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Clinical Examination in Neuro-Ophthalmology
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Selvakumar Ambika, Krishnakumar Padmalakshmi
Interpretation: If all four dots are seen indicating:normal binocular response with no manifest deviationin the presence of manifest squint-harmonious anomalous retinal correspondenceOnly two red dots are seen—indicates left suppressionIf three green lights are seen—indicates right suppressionIf red and green dots alternate—alternate suppressionIf five dots are seen—diplopia is present
Rapid monocular adaptation of saccade amplitude in constant strabismus
Published in Jan-Tjeerd de Faber, 28th European Strabismological Association Meeting, 2020
H.J. Griffiths, D. Buckley, J.P. Whittle
The electronic feedback system applied to a target visible to one eye produced rapid disconjugate saccade adaptation in eight subjects with normal bifoveal BSV. The aim of this study was to determine whether subjects with manifest strabismus and no demonstrable BSV, normal or anomalous, could produce disconjugate saccades under such test conditions. The results demonstrated that three of the six strabismic subjects studied were able to produce appropriate disconjugate adaptations despite no clinically detectable binocular co-operation. The three subjects who adapted in the appropriate direction had small angled deviations (8Δ esotropia, 8Δ exotropia and 12Δ exotropia). These could therefore be considered likely candidates for development of abnormal retinal correspondence and anomalous binocular vision. Extreme care was taken clinically to investigate the subjects with detailed questioning for binocular tests requiring subjective responses and a complete investigation, with a full range of tests employed. Bucci et al. (1997) have demonstrated disconjugate adaptations in intermediate strabismus with abnormal binocular vision. They describe such adaptations in two subjects with 18 and 21Δ esotropia who had positive responses for Bagolini striated glasses, failed to demonstrate stereoacuity in free space (TNO and Titmus test) but demonstrated a stereoacuity of 3600 seconds of arc on the Synoptophore.
SKILL Cover testing
Published in Sam Evans, Patrick Watts, Ophthalmic DOPS and OSATS, 2014
Alignment of the eyes is a prerequisite for binocular single vision (BSV). Thus, it follows that failure of alignment denies the visual system the opportunity to develop or maintain complete BSV and stereopsis. The alignment need not be foveal, as anomalous retinal correspondence may coexist with some BSV, although the field of BSV may be reduced in these individuals. Nevertheless, high-quality vision (with foveal fixation), with good alignment of both eyes, provides the greatest stimulus for BSV and is likely to result in the largest field of BSV possible. Therefore, there are strong drivers to maintain eye alignment. When this breaks down, strabismus is present.
Prism adaptation response and surgical outcomes of acquired nonaccommodative comitant esotropia
Published in Strabismus, 2023
Noriko Nishikawa, Yuriya Kawaguchi, Rui Fushitsu
A short PAT was performed in the outpatient clinic on the day of the preoperative examination in the period from 3 weeks to the day before the surgery as follows: press-on Fresnel trial prisms were set to neutralize the deviation under refractive correction. The patient wore them for 15–20 minutes; if residual esotropia was observed with the prisms, the process was repeated until the angle was stable.18 The Bagolini striated glass test was performed to confirm binocular visual function and retinal correspondence under prism adaptation. In some patients, these procedures were performed more than once to confirm the response. Based on these responses, patients were defined as either prism builders (the angle of deviation increased by ≥ 10 PD compared to the entry angle at distance) or prism non- builders (the angle of deviation increased by < 10 PD).
Hemifield-slide diplopia successfully managed with botulinum toxin injection in a patient with traumatic chiasmal disruption
Published in Clinical and Experimental Optometry, 2022
Kaveh Abri Aghdam, Ali Aghajani, Faeze Hashemi Rahbarian, Mostafa Soltan Sanjari
Some authors have proposed different ways for managing symptoms in these patients. Prism and stereo-typoscope (a novel fusion aid that utilises midline stereopsis) have been used successfully in one study.7 Surgical management of squint and diplopia is another proposed treatment modality. Van Waveren et al.6 suggested surgery in these patients in cases of normal retinal correspondence. They proposed that surgery could be performed after observing functional improvement under prismatic correction and weighing the reduction of the binocular visual field against its sensory outcome. However, the result of surgery is not always favourable and sensory abnormalities may persist despite apparent elimination of ocular misalignment.1 On the other hand, some patients might not consent to surgery (as in this case), and thus we explored treatment alternatives. Based on the previous reports of successful application of botulinum toxin in small-angle exotropia,8 the authors decided to inject botulinum toxin A (Dysport®; Ipsen, Paris, France) in both lateral rectus muscles; the result of which was satisfying and long-lasting.
Small-angle hypertropia in a case of inferior rectus aplasia: an intraoperative surprise
Published in Strabismus, 2021
Mohadaseh Feizi, Mahya Golalipour, Abbas Bagheri, Amir A. Azari
The amount of primary position hypertropia in most of the previously reported cases of unilateral IR aplasia was large, ranging from 25 to 70 PD,4,7,8 but our patient had a relatively small angle hypertropia in the primary position (14 PD) and the eye passed the midline in the straight downgaze. Intraoperatively, there were only a few strands of fibrovascular tissue in the region of IR and multiple coronal planes of the orbital CT scan showed that the IR muscle was entirely absent. Ipsilateral superior oblique over-action in our patient may have compensated for the lack of IR muscle and provided some downward force, thus reducing the observed primary position hypertropia. Ipsilateral superior oblique overaction was also reported by Taylor in a patient with IR aplasia who had 20 PD of hypertropia in the primary position.5 Absence of IR muscle in conjunction with ipsilateral SO muscle overaction made 12 degrees of incyclotorsion in our patient, but he did not complain of any tortional or vertical diplopia. This is probably due to the creation of some degree of abnormal retinal correspondence. To differentiate IR aplasia from IR paresis, neither the amount of deviation nor the severity of downgaze limitation is useful; to make the definitive diagnosis, orbital imaging is needed before surgery. Imaging with AS-OCT9 or UBM10 can detect rectus muscle insertions as far back as the equator and may spare the cost and logistic problems of an MRI or CT scan, but they were not available in our center.