Evidence map›Paper›PMID 32918906›Full record

ArticleAmerican journal of ophthalmology2021

Functional Anatomy of Muscle Mechanisms: Compensating Vertical Heterophoria.

Joseph L Demer, Robert A Clark

Open access · greenAbstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in American journal of ophthalmology, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
0.4field-weighted citation impact, top 37% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed, 6 citations in OpenAlex.

  1. Article
  2. Article
  3. Article
  4. Reply to Comment on: Masquerading superior oblique palsy.American journal of ophthalmology · 2023
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors at 1 institution in 1 country.

Joseph L DemerDepartment of Ophthalmology, University of California, Los Angeles, Los Angeles, CA, USA; Department of Neurology, University of California, Los Angeles, Los Angeles, CA, USA; Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA, USA; Biomedical Engineering Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA, USA; David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA. Electronic address: jld@jsei.ucla.edu.
Robert A ClarkDepartment of Ophthalmology, University of California, Los Angeles, Los Angeles, CA, USA; David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
University of California, Los Angeles · US

Funding

Vision Research Core at UCLAP30EY000331 · NEI · UNIVERSITY OF CALIFORNIA LOS ANGELES · PI Xian-Jie Yang · 1985 to 2026
$16.8M
BIOMECHANICAL ANALYSIS IN STRABISMUS SURGERYR01EY008313 · NEI · UNIVERSITY OF CALIFORNIA LOS ANGELES · PI JOSEPH Louis DEMER · 1991 to 2026
$15.0M
NEI NIH HHS P30 EY000331NEI NIH HHS R01 EY008313
6 · The paper itself

Abstract

purposeMagnetic 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).

designProspective case series.

methodsAt 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).

resultsFive 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 VFV. Vertical strabismus was compensated mainly by significant contractility of the lateral more than the medial compartment of the inferior rectus (IR) in both eyes (P < .005). The superior rectus (SR) and inferior oblique muscles had no significant contractile contribution, although the hypotropic SO relaxed significantly. The IR lateral compartment and SR medial compartment significantly co-relaxed when binocular fusion was attained from monocular target fixation (P < .01).

conclusionsAlthough VFV protects patients from small muscle imbalances over the lifespan, even enhanced VFV may be inadequate to avert diplopia. Compensation of hyperphoria by VFV is accomplished mainly by IR muscle relaxation in the hypotropic eye, principally in its selectively innervated lateral compartment, whereas the SO contributes little. Fusion involves compartmentally selective co-relaxation in hypotropic eye vertical rectus muscles. Taken together, these overall findings suggest a physiologic basis to prefer therapeutic surgical weakening of the medial IR in the hypotropic eye.

Indexed as

AdultDiplopiaFemaleFixation, OcularHumansMagnetic Resonance ImagingMaleMiddle AgedMuscle ContractionOculomotor MusclesProspective StudiesStrabismusVision, Binocular

Identifiers

PMID32918906
PMCPMC7736372
OpenAlexW3084301175

What OpenQuestion holds

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.