Treatment Of Strabismus Research Articles

Surgical treatment of vertical strabismus. Part 2. Indications, scheduling, methods

Treatment of vertical strabismus will almost inevitably involve surgery when it is associated with hyperfunction of the inferior oblique muscle due to the weakness of vertical fusion (3.0-4.0 ave dptr), the presence of cyclotropy and torsional diplopia. Many operations aimed at weakening the lower oblique muscle have been described. However, they have a number of negative aspects associated with high invasiveness, difficulty of technical implementation due to the need for manipulations in the inaccessible area of the eye in proximity to the optic nerve, macular area, large vessels, as well as long duration of the operation, inability to dosage the result of the operation, low functional results. They are, to a large extent, absent in the operation of anterior transposition in which the neurofibrovascular bundle serves as the axis of rotation of the lower oblique muscle changing the vector of its action and increasing the effectiveness of treatment. Despite all the advantages of that technique, its use is still limited due to the lack of methods for controlling the amount of anterior transposition for the treatment of hyperfunction of the inferior oblique muscle, especially of small degrees.

Surgical treatment of vertical strabismus. Part 1. Classification and diagnostics

Vertical strabismus caused by hyperfunction of the inferior oblique muscle is a common oculomotor disorder. It is found in one third of all patients with strabismus, and in 70% of cases it is combined with esotropia. To date, there is no single approach to determining the degree of hyperfunction of the inferior oblique muscle, and the most common classifications are very subjective and inaccurate. Thus, in connection with the need to understand the severity of the disease, as well as to determine the tactics of treatment and prognosis of the surgical outcomes, it is necessary to standartize the classification of this pathology. The mechanism of action of the inferior oblique muscles of the eye is very complex and depends on the position of the eyeball at the time of their contraction. In addition to horizontal and vertical movements, they provide torsional movement. Any impairment of these muscles leads to the development of not only vertical strabismus, but excyclotropia that reduces the effectiveness of strabismus treatment. To identify all the symptoms associated with hyperfunction of the inferior oblique muscle, taking into account the peculiarities of its triple action, it is necessary to conduct a thorough diagnostic study.

Bupivacaine injection for comitant horizontal strabismus: clinical and radiological results.

To report the outcomes of bupivacaine injection for the treatment of comitant horizontal strabismus and evaluate clinical effectiveness and associated radiological changes. This prospective observational clinical study was conducted on 10 patients with comitant horizontal strabismus of up to 40 prism diopters. Ophthalmologic examinations and three-dimensional orbital magnetic resonance imaging were performed pre and post-injection (at first, third, and 12th months). A 4.5 ml of 0.5% bupivacaine was injected into the extraocular muscle under topical anesthesia using an electromyography in all patients. The mean follow-up time at post bupivacaine injection and mean deviation at primary position were was 17 ± 2 months and 21.3 prism diopters, respectively. The mean changes in ocular alignment, enlargement of the cross-sectional area in the injected muscle, and volumetric enlargement were 7.7 PD, 12%, and 17% at the first year post-injection, respectively. No severe or persistent complication was observed. Ptosis and mydriasis were noted post-injection due to the anesthetic effects of bupivacaine but disappeared within 2 h post-injection. Bupivacaine injection improved eye alignment in small-angle horizontal comitant strabismus, effectively diagnosed with orbital magnetic resonance imaging to evaluate volumetric changes of the extraocular muscles. Further clinical studies with larger numbers of patients should be performed to define optimal dosages, concentration, and application method and dose-response relationship.

Zastosowanie trójwymiarowej wizualizacji podczas chirurgii przedniego odcinka oka

The heads-up surgery is becoming more and more common and acceptable as it eliminates restrictions imposed by the use of a standard microscope, and minimizes surgeon's fatigue, and allows surgery in much more natural and physiological positions of the body. It also does not affect the image quality and surgical technique. It is increasingly used not only in retinal and vitreous surgery but also in procedures preformed on the anterior segment of the eye. Preliminary observations of the results of surgical treatment of cataracts, posttraumatic changes, strabismus and bullous keratopathy with three-dimensional (3D) visualization technologies, confirmed the safety profile of treatments as compared to conventional methods. Besides, 3D imaging is distinguished by educational values and enables the performance of the light-out operation.

