https://doi.org/10.1177/1120672119827764 European Journal of Ophthalmology 1–5 © The Author(s) 2019 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1120672119827764 journals.sagepub.com/home/ejo EJO European Journal of Ophthalmology Introduction Exotropia is one of the most common types of strabis- mus, 1–3 and intermittent exotropia is the most common form in childhood. 4,5 Both surgical and non-surgical meth- ods are commonly used for its treatment. One of the major concerns about surgery in these chil- dren is overcorrection and consecutive esotropia, which can also cause defects in fusion and stereopsis. The proponents of non-surgical methods suggest that surgery should be postponed until the child is capa- ble of cooperating for pre-surgical measurements. Doing so might reduce the risk of complications such as overcorrection. Occlusion of the better eye or alternate occlusion is a non-surgical method prescribed for children with intermittent exotropia. 6–9 This method is often used to delay surgery by limiting suppression, reducing frequency and amplitude of the deviation, changing nature of the devia- tion (from constant to intermittent exotropia or from inter- mittent exotropia to exophoria), or a combination of the above. 10–19 However, there may be this concern that The effect of alternate occlusion on control of intermittent exotropia in children Mohammad Reza Akbari 1 , Ali Mirzajani 2 , Mohammad Reza Moeinitabar 1 , Arash Mirmohammadsadeghi 1 , Masoud Khorrami-Nejad 1 and Leila Sharbatoghli 3 Abstract Purpose: The aim is to investigate the effect of alternate occlusion on control of intermittent exotropia in children 3 to 8 years old. Methods: The ability of 28 children to control of the deviation at far and near was evaluated based on 3-point and 6-point control scales. Stereopsis and fusion were assessed using the Titmus and Worth 4-dot tests, respectively. Two- hour alternate daily occlusion was prescribed for children with no dominancy. For children with a dominant eye, 2-h occlusion of the dominant eye for 5 days and the non-dominant eye for 2 days. All measurements were repeated at 3, 6, and 9 months after the treatment. Results: For all children with a mean age of 4.7 ± 1.56 years, deviation control at far improved significantly after 3, 6, and 9 months of treatment using both control scales when compared with baseline (p = 0.005 after 3 months and p = 0.008 after 6 and 9 months for the 3-point scale, and p < 0.001 after 3 and 6 months and p = 0.010 after 9 months for the 6-point scale). Control at near showed a significant improvement after 3, 6, and 9 months of treatment based on the 6-point scale (p = 0.007 for 3 months, p = 0.004 for 6 months, and p = 0.014 for 9 months). Near stereopsis improved significantly after 9 months of treatment (p = 0.043). Conclusion: Alternate occlusion is significantly effective on control of intermittent exotropia. As a result, it can be used as a useful method to postpone or even eliminate the need for surgery in intermittent exotropia. Keywords Intermittent exotropia, alternate occlusion, fusion, Worth 4-dot test Date received: 2 August 2018; accepted: 11 January 2019 1 Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran 2 Rehabilitation School, Iran University of Medical Sciences, Tehran, Iran 3 Noor Eye Hospital, Tehran, Iran Corresponding author: Mohammad Reza Moeinitabar, Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Qazvin Square, South Karegar Street, Tehran 1336616351, Iran. Email: moeinitabar@gmail.com 827764EJO 0 0 10.1177/1120672119827764European Journal of OphthalmologyAkbari et al. research-article 2019 Original Research Article