Major Amblyoscope Research Articles

Influence of eye dominance on objective and subjective excyclotorsion in unilateral superior oblique muscle palsy: objective cyclotorsion measured by fundus photography.

To study the effect of eye dominance on excyclotorsion in unilateral superior oblique palsy (USOP). Retrospective clinical study METHODS: Objective excyclotorsion was measured as the disc-to-fovea angle by fundus photography OU. Subjective excyclotorsion was determined with a major amblyoscope based on the difference in the earth vertical and subjective visual vertical. Eye dominance was determined by the hole-in-the-card method. A p-value ≤ 0.05 was considered statistically significant. Data of 24 USOP patients were retrospectively collected. The diagnosis was mainly made by the Parks 3-step method, history and the presence of characteristic excyclotorsion. When possible, orbital magnetic resonance imaging findings were obtained. The median angle of objective excyclotorsion in the paretic eyes was significantly larger than in the nonparetic eyes. Both median angles of objective/subjective excyclotorsion in the dominant eye were significantly smaller than those of the non-dominant eye. Patients were subdivided into two groups: group A, those whose paretic eye was the dominant eye (n = 13); group B, those whose paretic eye was the non-dominant eye (n = 11). The objective/subjective excyclotorsional angles of the paretic eye were significantly larger than of the non-paretic eye only in group B. In USOP the angle of excyclotorsion in the dominant eye is smaller than in the non-dominant eye. This may imply that the vertical sense of visual space is mainly adapted to the dominant eye, keeping the subjective vertical close to the earth vertical.

Differences in the Stimulus Accommodative Convergence/Accommodation Ratio using Various Techniques and Accommodative Stimuli

ABSTRACTPurpose: To investigate differences in the stimulus accommodative convergence/accommodation (AC/A) ratio using various techniques and accommodative stimuli, and to describe a method for determining the stimulus AC/A ratio.Methods: A total of 81 subjects with a mean age of 21 years (range, 20–23 years) were enrolled. The relationship between ocular deviation and accommodation was assessed using two methods. Ocular deviation was measured by varying the accommodative requirement using spherical plus/minus lenses to create an accommodative stimulus of 10.00 diopters (D) (in 1.00 D steps). Ocular deviation was assessed using the alternate prism cover test in method 1 at distance (5 m) and near (1/3 m), and the major amblyoscope in method 2. The stimulus AC/A ratios obtained using methods 1 and 2 were calculated and defined as the stimulus AC/A ratios with low and high accommodation, respectively, using the following analysis method. The former was calculated as the difference between the convergence response to an accommodative stimulus of 3 D and 0 D, divided by 3. The latter was calculated as the difference between the convergence response to a maximum (max) accommodative stimulus with distinct vision of the subject and an accommodative stimulus of max minus 3.00 D, divided by 3.Results: The median stimulus AC/A ratio with low accommodation (1.0 Δ/D for method 1 at distance, 2.0 Δ/D for method 1 at near, and 2.7 Δ/D for method 2) differed significantly among the measurement methods (P < 0.01). Differences in the median stimulus AC/A ratio with high accommodation (4.0 Δ/D for method 1 at distance, 3.7 Δ/D for method 1 at near, and 4.7 Δ/D for method 2) between method 1 at distance and method 2 were statistically significant (P < 0.05), while method 1 at near was not significantly different compared with other methods.Conclusions: Differences in the stimulus AC/A ratio value were significant according to measurement technique and accommodative stimuli. However, differences caused by measurement technique may be reduced by using a high accommodative stimulus during measurements.

Comparison of Three Vision Therapy Approaches for Convergence Insufficiency.

Purpose:We compared the effectiveness of three active vision therapy approaches for convergence insufficiency (CI).Methods:This randomized clinical trial included patients meeting the eligibility criteria and with symptomatic CI, who were allocated into three groups. In the home-based vision orthoptic therapy (HBVOT) group, patients performed the pencil push-up procedure 15 min/day for 5 days/week. In the office-based vision orthoptic therapy (OBVOT) group, patients underwent 60-min orthoptic therapy using a major amblyoscope twice weekly with additional home orthoptic therapy. In the augmented office-based vision orthoptic therapy (AOBVOT) group, patients performed orthoptic exercises using 3-diopter over-minus lenses and a base-out prism in addition to major amblyoscope therapy, and additional home reinforcement was prescribed during the same time period.Results:All 84 subjects (mean age, 26.8 ± 8.3 years) showed a statistically significant improvement in near exophoria, positive fusional vergence (PFV) at near, near point of convergence (NPC), stereoacuity, and Convergence Insufficiency Symptom Survey (CISS) scores at follow-up. Exophoria decreased by 64%, 68%, and 85% in the HBVOT, OBVOT, and AOBVOT groups, respectively (P = 0.2). PFV increased by 68%, 100%, and 100% in the HBVOT, OBVOT, and AOBVOT groups, respectively (P < 0.001). NPC decreased (improved) by 86%, 89%, and 96% in the HBVOT, OBVOT, and AOBVOT groups, respectively (P = 0.4). The CISS scores decreased by 75%, 96%, and 100% in the HBVOT, OBVOT, and AOBVOT groups, respectively (P = 0.003).Conclusion:Our results showed that in adults with CI, the augmented office-based orthoptic treatment was relatively more effective than the other treatments.

