Neural Changes after Vision Therapy in Convergence Insufficiency: A Systematic Review

Area of Science:

• Neuroscience
• Ophthalmology
• Clinical Research

Background:

• Convergence insufficiency (CI) is a common binocular vision disorder.
• Vision therapy (VT) is a primary treatment for CI, but its neural underpinnings are not well understood.

Purpose of the Study:

• To systematically review the literature on the neural impact of vision therapy (VT) in patients with convergence insufficiency (CI).
• To correlate observed neural changes with clinical improvements following VT for CI.

Main Methods:

• A systematic literature search was conducted in PubMed and Scopus.
• Four studies met inclusion criteria after analyzing 17 initially identified articles.
• Study quality was assessed using the GRADE tool.

Main Results:

• Functional magnetic resonance imaging (fMRI) studies suggest potential modifications in brain areas like the frontal fields, oculomotor vermis, and cerebellum after VT for CI.
• Findings regarding the direction of functional activity changes (increase or decrease) are contradictory, possibly due to differing fMRI protocols.
• Serious concerns regarding risk of bias, inconsistency, indirectness, and imprecision were identified, leading to very low certainty of evidence.

Conclusions:

• Current evidence is insufficient to confirm neural changes following VT in CI due to very low study quality and methodological concerns.
• Further high-quality research is required to elucidate the neural mechanisms underlying VT for CI.