Strabismus Surgical Correction with Adjustable Sutures (Clinical Cases)

RETRACTED . Methods for external surgery of the eye muscles are different and include the use of both adjustable and non-adjustable sutures, which affects the result in a long follow-up period. Surgical intervention using the method of adjustable sutures has been used for a number of years to improve the functional results of strabismus treatment. The basic principle of the method of adjustable sutures is to ensure the safety of extraocular muscles using a temporary or sliding node. The aim of the work is the development of a surgical treatment method of repeatedly operated strabismus with hypereffect and the analysis of clinical cases. We have proposed a method for correcting repeatedly operated strabismus with hypereffect using the method of adjustable sutures. Three clinical cases are described. 1) The patient is 34 years old, previously operated esophoria, deviation angle 15 degrees. A recession of the internal rectus muscle 4 mm and resection of the external rectus muscle 5 mm were performed. The next day after surgery, due to the hypoeffect, the sutures were adjusted. After 1 month, the deviation angle is 0 degrees. 2) The patient is 29 years old, with an exophoria, a deviation angle of 35 degrees, previously operated on for esophoria on the left eye. An operation on the left eye is done. The next day after the operation, the presence of hypereffect was revealed, for the correction of which, the repressed muscle was weakened and the recession was strengthened in accordance with the proposed method. We achieved the desired cosmetic result. After 1 month, the deviation angle is 0 degrees. 3) The patient is 24 years old, previously operated exophoria, the deviation angle is 15–20 degrees. The internal rectus muscle was repositioned by 4 mm, the external straight recession was 4 mm. The day after surgery, the desired cosmetic result is achieved. After 1 month, the deviation angle is 0 degrees. The presented method of surgical intervention and clinical cases indicate that the approach to the treatment of strabismus using adjustable sutures is a promising direction in ophthalmic surgery.

Дозированное хирургическое лечение вертикального косоглазия с применением методики передней транспозиции нижней косой мышцы

«Российская офтальмология онлайн» - электронное информационное издание, создается с 1 марта 2010 года под эгидой Российского общества офтальмологов. Основная задача проекта - научно-информационная поддержка специалистов в области офтальмологии.

Efficacy of horizontal muscle augmentation combined inferior oblique muscle shortening for pediatric strabismus: Study Protocol.

Background:This study will explore the efficacy and safety of horizontal muscle augmentation (HMA) combined inferior oblique muscle shortening (IOMS) for the treatment of pediatric strabismus (PS).Methods:Literature search for studies will be carried out in the following databases: Cochrane Library, MEDILINE, EMBASE, CINAHL, Web of Science, PsycINFO, CBM, and CNKI. We will search all these databases without language and publication status restrictions. Two independent authors will perform selection of studies, data collection and management, risk of bias evaluation. A third author will be consulted with the help of discrepancies.Results:This study will provide a synthesis of existed evidence for HMA combined IOMS for the treatment of PS.Conclusion:The results of this study will provide evidence to evaluate the efficacy and safety of HMA combined IOMS for the treatment of PS, which can help to guide clinical decision-making.Systematic review registration:PROSPERO CRD42019149716.

Achromatic refractive–diffractive double-relief microprisms

The Fresnel-prism technique has become an important medical option for the diagnostics and treatment of strabismus in children. However, the application of prisms in ophthalmology generally involves chromaticity problems: the formed optical images are distorted due to the dispersion of white light at the microrelief and the applied microprisms reduce the contrast of the images of the test charts, and in turn, the accuracy of eye diagnostics drops. In this study, a novel method was developed for the total chromatism compensation using a special microprismatic refractive–diffractive structure with double microrelief: the first refractive microrelief was used for light beam deflection, whereas the second diffractive one was used for compensating the chromatism of the first microprism. The dispersion chromatism of the first refractive prism and the diffraction chromatism of the second microprism grating are oppositely directed. Thereby, dispersion chromatism can be completely compensated by diffraction grating. The optimal characteristics of these achromatic refractive–diffractive structures were calculated, and the necessary angles and optimal relief pitches of the ophthalmic microprisms were obtained. Achromatic structures were manufactured according to the calculated parameters, and their optical characteristics were experimentally investigated. The main advantage of such optical devices is that they are flat and very thin. The findings indicate the possibility of designing effective achromatic microprisms.

