Ocular torsion induced by Coriolis stimulation.

OBJECTIVE: The present study aimed to observe and analyze the ocular movements induced by Coriolis stimulation (eccentric pitch while rotating: PWR) that induces Coriolis forces on the vestibular apparatus of healthy human individuals. METHODS: A total of 31 healthy subjects participated in the study. Eccentric PWR was performed on 27 subjects, by pitching the participants' heads forward and backward at an angle of 30° each on an axis parallel and 7 cm below inter-aural axis, at a frequency of 0.5 Hz while on a chair rotating at a constant angular velocity of 97.2°/s on the earth-vertical axis. Ocular movements during stimulation were recorded using three-dimensional video-oculography. As a subsidiary analysis, 0.5 Hz head roll tilt was used as another stimulus that also induced torsional ocular movements. The forces induced on the vestibular apparatus, and phases of ocular torsion against the stimulus were calculated from the observed data. RESULTS: In the Coriolis stimulation during rightward yaw rotation, a rightward ocular torsion of 4.8° on average, was observed when the head pitched forward, and the direction of ocular torsion reversed when the head pitched backward. During leftward yaw rotation, these relationships were reversed with an average amplitude of 4.7° The phase of ocular torsion preceded that of Coriolis force by 0.2 s during rightward rotation and 0.14 s during leftward rotation. There were no significant differences in amplitude or phase between the directions of rotation. The phase lead of 0.5 Hz roll-tilt was significantly smaller than that of Coriolis stimulation (p < 0.01). CONCLUSION: Coriolis stimulation induced a specific pattern of ocular torsion, where its direction and phase suggested that the mechanism likely involved both the otolith and semicircular canals. Further studies may provide a clue to the magnitude of the otolith and semicircular canal contributions.

Temporal dynamics of ocular torsion and vertical vergence during visual, vestibular, and visuovestibular rotations.

Ocular torsion and vertical divergence reflect the brain's sensorimotor integration of motion through the vestibulo-ocular reflex (VOR) and the optokinetic reflex (OKR) to roll rotations. Torsion and vergence however express different response patterns depending on several motion variables, but research on their temporal dynamics remains limited. This study investigated the onset times of ocular torsion (OT) and vertical vergence (VV) during visual, vestibular, and visuovestibular motion, as well as their relative decay rates following prolonged optokinetic stimulations. Temporal characteristics were retrieved from three separate investigations where the level of visual clutter and acceleration were controlled. Video eye-tracking was used to retrieve the eye-movement parameters from a total of 41 healthy participants across all trials. Ocular torsion consistently initiated earlier than vertical vergence, particularly evident under intensified visual information density, and higher clutter levels were associated with more balanced decay rates. Additionally, stimulation modality and accelerations affected the onsets of both eye movements, with visuovestibular motion triggering earlier responses compared to vestibular motion, and increased accelerations leading to earlier onsets for both movements. The present study showed that joint visuovestibular responses produced more rapid onsets, indicating a synergetic sensorimotor process. It also showed that visual content acted as a fusional force during the decay period, and imposed greater influence over the torsional onset compared to vergence. Acceleration, by contrast, did not affect the temporal relationship between the two eye movements. Altogether, these findings provide insights into the sensorimotor integration of the vestibulo-ocular and optokinetic reflex arcs.

Pattern Strabismus in a Tertiary Hospital in Southern China: A Retrospective Review.

