Changes in ocular biometrics following cycloplegic refraction in strabismic and amblyopic children.

This study was aimed to analyze ocular biometric changes following cycloplegia in pediatric patients with strabismus and amblyopia. Cycloplegia is routinely used to measure refractive error accurately by paralyzing accommodation. However, effects on axial length (AL), anterior chamber depth (ACD), keratometry (Km), and white-to-white distance (WTW) are not well studied in this population. This retrospective study examined 797 patients (1566 eyes) undergoing cycloplegic refraction at a Samsung Kangbuk hospital pediatric ophthalmology clinic from 2010 to 2023. Ocular biometry was measured before and after instilling 1% cyclopentolate and 0.5% phenylephrine/0.5% tropicamide. Patients were categorized by strabismus diagnosis, age, refractive error and amblyopia status. Differences in AL, ACD, Km, WTW, and refractive error pre- and post-cycloplegia were analyzed using paired t tests. ACD (3.44 ±â€…0.33 vs 3.58 ±â€…0.29 mm, P < .05) and WTW (12.09 ±â€…0.42 vs 12.30 ±â€…0.60 mm, P < .05) increased significantly after cycloplegia in all groups except other strabismus subgroup (Cs) in both parameters and youngest subgroup (G1) in ACD. Refractive error demonstrated a hyperopic shift from -0.48 ±â€…3.00 D to -0.06 ±â€…3.32 D (P < .05) in overall and a myopic shift from -6.97 ±â€…4.27 to -8.10 ±â€…2.26 in high myopia (HM). Also, AL and Km did not change significantly. In conclusion, cycloplegia impacts ocular biometrics in children with strabismus and amblyopia, significantly increasing ACD and WTW. Refractive error shifts hyperopically in esotropia subgroup (ET) and myopically in high myopia subgroup (HM), eldest subgroup (G3) relating more to anterior segment changes than AL/Km. Understanding cycloplegic effects on biometry is important for optimizing refractive correction in these patients.

Long-term visual and neurodevelopmental outcomes in children with Congenital Zika Syndrome after undergoing strabismus surgery.

Purpose: To assess long-term visual and neurodevelopmental outcomes in children with congenital Zika syndrome (CZS) after strabismus surgery. Methods: A consecutive sample of five children with CZS who underwent strabismus surgery was enrolled. All children underwent a standardized pre- and postoperative protocol including binocular best-corrected visual acuity (BCVA) using the Teller Acuity Cards II (TAC II), ocular alignment, functional vision using the functional vision developmental milestones test (FVDMT), and neurodevelopmental milestone evaluation using the Bayley Scales of Infant Development-Third Edition (BSID-III). Scores of the FVDMT outcomes considering the child's developmental age based on the BSID-III score were compared with scores from postoperative assessment. Results: Five children with CZS (3 girls, 2 boys) were enrolled with a mean age at baseline (preoperative) of 35.0 ± 0.7 months (range, 34-36 months) and at final assessment of 64.4 ± 0.5 months (range, 64-65 months). Preoperative BCVA was 1.2 ± 0.5 logMAR and at final assessment 0.7 ± 0.1 logMAR. Successful strabismus surgery outcome was maintained in 4/5 (80.0%) of children at final assessment. The children's BSID-III scores showed significant neurodevelopment delay at the initial assessment (corresponding developmental mean age was 4.7 months) and at their final assessment (corresponding developmental mean age was 5.1 months). There was improvement or stability in 34/46 items evaluated in the FVDMT (73.9%) when comparing baseline with 2-year follow-up. Conclusions: Strabismus surgery resulted in long-term ocular alignment in the majority of children with CZS. All the children showed improvement or stability in more than 70.0% of the functional vision items assessed. Visual and neurodevelopmental dysfunction may be related to complex condition and associated disorders seen in CZS including ocular, neurological, and skeletal abnormalities.

Novel superior oblique anterior fiber plication with or without adjustable sliding knot for extorsion.

