Congenital Fibrosis of Extraocular Muscles: A Retrospective Study of 76 Patients.

Background Congenital fibrosis of the extraocular muscles (CFEOM) is a non-progressive sporadic or familial disease characterized by abnormal innervation of the extraocular muscles. This study aims to evaluate the types of diseases, management steps, and surgical outcomes. Methodology A total of 76 patients diagnosed with CFEOM between 2000 and 2022 were evaluated retrospectively. Patients were divided into CFEOM 1, 2, or 3 based on clinical findings. Preoperative and postoperative ocular deviations, as well as abnormal head positions (AHPs), of the patients were evaluated. Excellent outcomes for the head position were defined as less than 5°, good as less than 10°, and poor as greater than 10°. Excellent alignment for strabismus was considered to be less than 10 prism diopters (PD), good as less than 20 PD, and poor as greater than 20 PD. Results The average age at the first surgery in our clinic was 11.6 (1-51) years. The mean follow-up was 28.6 ± 7.4 months (range = 4-56 months). Type 1 disease was detected in 48 (63.2%) patients, type 2 disease in eight (10.5%), and type 3 disease in 20 (26.3%) patients. Of the 49 patients with AHP, 20 achieved excellent outcomes, 17 had good outcomes, and the remaining had poor outcomes. Ocular alignment in the primary position following the latest surgery was excellent in 30 patients, good in 26 patients, and poor in 20 patients. Conclusions No single best surgical method can be universally applied to every patient diagnosed with CFEOM. Patients must be evaluated individually and carefully, and the appropriate surgical procedure must be chosen. In this way, satisfactory gaze alignment and improvement of the AHP can be achieved.

Binocular Alignment Changes Between Sitting and Supine Positions in Patients with Dizziness.

Vertical and torsional ocular misalignment can occur from mild traumatic brain injury or inner ear pathology, which may vary depending on head position. Here, we evaluate differences in a behavioral measure of binocular alignment in both upright and supine head position. Ocular perception of vertical and torsional alignment was measured using the torsional and vertical alignment nulling (TAN, VAN) task in N = 52 veterans with dizziness (N = 38 with traumatic brain injury), N = 41 civilians with vestibular schwannoma resection (UVD), and N = 33 healthy controls for both positions. The interquartile range within each group, regardless of head position, was greater for torsional compared to vertical misalignment. We use generalized estimating equations to compare average TAN (torsional) scores and VAN (vertical) scores between groups and test position. Compared to the healthy controls, TAN was significantly increased by + 0.4186° in veterans (P = 0.030) and by + 0.5747° in UVD (P = 0.010), but there was no difference with head position. For VAN, no difference was found between the three groups, but the misalignment did worsen by 0.0888° (P = 0.0070) as the head position moved from upright to supine. Head position had negligible effects on this behavioral measure of vertical and torsional binocular misalignment, and torsional misalignments were worse than controls in both veterans with dizziness and patients with vestibular nerve resection although neither reported torsional diplopia. Our data suggests that the tolerance for roll misalignment may be abnormally large in patients with dizziness. Alternatively, perceptual roll misalignments may be a manifest cause for dizziness, and therefore a useful proxy for distinguishing differences in putative otolith function in veterans with dizziness.

Longitudinal Rehabilitation of Binocular Function in Adolescent Intermittent Exotropia After Successful Corrective Surgery.