Background and objectives: To analyze demographic and clinical features of pattern strabismus patients and assess the relationship among these clinical variables and risk factors. Materials and Methods: Medical records of pattern strabismus patients who had undergone strabismus surgery at our center between 2014 and 2019 were retrospectively reviewed. Data collected included gender, age at onset, age at surgery, refraction, Cobb angle, pre- and post-operative deviations in the primary position, up- and downgaze, angle of ocular torsion, type/amount of pattern, grade of oblique muscle function and presence/grade of binocular function. To verify the clinical significance of the Cobb angle, 666 patients who had undergone surgery within one week after ocular trauma between 2015 and 2021 were enrolled as controls. Results: Of the 8738 patients with horizontal strabismus, 905 (507 males and 398 females) had pattern strabismus, accounting for 10.36%. Among these 905 patients, 313 showed an A-pattern and 592 showed a V-pattern. The predominant subtype was V-exotropia, followed by A-exotropia, V-esotropia and A-esotropia. Over half of these patients (54.6%) manifested an A- or V-pattern in childhood. The overall mean ± SD Cobb angle was 5.03 ± 4.06° and the prevalence of thoracic scoliosis was 12.4%, both of which were higher than that observed in normal controls (4.26 ± 3.36° and 7.8%). Within A-pattern patients, 80.2% had SOOA and 81.5% an intorsion, while in V-pattern patients, 81.5% had IOOA and 73.4% an extorsion. Patients with binocular function showed decreases in all of these percent values. Only 126 (13.9%) had binocular function, while 11.8% of A-pattern and 15.1% of V-pattern patients still maintained binocular function. Pre-operative horizontal deviation was negatively correlated with binocular function (r = −0.223, p < 0.0001), while the grade of oblique muscle overaction was positively correlated with the amount of pattern (r = 0.768, p < 0.0001) and ocular torsion (r = 0.794, p < 0.0001). There were no significant correlations between the Cobb angle and any of the other clinical variables. There were 724 patients (80.0%) who had received an oblique muscle procedure and 181 (20.0%) who received horizontal rectus muscle surgery. The most commonly used procedure consisted of horizontal rectus surgery plus inferior oblique myectomy (n = 293, 32.4%), followed by isolated horizontal rectus surgery (n = 122, 13.4%). Reductions of pattern were 14.67 ± 6.93 PD in response to horizontal rectus surgery and 18.26 ± 7.49 PD following oblique muscle surgery. Post-operative deviations were less in V- versus A-pattern strabismus. Post-operative binocular function was obtained in 276 of these patients (30.5%), which represented a 16.6% increase over that of pre-operative levels. The number of patients with binocular function in V-pattern strabismus was greater than that of A-pattern strabismus (p = 0.048). Conclusions: Of patients receiving horizontal strabismus surgery, 10.36% showed pattern strabismus. In these patients, 54.6% manifested an A- or V-pattern in childhood, and V-exotropia was the most frequent subtype. Pattern strabismus patients showed a high risk for developing scoliosis. Cyclovertical muscle surgery was performed in 724 of these patients (80.0%), and horizontal rectus surgery was effective in correcting relatively small levels of patterns. Binocular function represented an important factor as being involved with affecting the occurrence and development of pattern strabismus.

Análisis de fiabilidad y concordancia entre 5 métodos subjetivos de medición de la torsión ocular / Reliability and agreement analysis among 5 subjective methods of ocular torsion measurement

Objetivo Evaluar la fiabilidad en la medición de la torsión ocular y la concordancia de los siguientes métodos subjetivos: test de Maddox bilateral, sinoptóforo, torsionómetro de Gracis, pantalla de Harms y test de ciclodesviaciones de Awaya. Método Se seleccionaron pacientes con estrabismo vertical adquirido en la edad adulta y se realizó la medición de la torsión ocular con los 5 métodos descritos en 3 ocasiones. Al no existir un gold standard en la medición subjetiva de la torsión ocular, se eligió como prueba de referencia aquella que obtuviera mejores datos de repetibilidad. Resultados Veinticinco pacientes fueron incluidos en el estudio. Se estudió la repetibilidad de cada prueba: test de Maddox bilateral (CCI=0,783, CV=29,33%), sinoptóforo (CCI=0,976, CV=6,71%), torsionómetro de Gracis (CCI=0,937, CV=20,10%), pantalla de Harms (CCI=0,962, CV=11,86%) y test de Awaya (CCI=0,987, CV=52,58%). La prueba de referencia para comparar la concordancia fue el sinoptóforo. Se encontraron diferencias estadísticamente significativas al comparar los rangos de torsión ocular entre el sinoptóforo y el torsionómetro de Gracis (p=0,008) y entre el sinoptóforo y el test de Awaya (p=0,02). Conclusiones El test de Maddox bilateral, el sinoptóforo, el torsionómetro de Gracis y la pantalla de Harms son métodos fiables con buenos índices de reproducibilidad. Entre ellos, el sinoptóforo es el método más consistente. El test de Awaya no demostró buena fiabilidad. El test de Maddox bilateral, el torsionómetro de Gracis y la pantalla de Harms fueron métodos con buena concordancia con el sinoptóforo, que se determinó como test de referencia. El test de Awaya no demostró buena concordancia con el sinoptóforo (AU)

