Electrical Microstimulation of the Superior Colliculus in Strabismic Monkeys.

PURPOSE: Visually guided saccades are disconjugate in human and nonhuman strabismic primates. The superior colliculus (SC) is a region of the brain topographically organized in visual and motor maps where the saccade goal is spatially coded. The present study was designed to investigate if a site of stimulation on the topographic motor map was evoking similar or different saccade vectors for each eye. METHODS: We used microelectrical stimulation (MS) of the SC in two strabismic (one esotrope and one exotrope) and two control macaques under binocular and monocular viewing conditions. We compared the saccade amplitudes and directions for each SC site and each condition independently of the fixating eye and then between each fixating eye. A comparison with disconjugacies of visually guided saccades was also performed. RESULTS: We observed different saccade vectors for the two eyes in strabismic monkeys, but conjugate saccades in normal monkeys. Evoked saccade vectors for the left eye when that eye was fixating the target were different from those of the right eye when it was fixating. The disconjugacies evoked by the MS were not identical but similar to those observed for visually guided saccades especially for the dominant eye. CONCLUSIONS: Our results suggest that, in strabismus, the saccade generator does not interpret activation of a single location of the SC as the same desired displacement for each eye. This finding is important for advancing understanding of the development of neural circuits in strabismus. French Abstract.

Tratamiento del estrabismo paralítico con toxina botulínica A / Treatment of paralytic strabismus with botulinum toxin A

Objetivos: evaluar los resultados obtenidos con el uso de la toxina botulínica A en la corrección del estrabismo paralítico e identificar los factores asociados que influyen sobre la respuesta terapéutica. Métodos: se realizó un estudio descriptivo en una serie de 93 casos con estrabismo paralítico, que recibieron tratamiento con toxina botulínica A. Resultados: se diagnosticaron 53 casos con estrabismo leve, 38 moderado y solo dos en estado grave. El tiempo de evolución y la gravedad clínica fueron los factores asociados que interfirieron con la respuesta terapéutica. Conclusiones: la toxina botulínica A es efectiva en la mayoría de los casos tratados. Los mejores resultados se obtienen en los casos con menor grado de desviación y con menor tiempo de evolución entre el inicio del estrabismo y la inyección del medicamento(AU)

Objectives: to assess the results of the use of botulinum toxin A in correcting paralytic strabismus and to identify those associated factors that have an impact on the therapeutic response. Methods: a descriptive study of a series of 93 cases with paralytic strabismus which were treated with botulinum toxin A. Results: fifty three cases were diagnosed with mild, 38 with moderate and just two with severe strabismus. The time of progression and the clinical severity were related factors that influence the therapeutic response. Conclusions: botulinum toxin A is effective in most of cases. The best results are achieved in those people with lower deviation degree and less time of progression elapsed from the onset of strabismus to the administration of the injected medication(AU)

Efectividad de remedios homeopáticos en niños operados de estrabismo / Effectiveness of homeopathic remedies in children operated for strabismus

Se realizó una intervención terapéutica en 100 pacientes operados de estrabismo, atendidos en la consulta oftalmológica del Hospital Infantil Sur de Santiago de Cuba, desde octubre del 2006 hasta igual periodo del 2013, a fin de evaluar la efectividad del tratamiento homeopático en ellos. Los afectados fueron divididos en 2 grupos de 50 integrantes cada uno: el de estudio, que recibió tratamiento homeopático, y el de control, tratado convencionalmente. No existió diferencia significativa en cuanto a la edad y el sexo en ambos grupos (p>0,5). Luego de aplicadas las terapias se obtuvo una efectividad marcada del tratamiento homeopático (96,0 por ciento) en relación con el convencional, con una diferencia significativa entre ambos grupos p<0,5(AU)

A therapeutical intervention in 100 patients operated of strabismus, assisted in the Ophthalmology Department of the Southern Children Hospital in Santiago de Cuba, was carried out from October, 2006 to the same period of 2013, in order to evaluate the effectiveness of the homeopathic treatment in them. The affected ones were divided in 2 groups of 50 members each: the study group which received homeopathic treatment, and the control group, treated conventionally. There was no significant difference as for age and sex in both groups (p>0.5). After applying the therapies a marked effectiveness of the homeopathic treatment was obtained (96.0 percent) in relation to the conventional one, with a significant difference between both groups p <0.5(AU)

[Laser speckle-based method for binocular vision recovery in diploptic treatment of concomitant strabismus].

