopia or squint. Conclusion: With nonsurgical management involving refractive error correction, FVT, and prism, consecutive esotropia was resolved in 74% cases. Management of consecutive esotropia with FVT can result in satisfactory sensory fusion and successful motor alignment.

Vergencias fusionales. Exploración e importancia en la práctica clínica / Fusion Vergences. Exploration and Importance in Clinical Practice

La vergencia fusional se define como la vergencia estimulada por la disparidad retiniana que genera un movimiento vergencial para mantener la visión binocular simple, son movimientos binoculares disyuntivos en los que ambos ojos se dirigen en la misma dirección para fijar un objeto y a la vez se desplazan en sentido opuesto. La amplitud de fusión desempeña un importante papel en mantener una visión binocular simple. Los valores fuera de la norma son significativos en el diagnóstico de posibles disfunciones binoculares no estrábicas. Con este artículo se pretende mostrar los diferentes criterios relacionados con la evaluación de la amplitud de las reservas fusionales, cual es la prueba más usada y los rangos considerados dentro de límites normales, para lo que se realizó una búsqueda en diferentes publicaciones y textos de la especialidad(AU)

Fusional vergence is defined as the vergence stimulated by retinal disparity that generates a vergence movement to maintain simple binocular vision, they are disjunctive binocular movements in which both eyes are directed in the same direction to fix an object and at the same time they move in opposite way. Fusion amplitude plays an important role in maintaining single binocular vision. Values outside the norm are significant in the diagnosis of possible non-strabismic binocular dysfunctions. This article aims to show the different criteria related to the evaluation of the amplitude of fusional reserves, which is the most used test and the ranges considered within normal limits, for which a search was carried out in different publications and texts of the specialty(AU)

The Influence of Fusional Vergence on the Postoperative Ocular Alignment in Intermittent Exotropia

The purpose of this study was to evaluate the influence of fusional vergence on the ocular alignment after surgery in intermittent exotropia. We evaluated fusional convergence and divergence with rotary prism. We examined 44 patients with intermittent exotropia who were followed up postoperatively for at least 6 months from January 1995 to June 1998. The angle of deviation was measured preoperatively, 1 week after surgery and on the last follow-up day. We evaluated the break and recovery point of fusional convergence and divergence at near and far at each measurement of angle of deviation. The subjects were divided into two groups according to the deviation at the last visit : Orthophoria group and Undercorrection group. Orthophoria group was defined as having the deviation equal to or less than 15 delta of exodeviation, and undercorrection group was defined as having the deviation more than 15 delta of exodeviation. In Orthophoria group, break point and recovery point of convergence were 28.07 delta and 26.34 delta at near, 25.52 delta and 22.55 delta at far. The break point and recovery point of divergence were 18.21 delta and 12.38 delta at near, 12.70 delta and 7.73 delta at far. In Undercorrection group, break point and recovery point of convergence were 25.86 delta and 24.71 delta at near, 25.20 delta and 25.80 delta at far. The break point and recovery point of divergence were 18.86 delta and 13.29 delta at near, 17.90 delta and 15.40 delta at far. There was no significant difference between two groups. According to the change from deviation at postoperative 1 week to final deviation, the subjects were divided into four groups. We evaluated the difference of fusional convergence and divergence, according to the change of angle of deviation between postoperative 1 week and the last follow-up day, but there was no significant difference. In conclusion, we can not find any significant influence of fusional vergence on the ocular alignment after surgery in intermittent exotropia.