Objective To evaluate the reliability in the measurement of ocular torsion and the agreement of the following subjective methods: double Maddox test, synoptophore, Gracis torsionometer, Harms screen and Awaya cyclodeviation test. Method Patients with vertical strabismus acquired in adulthood were recruited and ocular torsion was measured with the 5 methods described on 3 occasions. As a gold standard test does not exist, the one that obtained the best repeatability data was chosen as the reference test. Results Twenty-five patients were included in the study. The repeatability of each test was studied: double Maddox test (ICC=0.783, CV=29.33%), synoptophore (ICC=0.976, CV=6.71%), Gracis torsionometer (ICC=0.937, CV=20.10%), Harms screen (ICC=0.962, CV=11.86%) and Awaya test (ICC=0.987, CV=52.58%). The reference test to compare the agreement was the synoptophore. Statistically significant differences were found when comparing the ocular torsion ranges between the synoptophore and the Gracis torsionometer (P=.008) and between the synoptophore and the Awaya test (P=.02). Conclusion The double Maddox test, the synoptophore, the Gracis torsionometer, and the Harms screen are reliable methods with good reproducibility indices. Among them, the synoptophore is the most consistent method. The Awaya test did not show good reliability. The bilateral Maddox test, the Gracis torsionometer, and the Harms screen were methods with good agreement with the synoptophore, which was determined as the reference test. The Awaya test did not show good agreement with the synoptophore (AU)

Comparison of subjective cyclofusion ranges and objective ocular torsion in normal participants according to age.

PURPOSE: To investigate the relationship between subjective cyclofusion ranges and objective ocular torsion in normal participants according to age. METHODS: This cross-sectional study included 120 participants aged ≥ 20 years with no ocular diseases. The subjective cyclofusion ranges were measured centrifugally and centripetally in the direction of excyclotorsion and incyclotorsion, respectively, concurrently with rotational diplopia production by rotation using synoptophore. Disc fovea angle (DFA) was defined as the angle formed by two lines: a line passing through the center of the optic nerve papilla and fovea and a horizontal line passing through the center of gravity of the optic papilla using fundus photographs. RESULTS: The participants were aged 49.1 ± 17.7 years. The total cyclofusion centrifugal (sum of extorsion and intorsion) and centripetal ranges were 10.9 ± 2.2° and 7.2 ± 1.8°, respectively, both of which decreased in participants in their 60 s and 70 s (p < 0.01). The DFA was - 7.0 ± 3.4° in the right eye (- : excyclo, + : incyclo) and - 8.0 ± 3.2° in the left, which was associated with age (p < 0.001). The correlation between the DFA and centrifugal (r = - 0.13, p = 0.16) and centripetal (r = - 0.002, p = 0.99) cyclofusion ranges of extorsion was not significantly different. The centrifugal (r = 0.37, p < 0.001) and centripetal (r = 0.40, p < 0.001) cyclofusion ranges of intorsion were positively correlated. CONCLUSION: Subjective cyclofusion ranges decreased in both extorsion and intorsion in the elderly. Objective ocular torsion showed excyclotorsion with age. When strabismus surgery is performed in elderly patients with torsional strabismus, the decrease in subjective cyclofusion ranges should be considered.

