Functional Anatomy of Muscle Mechanisms: Compensating Vertical Heterophoria.

ABSTRACT:

Purpose

Magnetic resonance imaging (MRI) of extraocular muscle function was used to evaluate the role of newly recognized mechanisms underlying compensation of large heterophoria by vertical fusional vergence (VFV).

Design

Prospective case series.

Methods

At one academic center, 8 adults with large hyperphoria and supernormal VFV underwent MRI during monocular and binocular fixation of a centered, near target. Contractility of the rectus and superior oblique (SO) extraocular muscles in hypertropic and hypotropic eyes was determined from changes in posterior partial volume (PPV).

Results

Five of 8 patients could sustain binocular fusion in the scanner. In those patients, VFV corrected approximately 5-degree misalignment, approximately 5-fold greater than normal

SUBMITTER: Demer JL 

PROVIDER: S-EPMC7736372 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature