Surgical Treatment Of Strabismus Research Articles

Comparison of sensory fusion recovery in different types programming of liquid crystal glasses

Objective: to compare the effectiveness of new method of sensory fusion recovery in patients with personalized adjustment of the frequency of alternation of liquid crystal glasses (LCG) compared with the empirical selection of the frequency of alternation. Material and methods. The study included 39 patients with concomitant convergent strabismus with orthotropy and no sensory fusion after surgical treatment of strabismus, who were prescribed LCG. The glasses were programmed empirically at 2 Hz in 21 patients (empiric group), in 18 patients — using the developed formula for calculating the frequency of alternation of LCG (calculated group). The compared groups did not differ in gender, age, visual acuity, and other characteristics. Results. Recovery of sensory fusion occurred more often with LCG in calculated group (16 patients, 88.9%) than in empiric group (9 patients, 42.9%), the difference is highly reliable (p=0.001). Conclusions. Anew method for personalized selection of the frequency of alternating LCG using video oculography is more efficient than empirical programming for sensory fusion restoration in children after surgery for concomitant convergent strabismus.

Comparison of sensory fusion recovery in different types programming of liquid crystal glasses

Objective: to compare the effectiveness of new method of sensory fusion recovery in patients with personalized adjustment of the frequency of alternation of liquid crystal glasses (LCG) compared with the empirical selection of the frequency of alternation. Material and methods. The study included 39 patients with concomitant convergent strabismus with orthotropy and no sensory fusion after surgical treatment of strabismus, who were prescribed LCG. The glasses were programmed empirically at 2 Hz in 21 patients (empiric group), in 18 patients — using the developed formula for calculating the frequency of alternation of LCG (calculated group). The compared groups did not differ in gender, age, visual acuity, and other characteristics. Results. Recovery of sensory fusion occurred more often with LCG in calculated group (16 patients, 88.9%) than in empiric group (9 patients, 42.9%), the difference is highly reliable (p=0.001). Conclusions. Anew method for personalized selection of the frequency of alternating LCG using video oculography is more efficient than empirical programming for sensory fusion restoration in children after surgery for concomitant convergent strabismus.

Некоторые осложнения хирургии косоглазия

Surgical treatment of strabismus is aimed at achieving a cosmetic effect and restoring the operation of the binocular apparatus. But this type of treatment can lead to complications ranging from mild and self-limiting to severe, causing loss of vision. The purpose of our work is to present literature data on some complications of strabismus surgery, their clinical signs, methods of treatment and preventive measures. The material for writing the article was foreign publications from the international citation database Pubmed, which contained the keywords «strabismus», «strabismus surgery», «strabismus surgery complication». For the review, 27 articles were selected that meet the purpose of our work. The analysis of literature sources showed that the complications of strabismus surgery are diverse and include changes in the conjunctiva (damage to the plica semilunaris, chemosis, pyogenic granuloma, extruded of the Tenon's fascia, conjunctival cyst), impaired blood supply (anterior segment ischemia), scleral perforation, postoperative infection (endophthalmitis, subconjunctival abscess), the loss rectus muscle, fat adherense syndrome, eyelid retraction and ptosis following vertical rectus muscle surgery. Despite the rare occurrence, the listed complications can be the cause of functional or cosmetic changes. Keywords: strabismus, strabismus surgery, complication, oculomotor muscles

Результаты оперативного лечения содружественного косоглазия у взрослых в амбулаторных условиях

Aim. To evaluate the effectiveness of surgical treatment of concomitant strabismus in adult patients on an outpatient basis. Methods. 73 patients (73 eyes) with a diagnosis of concomitant strabismus without a paralytic component, aged from 19 to 62 years, were under observation. All patients underwent surgical treatment of strabismus for cosmetic purposes. Results. A decrease in the deviation angle was achieved in all patients. The state of orthotropy was obtained in 58 (79.5 %) patients. Conclusions. Surgical treatment of strabismus makes it possible to achieve the correct position of the eyeballs and a good cosmetic effect in 80 % of cases with a one-stage intervention and 94.5 % with a phased surgical treatment. Observation of patients in the long term (3 years) revealed a fairly persistent cosmetic effect of the intervention. Key words: strabismus in adults; strabismus surgery.