Reliability and agreement analysis among 5 subjective methods of ocular torsion measurement.

OBJECTIVE: To evaluate the reliability in the measurement of ocular torsion and the agreement of the following subjective methods: double Maddox test, synoptophore, Gracis torsionometer, Harms screen and Awaya cyclodeviation test. METHOD: Patients with vertical strabismus acquired in adulthood were recruited and ocular torsion was measured with the 5 methods described on three occasions. As a gold standard test does not exist, the one that obtained the best repeatability data was chosen as the reference test. RESULTS: 25 patients were included in the study. The repeatability of each test was studied: double Maddox test (ICC = 0.783, CV = 29.33%), synoptophore (ICC = 0.976, CV = 6.71%), Gracis torsionometer (ICC = 0.937, CV = 20.10%), Harms screen (ICC = 0.962, CV = 11.86%) and Awaya test (ICC = 0.987, CV = 52.58%). The reference test to compare the agreement was the synoptophore. Statistically significant differences were found when comparing the ocular torsion ranges between the synoptophore and the Gracis torsionometer (p = 0.008) and between the synoptophore and the Awaya test (p = 0.02). CONCLUSIONS: The double Maddox test, the synoptophore, the Gracis torsionometer, and the Harms screen are reliable methods with good reproducibility indices. Among them, the synoptophore is the most consistent method. The Awaya test did not show good reliability. The bilateral Maddox test, the Gracis torsionometer, and the Harms screen were methods with good agreement with the synoptophore, which was determined as the reference test. The Awaya test did not show good agreement with the synoptophore.

Bechterew's Phenomenon in Bilateral Sequential Vestibular Neuritis: A Report of Two Cases.

The brain can compensate for the vestibular imbalance. When the unilateral labyrinthine function is lost, the asymmetry between the peripheral vestibular inputs is compensated centrally by readjusting the signal difference from both ears and regaining vestibular balance. If the other healthy labyrinth is destroyed, the vestibular nuclei become imbalanced again, creating spontaneous nystagmus even though there is no input to the vestibular nuclei from either labyrinth. This is called Bechterew's phenomenon; a rare and not widely recognized phenomenon that occurs in cases of bilateral sequential vestibular neuritis. This is of clinical importance because spontaneous nystagmus with bilaterally absent or diminished caloric responses may give a misleading impression of a central lesion rather than a second peripheral lesion superimposed upon the effects of central compensation for the first. Although well-documented in experimental animals, this phenomenon rarely occurs in human beings. The objective of this study is to highlight the characteristics and the progression of test results from two patients from our own experience. Along with careful history taking and physical examination, a complex interpretation of various vestibular function tests, including induced nystagmus, head impulse test, caloric test, and fundus photography, is needed to make an accurate diagnosis of bilateral sequential vestibular neuritis (BSVN).

Minimal detectable change of the disc-fovea angle for ocular torsion assessment.

PURPOSE: The disc-fovea angle (DFA) is used as a relevant indicator of ocular torsion change in cyclovertical strabismus. However, interpretation of the variation in time must differentiate whether a real change has occurred or if the disparity is due to random measurement error. The aim of the study was to obtain the minimal detectable change (MDC) of the DFA. It represents the minimal variation between two measurements that may be considered a real ocular torsion change. METHODS: A prospective cross-sectional study was conducted in San Carlos Clinical Hospital of Madrid, Spain. Sixty healthy right eyes from 60 patients (31 men and 29 women) were recruited. Three digital fundus photographs were obtained, and between measurements, the patient moved their head away from the head support and then returned. Two observers quantified the DFA with software designed with MATLAB. Test-retest and interrater reliability were calculated. RESULTS: Mean participant age was 56.1 years (SD 16.6, range 25-85). Mean DFA was 8.1° (SD 3.5, range 1.3-18.5). Test-retest reliability for Observer 1 (Ob1), Observer 2 (Ob2) and interrater reliability were excellent (ICC 0.80, 0.83 and 0.95, respectively). Precision was 2.9° (Ob1) and 3.0° (Ob2), and the MDC95 was 4.1° (Ob1) and 4.2° (Ob2). Bland-Altman analysis revealed an absence of bias and a homoscedastic distribution of the differences. CONCLUSIONS: The MDC of the DFA in fundus photography was 4°, which represents the minimal change that may be considered a real change in ocular torsion. This result may improve the interpretation of ocular torsion changes in surgery and clinical scenarios.