OBJECTIVE: to investigate the effectiveness of the method of "dissociation" for concomitant strabismus treatment, which involves laser speckles and polaroid separation of visual fields. MATERIAL AND METHODS: A total of 40 patients with different types of concomitant strabismus and the average age of 9.8 years were enrolled. The treatment method implies the use of the Forbis device with polaroid separation of visual fields and low-energy helium-neon laser speckle patterns (green and red, 0.53 pm and 0.65 pm correspondingly). Binocular vision recovery was performed in the conditions of alternating exertion and relaxation of accommodation obtained through plus and minus spherical lenses. CONCLUSIONS: The method ensures an increase in the number of individuals capable of stereopsis from 31.2-44.4% (conventional treatment) to 54.4% as well as widening of the range of tolerated plus/minus spherical lenses, in which the binocular fusion is retained at the same degree of convergence.

[Electrodiagnostics and electrostimulation for the combined treatment of concomitant squint in children].

Methods for the electrodiagnostics and combined treatment of concomitant squint in children including pulsed electrostimulation of oculomotor muscles, pre- and ortoptical exercise therapy with the use of a synoptophor to correct concomitant strabismus. Indications and contraindications to these treatments are specified. High therapeutic effectiveness of oculomotor electrostimulation has been demonstrated in the study including 208 children with strabismus.

[Clinical observation on acupuncture for treatment of paralytic strabismus].

OBJECTIVE: To compare therapeutic effects of acupuncture at local points of eye and western medicine on paralytic strabismus. METHODS: One hundred cases were randomly divided into an acupuncture group and a medication group. The acupuncture group (58 cases) was treated with acupuncture at local points of eye, Jingming (BL 1), Tongziliao (GB 1), Shangming (Extra) etc. were selected; and the medication group (42 cases) was treated with oral administration of Methycobal and Vitamin B1. After treatment of 5 courses, the therapeutic effects in the two groups were observed. RESULTS: The total effective rate of 94.8% in the acupuncture group was superior to that of 85.7% in the medication group (P<0.01); the therapeutic effects of the acupuncture group for treatment of oculomotor nerve and abducent nerve were significantly better than that of the medication group (P<0.05); the acupuncture group was better than the medication group in synoptophore examination results and improvement of rima oculi and pupil (P<0.01, P<0.05), the acupuncture group was superior to the medication group in improvement of the function of paralysis eye muscle, including medial rectus and lateral rectus except superior oblique (P<0.01, P<0.05). CONCLUSION: Acupuncture on local points of eye is an effective therapy for paralytic strabismus.

Toward an implantable functional electrical stimulation device to correct strabismus.

PURPOSE: To investigate the feasibility of electrically stimulating the lateral rectus muscle to recover its physiologic abduction ability in cases of complete sixth cranial (abducens) nerve palsy. METHODS: In the feline lateral rectus muscle model, the effects of a charge-balanced, biphasic, current-controlled stimulus on the movement of the eye were investigated while stimulation frequency, amplitude, and pulse duration was varied. Eye deflection was measured with a force transducer. Denervated conditions were simulated by injection of botulinum toxin A. RESULTS: Three chemically denervated and 4 control lateral rectus muscles were analyzed. In control lateral rectus muscles, the minimum fusion frequency was approximately 170 Hz, and the maximum evoked abduction was 27 degrees. The minimum fusion frequency was unchanged after 4 weeks of chemical denervation. Stimulation of chemically denervated lateral rectus muscle resulted in 17 degrees of abduction. For both innervated and chemically denervated lateral rectus muscle, frequencies greater than 175 Hz yielded very little increase in abduction. Modulating amplitude produced noticeable movement throughout the tested range (0.2 to 9 mA). CONCLUSIONS: Results from the feline lateral rectus muscle showed that electrical stimulation is a feasible approach to evoke a contraction from a denervated lateral rectus muscle. The degree of denervation of the feline lateral rectus muscle was indeterminate. Varying the stimulation amplitude allowed greater eye movement. It is very likely that both frequency and amplitude must be modulated for finer control of static eye position.