Short-Term Near Stereoacuity Improvements Following Favorable Surgical Alignment in Exotropic and Esotropic Patients

ABSTRACT Purpose Surgical treatment for strabismus is to promote binocular vision, and the study is to evaluate the effect of surgical realignment on near stereopsis in exotropic and esotropic patients. Methods The records of patients who underwent strabismus surgery were retrospectively reviewed. Visual acuity, ocular deviations, fusion control, ocular motility, strabismus subtype and duration, surgery procedures, and stereopsis at before and at one month after surgery were collected. RMANOVA was performed to analyze stereopsis improvement by surgery. A logistic analysis was used to investigate the factors for stereopsis improvement. Results 143 exotropic and 40 esotropic patients were enrolled. The stereopsis was not significantly improved in patients with exotropia (p > .05), but not in esotropic patients (p < .01). Small degree of near deviation (β = 0.01), without vertical surgery (β = 0.11), and the high pre-surgery Titmus (β = −0.44) were related factors for stereopsis improvement in exotropia patients; male (β = 0.21) and the high pre-surgery Titmus (β = −0.36) were related factors for stereopsis improvement in esotropia patients. Conclusion The loss of stereopsis was significantly restored by surgery in esotropia patients and the extent of stereopsis recovery by surgery depends on the deviation at near distance, vertical surgery, and pre-surgery stereopsis in exotropes and on sex and pre-surgery Titmus in esotropes.

Fixation stability after surgical treatment of strabismus and biofeedback fixation training in amblyopic eyes

BackgroundVisual fixation may be affected in amblyopic patients and, moreover, its stability may be associated with the effects of amblyopic treatments on visual performance in patients with strabismus. Therefore, fixation stability is a relevant biomarker that might predict the recurrence of amblyopia after a therapeutic intervention. Microperimetric biofeedback fixation training (BFT) can stabilize visual fixation in adult patients with central vision loss. It was the purpose of the present study to evaluate the effects of BFT on fixation stability in adult amblyopic patients after surgical intervention to treat strabismus.MethodsParticipants were 12 patients with strabismus (mean age = 29.6 ± 8.5 years; 6 females) and 12 healthy volunteers (mean age = 23.8 ± 1.5 years; 9 females). The protocol included ophthalmological and microperimetric follow-ups to measure fixation stability and macular sensitivity. BFT was applied monocularly to four amblyopic eyes either on the spontaneous preferential retinal locus or to a fixation area closer to the anatomical fovea after surgical treatment of strabismus.ResultsBaseline measurements showed significantly altered microperimetric average threshold in amblyopic eyes compared to fellow eyes (p = 0.024) and compared to control eyes (p < 0.001). Fixation was unstable in amblyopic eyes compared to control eyes (p < 0.001). Fixation stability did not significantly change after surgical alignment of strabismus (p = 0.805). BFT applied to operated eyes resulted in a more stable fixation with improvements of about 50% after three months of training.ConclusionsFixation stability improvements following BFT highlight its potential use in adult amblyopic eyes after the surgical alignment of the strabismus. Future investigations may also consider applying this method in combination with standard treatments to improve vision in amblyopic patients.

Surgical treatment of strabismus in thyroid eye disease: characteristics, dose–response, and outcomes

To describe the surgical management, dose-response, and postoperative outcomes of strabismus surgery in patients with thyroid eye disease. The medical records of patients operated on between 2014 and 2018 were reviewed retrospectively. Patient characteristics and surgical data were collected. Motor success was defined as vertical deviation of ≤5Δ and horizontal deviation of ≤10Δ; sensory success, as no diplopia in primary gaze. A total of 76 patients (mean age, 62.2±12.9years; 50 females) underwent 87 surgeries, most commonly unilateral inferior rectus recession (unilateral IR, 48%) and bilateral medial rectus recession (bilateral MR, 23%). Motor success was achieved in 69% and sensory success in 58%. For unilateral IR surgery, the dose-responses were 3.25Δ/mm (SE=0.616; β=0.650; P<0.001) at distance and 2.48Δ/mm (SE=0.752; β=0.472; P=0.002) at near; for bilateral MR surgery, 3.93Δ/mm (SE=0.997; β=0.680; P=0.001) at distance and 5.05Δ/mm (SE=1.374; β=0.655; P=0.002) at near. Median (Q1, Q3) postoperative drift was toward overcorrection for both procedures (unilateral IR, -2Δ [-8, 0] at distance and -2Δ [-7, 0] at near; bilateral MR, -2Δ [-8, 2] at distance and -2Δ [-10, 0] at near). Sex, age, duration of strabismus, prior orbital decompression, and concurrent vertical and horizontal procedures were not associated with dose-response or postoperative drift. Concurrent vertical and horizontal surgery did not affect the motor success rate, dose-response, or postoperative drift. Although unilateral IR surgery had a larger dose-response at distance, bilateral MR surgery had a larger dose-response at near. Most procedures tended to have a postoperative drift toward overcorrection.