A simple marking system for accurate intraoperative monitoring and adjustment of cyclotorsion strabismus surgery.

Ocular cyclotorsion is treatable only with surgery. The surgical procedure must be tailored individually to the specific etiologies causing the horizontal and vertical strabismus and its torsional components. An adjustable surgical approach is often used for postoperative or intraoperative adjustments. However, the methods currently used have some limitations. In this study, we propose a simple intraoperative marking system for all cyclotorsion correction surgery. The proposed marking system used three sets of surface markers: external horizontal markings, ocular horizontal markings, and surgical torsion markings, drawn in sequence. We retrospectively analyzed the surgical results using this novel marking system in this single-center, single-surgeon study. Fifteen patients with cyclotorsion who underwent treatment using the proposed marking system as an intraoperative aid between August 2019 and August 2021 were included. The medical charts were thoroughly reviewed, and the pre-and postoperative subjective and objective cyclotorsion were analyzed. Among the study subjects (10 males, 5 females; age range: 6-89 years), 13 had excyclotorsion and 2 incyclotorsion. Preoperative mean net subjective cyclotorsion measured by the double Maddox rod (DMR) test was 6.0° (standard deviation: 10.8°) and mean net disc-to-fovea angle (DFA) was 20.23° (13.21°). The postoperative net DMR and DFA were 0.2° (2.1°) and 14.09° (5.97°), respectively. The mean absolute net DMR and DFA being treated were 9.8° (4.8°) and 9.76° (4.61°). Overall, the proposed intraoperative marking system is a simple and quantitative method to assess, monitor, and adjust the torsional aspect for all strabismus surgeries.

Comparison of the objective ocular torsion measured with GMPE module-based OCT and fundus color photography / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To compare the consistency and feasibility of objective ocular torsion measured with GMPE module-based optical coherence tomography(OCT)and fundus color photography(FCP).METHODS: Patients were enrolled in our strabismus clinic from December 2020 to March 2021, and the objective ocular torsion of the eyes was measured by both GMPE module-based OCT and FCP on the same day. FCP was used to measure the fovea-disc angle(FDA)manually by using the Adobe Photoshop software, while the GMPE module-based OCT software positioned automatically the macula and the center of the optic disc to measure the FDA.RESULTS: Fifty-five patients were included, the FDA measured by OCT was -6.6°±4.5° in the right eye and -8.8°±4.7° in the left eye, respectively; The FDA measured by FCP was -6.6°±4.7° in the right eye and -8.4°±4.1° in the left eye, respectively, with no statistically significant difference between the results of the two methods(Pright eye=0.90, Pleft eye=0.08). In patients with exotropia, the FDA measured by OCT was -5.8°±4.9° in the right eye and -9.1°±4.5° in the left eye, respectively, the FDA measured by FCP was -5.7°±5.0° in the right eye and -8.6°±4.3° in the left eye, respectively,(Pright eye=0.75, Pleft eye=0.15). Similarly, the patients with esotropia, the FDA measured by OCT was -9.0°±7.3° in the right eye and -11.3°±3.5° in the left eye, respectively, while the FDA measured by FCP was -10.0°±7.0° in the right and -10.1°±2.8° in the left eye(Pright eye=0.21, Pleft eye=0.10), respectively. There were no significant differences between the two methods in patients with esotropia or exotropia(P>0.05). The results of both Pearson test and Bland-Altman analysis were highly correlated(rright eye=0.93, rleft eye=0.94, P<0.01). CONCLUSION: GMPE module-based OCT can be used for objective ocular torsion measurement with high reliability and reproducibility, and is a promising clinical alternative to the fundus color photographic method.