PURPOSE: To report a novel surgical technique to correct excyclotropia, consisting of a superior oblique anterior fibers plication (SOAFP) with or without a hemihangback anterior knot, allowing access for postoperative adjustment. METHODS: A retrospective interventional case series was conducted. Fourteen patients, 21-92 years of age, underwent SOAFP (18 eyes, 14 eyes on adjustable), at the Mayo Clinic in Rochester, Minnesota. SOAFP was the only procedure performed in 12 eyes; in 6 it was performed in conjunction with up to four horizontal rectus muscle recession, resection, and/or plication. Ocular alignment was assessed with prism and alternate cover and double Maddox rod tests; preoperatively, at initial and final (closest to 6-8 weeks) postoperative visits. RESULTS: Preoperative torsion ranged from 2° to 30° of extorsion (mean, 10.14 ± 7.01). A SOAFP of 2-30 mm (mean, 8.93 ± 5.63) was performed. At the initial postoperative examination, mean intorsional shift was 11.18 ± 7.37, accounting for 1.86° ± 1.04° of correction per millimeter of plication. Three eyes were adjusted after the initial visit to obtain a stronger plication effect targeting of 5° intorsion. At the final visit, 61 ± 23 days postoperatively, mean extorsion was 1.21° ± 2.29°, ranging from 5° of extorsion to 3 of intorsion. Mean final intorsional shift was 9.14 ± 7.53°, accounting for a 1.16 ± 0.50° of correction per millimeter of plication. Of our 14 patients, 13 had improvement in diplopia. CONCLUSIONS: In our study cohort, SOAFP allowed for targeted and easily adjustable correction of extorsion.

Peripheral Binocular Imbalance in Anisometropic and Strabismic Amblyopia.

Purpose: Individuals with amblyopia experience central vision deficits, including loss of visual acuity, binocular vision, and stereopsis. In this study, we examine the differences in peripheral binocular imbalance in children with anisometropic amblyopia, strabismic amblyopia, and typical binocular vision to determine if there are systematic patterns of deficits across the visual field. Methods: This prospective cohort study recruited 12 participants with anisometropic amblyopia, 10 with strabismic amblyopia, and 10 typically sighted controls (age range, 5-18 years). Binocular imbalance was tested at 0°, 4°, and 8° eccentricities (4 angular locations each) using band-pass filtered Auckland optotypes (5 cycles per optotype) dichoptically presented with differing contrast to each eye. The interocular contrast ratio was adjusted until the participant reported each optotype with equal frequency. Results: Participants with anisometropic and strabismic amblyopia had a more balanced contrast ratio, or decreased binocular imbalance, at 4° and 8° eccentricities as compared with central vision. Participants with strabismic amblyopia had significantly more binocular imbalance in the periphery as compared with individuals with anisometropic amblyopia or controls. A linear mixed effects model showed a main effect for strabismic amblyopia and eccentricity on binocular imbalance across the visual field. Conclusions: There is evidence of decreased binocularity deficits, or interocular suppression, in the periphery in anisometropic and strabismic amblyopia as compared with controls. Notably, those with strabismic amblyopia exhibited more significant peripheral binocular imbalance. These variations in binocularity across the visual field among different amblyopia subtypes may necessitate tailored approaches for dichoptic treatment.

Anterior transposition of the inferior oblique and anti-elevation syndrome - how far to go?

Purpose: To study the incidence of postoperative anti-elevation syndrome in relation to the magnitude of anterior transposition of the inferior oblique. Methods: A retrospective chart review was conducted for all patients submitted to anterior transposition of the inferior oblique from 2000 to 2020. Anti-elevation syndrome was defined as limitation of elevation of the abducting eye, resulting in a secondary upshoot of the contralateral adducting eye. Results: A total of 312 eyes of 170 patients were enrolled in the study. The incidence of anti-elevation syndrome was 20.4% when the inferior oblique was positioned 4 mm posterior to the temporal border of the inferior rectus insertion; 23.5% when sutured 2 mm posterior to the temporal border of the inferior rectus insertion and 32.8% when placed at the same level of the inferior rectus insertion with two sutures vertically aligned. When the posterior border of the inferior oblique was horizontally aligned with the anterior border and positioned adjacent to the inferior rectus insertion, in a "J shape" fashion, the incidence of anti-elevation was 41.8%. Conclusions: The anterior transposition of the inferior oblique with "J" deformity increases the risk of anti-elevation syndrome. Additionally, placing the sutures more anteriorly than 2 mm posterior to the inferior rectus insertion increases the incidence of this finding.

