Evidence map›Paper›PMID 29606378›Full record

ArticleOphthalmology2018

The Globe's Eccentric Rotational Axis: Why Medial Rectus Surgery Is More Potent than Lateral Rectus Surgery.

Robert A Clark, Joseph L Demer

RetractedAbstract readRetracted Publication
PubMed Full text at PMC Publisher
In one paragraph

Article in Ophthalmology, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It has been retracted, and should not be counted. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
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

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

2 authors.

Robert A ClarkDepartment of Ophthalmology, University of California, Los Angeles, California; Stein Eye Institute, University of California, Los Angeles, California; David Geffen Medical School at the University of California, Los Angeles, California.
Joseph L DemerDepartment of Ophthalmology, University of California, Los Angeles, California; Stein Eye Institute, University of California, Los Angeles, California; Department of Neurology, University of California, Los Angeles, California; Neuroscience Interdepartmental Program, University of California, Los Angeles, California; Bioengineering Interdepartmental Program, University of California, Los Angeles, California; David Geffen Medical School at the University of California, Los Angeles, California.

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

purposeTables typically recommend greater lateral rectus (LR) than medial rectus (MR) surgical doses for horizontal strabismus of any given magnitude, a difference unexplained by mechanical models that assume globe rotation about its center. We tested this assumption during horizontal ductions.

designProspective observational study.

participantsEighteen adult subjects with normal binocular vision.

methodsSurface coil magnetic resonance imaging at 390 or 430 μm resolution was obtained using 2-mm-thick contiguous axial planes while subjects fixated targets in central, right, and left gaze. Angular displacements of lines connecting the corneal apex through the minor lens axis to the retina were measured to approximate clinical ductions. Globe centers were calculated from their area centroids. Apparent lens and globe-optic nerve (ON) junction rotations around the globe center were then compared with clinical ductions.

main outcome measuresApparent angular rotations of lenses and globe-ON junctions during horizontal ductions.

resultsGlobe-ON junctions appeared to rotate significantly less around globe centers than did lenses for abduction (20.6°±4.7° vs. 27.4°±7.4°, ± standard deviation (SD), P < 0.001) and adduction (25.3°±6.7° vs. 31.9°±8.3°, P < 0.001). Both rotations differed significantly from clinical adduction (27.9°±8.3°, P < 0.007), but only in abduction was globe-ON junction rotation significantly less than clinical abduction (28.6°±9.4°, P < 0.001). The true geometric globe rotational center was 2.2±0.5 mm medial and 0.8±1.0 mm posterior to the geometric globe center and was displaced farther medially and posteriorly during adduction. This eccentricity imbues each millimeter of MR recession with approximately 30% more trigonometric rotational effect than equivalent LR recession.

conclusionsThe medial and posterior eccentricities of the normal ocular rotational axis profoundly influence horizontal rectus action. The proximity of the globe's rotational axis to the MR shortens its lever arm relative to the LR, explaining why mechanical effects of smaller MR recessions are equivalent to larger LR recessions.

Identifiers

PMID29606378
PMCPMC6056332

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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.