Resolution of Diplopia and Torsion Following Yttrium Aluminum Garnet (YAG) Laser Capsulotomy in a Patient With the Ocular Tilt Reaction.

The ocular tilt reaction is a rare neuro-ophthalmological phenomenon commonly occurring due to an injury to the vestibulo-ocular pathway, or a thalamic, brainstem, or cerebellar lesion. Most ocular tilt reactions are transient and demonstrate spontaneous recovery. This report documents the immediate resolution of diplopia and the patient's ocular tilt reaction following visual recovery from left yttrium aluminum garnet laser capsulotomy.

The effect of uncorrected ametropia on ocular torsion induced by changes in fixation.

BACKGROUND AND OBJECTIVE: Ocular torsion, the eye movements to rotating around the line of sight, has not been well investigated regarding the influence of refractive errors. The purpose of this study was to investigate the effect of uncorrected ametropia on ocular torsion induced by fixation distances. METHODS: Seventy-two subjects were classified according to the type of their refractive error, and ocular torsion of the uncorrected eye was compared based on changes induced by different fixation distances. Ocular torsion was measured using a slit-lamp biomicroscope equipped with an ophthalmic camera and a half-silvered mirror. RESULTS: In all groups, excyclotorsion values increased as the fixation distance decreased, but the myopia and astigmatism groups had larger amounts of ocular torsion than the emmetropia group. In addition, as the amount of uncorrected myopia and astigmatism increased, the amount of ocular torsion increased. CONCLUSION: Since the amount of ocular torsion caused by a change to a shorter fixation distance was larger when the refractive error was uncorrected, we suggest that ametropia should be fully corrected in patients frequently exposed to ocular torsion due to changes in fixation distance.

Non-invasive recognition of eye torsion through optical imaging of the iris pattern in ocular proton therapy.

The introduction of non-invasive imaging techniques such as MRI imaging for treatment planning and optical eye tracking for in-room eye localization would obviate the requirement of clips implantation for many patients undergoing ocular proton therapy. This study specifically addresses the issue of torsional eye movement detection during patient positioning. Non-invasive detection of eye torsion is performed by measuring the iris pattern rotations using a beams eye view optical camera. When handling images of patients to be treated using proton therapy, a number of additional challenges are encountered, such as changing eye position, pupil dilatation and illumination. A method is proposed to address these extra challenges while also compensating for the effect of cornea distortion in eye torsion computation. The accuracy of the proposed algorithm was evaluated against corresponding measurement of eye torsion using the clips configuration measured on x-ray images. This study involves twenty patients who received ocular proton therapy at Paul Scherrer Institute and it is covered by ethical approval (EKNZ 2019-01987).

Can Imaging of Temporal Raphe Orientation with fundusphotos or SD-OCT be helpful for the Assessment of Ocular Torsion in Patients with Cranial Nerve Four Paresis?

Strabismic deviations can be horizontal, vertical, cyclorotational, or a combination of all three. Previous literature has established the difference between subjective and traditional objective torsional angles; however, often there is a failure to consider the physiological position of a normal fovea-optic nerve head (ONH) relationship. Using the temporal raphe (TR) orientation has been suggested as a solution for this discrepancy. The current study, approved by IWK Health Center research ethics board was created to assess the viability of using the TR in assessment of ocular torsion as well as investigate the effect of the physiological position of the fundus. Subjective tests were compared to traditional fundus photographs and novel TR scans in patients with long-standing unilateral fourth nerve palsies. Results found no differences between subjective and objective angles when considering the physiological fundus position and that TR angles were not comparable to other torsional testing methods. Therefore, it was concluded that the physiological position should be considered when determining the true amount of abnormal fundus torsion. As well, we found no significant value to using TR imaging by optical coherence tomography compared to the traditional fovea-ONH relationship by fundus photography to assess ocular torsion.