PURPOSE: To study the longitudinal rehabilitation of binocular visual function in adolescent intermittent exotropia (IXT) after successful surgery and compare the results with those of a normal population. The role of binocular function in ocular alignment stability was also evaluated postoperatively. METHODS: In this prospective study, 30 adolescents with IXT successfully corrected after 1 month were followed for 12 months, and 30 children with normal vision were enrolled as controls. Stereopsis, the fusional vergence amplitude, sensory fusion, and accommodative flexibility were measured to assess binocular function at baseline and 6 and 12 months postoperatively. The controls were tested once when they were enrolled in the study. RESULTS: The deviation was -32.00 ± 8.60 prism diopters (PD) at distance fixation and -36.0 ± 9.10 PD at near fixation preoperatively with an average correction of 28.53 ± 3.79 PD and 30.67 ± 1.34 PD at 1 month postoperatively. Distance stereoacuity and near stereoacuity improved from 1 to 12 months postoperatively (p = 0.025 and p = 0.041, respectively). Compared with the controls, the fusional convergence reserve at distance (p = 0.025) and near (p = 0.033) fixations and fusion reserve ratio at distance (p = 0.000) and near (p = 0.000) fixations remained subnormal, whereas sensory fusion (p = 0.237), distance stereopsis (p = 0.120), and the fusional divergence amplitude at a distance (p = 0.168) were normal. However, no significant correlations were found between binocular functions at 1 month postoperatively and the postoperative drift. CONCLUSION: Binocular function significantly improved from before to after successful corrective surgery and continued to improve from 1 to 12 months postoperatively in adolescents with IXT. No significant correlations were found between binocular functions at 1 month postoperatively and ocular alignment stability.

Botulinum Toxin Injection for the Treatment of Strabismus: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the available evidence comparing the effectiveness of extraocular muscle botulinum toxin type A (BTXA) injection with eye muscle surgery for restoring ocular alignment in children and adults with nonparalytic, nonrestrictive horizontal strabismus. METHODS: Literature searches in the PubMed Cochrane Library, and clinical trial databases with no date restrictions, but limited to articles published in English, were conducted last on January 10, 2021. The searches yielded 515 citations, 40 of which were reviewed in full text by the first author. Fourteen articles met the criteria for inclusion (randomized or nonrandomized comparative studies, or case series with a minimum 50 patients; evaluating extraocular muscle BTXA injection for initial or repeat treatment of horizontal, nonparalytic, nonrestrictive strabismus; with at least 6 months of follow-up) and were graded by a methodologist. RESULTS: The 14 included studies consisted of 2 randomized clinical trials, 3 nonrandomized comparative studies, and 9 case series. All 5 comparative studies were graded level II evidence, and the 9 case series were graded level III evidence. Successful motor outcomes after BTXA injection were relatively consistent across 4 of the 5 comparative studies at 60%, when adjustment was made for differential selection bias in 1 of the studies. In the 4 studies, successful motor outcomes after surgery ranged from 66% to 77% with a mean follow-up of 23 to 75 months, and the outcomes were not significantly different from those after BTXA injection. In the fifth level II study, success was significantly higher with BTXA injection than with surgery (94% vs. 72%). The level III BTXA case series demonstrated higher motor success rates of 87% to 89% when children were treated in 2 muscles at a time; rates were lower in adults treated with single-muscle BTXA injection. CONCLUSIONS: Extraocular muscle injection of BTXA achieves a high rate of successful motor alignment, comparable with that achieved after eye muscle surgery for nonparalytic, nonrestrictive horizontal strabismus. Good alignment may require multiple BTXA injections, and it is not yet clear whether sensory outcomes are equivalent for BTXA injections versus eye muscle surgery in young children.

Diagnosis and surgical management of isolated inferior oblique palsy.

AIM: To describe the etiology, clinical characteristics, surgical options and surgical outcomes of isolated inferior oblique palsy (IOP). METHODS: A retrospective review was performed on patients with isolated IOP who were seen between January 2010 and June 2017. The following clinical data were obtained from the patients' charts: visual acuity, ocular alignment, ocular motility, cyclotorsion, stereoacuity, Parks three-step test, surgical methods, surgical outcomes and complications. Surgical success was defined as horizontal deviation ≤10 prism diopters (PD) and a vertical deviation ≤5 PD in primary gaze at both near and distant vision as assessed at last follow-up. RESULTS: The records from a total of 18 patients (8 males and 10 females) with an average age of 27.56y were included in this study. The right eye was affected in 11 patients, the left in 6 patients and both eyes in 1 patient. Twelve cases (66.7%) were congenital and 6 (33.3%) were acquired IOP. The 6 acquired cases involved 2 resulting from orbital trauma/surgery, 2 from midbrain microvascular ischemia, 1 from myasthenia gravis and 1 of unknown etiology. Strabismus surgery was performed in 13 cases. Surgical techniques included weakening of superior oblique and vertical rectus recession and resection. After a mean follow-up of 15.11mo, the corrected vertical deviation in primary position was 19.92±8.52 PD (P=0.000) and the corrected horizontal deviation was 14.31±12.68 PD (P=0.002). The surgical success rate was 61.5% and no surgical complications were present. CONCLUSION: Isolated IOP represents a rare condition, with most cases (66.7%) involving a congenital basis. The acquired cases included vascular, orbital trauma/surgery and myasthenia gravis. Weakening of the ipsilateral superior oblique muscle and/or contralateral superior rectus recession often resulted in favorable surgical outcomes with a surgical success rate of 61.5%.