Features of Tissue Reaction in the Tenon Capsule in Progressive Myopia

Background: Research actuality is determined by the first, the prevalence of refraction errors including progressive myopia among children secondly, high risk and tends to develop complications from the visual organ in refractive disorders.Aims: To investigate tissue reactions occurring in the Tenon’s capsule with anomalies of refraction, including with progressive myopia.Materials and methods: A one-step study of the Tenon’s capsule of 47 samples (25 with hyperopia and 22 with progressive myopia) was carried out. The material of the Tenon’s capsule was obtained during surgical treatment of strabismus and sclera strengthening operations with progressive myopia. The Tenon’s capsule was studied at different levels: tissue, cellular, subcellular. Fragments of Tenon’s capsule were stained with hematoxylin-eosin and picrofuchsin mixture by the method of van Gieson at the tissue level. This allowed obtaining a general picture of the morphology of Tenon’s capsule. Fragments of Tenon’s capsule were stained by toluidine blue in tetraborate sodium at the cellular level. This gave the opportunity to define the scope for ultratome and spend morphometry of cellular composition. A fragment of Tenon’s capsule was studied by transmission electron microscopy (TEM) at the subcellular level and was performed ultrastructural morphometry of fibroblasts, evaluation of the density of the collagen fibers.Results: Were evaluated by qualitative and quantitative characteristics of the structure of Tenon’s capsule with two anomalies of refractions: progressive myopia and hyperopia: with progressive myopia in Tenon’s capsule, in contrast to hyperopia, the following number of fibroblasts (1.56±0.12 per 104 µm2), mast cells (0.08±0.02 per 104 µm2), adipocytes (0.01±0.001 per 104 µm2) were observed; ultrastructural features of fibroblasts were represented by such quantitative characteristics: the area of the fibroblast nucleus was 1.60±0.82 in µm2, the length of the karyolemma was 6.99±0.189 µm, the number of nucleoli was 0.17±0.015 per 1 µm2, the number of mitochondria and lysosome -2.05±0.14 per 1 µm2; 0.64±0.08 per 1 µm2, respectively); the density of collagen fiber was 28.72±4.18%, fibrillar fibrillation and fragmentation were recorded.Conclusions: Hyperplasia of fibroblasts and their ultrastructures, mast cells, reduction in the level of adipocytes and the density of collagen fibrils ― these changes are features of the tissue reaction in the tenon capsule and reflect the adaptive nature of the processes occurring during progressive myopia.

Neural Plasticity Following Surgical Correction of Strabismus in Monkeys.

PurposeAlthough widely practiced, surgical treatment of strabismus has varying levels of success and permanence. In this study we investigated adaptive responses within the brain and the extraocular muscles (EOM) that occur following surgery and therefore determine long-term success of the treatment.MethodsSingle cell responses were collected from cells in the oculomotor and abducens nuclei before and after two monkeys (M1, M2) with exotropia (divergent strabismus) underwent a strabismus correction surgery that involved weakening of the lateral rectus (LR) and strengthening of the medial rectus (MR) muscle of one eye. Eye movement and neuronal data were collected for up to 10 months after surgery during a monocular viewing smooth-pursuit task. These data were fit with a first-order equation and resulting coefficients were used to estimate the population neuronal drive (ND) to each EOM of both eyes.ResultsSurgery resulted in a ∼70% reduction in strabismus angle in both animals that reverted toward presurgical misalignment by approximately 6 months after treatment. In the first month after surgery, the ND to the treated MR reduced in one animal and ND to the LR increased in the other animal, both indicating active neural plasticity that reduced the effectiveness of the treatment. Adaptive changes in ND to the untreated eye were also identified.ConclusionsActive neural and muscle plasticity corresponding to both the treated and the untreated eye determines longitudinal success following surgical correction of strabismus. Outcome of surgical treatment could be improved by identifying ways to enhance “positive” adaptation and limit “negative” adaptation.

THE APPLICATION OF TYPE A BOTULINUM TOXIN FOR THE TREATMENT OF PATIENTS PRESENTING WITH VARIOUS FORMS OF STRABISMUS

The use of type A botulinum toxin (BTX-A) for the treatment of strabismus was for the first time proposed in the early 1980s by the American ophthalmologist Alan Scott. The earliest applications of the botulinum toxin in the clinical practice included the treatment of strabismus and blepharospasm. The use of this agent can be particularly useful in the situations where the surgical treatment of strabismus is either undesirable or impracticable for one or another reasons; moreover, injections of BTX-A were successfully used to treat the patients presenting with severe diplopia. The results of the application of the botulinum toxin reported by different authors vary considerably which dictates the necessity of a deeper insight into the mechanisms underlying its action and their further investigation. The commonest complications of therapy with this medication are a temporary ptosis and vertical deviation. The systemic complications of BTX-A application have never been documented; its repeated injections are believed to be safe for the patients.