Objective cyclodeviation measurement in normal subjects by means of Cyclocheck® application.

PURPOSE: To evaluate the range of cyclodeviation in normal individuals by means of Cyclocheck® application recently designed by the authors and freely available at www.cyclocheck.com. METHODS: Healthy subjects with normal muscle balance, best-corrected visual acuity of ⩾0.8, and stereopsis on Randot charts of ⩽100 s of arc were included in the study. Two separate digital fundus photographs were taken of each eye of every patient. The disk-foveal angle was calculated using the Cyclocheck® application. The average result of the disk-foveal angle measurements were considered for data analysis. RESULTS: A total of 131 patients met inclusion criteria for the study population. The mean value of the disk-foveal angle in the whole study group (both right and left eye) was 6.39° ± 2.72° with 5.26° ± 2.56° (range from -0.4° to 12.55°) in the right eye and 7.52° ± 2.39° (range from 1.25° to 12.76°) in the left eye. The mean value of the disk-foveal angle of the left eye was greater by 2.26° than that of the right eye. CONCLUSION: Cyclocheck® software allows easy assessment of cyclodeviation. Normal individuals present with a positive value of the disk-foveal angle with a certain spread of the results. The analysis of obtained measurements revealed a significant asymmetry between both eyes with the left eye being more excyclodeviated in an otherwise orthotropic population, which remains a subject for further investigations.

Surgical treatment for small-angle vertical strabismus.

To assess the indications for and results obtained with partial vertical recti muscle recession in patients with diplopia and small-angle vertical strabismus. Retrospective study of patients who underwent partial temporal or nasal recession of the superior rectus (SR) or inferior rectus (IR). Outcome was considered favorable when diplopia had resolved in primary position and downward gaze at the end of the follow-up. A total of 17 cases were included. Mean age was 69.11 years (47% women). The diagnoses were fourth nerve paresis (6), hypertropia (3), incomplete third nerve paresis (3), sagging eye (1), age-related strabismus (1), ocular myasthenia gravis (1), and restrictive strabismus after retinal surgery (2). Mean preoperative vertical deviation was 6.11 pd in primary position, and postoperative vertical deviation was 2.05 (the mean difference was statistically significant, p < 0.001). Surgery was performed on the right eye in 29.41% of patients and on the left eye in 70.58%. The SR was treated in 11 cases (temporal pole in 7 and nasal in 4) and the IR in 6 (temporal pole in 3 and nasal in 3). Mean recession was 4.14 mm ± 0.42. Outcome was favorable in 76.47% of cases at the end of the follow-up (mean, 10 months), and the previous torsion was eliminated in 5. No overcorrections were recorded. Partial SR or IR recessions were successful in most cases of small-angle vertical strabismus. There were no overcorrections in primary position gaze.

Effect of unilateral inferior oblique weakening on fundus torsion in bilateral eyes of children with congenital superior oblique palsy.

