What is the aim of this review?
The purpose of this Cochrane Review was to find out whether any treatment (e.g. surgery or non-surgery) is better than another to treat esotropia (eye turns inward) that occurs in children within the first six months of life. This condition is called infantile esotropia. We looked for all relevant studies to answer this question, and found two.
What was studied in the review?
Infantile esotropia can affect the vision in the eye, the ability to use the two eyes together (binocularity), and can also be a cosmetic issue to the child or parents. Treatment includes surgical and non-surgical treatments to reduce how much the eye turns in, and to improve binocularity. Binocularity is the ability to focus on an object with both eyes and only see a single image. This review looked at different treatments, and the timing of each treatment.
What are the main results of the review?
We found two relevant studies that enrolled a total of 234 children. One study was from South Africa (110 children). The children received either surgery or botulinum toxin injections, and were followed in six months. Botulinum toxin is a toxin that is used in small amounts to relax muscles, including those in the eyes. This study found that surgery may achieve better good eye alignment, with minimal risk, compared with botulinum toxin injections. But we have very little confidence in the evidence, because we only had one study, with a small number of children, and the study was not well-designed or conducted.
The other study enrolled 124 children in Germany and the Netherlands. It compared unilateral (i.e. one eye only) and bilateral (i.e. both eyes) surgery. They found that there was no evidence of an important difference in how much the eye turned in or how many children were able to use both eyes to focus on an object between these surgeries. But we have very little confidence in the evidence, because we only had one study, with a small number of children, and the study was not well-designed or conducted.
This review does not resolve the controversy regarding the best type of surgery, the value of non-surgical interventions, or the best age of treatment. It highlights a need for further research in this area.
How up-to-date is this review?
Information specialist searched for studies that had been published up to 30 November 2021.
Medial rectus recessions may increase the incidence of treatment success compared with botulinum toxin injections alone, but the evidence was very uncertain. No evidence of important difference was found between bilateral surgery and unilateral surgery.
Due to insufficient evidence, it was not possible to resolve the controversies regarding type of surgery, non-surgical intervention, or age of intervention in this review. There is clearly a need to conduct good quality trials in these areas to improve the evidence base for the management of IE.
Infantile esotropia (IE) is the inward deviation of the eye. Various aspects of the clinical management of IE are unclear; mainly, the most effective type of intervention and the age at intervention.
To examine the effectiveness and optimal timing of surgical and non-surgical treatment options for IE to improve ocular alignment and achieve or allow the development of binocular single vision.
We searched CENTRAL, MEDLINE, Embase, one other database, and three trials registers (November 2021). We did not use any date or language restrictions in the electronic searches for trials.
We included randomized trials and quasi-randomized trials comparing any surgical or non-surgical intervention for IE.
We used standard Cochrane methodology and graded the certainty of the body of evidence for six outcomes using the GRADE classification.
We included two studies with 234 children with IE. The first study enrolled 110 children (mean age 26.9 ± 14.5 months) with an onset of esotropia before six months of age, and large-angle IE defined as esotropia of ≥ 40 prism diopters. It was conducted between 2015 and 2018 in a tertiary care hospital in South Africa. It compared a maximum of three botulinum toxin injections with surgical intervention of bimedial rectus muscle recession, and children were followed for six months. There were limitations in study design and implementation; the risk of bias was high, or we had some concerns for most domains.
Surgery may increase the incidence of treatment success, defined as orthophoria or residual esotropia of ≤ 10 prism diopters, compared with botulinum toxin injections, but the evidence was very uncertain (risk ratio (RR) of treatment success 1.88, 95% confidence interval (CI) 1.27 to 2.77; 1 study, 101 participants; very low-certainty evidence). The results should be read with caution because 23 children with > 60 prism diopters at baseline in the surgery arm also received botulinum toxin at the time of surgery to augment the recessions. There was no evidence of an important difference between surgery and botulinum toxin injections for over-correction (> 10 prism diopters) of deviation (RR 0.29, 95% CI 0.06 to 1.37; 1 study, 101 participants; very low-certainty evidence), or additional interventions required (RR 0.66, 95% CI 0.36 to 1.19; 1 study, 101 participants; very low-certainty evidence). No major complications of surgery were observed in the surgery arm, while children experienced various complications in the botulinum toxin arm, including partial transient ptosis in 9 (16.7%) children, transient vertical deviation in 3 (5.6%) children, and consecutive exotropia in 13 (24.1%) children. No other outcome data for our prespecified outcomes were reported.
The second study enrolled 124 children with onset of esotropia before one year of age in 12 university hospitals in Germany and the Netherlands. It compared bilateral recession with unilateral recession surgeries, and followed children for three months postoperatively. Very low-certainty evidence suggested that there was no evidence of an important difference between bilateral and unilateral surgeries in the presence of binocular vision (numbers with event unclear, P = 0.35), and over-correction (RR of having exotropia 1.09, 95% CI 0.45 to 2.63; 1 study, 118 participants). Dissociated vertical deviation, latent nystagmus, or both were observed in 8% to 21% of participants.