Structural and functional analysis of binocularity after surgery for longstanding strabismus

Purpose: Assess structurally and functionally binocularity and deviation before and after strabismus surgery on patients with long‐standing strabismus. Methods: Four patients with strabismus of more than 1 year of evolution were evaluated in three visits: 1 week before surgery (preoperative), in the first week (immediate postoperative) and 1 month after (delayed postoperative). For functional assessment, visual acuity test with Snellen optotype, near vision test, TNO and Titmus test to assess stereopsis, quantification of deviation with prisms and binocular computerized campimetry were performed. For structural analysis, optical coherence tomography (OCT) was performed with Spectralis and Triton devices. Results: All patients presented significant changes with respect to the preoperative period both in the number of prismatic diopters and in the results of the OCT test in the immediate and delayed postoperative period. The binocular campimetric results also showed significant differences in the delayed postoperative period with respect to the patient's preoperative situation. In none of the cases were significant variations observed in the thickness of retinal ganglion cells, inner plexiform layer or retinal nerve fibres. Conclusions: Strabismus surgery provides improvements, not only in the correction of the alignment of both eyes, but also in the patient's stereopsis and binocular visual field. The traction movements of the eyeball or the changes caused during surgery do not seem to be a risk factor for axonal damage or damage to the inner retinal layers.