Abstract
Purpose :
To investigate the effect of atropine on the evolution, control, deviation angle, suppression, and stereoacuity of intermittent exotropia (IXT)
Methods :
In a pilot study, twenty-three patients with basic or simulated divergence excess (proximal convergence excess) IXT, aged 3-6 years old, and fair to poor control (≥3 by revised Newcastle Control Score, NCS) were randomly assigned to atropine once a week (n=13) or 2h of occlusion daily (n= 10) in the eye preferred for fixation. Deviation angle (PD) by prism and alternate cover test (APCT) at distance and near after 45 minutes of occlusion, followed by +3.00 D lens at near, stereoacuity (log arcsec), suppression by Bagolini and Worth 4 dot test (WFD), were measured before and after 6 months of treatment. Deterioration in control (NCS), angle or stereoacuity were the outcome variables studied. Variables were compared using nonparametric tests (Mann-Whitney, Wilcoxon, Fisher exact test), and the influence of potential confounding variables was studied (including age, initial deviation and degree of deviation control, and initial stereoacuity) using nonparametric tests and bootstrap multiple regression.
Results :
Amblyopia was not observed in this cohort. Deterioration, defined as 3-point increase in the revised NCS, impairment of 2-octave or more in stereoacuity or 8-PD increase in distance deviation by APCT, was not observed in any case during the study period. Change in APCT at distance (-3.07 vs -3 PD, p=0.9) and near (-2.30 vs -1.50 PD, p=0.4), change in stereoacuity at near (-0.04 vs -0.02 log arcsec, p=0.7), and in revised NCS (-1.3 vs -1.9, p=0.2) were not significantly different between the two groups. Although suppression was more frequently detected in the atropine than occlussion group by Bagolini (6/13 vs 2/10, p=0.3) and WFD at distance (5/13 vs 3/10, p=0.6) at near (4/13 vs 1/10, p=0.3), differences did not reach significance. Age, initial deviation, revised NCS, and stereoacuity were not significant confounding variables (p=0.2; 0.4; 0.1; 0.6, respectively).
Conclusions :
Although these are preliminary data of a pilot study that require confirmation, atropine is not different from occlusion in the control of basic or simulated divergence excess IXT at short or middle term.
This is a 2021 ARVO Annual Meeting abstract.