Comparison of unilateral recession or resection of the inferior oblique muscle during anterior transposition for treatment of asymmetric vertical strabismus

Dissociated vertical deviation (DVD) and overelevation in adduction (OEAd) occur frequently in children with infantile strabismus. This study evaluated the efficacy of combining bilateral inferior oblique muscle anterior transposition (IOAT) with unilateral recession or resection of the muscle for patients with asymmetric DVD and OEAd.

Bilateral full tenectomy of the superior oblique muscle for the treatment of A-pattern strabismus

Superior oblique full tenectomy close to the scleral insertion was originally described as a treatment for moderate A-pattern strabismus. The purpose of this study is to evaluate the efficacy of this technique for A patterns of all magnitudes in a large retrospective clinical record review.

Результаты хирургического лечения сходящегося содружественного неаккомодационного косоглазия у детей, оперированных с использованием новой индивидуальной схемы дозирования

Результаты хирургического лечения сходящегося содружественного неаккомодационного косоглазия у детей, оперированных с использованием новой индивидуальной схемы дозирования

Результаты использования альтернирующего предъявления стимулов в ортоптическом лечении у детей

Purpose. To evaluate the results in the use of different modes for alternating presentation of stimuli in the orthoptic treatment of strabismus in children. Material and methods. The study included 41 patients with a nonparalytic strabismus (30 children with esotropy and 11 children with exotropy) aged from 7 to 16 years. For additional studies of binocular functions, we used a modified Bagolini test and our own stereo-test created for the conditions of anaglyph separation of visual fields. During the first examination the results with all the used stereo-tests (the Flytest, the Lang-test, and the stereo image that we created) were negative. Besides to the static presentation of test images, three different modes of alternating presentation of stimuli were used: 1) with consecutive monocular presentation of visual stimuli corresponding to the right and left eye; 2) with the presence of an empty interval between monocular phases; 3) with the presence of a binocular phase between monocular phases. The duration of the monocular and binocular phases, as well as the empty interval, was regulated by the researcher. Depending on the results of the examination, an optimal mode of alternative presentation of stimuli for the orthoptic tr eatment was selected individually. Results. In the duration of the monocular phase 50 ms in combination with the duration of an empty interval 50 ms, the majority of children (32 of 41) with strabismus were able to have stereovision. As a result of orthoptic exercises, the number of patients capable of bifoveal fusion increased from 24.4% to 48.8%. Stereovision appeared in 39% of children according to the Fly-test and in some cases according to the Lang-test. In all children with moderate amblyopia the visual acuity increased on average from 0.23±0.01 to 0.52±0.05 (p<0.001), in children with mild amblyopia the visual acuity increased on average from 0.66±0.02 to 0.93±0.01 (p<0.001). A reduction of the strabismus angle or an elimination of postsurgical microdeviation occur in one-third of children. Conclusion. The proposed method for the study of binocular functions in patients with strabismus allows to evaluate the ability to the bifoveal fusion and stereo perception not only with static presentation of visual stimuli, but also with the use of different modes of their alternating presentation. The most favorable mode for the elimination of functional inhibition is the mode of alternating presentation of stimuli with the presence of an empty interval not less than 50 ms between the monocular phases, which are also not less than 50 ms. This mode with the combination of monocular phase duration and empty interval duration in the range from 30 to 60 ms creates the most favorable conditions for the appearance of the stereo effect in the majority of the patients. The use of optimal individually chosen regime of alternating presentation of the stimuli allows to improve significantly the binocular functions, to increase the visual acuity, and in some cases to reduce the angle of strabismus or to eliminate postsurgical microdeviations.

Implementation of a Virtual Reality rendered in Portable Devices for Strabismus Treatment based on Conventional Visual Therapy.