The stability of horizontal ocular alignment of triad exotropia after one-step triple surgery.

PURPOSE: A-pattern exotropia, superior oblique muscle overaction, and dissociated vertical deviation may coexist and are referred to as triad exotropia. The present study evaluated the postoperative stability of horizontal ocular alignment of triad exotropia and possible prognostic factors. METHODS: Medical records of patients with triad exotropia who had one-step triple surgery of superior oblique muscle weakening, superior rectus muscle recession, and lateral rectus muscle recession were reviewed. The horizontal alignment and postoperative drift of triad exotropia were analyzed and compared with constant exotropia. RESULTS: The triad exotropia showed a mean of 7.7△ (± 8.5△) eso-drift, while the constant exotropia was (3.5△ ± 3.4△) exo-drift. Multiple linear regression analysis showed that the degree of superior oblique muscle overaction after surgery (P = 0.011) was the only factor associated with horizontal drift. Patients with superior oblique muscle underaction showed larger eso-drift when compared to patients without superior oblique muscle underaction (- 18.0△ ± 11.1△ vs. - 5.1△ ± 5.7△; P = 0.024). The final success rates of the triad exotropia and constant exotropia groups were 53.3% and 69.2%, respectively, and the overcorrection rates were 26.7% and 2.6% (P = 0.035). CONCLUSIONS: An overall trend of eso-drift in primary position occurred in triad exotropia after triple surgery up to a follow-up of 25 months. Patients presenting superior oblique muscle underaction after surgery seemed to have large angles of eso-drift, which might be taken into account in surgical planning and follow-up.

Bifocals reduce strabismus in children with Down syndrome: Evidence from a randomized controlled trial.

PURPOSE: Children with Down syndrome (DS) more often have strabismus, refractive errors, accommodative lags and reduced visual acuity (VA) than typically developing children. In this study, we compare the effects of bifocal glasses with those of unifocal glasses in children with DS. Changes in angle of strabismus, accommodation and refractive error were analysed in this paper. METHODS: In a multicentre randomized controlled trial, 119 children with DS, aged 2-16, were randomly allocated for bifocal or unifocal glasses (with full correction of refractive error in cycloplegia). The 15 centres, all in the Netherlands, followed the participants for 1 year. Changes in refractive error, accommodative accuracy, strabismus, binocularity and stereopsis were compared across 4 subsequent visits. RESULTS: Refractive errors and accommodative errors showed no significant change throughout the course of our study in either intervention group. The manifest angle of strabismus, however, reduced significantly in the bifocal group. This improvement was observed shortly after the children received their new correction (~6 weeks) (linear regression: t = 3.652, p < 0.001) and remained present in the final measurements after 1 year (linear regression: t = 3.604, p < 0.001). The percentage of children with positive binocularity and stereo tests showed no significant differences between the groups. CONCLUSION: Bifocals with full correction of refractive error reduce the manifest angle of strabismus within a few weeks. No effects on accommodation, refractive error, stereopsis and binocularity occurred over the course of 1 year.

Validation of StrabisPIX, a Mobile Application for Home Measurement of Ocular Alignment.