Comparison of simultaneous prism and cover test (SPCT) and prism and alternate cover test (PACT) measurements with final power of Press-On prism power dispensed.

PURPOSE: To investigate the association of strabismic angle obtained by simultaneous prism and cover test (SPCT) and prism alternate cover test (PACT) with the final power of Press-On prism used in adults with symptomatic strabismus. METHODS: The medical records of consecutive patients seen by a single orthoptist at an urban, tertiary care hospital over a 36-month period were reviewed retrospectively. All subjects had been prescribed Press-On prism for diplopia after evaluation with SPCT and PACT measurements at distance fixation. Prism dispensed was chosen by the patient using a trial Press-On prism set. RESULTS: A total of 244 charts were reviewed. Of these, 108 adult patients had prism dispensed, and 32 had both SPCT and PACT measurements. Mean SPCT measurement was 7Δ (median, 6Δ; range, 3Δ-14Δ); mean PACT, 13Δ (median, 11Δ; range, 8Δ-20Δ). The mean prism power dispensed was 7Δ (median, 6Δ; range, 1Δ-15Δ); this was not significantly different from mean SPCT (P = 0.35). There was a large difference (6Δ) between mean PACT measurements and mean prism dispensed (P < 0.001). At follow-up of 1 year, 21 patients (66%) remained in prism. Nine patients (4%) elected to undergo eye muscle surgery, 7 with horizontal strabismus, 6 of whom had SPCT measurements of >10Δ and PACT measurements of >15Δ. CONCLUSIONS: Press-On prism power used was more closely tied to the angle of strabismus obtained by SPCT. Overall success rate of Press-On prism was good when the prism power dispensed was close to the SPCT measurement, suggesting that it is reasonable to initiate treatment with a weaker prism, approximating the SPCT measurement, building up only if there are continuing symptoms.

Wearable apparatus for correction of visual alignment under torsional strabismus.

SIGNIFICANCE: A wearable optical apparatus that compensates for eye misalignment (strabismus) to correct for double vision (diplopia) is proposed. In contrast to prism lenses, commonly used to compensate for horizontal and/or vertical misalignment, the proposed approach is able to compensate for any combination of horizontal, vertical, and torsional misalignment. PURPOSE: If the action of the extraocular muscles is compromised (e.g., by nerve damage), a patient may lose their ability to maintain visual alignment, negatively affecting their binocular fusion and stereo depth perception capability. Torsional misalignment cannot be mitigated by standard Fresnel prism lenses. Surgical procedures intended to correct torsional misalignment may be unpredictable. A wearable device able to rectify visual alignment and restore stereo depth perception without surgical intervention could potentially be of great value to people with strabismus. METHODS: We propose a novel lightweight wearable optical device for visual alignment correction. The device comprises two mirrors and a Fresnel prism, arranged in such a way that together they rotationally shift the view seen by the affected eye horizontally, vertically, and torsionally. The extent of the alignment correction on each axis can be arbitrarily adjusted according to the patient's particular misalignment characteristics. RESULTS: The proposed approach was tested by computer simulation, and a prototype device was manufactured. The prototype device was tested by a strabismus patient exhibiting horizontal and torsional misalignment. In these tests, the device was found to function as intended, allowing the patient to enjoy binocular fusion and stereo depth perception while wearing the device for daily activities over a period of several months. CONCLUSIONS: The proposed device is effective in correcting arbitrary horizontal, vertical, and torsional misalignment of the eyes. The results of the initial testing performed are highly encouraging. Future study is warranted to formally assess the effectiveness of the device on multiple test patients.