In order to propose alternative treatments for strabismus, conventional visual therapies implemented in VR, which could be rendered in portable devices for pediatric strabismus treatment is proposed in this paper. In comparison with other virtual environments for visual correction proposes, the proposed system is based on conventional visual therapies for amblyopia and strabismus treatment. Three fundamental visual therapeutic exercises were considered in the present proposal: (1) Brock cord, (2) approach technique, and (3) convergence and divergence. The first exercise, Brock Cord, has the purpose of improving the binocular fixation for exotropia and esotropia. The second exercise pursues to normalize the Cerebral Perfusion Pressure by an approach technique. The third exercise known as fusion of eccentric circles, aims vision training by converging and diverging objects at specific distances. Before a clinical application, it was paramount important to guarantee system simplicity and versatility for both clinicians and infant patients. Therefore, the user experience evaluation of a sample of 45 students between 17 and 28 years old was undertaken. The system proposed in this paper achieved a pragmatic quality above average (1.73), a parameter that reflects simplicity and versatility. In addition, the present VR system displayed attractiveness (2.03) and hedonic (1.90) qualities above average. Then, it is expected that end-users will follow the visual exercise program.

Prospects for the Botulinum Toxin Use in the Treatment of Children`s Strabismus. Review

The review presents information concerning the botulinum toxin use in the treatment of children`s strabismus; highlights aspects of the safety and the complications frequency. It contains information about the methods and doses of botulinum toxin injection, and also considers the cases of necessity of further surgery. There are several ways of introducing BTA: the traditional transconjunctival method of administration under the control of electromyography, used by most ophthalmologists, is not acceptable for treating pediatric patients, transconjunctivally into the subtenon space 10 mm from the limbus into the projection zone of the medial rectus muscle using a 1.0 ml tuberculin syringe with 27G needle, introduction to the muscle with the opening of the conjunctiva, which is safer, is carried out under complete visual control and with the release of extraocular muscle. According to the domestic and foreign literature data we can conclude that the injection of botulinum toxin may be an alternative or complement to surgical techniques, injection of botulinum toxin in the treatment of strabismus in children may be an alternative or complement to surgical and pleopto-orthopto-diploptic correction methods, although not in all clinical cases. The treatment approach of such patients should be comprehensive. There are reports that BoNT-A reduces eye deflection in more than 50 % of patients and provides satisfactory long-term results in infants and children. The average safe dose for Botox is 1-3 units for the muscle. The frequency of complications increases with higher doses (especially&gt; 10 units) and with the transconjunctival route of administration without electromyographic control. This clinical example illustrates the effectiveness of botulinum toxin for the non-concomitant strabismus treatment.

Применение ботулотоксина типа А при лечении сходящегося косоглазия различной этиологии у детей

Применение ботулотоксина типа А при лечении сходящегося косоглазия различной этиологии у детей

Utility of Magnetic Resonance Imaging (MRI) in Children With Strabismus.

Magnetic resonance imaging (MRI) of the brain can provide valuable information about structural abnormalities in strabismus. The aim of this study was to evaluate the utility of MRI in this regard and to identify risk factors for abnormal MRI results in children with strabismus. A retrospective analysis of children <18 years of age presenting with strabismus, who underwent brain MRI at Pusan National University Hospital (Busan, Korea) between January 2012 and March 2017, was performed. Clinical characteristics, MRI results, and ophthalmologic findings were reviewed. Findings were classified as normal or abnormal according to MRI results. Additionally, patients were divided according to age to compare characteristics of infantile and childhood strabismus. A total of 90 patients (47 [52.2%] male, 43 [47.8%] female; mean age, 2.19 ± 0.53 years) were enrolled. Of those, 64 (71.1%) presented with normal and 26 (28.9%) with abnormal MRI results. The age at presentation was lower and abnormal findings on fundus examination were more common in the abnormal MRI group (P = .002 and P = .008, respectively). Among the patients, 46 (51.1%) had infantile strabismus and 44 (48.9%) had childhood strabismus. Global developmental delays, speech delays, and MRI abnormalities were more common in patients with infantile than in those with childhood strabismus. Ptosis and headaches were more common in patients with childhood strabismus (P = .025, P = .025, respectively). Brain MRI was helpful for accurate diagnosis and treatment of strabismus in younger children, those with abnormal findings on fundus examination, and infants with developmental, especially speech, delays.