Outcome of strabismus surgery by nonadjustable suture among adults attending a university hospital of Saudi Arabia.

To describe the outcome and safety of surgical treatment of Saudi adult patients with strabismus by nonadjustable suture and to evaluate the prevalence of diplopia and binocularity after strabismus correction. Retrospective analysis of medical records of 96 patients above the age of 16-years old with strabismus seen at the King Fahd Hospital of the King Faisal University (KFUH) from July 1st, 2000 to June 30th, 2007 who were underwent strabismus correction surgery. The demographic variables: pre- and post-operative alignment, binocularity, and visual acuity were analyzed. A total of 96 patients of whom 63 (66%) patients were male and 33 (34%) patients were female, aged 16 years and above underwent strabismus correction, 83 (86%) patients ended with postoperative orthophoria, 13 (14%) patients ended with postoperative residual deviation, 83 patients (86%) had defective vision with amblyopia. Improvement of binocularity and binocular visual acuity postoperatively was achieved in 32(33%). Forty (42%) of our patients developed transient diplopia postoperatively which disappeared within 6 weeks while only three developed permanent diplopia. The main cause of adult strabismus was childhood squint in 83 (86%) patients and traumatic in 3 (13%). Surgical treatment of strabismus in Saudi adult with nonadjustable suture is safe and effective procedure with low risk of complication and the incidence of diplopia is rare with better binocularity and binocular visual acuity.

Surgical Treatment of Strabismus in Children

Surgical Treatment of Strabismus in Children

Результаты хирургического лечения больных косоглазием на основе комплексного автоматизированного метода диагностики

Результаты хирургического лечения больных косоглазием на основе комплексного автоматизированного метода диагностики

Pseudotumor cerebral associado ao uso de minociclina para tratamento de acne vulgar: relato de caso

INTRODUCTION: minocycline hydrochloride used to treat acne vulgaris has been associated with the development of pseudotumor cerebri in children and adolescents. Ophthamologic alterations, including papilled ema, diplopia, and changes in ocular motility, have been reported. METHODS : case description based on a review of hospital records and ophthalmology records, including surgical treatment of strabismus. RESULTS : spontaneous regression of all signs and sympt oms except for diplopia and convergent strabismus, which required surgical correction of the ocular deviation. CONCLUSION: the use of minocycline hydrochloride to treat acne vulgaris should be a last resort, when no other therapeutic option is viable.

Polytetrafluoroethylene (Goretex®) for muscle elongation in the surgical treatment of strabismus with restricted motility

Repeated strabismus surgery as well as eye muscle fibrosis in various forms of strabismus, can be followed by restriction of the motility of the eye. Tendon elongation may be necessary if further improvement of the deviation and duction of the eye muscle is to be achieved. We used polytetrafluoroethylene (Goretex) and looked at its user comfort, compatibility and dose-rate relationship. Three patients with consecutive exotropia after repeated operations for congenital esotropia, two patients with VI nerve palsy and residual head turn after combined convergence operation and one child with congenital fibrosis syndrome underwent muscle tendon elongation with Goretex (7-15 mm) of either the medial or the lateral rectus muscle, which had already been resected and/or recessed in former surgeries. Forced duction under general anaesthesia was restricted in all patients. The correction of the deviation in primary position (deviation at distance + 3 degrees to - 4 degrees and at near - 1 degrees to - 8 degrees ) and in side gaze was satisfactory and motility was clearly improved. There were no postoperative complications (infection, shrinkage, scarring) and the postoperative results in terms of the angle of deviation and the improvement in motility remained stable for 1-6 years. Polytetrafluoroethylene (Goretex) is a good material with which to resolve complicated cases of strabismus in which muscle tendon elongation for bulbus restriction is necessary.

