The effects of topical cycloplegics in acute acquired comitant esotropia induced by excessive digital device usage

Abstract

Background: Acute acquired comitant esotropia induced by excessive digital device usage, especially smartphones (SAACE), has been increasing over the past few years. One suggested mechanism is convergence spasm induced by excessive near work, with refraining from digital device use considered to be an effective method for decreasing the degree of esodeviation. However, if symptoms persist and are untreated over time, recovery becomes more difficult. The present study evaluated the effects of topical cycloplegics on persistent SAACE untreated for over 1 year.

Methods: Patients with sustained SAACE that was untreated for over 1 year were evaluated. Digital device usage was discouraged and a topical cycloplegic, 0.4% tropicamide, was prescribed at bedtime. After obtaining informed consent, the 14 out of 23 enrolled patients who agreed to eye drop administration were defined as the study group, with the others serving as the controls. After a 3-month follow-up, patients who elected to undergo surgery were analyzed as the surgery group. Changes in esotropia angles, stereoacuity and diplopia complaints were evaluated after a 3-month follow-up.

Results: Esotropia angles decreased and stereoacuity improved after a 3-month treatment in the study group (P < 0.01). Diplopia disappeared in 13 patients (92.9%, totally disappeared or disappeared when using glasses with built-in prisms). Among 11 patients with untreated esotropia ranging from 1-3 years, decreases in esotropia angles were correlated to untreated esotropia duration (near: R = -0.6; distance: R = 0.7; both P < 0.05). Esotropia angles in the control group exhibited a tendency to increase while stereoacuity tended to deteriorate after the 3-month follow-up. As diplopia did not disappear in any patients, 7 elected to undergo surgery and were enrolled as the surgery group. While esotropia angles decreased in the study group, they were lower than the surgery group (P < 0.01), but higher than the control group (P < 0.01). Stereoacuity was worse in the control versus the study and surgery groups (both P < 0.05).

Conclusion: Results suggest short-acting topical cycloplegics are effective in SAACE patients with long untreated periods. Decreases in esotropia angles were negatively correlated to untreated esotropia duration, which suggests the necessity of early treatment.

Keywords: Acute acquired comitant esotropia; Excessive usage of digital devices; Topical cycloplegics; smartphone.

Fig. 1

Protocol for dividing patients into groups. Enrolled patients were divided into the study and control groups according to whether they agreed to use eye drops. After 3 months of observation, surgery was performed on patients who still had sustained diplopia when using glasses with built-in prisms

Fig. 2

Changes in the study group. a Changes in the angles of esotropia. In the study group, there were significant associations between the pre-and post-treatment angles of esotropia. There were no increases in the angles of esotropia in the study group. b Changes in the stereoacuity in the study group. In the study group, there were significant associations between the pre-and post-treatment stereoacuity. There was no deterioration of the stereoacuity in the study group

Fig. 3

Improvement of diplopia. a In the study group, diplopia disappeared in 4 patients (28.6%). Diplopia was corrected using glasses with built-in prisms in 9 patients (64.3%, 3 with 6⊿, 4 with 8⊿, and 2 with 14⊿). b In the control group, all 9 patients in the control group had sustained diplopia that could not be corrected when using glasses with built-in prisms. Of these, 2 patients who declined surgery underwent corrections using a Fresnel membrane prism. The other 7 patients who did undergo surgery were included in the surgery group

Fig. 4

Correlation between untreated periods and decreases in the angles of deviation in the study group. Only patients with untreated periods less than 3 years were included in the analyses of the correlation. Decreases in the angles of esotropia were negatively correlated to the untreated period, with the longer the untreated period, the less the observed decreases in the angles of esotropia

Fig. 5

Correlation between refraction errors and decreases in the angles of deviation in the study group. There was no correlation between the refraction errors and decreases in the angles of deviation in the study group

Fig. 6

Changes in the control group. a Changes in the angles of esotropia. There were significant associations between the pre-and post-treatment angles of esotropia. There was a tendency for an increase in the angles of esotropia at near fixation after a 3-month observation period. b Changes in the stereoacuity in the control group. There were significant associations between the pre-and post-treatment stereoacuity. There was a tendency for deterioration in the stereoacuity after a 3-month observation period

Fig. 7

Comparisons among the study, control and surgery groups. a Comparisons of decreases in the angles of deviation. Compared to the findings observed in the surgery group, while the decreases in the angles of esotropia in the study group were lower, they were higher than that observed in the control group for both the near and distance fixation. b Comparisons of stereoacuity. Compared to the findings observed in the control group, the stereoacuity in the study group was better, with a level similar to that observed in the surgery group