Relationship of Hypertropia and Excyclotorsion in Superior Oblique Palsy

PurposeTo evaluate the correlation between hypertropia and excyclotorsion in acquired superior oblique palsy (SOP).MethodsThirty-one patients with acquired unilateral SOP were recruited for this study. The torsional angle of each patient was assessed via one objective method (fundus photography) and two subjective methods (double Maddox rod test and major amblyoscope). The patient population was divided into two groups (concordance group, n = 19 and discordance group, n = 12) according to the correspondence between the hypertropic eye (paralytic eye) and the more extorted eye (non-fixating eye), which was evaluated by fundus photography.ResultsThe mean value of objective torsion was 5.09° ± 3.84°. The subjective excyclotorsion degrees were 5.18° ± 4.11° and 3.65° ± 1.93° as measured by double Maddox rod test and major amblyoscope, respectively. Hypertropia and the excyclotorsional angle did not differ significantly between the groups (p = 0.257). Although no correlation was found in the discordance group, the concordance group showed a significant and positive correlation between hypertropia and excyclotorsion (p = 0.011).ConclusionsTorsional deviation was not related to hypertropia. However, in the concordance patients in whom the hypertropic eye showed excyclotorsion, a significant positive correlation was found between hypertropia and excyclotorsion.

Analysis of 54 cases of amblyopia of children treated by using Huaiqihuang Granules combined with Auricular Point Pressing

Objective To observe the effect of the therapy of using Huaiqihuang Granules combined with Auricular Point Pressing for children in amblyopia. Methods Amblyopia in children of our clinic as a treatment group (54 cases, total 88 eyes), the treatment group was treated by using Huaiqihuang Granules combined with Auricular Point Pressing. The control group was treated by using SI LI BA combined with major amblyoscope (46 cases, total 76 eyes). And analysing the amblyopia type, the degree of amblyopia, the nature of amblyopia watch. Results The basic cure rate and total effective rate in treatment group were 65.9% and 95.5%, and its in control group were 50% and 84.2%. Between two groups,the basic cure rate of treatment group was significantly better than that in control group (P＜ 0.05). The effect of treatment was better for the ametropic and anisometropic amblyopia, center fixation, but it was poor in strabismic amblyopia, paracentral fixation. The lighter degree of amblyopia had the better effect. Conclusions Compared with western medicine, traditional chinese medicine shows outstanding advantages in treatment, Huaiqihuang Granules combined with Auricular Point Pressing is an safe and effective TCM therapy for the children with amblyopia, the therapy has convenient usage, fast and remarkable effect, which is worth clinical application and further study. Key words: Amblyopia/TCM therapy; Amblyopia/Acupuncture; Huaiqihuang Granules/thera peutic effect; Auricular Point; Children

A novel apparatus for testing binocular function using the ‘CyberDome’ three-dimensional hemispherical visual display system

Virtual reality has recently been highlighted as a promising medium for visual presentation and entertainment. A novel apparatus for testing binocular visual function using a hemispherical visual display system, 'CyberDome', has been developed and tested. Subjects comprised 40 volunteers (mean age, 21.63 years) with corrected visual acuity of -0.08 (LogMAR) or better, and stereoacuity better than 100 s of arc on the Titmus stereo test. Subjects were able to experience visual perception like being surrounded by visual images, a feature of the 'CyberDome' hemispherical visual display system. Visual images to the right and left eyes were projected and superimposed on the dome screen, allowing test images to be seen independently by each eye using polarizing glasses. The hemispherical visual display was 1.4 m in diameter. Three test parameters were evaluated: simultaneous perception (subjective angle of strabismus), motor fusion amplitude (convergence and divergence), and stereopsis (binocular disparity at 1260, 840, and 420 s of arc). Testing was performed in volunteer subjects with normal binocular vision, and results were compared with those using a major amblyoscope. Subjective angle of strabismus and motor fusion amplitude showed a significant correlation between our test and the major amblyoscope. All subjects could perceive the stereoscopic target with a binocular disparity of 480 s of arc. Our novel apparatus using the CyberDome, a hemispherical visual display system, was able to quantitatively evaluate binocular function. This apparatus offers clinical promise in the evaluation of binocular function.

