This protocol addresses partial abducens nerve palsy (paresis) in patients with residual lateral rectus function — a sub-population defined by preserved, though impaired, lateral movement in which abduction can still pass the midline. This distinguishes partial palsy from complete palsy, where abduction cannot reach the midline at all.
Persistent esotropia and abduction deficit remain the central findings driving further management.
First-line management of partial abducens nerve palsy prioritises treating the underlying etiology. During the acute phase, diplopia is managed with occlusion therapy (alternate eye patching or opaque lenses such as Bangerter foils) or, when the deviation is small and fairly comitant, with ground-in or Fresnel prisms.
This protocol is the appropriate next step when those first-line goals have not been met: diplopia relief is inadequate and spontaneous recovery has not occurred — meaning esotropia and the abduction deficit have not resolved within the expected 3–6 month window.
For patients with persistent misalignment and diplopia despite etiological treatment, surgery is indicated. In the setting of residual lateral rectus function, the preferred strategy centres on augmented horizontal rectus muscle surgery involving the lateral rectus. The complete approach — including which additional muscles may be involved, how the surgical plan is calibrated, and how dosage parameters are determined — is detailed in the full structured protocol.
DOI: 10.1016/j.apjo.2026.100297