PURPOSE: StrabisPIX is a smartphone application that allows clinicians to prescribe a series of self-obtained images of head position and eye alignment in nine positions of gaze that are uploaded onto a secure platform for clinician review. This study evaluates the clinical utility of this application. METHODS: In this prospective, nonmasked, cross-sectional study, 30 strabismus patients aged ≥2 years were evaluated. Participants received standardized instructions, used StrabisPIX to obtain images as prompted, and completed a satisfaction survey. During the same visit, an orthoptist obtained standard clinical images with a professional camera. All 60 image sets were evaluated by three observers. RESULTS: StrabisPIX image quality was similar to that of clinic photographs. Clinic photographs had significantly higher acceptability for horizontal versions (81% vs. 67%), vertical versions (76% vs. 60%), and head posture (93% vs. 81%). Abnormalities were detected at a similar rate for versions, head posture, eyelid position, and pupil size. StrabisPIX had significantly higher detection of alignment abnormalities (89% vs. 77% for clinical photos). Interrater/intrarater agreements were moderate to high (κ = 0.44-1.00) for all parameters except pupil abnormality, which had poor to fair agreement. Most patients reported that StrabisPIX was easy to learn and use. CONCLUSIONS: Overall, StrabisPIX images had similar quality and were as useful as images obtained in the clinic in detecting abnormalities. TRANSLATIONAL RELEVANCE: The StrabisPIX application will enhance the use of telemedicine by allowing physicians to prescribe self-obtained images documenting strabismus.

The Effect of Amblyopia Treatment with Patching on Ocular Alignment

PURPOSE: To evaluate the effect of patching on ocular alignment in children with unilateral amblyopia. METHODS: We evaluated the change in ocular alignment during and after patching in patients who had started amblyopia treatment with patching, and analyzed the aspects of change according to the cause and severity of amblyopia, type and magnitude of deviation, type of refractive error, and age at initiation. A change of eight prism diopters (PD) or more in horizontal deviation, or two PD or more in vertical deviation was considered significant. RESULTS: A total of 209 patients were enrolled; 135 had amblyopia associated with anisometropia, 50 with strabismus, 19 with combined cause, and 5 with deprivation. After patching, there was no change in distant deviation in 177 patients (84.7%), while a decrease was noted in 23 patients (11.0%) and an increase in nine patients (4.3%). The angle of deviation decreased in 7.4% of anisometropic amblyopia, 20.0% of strabismic amblyopia, 10.5% of combined amblyopia, and 20.0% of deprivation amblyopia. The angle of deviation increased in 4.4% of anisometropic amblyopia, 5.3% of combined amblyopia, and 40.0% of deprivation amblyopia. The angle of deviation decreased in 24.2% of exodeviation, and 21.6% of esodeviation, but there was no change in vertical deviation among the studied patients. The angle of deviation decreased in 31.9% of patients with deviation greater than 8 PD. The change did not differ according to severity of amblyopia, type of refractive error, or age. Among the successes, decrease in deviation was more common until they achieved equal visual acuity between both eyes, while the increase during tapering of patching. CONCLUSIONS: Change in ocular alignment may occur after patching in some patients with amblyopia, and seems to be more frequent in cases associated with horizontal deviation greater than 8 PD.

2014 updated recommendations for preschool vision screening: Guidelines for Filipino children entering the Philippine public school system

@#In 2004, the University of the Philippines Manila published the Philippine Guidelines on Periodic Health Examination (PHEX): Effective Screening for Diseases among Apparently Healthy Filipinos. 1 The document was envisioned to “contribute… to the quality and efficiency of health care and health maintenance for all Filipinos… It was an appeal for rational medical decision-making, and an important step toward “equitable distribution of health and health resources.” The guidelines were prepared by designated task forces, with vision disorders, specifically vision impairment, and glaucoma identified as areas of interest. PHEX recommendations were drafted using standardized principles and a common protocol, with each statement undergoing four phases of development: (1) preparation of the evidence- based draft; (2) en banc meeting that gave panelists a chance to assess and revise the draft, where issues of feasibility, resource limitations, value judgment, and experts’ opinions were taken into account. A consensus was declared when at least 75% agreed on a recommendation; (3) for unresolved issues, modified Delphi technique was employed by correspondence until a consensus was reached or a maximum of three circulations were accomplished. If still unresolved, the issue was labeled as such and included in the final draft; (4) lastly, a public forum was conducted before the final draft was written. In this manner, the recommendations for Screening for Visual Impairment were written by the Task Force for Vision Disorders.

