Comparison of Binocular Function and Surgical Outcomes of Tenacious Proximal Fusion and High Accommodative Convergence/Accommodation Ratio Types of Intermittent Exotropia

Abstract

PurposeTo compare the characteristics and surgical outcomes in patients with tenacious proximal fusion (TPF) and high accommodative convergence/accommodation ratio (AC/A) types of intermittent exotropia.MethodsThis study retrospectively enrolled 40 patients with intermittent exotropia, 23 with TPF and 17 with high AC/A. Binocular function was evaluated by Worth's 4-dot test. Patients underwent lateral rectus recession, and surgical outcomes were compared. Surgical success was defined as less than ±10 prism diopters (PD) at 12 months postoperatively.ResultsThe proportion of diplopia at near, evaluated by Worth's 4-dot test, was significantly higher in patients with high AC/A than in those with TPF (35.3% vs. 4.3%, p = 0.029). The mean preoperative angles of deviation in TPF and high AC/A types were 28.3 ± 4.4 and 28.8 ± 4.5 PD at distances, and 14.7 ± 4.2 and 15.1 ± 4.1 PD at near. Twelve months after surgery, the mean angles of deviation in TPF and high AC/A types were 2.9 ± 9.8 and 1.2 ± 9.6 PD, respectively, at distance and 1.7 ± 7.7 and −1.3 ± 11.3 PD at near. The surgical success rates were similar in the TPF and high AC/A types (74.0% vs. 64.7%). Five (21.7%) patients with TPF and 2 (11.8%) with high AC/A type experienced recurrence, with consecutive esotropia occurring in 1 (4.3%) patient with TPF and 4 (23.5%) patients with high AC/A.ConclusionsThe proportion of diplopia at near was higher in patients with high AC/A type than in those with TPF intermittent exotropia. However, the surgical success rates were not significantly different between the types.

Analysis of Improvement Time and Influencing Factors of Diplopia after Intermittent Exotropia in Children

“…A small degree of intermittent exotropia is often neglected and facilitates the progression of the disease, resulting in the destruction of binocular visual function and seriously promoting the development of children's visual function. However, till now, the timing and amount of surgery for intermittent exotropia have been debated by scholars, and the regression of eye position after the operation has become a consensus, but the factors and quantity that modulate the regression of eye position remain unclear [21]. Scholars performed two methods and reported that the stereopsis of patients with intermittent exotropia after operation increased [22].…”

Surgical outcomes of bilateral lateral rectus recession versus unilateral recession and resection for the divergence excess type of intermittent exotropia

“…[ 24 ] Somewhat surprisingly, within a large number of IXT cases as reviewed in our hospital over the period from 2009 to 2013, very few divergence excess IXT cases were identified in our medical records,[ 18 ] although we found this incidence to be 5.2% in this study.v BLR has been a well-established and accepted procedure for the management of divergence excess IXT. [ 3 5 12 16 23 25 ] With BLR, there is a greater improvement in distant versus near outward deviation. However, patients with divergence excess IXT have a greater risk for consecutive esotropia, especially for near inward deviation.…”

Comparison of AC/A Ratio in True and Simulated Divergence Excess Exotropia

“…The AC/A ratio can be modified permanently by surgery of the extra ocular muscles and temporarily by drugs and lenses. 8 Different methods are used to measure AC/A ratio; heterophoria method, gradient method, fixation disparity method and graphical method. Most common method is heterophoria method in which a prism cover test is performed for distance and near fixation .Inter-pupillary distance is measured.…”