Long-term surgical outcomes of one-muscle vs. two-muscle horizontal strabismus surgery.

PURPOSE: While horizontal strabismus surgery is generally considered to have favorable outcomes, success rates can vary by type of procedure. Our purpose is to compare the long-term outcomes of patients who underwent one-muscle vs. two-muscle horizontal strabismus surgery. METHODS: This is a retrospective study comparing one-muscle to two-muscle strabismus surgery for small to moderate angle horizontal strabismus. Demographic data and eye exam parameters were compared at baseline and postoperatively (6 months up to 6 years). Surgical success was defined as a post-operative angle of 10 PD or less. We also compared outcomes by strabismus type: esotropia vs exotropia and adjusted the analysis for previous strabismus surgery. RESULTS: Out of 89 patients with moderate angle horizontal strabismus (25 PD or less), 17 patients had a one-muscle operation, and 72 patients had two-muscle surgery. The mean age was 14.12 ± 9.30 years and 11.70 ± 11.30 years for the one-muscle and two-muscle groups, respectively (p = .74). The baseline characteristics of both groups were comparable. Follow-up time was 32.82 ± 26.93 months in one-muscle and 37.67 ± 23.81 in two-muscle groups (p = .29). Success rate was 70.6% for the one-muscle group and 68.10% for the two-muscle group (p = .69). Outcomes were similar when divided into esotropia and exotropia. The success rate was not affected by previous strabismus surgeries nor by the initial angle of deviation. CONCLUSION: One-muscle and two-muscle horizontal strabismus surgery had similar long-term outcomes and did not differ by strabismus type nor by angle of deviation.

An unusual ophthalmologic finding in a patient with congenital central hypoventilation syndrome.

INTRODUCTION: Congenital Central Hypoventilation Syndrome (CCHS) is a rare disease due to a severely impaired central control of breathing and dysfunction of the autonomic nervous system. Ophthalmologic abnormalities are common in patients with CCHS and include horizontal strabismus, pupil and iris abnormalities and ptosis. We report a unique case of CCHS in association with monocular elevation deficit (MED) in a boy diagnosed with CCHS at birth. CASE DESCRIPTION: We report a case of a boy with a confirmed diagnosis of CCHS (complete sequencing of the paired-like homeobox 2b (PHOX2B) gene) after presenting little respiratory effort and cyanosis at birth. The ophthalmological examination shows an impaired elevation of the left eye, both in adduction and abduction, associated with mild and variable left ptosis. His mother has observed that the left eyelid elevates when the child feeds. A deviation in the primary gaze position or a chin-up position are not present. The funduscopic examination is normal. Given that deviation is limited to upgaze, the ptosis is mild and the patient's age, observation is decided. CONCLUSIONS: Ophthalmologic abnormalities are common in patients with CCHS and include horizontal strabismus, pupil and iris abnormalities and ptosis. To the best of our knowledge, this is the first report of MED in association with CCHS. Further studies are needed to determine if an association between MED and CCHS exists or is just a casual finding in this case.

Pediatric myopic strabismus fixus: clinical features and surgical outcomes of silicone band loop myopexy.

PURPOSE: To evaluate the clinical profile of myopic strabismus fixus (MSF) in children and surgical outcomes of silicone band loop myopexy. METHOD: We retrospectively reviewed records of children presenting with MSF who underwent silicone band loop myopexy between January 2008 and December 2020 at a tertiary eye care center. Data concerning demographics, refractive error, axial length, extra-ocular motility, and ocular alignment pre-operatively and post-operatively, intra- and post-operative complications, ocular and systemic associations, were evaluated. The long-term effects of band loop myopexy on ocular alignment stability, motility improvement, and myopia progression were analyzed. Surgical outcome was defined as post-operative orthotropia or heterotropia less than or equal to 20 PD. RESULTS: A total of0 eyes of 7 patients (median age: 5 years; 5 boys and 2 girls) who underwent band loop myopexy were included in the study. Among them, three children underwent bilateral and four children underwent unilateral band loop myopexy. Medial rectus recession was performed only in two patients as a part of initial procedure. The median follow-up duration was 7 years. Most of the children, i.e. six of them presented with esotropia-hypotropia and only one patient presented with exotropia-hypotropia complex. The median pre-operative measurements were esotropia of 62.5 PD, hypotropia of5 PD, and exotropia of4 PD. Postoperative average primary position deviation measured was close to 9-10 PD of esotropia. The overall motility improved to -1 from -3. CONCLUSION: The clinical profile of MSF in children is almost similar to adults. This condition is a rare entity among adults as well as children. Majority of children with MSF presented with esotropia-hypotropia complex. Silicone band loop myopexy with or without medial rectus recession proves to be a reliable surgical procedure as it provides stable outcomes in terms of ocular alignment and motility among children.