The effects of interocular differences in retinal illuminance on vision and binocularity

It is known that binocular function is affected by interocular differences in retinal image size, shape, clarity, and illumination. The present study was performed to systematically examine the effects of interocular differences in retinal illuminance on monocular visual acuity, fusion, and stereopsis. Fifty adults with normal binocularity and a best-corrected visual acuity of 20/20 or better were enrolled. We examined best-corrected visual acuity, fusion, and stereoacuity as monocular retinal illuminance was gradually reduced by increasing neutral density filters from 0.2 neutral density (ND; 63% transmission) to 3.0 ND (0.1% transmission) in increments of 0.2 ND. We measured the smallest size of fusion slide by major amblyoscope, and evaluated stereoacuity with the Titmus test and the Lang test. The best-corrected visual acuity began to decrease significantly when the value of the neutral density filter reached 2.0 ND (1% transmission; p<0.01). The level of fusion decreased significantly when monocular retinal illuminance was reduced to 2.0 ND (p<0.01). Stereoacuity began to decline significantly when the value of the neutral density filter was 1.4 ND (4% transmission) with the Titmus test and 1.6 ND (2.5% transmission) with the Lang test. A binocularly conducted Titmus test was the most sensitive to the presence of monocularly induced retinal illuminance deterioration.

ＡＣ／Ａ比の正常値とその加齢変化について 交代固視下ｍａｊｏｒ ａｍｂｌｙｏｓｃｏｐｅ法を用いて

ＡＣ／Ａ比の正常値とその加齢変化について 交代固視下ｍａｊｏｒ ａｍｂｌｙｏｓｃｏｐｅ法を用いて

動的立体視について

Dynamic stereopsis in 94 patients with amblyopia or esotropia was studied with the Synopto-five, a new major amblyoscope employing computer graphics. The findings for dynamic stereopsis were compared with those for other binocular functions.The results were as follows:1) Dynamic stereopsis could not be found in approximately half of the subjects.2) Patients with accommodative esotropia displayed better dynamic stereopsis than patients with partial accomodative esotropia.3) In cases of amblyopia, patients with anisometropic amblypia showed better dynamic stereopsis than patients with strabismic amblyopia.4) Patients with micro-abnormal retinal correspondence showed poorer dynamic stereopsis than patients with N. R. C.5) Evidence of a correlation between dynamic stereopsis and static stereopsis was found.

Efficacy of Computerized Vergence Therapy

The purpose of this study was to determine the efficacy of computerized fusional vergence therapy and the effect of two different vergence training velocities. Six subjects received positive vergence training using a slow vergence training rate (0.75 delta/s) and six subjects received positive vergence training using a fast vergence training rate (5.00 delta/s). Six subjects served as controls and did not receive therapy. The duration of therapy was 80 min over a period of 4 weeks. All training activities were monitored. All vergence evaluations were double masked. Subjects using a slow training rate showed significant increases in positive vergence ranges as measured with the major amblyoscope, whereas subjects training with fast rates did not. We conclude that vergence therapy using a computerized video display is an effective technique for increasing the amplitudes of positive fusional vergence and that slower rates are more productive than faster rates.

Diagnosis and measurement of cyclodeviation.

A simple, convenient, and accurate method of detecting and measuring even the smallest degree of cyclodeviation with the help of two special major amblyoscope slides is described. Routine use of these slides in the investigation of all paralytic squints to detect and measure cyclodeviation is suggested. This will prove useful in the correct diagnosis and in the adequate management of a case of cyclovertical muscle palsy.

The binocular function as an indicator for the success of and need for unilateral contact lenses.

Ninety‐five patients were referred for fitting with unilateral contact lenses. One half of the patients had non‐traumatic aphakia, a quarter of them had traumatic aphakia, and the rest had anisometropia or reduced vision for other reasons. Wearing a trial lens, all patients were examined at the major amblyoscope, prior to prescription.In prescribing a unilateral contact lens, the aim is to re‐establish a useful binocular vision. Pre‐existence of certain qualities of binocularity is thus considered to be a prerequisite for success. In consequence of this, about 30% of the patients were rejected primarily, mainly because of strabismus. This rather high frequency exceeds the general incidence of squint and points to the fact that the fusional range, even in adults, may disorganize when one eye has been deprived of useful vision. To prove this hypothesis, a contact lens was tried in a number of patients even though their binocular state was doubtful. Follow‐up studies demonstrated that simultaneous perception near zero degree, a fusional range around 20 pd. and stereopsis were found to have an ever increasing rate through the groups of unsuccessful to successful cases. Thus, an orthoptic study must not be underestimated as an indicator for the success of. unilateral contact lens prescription.

A Critical Evaluation of the Major Amblyoscope

Click to increase image sizeClick to decrease image sizeMajor amblyoscope;artifacts sensory anomalies;orthoptics

La Convergenza Fusionale come criterio di identificazione biologica del Gemello Guida

SUMMARYThe Authors have studied 87 pairs of MZ-twins, determining for each individual the values of both Fusional Convergence (FC) and Simultaneous Macular Perception (SMP) by means of the major amblyoscope. They have found a high degree of discordance in the FC, corresponding to 80,5 per cent, while the SMP showed a lower degree of discordance (17,2 per cent.). The Authors have observed that the highest values of FC mostly belong to the “leader twin”; they make the hypothesis that the unusual discordance of the FG in the MZ-twins depends on a higher level of will in the “leader twin”, thus representing a test of psychological discrimination between MZ-twins.

Modified major amblyoscope.

Modified major amblyoscope.