Reduction of Deviation Angle During Occlusion Therapy: In Partially Accommodative Esotropia with Moderate Amblyopia

PURPOSE: To evaluate changes in ocular alignment in partially accommodative esotropic children age ranged from 3 to 8 years during occlusion therapy for amblyopia. METHODS: Angle measurements of twenty-two partially accommodative esotropic patients with moderate amblyopia were evaluated before and at 2 years after occlusion therapy. RESULTS: Mean deviation angle with glasses at the start of occlusion treatment was 19.45+/-5.97 PD and decreased to 12.14+/-12.96 PD at 2 years after occlusion therapy (p<0.01). After occlusion therapy, 9 (41%) cases were indications of surgery for residual deviation but if we had planned surgery before occlusion treatment, 18 (82%) of patients would have had surgery. There was a statistical relationship between increase of visual acuity ratio and decrease of deviation angle (r=-0.479, p=0.024). CONCLUSIONS: There was a significant reduction of deviation angle of partially accommodative esotropic patients at 2 years after occlusion therapy. Our results suggest that occlusion therapy has an influence on ocular alignment in partially accommodative esotropic patients with amblyopia.

Update in the Diagnosis and Treatment of Strabismus

Strabismus is defined as an ocular misalignment. Since it can cause not only impaired visual function but also social handicap and tremendous emotional stress, the care of patients with strabismus should include psychological and social aspects. Although strabismus is one of the major fields in pediatric ophthalmology and neuro-ophthalmology, its precise mechanism and etiology are still unknown. It can be inherited from strabismic parents, or be derived from the anomalous structure, neurologic deficits, and refractive errors. The diagnosis of strabismus can be made by covering one eye, and the degree of strabismus can be quantified by the alternate prism cover test. Recently MRI is used widely for the diagnosis of various anomalous orbital and muscular structures, especially to investigate heterotopia of extraocular muscle pulley. The treatment modalities for strabismus are either surgical or nonsurgical. Surgical treatments can be made by recession or resection of the involved extraocular muscle. The adjustable suture technique was introduced in 1970s, which has been the gold standard among surgical treatment modalities. Nonsurgical treatments include prism, glasses, bifocal lenses, and drugs. A young strabismic patient may have amblyopia and decreased stereoacuity due to abnormal interaction between the sound eye and the deviating eye. Once amblyopia is detected, immediate treatment is needed to correct the visual dysfunction. Recent efforts to elucidate the mechanisms of strabismus are believed to unravel the mysterious pathophysiology in the near future.

The Influence of Fusional Vergence on the Postoperative Ocular Alignment in Intermittent Exotropia

The purpose of this study was to evaluate the influence of fusional vergence on the ocular alignment after surgery in intermittent exotropia. We evaluated fusional convergence and divergence with rotary prism. We examined 44 patients with intermittent exotropia who were followed up postoperatively for at least 6 months from January 1995 to June 1998. The angle of deviation was measured preoperatively, 1 week after surgery and on the last follow-up day. We evaluated the break and recovery point of fusional convergence and divergence at near and far at each measurement of angle of deviation. The subjects were divided into two groups according to the deviation at the last visit : Orthophoria group and Undercorrection group. Orthophoria group was defined as having the deviation equal to or less than 15 delta of exodeviation, and undercorrection group was defined as having the deviation more than 15 delta of exodeviation. In Orthophoria group, break point and recovery point of convergence were 28.07 delta and 26.34 delta at near, 25.52 delta and 22.55 delta at far. The break point and recovery point of divergence were 18.21 delta and 12.38 delta at near, 12.70 delta and 7.73 delta at far. In Undercorrection group, break point and recovery point of convergence were 25.86 delta and 24.71 delta at near, 25.20 delta and 25.80 delta at far. The break point and recovery point of divergence were 18.86 delta and 13.29 delta at near, 17.90 delta and 15.40 delta at far. There was no significant difference between two groups. According to the change from deviation at postoperative 1 week to final deviation, the subjects were divided into four groups. We evaluated the difference of fusional convergence and divergence, according to the change of angle of deviation between postoperative 1 week and the last follow-up day, but there was no significant difference. In conclusion, we can not find any significant influence of fusional vergence on the ocular alignment after surgery in intermittent exotropia.