Binocular Home Treatment for Amblyopia: Gains Stable for One Year.

PURPOSE: To report the long-term outcomes of a noninferiority randomized controlled trial (RCT) with a binocular eye-tracking-based home treatment (CureSight; NovaSight, Ltd.) in patients with amblyopia. DESIGN: Prospective, multicenter, nonrandomized, long-term follow-up observational study of an RCT. METHODS: Forty-three children 4 to <9 years of age with anisometropic, small-angle strabismic, or mixed-mechanism amblyopia were initially treated for 16 weeks (NCT05185076) with CureSight. In this planned observational follow-up study, 38 patients with no additional amblyopia treatment were evaluated at 12 weeks post-treatment, and 27 were evaluated at 1-year post-treatment. The main outcome measures were visual acuity (VA), stereoacuity, and amblyopia recurrence at 12- and 52-week post-treatment. RESULTS: At 12-week post-treatment, improvement in amblyopic eye VA was maintained vs baseline (0.27 ± 0.14 logMAR, P< .0001), with no change vs the end-of-treatment visit (P > .05). At 1 year there was a partial reduction in the amblyopic eye VA gain of 0.085±0.1 logMAR compared to end-of-treatment (P = .001), but the residual gain of 0.20±0.14 logMAR compared to baseline was statistically significant (P < .0001). Gains in stereoacuity and binocular VA were maintained vs baseline at both 12-weeks and 1-year post-treatment (P < .0001), with no change vs end-of-treatment (P > .05). Amblyopia recurrence (a worsening of ≥2 logMAR levels compared with end-of-treatment) occurred in 2/38 patients at 12-weeks post-treatment (5.3%), and in 5/27 patients at 1-year post-treatment (20.4%). CONCLUSIONS: VA and stereopsis gains following binocular treatment with CureSight were maintained at 1 year without additional treatment.

Outcomes of Strabismus Surgery Following Teprotumumab Therapy.

PURPOSE: To investigate the results of patients undergoing surgical treatment for strabismic diplopia in thyroid eye disease (TED) following teprotumumab. DESIGN: Multicenter, retrospective, case series. METHODS: We report 28 patients who underwent extraocular muscle surgery for strabismic diplopia after treatment with teprotumumab at 7 different academic centers. Elapsed time from last teprotumumab dose to the date of surgery, previous orbital decompression, primary preoperative horizontal and vertical deviation, surgical procedure, and 2-month postoperative results were collected from the patient records. RESULTS: Sixteen (57%) patients were diplopia-free after 1 surgery. Three (11%) chose prism spectacles to correct residual diplopia, 2 (7%) used compensatory head posture to resolve diplopia, and 1 (4%) had intermittent diplopia and was functionally improved (choosing no prisms or further surgery). These were considered treatment successes. Three (11%) patients required reoperation, and all were diplopia-free after their second procedure. CONCLUSIONS: Most patients requiring surgery for strabismic diplopia following teprotumumab achieve good outcomes with success rates comparable to series published before the availability of teprotumumab.

Application of Absorbable Suture in Strabismus Correction and Nursing Management Advantage of Watson Care Theory in Perioperative Period.