Application of MRI in the etiological diagnosis of special forms of strabismus

Objective: To explore the imaging features of patients with special forms of strabismus and summarize the subtypes by using MRI imaging techniques. Methods: A retrospective case series study. Among the patients who visited the Beijing Tongren Hospital between 2006 and 2016, 1 113 patients were identified with special forms of strabismus after complete ophthalmic and orthoptic evaluations. These patients were further evaluated using several types of high-resolution MRI techniques of the oculomotor nerves in the brain, the cavernous sinus, and the orbits. Results: Among the 1 113 patients, 818 patients (73.5%) were identified with MRI abnormal conditions, and 295 patients (26.5%) were identified with MRI normal conditions. Nine different disease types were identified in the studied populations, which included 257 patients (23.1%) with congenital cranial dysinnervation disorders, 209 patients (18.8%) with thyroid associated ophthalmopathy, and 169 patients (15.2%) with abnormalities of the extraocular muscles. Other diseases included orbital fractures (3.3%, 37 patients), intraorbital inflammations (2.7%, 30 patients), tumors (2.3%, 26 patients), injuries of medial rectus muscle after endoscopic sinus surgery (1.2%,13 patients), and lesions of cavernous sinus (2.0%, 22 patients). Additional 55 patients (4.9%) were identified with other causes such as high myopia fixed esotropia, and so on. Conclusion: Summarizing the common clinical characteristics and rules with the help of MRI can further clarify the etiology of special forms of strabismus, and accurately guide the diagnosis and treatment of strabismus. (Chin J Ophthalmol, 2019, 55: 361-368).

Botulinumtoxin in Ophthalmology

Botulinum toxin has been first applied in ophthalmology (as treatment for strabismus) and is nowadays widely used in many clinical areas. Currently the main application in ophthalmology is the treatment of essential blepharospasm and hemifacial spasm. Other important indications for botulinum toxin in ophthalmology are eyelid retraction in Graves' disease and the induction of protective ptosis in lagophthalmos or corneal diseases.

Innovative techniques for the treatment of adult strabismus

Adult strabismus is often characterized by surgical complexity. In recent years, several innovative techniques for the management of complex strabismus have been developed. Strabismus surgeons should understand the indications for various strabismus surgical techniques in the management of these difficult cases. This workshop describes several new surgical techniques to manage complex strabismus, including small-angle incomitant and very large-angle strabismus, torsional diplopia, and restrictive, paralytic, and secondary strabismus. Because strabismus surgery is an ever-evolving field, it is important to continue to refine our surgical armamentarium. Strabismus surgeons may wish to add these techniques to their surgical repertoire for select cases.

Etiology and Age Modifies Subjective Visual Function After Cerebral Hemispherectomy.

Cerebral hemispherectomy is typically used to treat patients with pharmacoresistant epilepsy. Visual-related outcomes are relatively unstudied in this population, aside from the knowledge that patients develop a complete homonymous hemianopia contralateral to the side of the hemispherectomy. The purpose of this study was to determine and characterize parent-reported functional visual, oculomotor, and postural changes in a large population of patients following cerebral hemispherectomy. An online survey was sent to parents of children who had undergone hemispherectomy for seizure control. Families were recruited by the Brain Recovery Project: Childhood Epilepsy Surgery Foundation. Parent-reported subjective visual function was assessed by the presence of peripheral field defects, ocular misalignment and anomalous head posture. A total of 196 (12.5%) participants responded. Postoperative follow-up was 92±78 months (range: 1-382). Ninety-three percent of parents reported the child had difficulties with peripheral vision. Torticollis was present postoperatively in 122 (62%) patients. Strabismus was noted in 93 (49%). Fifty-five (59%) of the strabismus patients demonstrated exotropia with the majority of exotropia patients demonstrating the exo-deviated eye in the direction contralateral to the hemispherectomy (74.5%). Both torticollis and strabismus were most frequently seen immediately after surgery. Sixty-six patients (34%) underwent strabismus treatment. Patients with younger age of seizure onset, younger age of surgery, and certain epilepsy etiologies (hemimegencephaly, Sturge-Weber syndrome) were more likely to develop strabismus and torticollis. Torticollis and strabismus are common after hemispherectomy and appear to be influenced by etiology and age at surgery. Preoperative discussion with parents and patients regarding those compensatory mechanisms is recommended, and postoperative ophthalmologic assessments are also encouraged.