Surgery for acute acquired comitant esotropia (AACE) in adults may positively affect motor and sensory outcomes, according to findings published in the journal BMC Ophthalmology. Although sensory outcome is favorable, researchers say that regaining bifoveal fixation takes time.
The investigators performed a retrospective analysis of the data from 24 adult patients who had undergone surgery for AACE between October 2012 and March 2020. Primary outcome measures included the final motor and sensory success rate after surgery, and the researchers found that they were 79.2% (n=19) and 50% (n=12), respectively. The postoperative followup took place during a 1- to 8-month range.
The researchers in this analysis considered motor success as alignment within 8 prism diopters at both near and distance, and the factor affecting this outcome was the type of surgery (P <.05). The patients underwent either unilateral medial rectus recession (RR, n=18) or bilateral medial rectus recession (BMR, n=6). Sensory success was measured by a stereoacuity of 60 sec/arc or greater. Postoperative follow-up time (P <.05) was a factor affecting success.
In this study 17 of 18 patients who underwent RR showed good outcomes and RR showed better outcomes overall than BMR. “It can be assumed that the mechanical strengthening effect of lateral rectus resection may be more effective in enhancing the weakened divergence amplitude in AACE patients,” the research shows.
The study explains that AACE manifests in adult patients for different reasons than in children and adolescents, and that more investigation needs to be done in that area. For example, the researchers say that extended periods of time using smartphones in those with weak convergence amplitudes or esophoria can lead to acute esotropia, but only 13 of the 24 patients in the study had claimed to participate in this activity. Patients’ smartphone use was not controlled for in this study.
The researchers cite several limitations. First, the lack of a control group makes it difficult to determine whether the results are limited to AACE only. Additionally, the postoperative stereoscopic value may not have been accurate due to the fact that all patients had diplopia before surgery.
Finally, the study explains that as well as the small sample size, accuracy in the study outcomes may have been affected by the difference in number of patients for each postoperative group (18 vs 6).
Kim D, Noh H. Surgical outcomes of acute acquired comitant esotropia of adulthood. BMC Ophthalmol. Published online January 18, 2021. doi:10.1186/s12886-020-01793-3.