Scleral Canal Size and Optic Nerve Head Drusen

doi:10.1016/0002-9394(85)90369-1

American Journal of Ophthalmology

Volume 99, Issue 3, March 1985, Pages 356-359

https://doi.org/10.1016/0002-9394(85)90369-1 Get rights and content

From projected optic disk photographs we measured the size of the scleral canal in two samples of emmetropic patients: one of patients with unilateral pseudopapilledema and drusen and the other of the general normal population. Measurements on the non-drusen-containing optic disk of patients with unilateral drusen were taken to reflect the scleral canal size of the fellow, affected eye. For both trained (t = 6.642) and untrained (t = 4.274) observers, the average diameters of the non-drusen-containing optic disks of patients with unilateral drusen were significantly smaller than those of the optic disks of normal patients (P = .0005, one-tailed independent t-test). The association of a small scleral canal with vascular anomalies, frequently noted in optic disks of patients with drusen, indicates a mesodermal dysgenesis of the optic nerve head.

References (14)

W.H. Spencer
Drusen of the optic disk and aberrant axoplasmic transport
The XXXIV Edward Jackson Memorial Lecture. Am. J. Ophthalmol.
(1978)
A.H. Friedman et al.
Drusen of the optic disc
Surv. Ophthalmol.
(1977)
M.O.M. Tso
Pathology and pathogenesis of drusen of the optic nerve head
Ophthalmology
(1981)
M.A. Rosenberg et al.
A clinical analysis of pseudopapilloedema. I. Population, laterality, acuity, refractive error, ophthalmoscopic characteristics, and coincident disease
Arch. Ophthalmol.
(1979)
S.J. Kennedy et al.
Interference fringe scale for absolute ocular fundus measurement
Invest. Ophthalmol. Vis. Sci.
(1983)
B. Bengtsson et al.
Some essential optical features of the Zeiss fundus camera
Acta Ophthalmol.
(1977)
H. Littman
Zur Bestimmung der wahren Grobe eines Objektes auf dem Hintergrund des lebenden Aunges
Klin. Monatsbl. Augenheilkd.
(1982)

There are more references available in the full text version of this article.

Cited by (107)

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This report describes pseudopapilledema in two siblings with Cockayne syndrome and examines a structural mechanism for its development.
Two siblings with genetically documented Cockayne syndrome, enophthalmos, and hyperopia were found to have pseudopapilledema. Magnetic resonance (MR) imaging disclosed retrodisplacement of the globes, axial foreshortening, posterior scleral flattening, and protrusion of the optic papilla into the vitreous.
In the setting of Cockayne syndrome, pseudopapilledema may arise from retrodisplacement of the globes causing indentation of the posterior sclera by the distal optic nerves. This anatomic aberration may contribute to the development of hyperopia as well.
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To determine if ocular ductions deform intrapapillary and peripapillary tissues in optic nerve head drusen (ONHD) and to compare these deformations with healthy eyes and eyes with other optic neuropathies.
Observational case series.
Twenty patients with ONHD.
Axial rasters of the optic nerve from a spectral-domain OCT device (Cirrus 5000; Carl Zeiss Meditec, Inc, Dublin, CA) were used to analyze the shape of the peripapillary basement membrane (ppBM) layer in 20 confirmed cases of ONHD. We compared registered images obtained from 2 eye positions: 10° to 15° in adduction and 30° to 40° in abduction. Geometric morphometrics was used to analyze the shape of the ppBM layer defined by placing 10 equidistant landmarks extending 2500 μm on both sides of the basement membrane opening. We also adapted an image strain tracking technique to measure regional intrapapillary strains in 6 patients. Using manually placed nodes on the reference image (in adduction), an iterative, block-matching algorithm is used to determine local displacements between the reference and its paired image in abduction. Displacement vectors were used to calculate the mean shear and effective strain (percent change).
Peripapillary shape deformations, intrapapillary shear strains, and effective strains.
We found a statistically significant difference in the shape of the ppBM layer between abduction and adduction (P < 0.01). The deformation was characterized by a relative posterior displacement temporally in adduction that reversed in abduction. Strain tracking in all 6 patients showed substantial gaze-induced shearing and effective strains. Mean effective strains were 7.5% outside the drusen. Shear and effective strains were significantly larger outside versus within the drusen (P < 0.003 and P < 0.01, respectively).
This study demonstrates that horizontal ocular ductions induce significant shearing deformations of the peripapillary retina and prelaminar intrapapillary tissues. We also found that the deformations in healthy persons are similar in magnitude to ONHD. Based on these findings, we speculate that patients with intrapapillary calcifications exposed to the long-term effects of repetitive shearing (induced by ocular ductions) may contribute to the progressive axonal loss and vascular complications associated with ONHD.
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Scleral Canal Size and Optic Nerve Head Drusen

The XXXIV Edward Jackson Memorial Lecture. Am. J. Ophthalmol.

Surv. Ophthalmol.

Ophthalmology

A clinical analysis of pseudopapilloedema. I. Population, laterality, acuity, refractive error, ophthalmoscopic characteristics, and coincident disease

Arch. Ophthalmol.

Interference fringe scale for absolute ocular fundus measurement

Invest. Ophthalmol. Vis. Sci.

Some essential optical features of the Zeiss fundus camera

Acta Ophthalmol.

Zur Bestimmung der wahren Grobe eines Objektes auf dem Hintergrund des lebenden Aunges

Klin. Monatsbl. Augenheilkd.