Tratamento cirúrgico do estrabismo: avaliação técnico-econômica

To evaluate, from the economic and technical point of view, the surgical treatment of strabismus. A retrospective survey of available consecutive medical charts from the Altino Ventura Foundation-Recife/PE, Brazil was performed. Data on 100 patients who underwent strabismus surgery (from January of 2001 to February of 2003) and 100 patients who underwent cataract surgery (January of 2003) were analyzed. The times to performed these surgical procedures were observed. The times to accomplish strabismus surgeries were compared to those of cataract surgeries. In addition the variability of time among different strabismus surgeries was also observed. Surgical mean time for strabismus correction was longer than that for cataract surgery (77.3+/-27.6 min versus 58.3+/-12.7 min; p<0.0001). A significant variability in time to accomplish strabismus surgeries was also observed. In the case of intervention in up to two muscles, mean time was less than in the case of intervention in more than two muscles (66.0+/-16.6 min versus 97.5+/-31.7 min; p<0.0001). Longer surgical time of strabismus surgeries as compared to cataract surgeries gives support to the idea that the medical remuneration for strabismus surgery should be, at least, equivalent to that of cataract surgery. In addition, the fact of surgical mean time being so variable, suggests that this procedure should have a different remuneration.

Stereopsis and disparity vergence in monkeys with subnormal binocular vision.

The surgical treatment for strabismus in infants generally results in microtropia or subnormal binocular vision. Although the clinical characteristics of these conditions are well established, there are important questions about the mechanisms of binocular vision in these patients that can best be investigated in an appropriate animal model. In the present psychophysical investigations, spatial frequency response functions for disparity-induced fusional vergence and for local stereopsis were studied in macaque monkeys, who demonstrated many of the major visual characteristics of patients whose eyes were surgically aligned during infancy. In six rhesus monkeys, unilateral esotropia was surgically induced at various ages (30-184 days of age). However, over the next 12 months, all of the monkeys recovered normal eye alignment. Behavioral measurements at 4-6 years of age showed that the monkeys' prism-induced fusional vergence responses were indistinguishable from those of control monkeys or humans with normal binocular vision. Investigations of stereo-depth discrimination demonstrated that each of the experimental monkeys also had stereoscopic vision, but their stereoacuities varied from being essentially normal to severely stereo-deficient. The degree of stereo-deficiency was not related to the age at which surgical esotropia was induced, or to the presence or absence of amblyopia, and was not dependent on the spatial frequency of the test stimulus. Altogether, these experiments demonstrate that a temporary, early esotropia can affect the binocular disparity responses of motor and sensory components of binocular vision differently, probably because of different sensitive periods of development for the two components.

Secondary hyperfunction of unoperated inferior oblique muscle after surgical treatment of strabismus.

Secondary hyperfunction of the inferior oblique muscle IO of one of the eyes is a frequent complication after unilateral recession of the overacting IO of the fellow's eye. It is often observed in cases with bilateral asymmetric hyperfunction of the IO's when these are surgically decreased. The pathogenesis of this secondary hyperfunction is not sufficiently explained yet. We evaluated the condition of unoperated IO in 42 children with unilateral hyperfunction of the IO. In all cases the operation we performed was recession combined with a fixed anteroposition. During the two years follow up period we found no secondary hyperfunction of the unoperated oblique muscle in 31 of the children, mild level of elevation in 7 of them, middle--in 2, and severe in 2 of the children. This observation confirmed our conviction of refraining from simultaneous surgical intervention on both IO muscles when there is hyperfunction of one of them.

A Text and Atlas of Strabismus Surgery

This book is based on a series of lectures on strabismus given to residents at the Manhattan (NY) Eye, Ear, and Throat Hospital by Richards. The author states that this volume is not intended to be a comprehensive reference book or just a picture atlas of strabismus surgery. However, for readers with some knowledge of the appropriate anatomy and some familiarity with strabismus problems, the book gives a useful outline of Richards' approach to the (mainly) surgical treatment of strabismus. In general, the author describes procedures and techniques that are careful and conservative and that are probably representative of the practice of most experienced strabismus surgeons. However, as might be expected, differences of opinion do exist in some areas. For example, the Harada-Ito procedure is stated to be the most commonly indicated procedure for the treatment of bilateral superior oblique palsy. Some surgeons prefer to weaken the inferior oblique muscles

Surgical management of nonparalytic exotropia.

IN REVIEWING the literature on the surgical treatment of strabismus, one is impressed by the fact that most of the recent reports have dealt with the management of the vertical muscles and esotropia. The paucity of reports on exotropia may mean that to many ophthalmologists this type of case presents no problem. We have been impressed, however, by the many types of operative procedures utilized by various surgeons in attempting to correct exotropia. Recently, while reviewing the surgical results in a series of intermittent exotropias, one of us (R. D. M.) was surprised to find that in a group of 31 clinic patients, 40 operations had been performed utilizing 13 different types of surgical procedures. We realize that the various combinations of operative procedures which are theoretically possible with the lengthening and shortening of the four lateral rectus muscles is greater than 13, but we do not believe that basically