[Observation on therapeutic effect of acupuncture combined with western medicine on paralytic strabismus].

OBJECTIVE: To find out a better therapy for paralytic strabismus. METHODS: Ninety cases were randomly divided into an acupuncture-medicine group, an acupuncture group, a western medicine group, 30 cases in each group. The acupuncture-medicine group were treated with acupuncture at Shuigou (GV 26), Fengchi (GB 20), Yifeng (TE 17), Yiming (EX-HN 14), Taiyang (EX-HN 5), Jingming (BL 1), Cuanzhu (BL 2), etc. intramuscular injection of Vit B1 and Vit B12, and oral administration of ATP; the acupuncture group were treated with simple acupuncture, and the western medicine group were treated with simple western medicine. Their therapeutic effects were compared. RESULTS: The cured rate of 66.7% in the acupuncture-medicine group was significantly higher than 26.7% in the acupuncture group and 26.7% in the western medicine group (both P < 0.01). CONCLUSION: Acupuncture combined with western medicine has obvious therapeutic effect, which is better than that of simple acupuncture or simple western medicine.

[Randomized controlled study on acupuncture for treatment of diabetic paralytic squint].

OBJECTIVE: To observe clinical therapeutic effect of acupuncture on diabetic paralytic squint. METHODS: Seventy-two cases of diabetic paralytic squint were randomly divided into a medication group, an acupuncture group and an acupuncture and medication group. The medication group were treated with intramuscular injection of Methyl vitamin B12 250 microg, once daily; the acupuncture group were treated by acupuncture at different acupoints according to different paralytic muscles of eyes with adjuvant acupoints selected according to symptoms; the acupuncture and medication group were treated with the routine medicine and acupuncture. The treatment was given for 28 days. RESULTS: The total effective rate of 87. 5% in the acupuncture group and 95.7% in the acupuncture and medication group were higher than 54.5% in the medication group (P < 0.05, P < 0.01), with no significant difference between the acupuncture group and the acupuncture and medication group (P > 0.05). CONCLUSION: Acupuncture has a definite therapeutic effect on diabetic paralytic squint, which is better than that of routine medication.

[Shutter-glasses haploscope with eye-tracking control for fusion therapy]. / Shutter-Brillen-Haploskop mit Eye-Tracker-Regelung zum Zweck der Fusionstherapie.

BACKGROUND: Common haploscopes require a manual input of the presented disparity and particularly prepared images; moreover, they can be used predominantly by orthoptists. We developed a device that makes possible a haploscope on the basis of a computer monitor with shutter-glasses. The presented disparity is determined with help of an eye-tracker. MATERIALS AND METHODS: A patient looks at a monitor through shutter-glasses, the eyes being recorded by a camera. An eye-tracking software determines the fixation points and the angle of strabismus. Images are presented at the monitor with a disparity that is regulated according to these measurements. This is controlled by means of a software so that the disparity is gradually decreased according to the patients abilities. Diagnostic data are recorded permanently. RESULTS: Any monitor contents, such as videos, TV or computer applications, can be used for fusion training or diagnostic purposes with the new apparatus. Initial investigations of patients with heterophoria or intermittent exophoria indicate a decrease of the subjective angle of strabismus by compensation and an increase of the fusional range. CONCLUSIONS: The developed shutter-glass-haploscope with eye-tracking control provides several methods for diagnosis. The appliance provides automated fusion training adapted to the patient that can be done at the working place or at home.

[Ametropia and heterophoria "against the rules": a solution with prisms]. / Amétropie et héterophorie "contre la régle": une solution prismatique.

