Simulated torsional disparity disrupts horizontal fusion and stereopsis

Georgievski, Zoran; Sleep, Michael; Koklanis, Konstandina

doi:10.1016/j.jaapos.2006.09.022

Cited by 17 publications

(16 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…9 Furthermore, torsional disparity may contribute to the alteration of binocular single vision when it exceeds the cyclofusion limits. 10 The torsion was not evaluated and measured in this study but these findings may be also likely to be of relevance to the development of amblyopia and defect in binocularity in BS. Furthermore, the binocular status of the patients may be affected in regard of the presence and also the depth of amblyopia as well.…”

Section: Resultsmentioning

confidence: 94%

Amblyopia and sensory features at initial presentation of Brown syndrome: an issue to recognize

Şekeroğlu

Muz

Sanaç

et al. 2013

Eye

View full text Add to dashboard Cite

Purpose To investigate the frequency of amblyopia and sensory features at initial presentation in patients who had unilateral congenital Brown syndrome (BS) and to identify the potential risk factors for amblyopia in BS. Methods The study conducted with patients who had unilateral congenital BS. Patient demographics, visual acuity, refractive errors, amount of horizontal and vertical deviations, abnormal head position, fusion, and stereopsis were all reviewed. The main outcome measure was the frequency of amblyopia at initial presentation. Results The review identified 44 patients with BS (median age 5 years). The frequency of amblyopia was 15.9% (seven patients) in BS at initial presentation. Patient age (P ¼ 0.297), ocular alignment at primary position (P ¼ 0.693), anisometropia (P ¼ 0.184), and stereoacuity (P ¼ 0.061) were found to have no significant relation with amblyopia. The main associated risk factor was the absence of sensory fusion (P ¼ 0.013). Conclusions Amblyopia may be encountered among patients with BS, and may be related to binocularity of the patient. Its recognition may be a critical step during the treatment planning and may determine presumably the success of future therapies.

show abstract

Section: Resultsmentioning

confidence: 94%

Amblyopia and sensory features at initial presentation of Brown syndrome: an issue to recognize

Şekeroğlu

Muz

Sanaç

et al. 2013

Eye

View full text Add to dashboard Cite

show abstract

“…It was recently reported in a study done by Georgievski et al 5 that a torsional disparity of 6° or more signifi cantly degrades both convergence and divergence amplitudes and reduces stereopsis. This is an server as a single binocular image, the eyes must be properly aligned so that the image seen separately by each eye falls on matching or corresponding retinal elements that share a common visual direction in subjective space.…”

Section: Torsionmentioning

confidence: 94%

Obstacles to Fusion: Strabismus and Diplopia

Clark

2008

American Orthoptic Journal

View full text Add to dashboard Cite

There are many potential obstacles to fusion for adult patients with diplopia. Monocular diplopia is the fi rst obstacle that should be ruled out in every adult patient before they are referred for a complete sensorimotor evaluation. Monocular diplopia is usually refractive in nature, but may also be the result of an ocular defect, or, in rare cases, the problem may be neurologic. Obstacles to motor fusion include: incomitant strabismus, insuffi cient fusional amplitudes, torsion, and nystagmus. Obstacles to sensory fusion include image disparity and sensory anomalies such as suppression, ARC, and eccentric fi xation. Sensory anomalies are the most diffi cult to treat and can result in intractable diplopia.

show abstract

“…Increasing torsional disparity adversely affects the quality of BSV (Georgievski et al. ). Enhanced torsional vergence stability during binocular compared with monocular viewing has been found, a probable effect of binocular visual feedback driving the vergence mechanism (Pansell et al.…”

Section: Introductionmentioning

confidence: 99%

“…As with horizontal and vertical alignment of the eyes, torsional alignment is dependent on visual and neural feedback and contributes to vergence motor control, enabling fusion and BSV. Increasing torsional disparity adversely affects the quality of BSV (Georgievski et al 2007). Enhanced torsional vergence stability during binocular compared with monocular viewing has been found, a probable effect of binocular visual feedback driving the vergence mechanism (Pansell et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Clinical measurements of normative subjective cyclotorsion and cyclofusion in a healthy adult population

Flodin

Pansell

Rydberg

et al. 2019

Acta Ophthalmologica

View full text Add to dashboard Cite

Purpose To investigate normative subjective cyclotorsion values and cyclofusion ranges in a healthy adult population. Methods A cross‐sectional investigation was performed in 120 healthy, non‐strabismic adults, 60 men and 60 women in the age range of 18–69 years. All subjects were assessed for cyclotorsion using the synoptophore and the single Maddox rod (SMR) methods. Cyclofusion was investigated with the synoptophore in 60 of the subjects. Results All age groups showed low values of subjective torsion, mainly excyclotorsion with mean values of −1 degree for both methods. Reference ranges of cyclotorsion were between −0.7 and −1.5 degrees for the SMR method and between −0.7 and −1.4 degrees using the synoptophore method. There were no significant differences between gender (p = 0.48), but the effect of age was significant for both methods (p = 0.026) demonstrating a slight increase in excyclotorsion with age. Cyclofusion showed a total mean amplitude of 16 degrees, the fusion range was +7 degrees of incyclotorsion to −9 degrees of excyclotorsion. Conclusions Subjective reference ranges for cyclotorsion and cyclofusion reveal that low values of torsion are to be expected upon clinical investigation in non‐strabismic adult individuals. Values outside of the reference range may be indicators of possible binocular abnormalities or physiological variations. The cyclotorsional measurements and prevalence in this adult population group can be regarded as normative data in clinical settings.

show abstract

Simulated torsional disparity disrupts horizontal fusion and stereopsis

Cited by 17 publications

References 12 publications

Amblyopia and sensory features at initial presentation of Brown syndrome: an issue to recognize

Amblyopia and sensory features at initial presentation of Brown syndrome: an issue to recognize

Obstacles to Fusion: Strabismus and Diplopia

Clinical measurements of normative subjective cyclotorsion and cyclofusion in a healthy adult population

Contact Info

Product

Resources

About