AIM: To study the change of torsion in both eyes after unilateral inferior oblique (IO) weakening on children with congenital superior oblique palsy (SOP). METHODS: This retrospective study enrolled all patients diagnosed with unilateral congenital superior oblique palsy (UCSOP) accompanied by inferior oblique overaction (IOOA). A total of 120 eyes of 60 patients were divided into group 1 (more extorted paretic eye) and group 2 (more extorted nonparetic eye). The degree of fundus torsion was evaluated before and 1mo after the IO weakening procedure. The torsion of the fundus was recorded by measuring the disk-foveal angle (DFA) using fundus photography. RESULTS: Group 1 included 26 cases and group 2 included 34 cases, thus the rate of extorsion was insignificantly higher in the nonparetic eye (P=0.10). The preoperative DFA in the paretic and nonparetic eyes was 13.21±5.95, 7.97±4.25 in group 1, and 4.65±3.79, 13.16±5.35 in group 2 (both P<0.001). The postoperative DFA in the paretic and nonparetic eyes was 8.57±4.87, 7.32±4.27 in group 1 (P=0.24), and 3.85±6.00 and 9.94±5.45 in group 2 (P<0.001). The amount of postoperative reduction of the DFA in the paretic and nonparetic eyes was 4.64±3.90, 0.65±0.76 in group 1 (P=0.002), and 0.80±0.81, 3.21±5.50 in group 2 (P=0.01). The difference in the amount of reduction of DFA in the more extorted eye in group 1 (paretic eye) vs group 2 (nonparetic eye) was insignificant (P=0.30). CONCLUSION: Excyclotorsion in the nonparetic eye has a similar probability in the paretic eye in UCSOP children, and weakening of the ipsilateral IO has a more obvious effect on the decrement of extorsion in the more extorted eye regardless of which eye is paretic.

A Novel Method for Evaluation of Ocular Torsion Angle by Optical Coherence Tomography.

Purpose: The Glaucoma Module Premium Edition (GMPE) software for the SPECTRALIS optical coherence tomography (OCT) is able to automatically track the anatomic centers of both the fovea and the optic disc. We investigated the efficacy of the OCT in measuring the ocular torsion angle before and after strabismus surgery. Methods: Between June 2017 and December 2018, 40 patients with cyclodeviation who had undergone strabismus surgery at Hyogo College of Medicine were enrolled. Ocular torsion angle measurements, including OCT and nonmydriatic fundus camera for objective measurements and synoptophore for subjective measurements, were performed before surgery and 1 day after surgery. Results: The ocular torsion angles were measured as follows: synoptophore preoperative (-8.8° ± 4.1°) and postoperative (-3.1° ± 2.8°), fundus photography preoperative (-27.2° ± 6.4°) and postoperative (-18.6° ± 5.9°), and OCT preoperative (-25.9° ± 6.8°) and postoperative (-18.2° ± 5.8°). In all cases, symptoms related to cyclodeviation resolved postoperatively. All measurements were positively correlated before surgery. Postoperatively, changes in all measurements were also correlated. However, all synoptophore-related data were underestimated when compared with OCT and fundus photography. Conclusions: For measuring the ocular torsion angle, the OCT-based technology GMPE appears to provide information regarding anatomic fundus torsion that is similar to that obtained using fundus photography. Translational Relevance: This new objective measurement for the ocular torsion angle is helpful for treating cyclotropia.

Contralesional subjective visual horizontal predicts endolymphatic hydrops.

Background: The subjective visual horizontal (SVH) is a test of utricular function that assesses conjugate ocular torsion which is a component of the ocular tilt reaction (OTR). In unilateral destructive peripheral vestibular lesions, the OTR and so the SVH tilt is usually ipsiversive.Aims/objective: Our study aimed to profile the causes of a contraversive SVH tilt in patients with a confirmed unilateral peripheral vestibular deficit.Materials and methods: The clinical records, nystagmus and vestibular investigation characteristics of 52 patients with a unilateral canal paresis (CP) on caloric of ≥30%, a contraversive SVH tilt of ≥4 degrees and at least one pure tone audiometry were retrospectively analysed.Results: The most common diagnosis of patients (n = 39) with a contraversive SVH and ipsilesional CP was endolymphatic hydrops: 35 (67.3%) had Meniere's disease (MD) and 4 (7.7%) had delayed endolymphatic hydrops (DEH). The remaining 13 (25%) of cases had other peripheral aetiologies or an unknown diagnosis. 16 (30.8%) patients had ictal spontaneous nystagmus at the time of SVH or caloric testing.Conclusions and significance: A contraversive SVH with unilateral CP suggests endolymphatic hydrops.