This study presents the results of the prescription of small prisms in ametropic patients whose glasses increase the associated heterophoria (which we have called heterophoria "against the rule"). It concerns the myopic eso (group I), the hyperopic exo (group II) and the presbyopic exo (group III) as a particular subgroup of the former. In a population of 211 patients wearing prisms, we have selected 53 in the first group, 34 in the second group and 20 in the third group. The 3 groups were compared according to the age and the fusional complaints of the patients. In 70 to 80% of the cases the associated ametropia was very small. In more than 60% of the cases the total prismatic prescription never exceeded 2 PD. A decrease or a suppression of the prisms was possible in 50% of the cases in groups I and II and in 15% in group III. Respectively 87%, 89% and 86% of the cases became asymptomatic in each category after a mean follow-up of 6.8--4.7--5.8 years (range: 2-12). No complaint was increasing during this period and no prismatic prescription exceeded a total amount of 5 PD. A familial factor was present in 18% of the cases. This study underlines the fact that the limit of tolerance of a latent phoric unbalance is more important that the amount of heterophoria itself. This observation is fundamental for understanding the apparent paradoxal behaviour of these patients and the efficacy of an apparent "homeopathic" prescription of prisms.

Is acupuncture an useful tool for pain-treatment in ophthalmology?

Pain that does not respond to conventional treatment procedures makes it necessary to look for alternative methods. Acupuncture is an ancient procedure with empirical effects on pain. Previous studies established the increased output of messengers at neuronal junctions in spinal cord and hypothalamic locations, especially of endorphins which inhibit the perception of pain. We treated several painful symptoms with acupuncture and evaluated the outcome of the treatment. Patients with various kinds of therapy-refractory pain and patients in whom conventional treatment methods could not be applied were included in the study. The diagnoses included glaucoma. Tolosa-Hunt-Syndrome, ophthalmic migraine, blepharospasm, and dry eyes. In one case acupuncture was used for analgesia during surgery. Acupuncture was performed with sterile disposable needles, at points known to have an empirical analgesic effect. The stimulation was adapted to the patient's individual needs. VAS assessments before and after acupuncture were compared. The t-test was used for statistical evaluation. Acupuncture had no side effects, but reduced pain to a variable extent. Especially in cases of severe pain and in surgery, very effective pain reduction was achieved. In general, pain was significantly reduced in all patients by the use of acupuncture. A statistically significant effect was noted (p < 0.05). Further studies should be conducted to demonstrate the specific effect in larger patient populations. Monitoring neurotransmitter activity will possibly help to illustrate the effect.

Postanesthetic hypotropia: a unique syndrome in left eyes.

PURPOSE: To investigate a recurring syndrome of postoperative hypotropia after cataract surgery performed under local anesthesia. SETTING: Hawaiian Eye Center, Wahiawa, Hawaii, USA. METHODS: Thirty-one left eyes in 2143 cataract surgeries developed postoperative hypotropia. Phacoemulsification and intraocular lens implantation were performed by one surgeon; the anesthetic (containing bupivacaine) was administered by one anesthesiologist who had treated 4200 patients without incident. We conducted epidemiologic, outcomes, and prevention studies to identify the etiology, evaluate hypotropia treatment, and test specific anesthetic techniques, respectively. RESULTS: Changes in preoperative and intraoperative management and surgical methods were unsuccessful in preventing the hypotropia. In 55% of the cases, strabismus surgery was required and in 13%, prism glasses. Early recession of the inferior rectus and conjunctiva was successful. After repeated observations of the anesthetic technique, it was noted that the right-handed anesthesiologist misdirected the retrobulbar needle into the left orbit. This resulted in a change in the anesthetic technique, and there has been no incidence of postoperative hypotropia in 3000 surgeries. CONCLUSION: We believe this syndrome resulted from mytoxicity or perimuscular inflammation, producing contracture hypotropia and restricted elevation of the globe. We propose the term postbupivacaine hypotropia for this chiefly left-sided syndrome.

[Use of hypnosis in certain forms of childhood strabismus]. / Uzití hypnózy u nekterých forem detského silhání.

The authors describe the case of a mentally very labile boy suffering from strabism. When he was excited, the deviation of the affected eye increased, diplopia, nausea and headache developed. Hypnosis was applied and the condition improved after 12 sessions. His behaviour changed and progress in school improved. The authors draw attention to new therapeutic possibilities of some forms of strabism in mentally labile children by application of hypnosis.

Management of binocular anomalies: efficacy of vision therapy, exotropia.

This paper presents a survey of the literature on management of the various forms of exotropia. Criteria for success of treatment are examined. A table summarizing the results of 11 studies is given.