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. 2020 Jul 4;32(3):217–225. doi: 10.4103/JOCO.JOCO_81_20

Table 5.

Summary of some previous studies that investigate different non-surgical management strategies of intermittent exotropia

Authors (year) Number of patients Age of the patients Treatment method Follow-up Mean results
Chung et al.35 114 Optical correction alone 6 months In hyperopic cases a narrow increase in exodeviation following hyperopic correction was seen
In myopic cases, the angle of deviation remained constant or decreased following wearing eyeglasses
Optical correction in cases with exotropia is useful prior to strabismus surgery and considering a new angle of deviation after spectacle correction should result in better results
Mohney et al.36 177 12-35 months Part-time occlusion versus observation alone 3 h daily for 5 months, followed by 1 month of no patching Observation does not result in the deterioration of IXT in the age range 12-35 months
Deterioration over 6 months was uncommon, with or without patching treatment
Buck et al.19 460 <12 years Observation 2 years follow up There is a very low risk of deterioration within 2 years after a diagnosis of IXT
Chen et al.37 58 3-6 years Minus therapy versus observation alone 8 weeks Minus therapy has a better effect on IXT control than no intervention at all
Cotter et al.38 358 3-10 years Part-time occlusion versus observation alone 3 h daily for 5 months, followed by 1 month of no patching A low rate of deterioration was observed in both groups (6.1% in the observation group and 0.6% in the occlusion group) No significant difference between observation and patching
Alkahmous and Al-Saleh39 21 4-10 years 6 h a day alternate occlusion 6 months Alternate occlusion improved the sensory status and strengthened the fusional amplitudes at near and distance. Moreover, alternate patching could also improve IXT control but did not improve the angle of deviation
Bayramlar et al.40 19 3-14 years Over-minus lenses therapy Median period of 18 months (6-33 months) Overcorrecting minus therapy could decrease deviation and improve the patient’s status and should be considered as the first line of treatment
Mangad et al.41 53 1-5 years Over-minus lenses therapy 1 year Over-minus correction improves IXT control (lowers the NCS score) and decreases the angle of deviation at distance and near
Samy et al.42 100 5-7 years Inverse prism addition versus conventional prism addition 12 months The two types of prism therapy showed comparable improvements in NCS
This study highlights the potential role of inverse prism therapy as a non-invasive method for enhancing basic IXT control
Hardesty et al.43 100 2-24 years Surgery alone versus surgery and orthoptic therapy Six and one tenth years (1-10 years) Improvement in 50% of the subjects who underwent both surgical intervention and orthoptic therapy while only 32% of the patients who only underwent surgery improved
Asadi et al.44 74 4-54 years Office and home-based training exercises 8 weeks Orthoptic treatment seems to be effective in reducing symptoms and improving signs of intermittent exotropia
Combination of in-office and home-based therapy tends to produce better results than does home-based therapy alone
Peddle et al.45 2 30 and 32 years Binocular vision therapy/orthoptics 30 weeks Vision therapy was highly successful in patients with childhood intermittent exotropia of the basic type
Vision therapy can eliminate the patients’ symptoms of asthenopia and diplopia without the need for surgery
Using vision therapy exotropia at distance and near was reduced, patients achieved required fusion at all distances, and their symptoms improved
Spencer et al.46 32 3-12 years Bilateral injections of 2.5 units botulinum toxin injection to the lateral rectus muscles 12-44 months Botulinum toxin is at least as effective as surgical outcomes reported previously for the treatment of intermittent exotropia in children
This treatment method is particularly effective in children between 2 and 4.5 years of age irrespective of the initial strabismic angle and is not associated with any secondary abnormalities
Etezad Razavi et al.47 21 5-18 years Botulinum toxin injection to the lateral rectus muscles 6 months Botulinum toxin injection to lateral rectus muscles seems to be a promising procedure in the management of fusional control, far and near deviations in patients with intermittent exotropia in short time

IXT: Intermittent exotropia, NCS: Newcastle Control Score