Abstract
Purpose :
To compare the characteristics and surgical outcomes in patients with tenacious proximal fusion (TPF) type and high accommodative convergence/accommodation ratio (AC/A) type of intermittent exotropia.
Methods :
This study retrospectively enrolled 28 patients with intermittent exotropia, 19 with TPF type and nine with high AC/A type. Stereopsis was evaluated using the Titmus test, and binocular function was evaluated by Worth’s 4-dot test. Patients underwent unilateral or bilateral lateral rectus recession, and surgical outcomes were compared in the TPF and high AC/A groups. Surgical success was defined as less than ±10 prism diopters (PD) at 12 months postoperatively.
Results :
Stereopsis was similar in patients with TPF and high AC/A type intermittent exotropia (75.6±50.5 vs. 89.5±78.1 seconds of arc (arcsec), P >0.05). However, the proportion of diplopia at near, evaluated by Worth’s 4-dot test, was significantly higher in patients with high AC/A type than with TPF (44.4% vs. 5.3%, P=0.026). The mean preoperative angles of deviation in TPF and high AC/A types were 30.5±5.5 PD and 31.1±4.9 PD, respectively, at distance and 15.3±4.7 PD and 15.9±4.2 PD, respectively, at near. Twelve months after surgery, the mean angles of deviation in TPF and high AC/A types were 4.1±10.4 PD and 1.0±10.6 PD, respectively, at distance and 2.1±8.4 PD and -1.6±9.4 PD, respectively, at near. The surgical success rates were similar in the TPF and high AC/A types (68.4% vs. 66.7%). Five (26.3%) patients with TPF and one (11.1%) with high AC/A type experienced recurrences, with consecutive esotropia occurring in one (5.3%) and two (22.2%) patients, respectively.
Conclusions :
The proportion of diplopia at near was higher in patients with high AC/A type than TPF type intermittent exotropia. However, success rates of unilateral or bilateral lateral rectus recession were similar in both types.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.