Objectives: The article is aimed at investigating the suture effect of absorbable suture in strabismus correction and the advantage of Watson care theory. Methods: 148 children with strabismus were enrolled in this study and divided into two groups. The control group received routine nursing, and on this basis, the observation group was given Watson care theory nursing and eye muscle suture with absorbable sutures. The degree of cooperation (induction compliance checklist (ICC) score), negative emotion (modified Yale preoperative anxiety scale (m-YAPS) score), pain (face pain scale (FPS) score), quality of nursing management, parents' satisfaction, clinical efficacy, and adverse reactions were compared. Results: After nursing and surgical treatment, all children's strabismus symptoms were improved, and the improvement of strabismus and visual function in the observation group was more obvious. Watson care nursing can effectively improve the nursing management quality, parents' satisfaction, children's negative emotions, and treatment compliance. Conclusions: As a result, Watson care theory nursing is of great significance for improving the relationship between nurses and patients and building a harmonious hospital.

Altered functional connectivity of primary visual cortex in adults with strabismus and amblyopia: a resting-state fMRI study.

Functional connectivity of the primary visual cortex was explored with resting functional magnetic resonance imaging among adults with strabismus and amblyopia and healthy controls. We used the two-sample test and receiver operating characteristic curves to investigate the differences in mean functional connectivity values between the groups with strabismus and amblyopia and healthy controls. Compared with healthy controls, functional connectivity values in the left Brodmann areas 17, including bilateral lingual/angular gyri, were reduced in groups with strabismus and amblyopia. Moreover, functional connectivity values in the right Brodmann area 17, including left cuneus, right inferior occipital gyrus, and left inferior parietal lobule, were reduced in adults with strabismus and amblyopia. Our findings indicate that functional connectivity abnormalities exist between the primary visual cortex and other regions. This may be the basis of the pathological mechanism of visual dysfunction and stereovision disorders in adults with strabismus and amblyopia.

Gray matter volume alterations in patients with strabismus and amblyopia: voxel-based morphometry study.

This study proposes the use of the voxel-based morphometry (VBM) technique to investigate structural alterations of the cerebral cortex in patients with strabismus and amblyopia (SA). Sixteen patients with SA and sixteen healthy controls (HCs) underwent magnetic resonance imaging. Original whole brain images were analyzed using the VBM method. Pearson correlation analysis was performed to evaluate the relationship between mean gray matter volume (GMV) and clinical manifestations. Receiver operating characteristic (ROC) curve analysis was applied to classify the mean GMV values of the SA group and HCs. Compared with the HCs, GMV values in the SA group showed a significant difference in the right superior temporal gyrus, posterior and anterior lobes of the cerebellum, bilateral parahippocampal gyrus, and left anterior cingulate cortex. The mean GMV value in the right superior temporal gyrus, posterior and anterior lobes of the cerebellum, and bilateral parahippocampal gyrus were negatively correlated with the angle of strabismus. The ROC curve analysis of each cerebral region confirmed the accuracy of the area under the curve. Patients with SA have reduced GMV values in some brain regions. These findings might help to reveal the potential pathogenesis of SA and its relationship with the atrophy of specific regions of the brain.

Measuring functional connectivity in patients with strabismus using stationary functional magnetic resonance imaging: a resting-state network study.

BACKGROUND: Strabismus (STR) is a common eye disease characterized by abnormal eye movements and stereo vision. Neuroimaging studies have revealed that STR patients have impaired functional connectivity (FC) in the visual cortex and sensorimotor cortex. PURPOSE: To investigate alterations in FC and connections within and between subnetworks of the visual network (VN), sensorimotor network (SMN), and default mode network (DMN) in patients with STR. MATERIAL AND METHODS: A total of 32 patients with STR (24 men, 8 women) and 32 age- and sex-matched healthy controls (HCs) (24 men, 8 women) were recruited. Participants underwent resting-state functional magnetic resonance imaging scans. The resting-state network (RSN) was examined by independent component analysis, and differences in RSN FC between STR and HC groups were evaluated with the t test. Functional network connectivity (FNC) analysis was performed for the three RSNs. RESULTS: Compared to the HC group, the STR group showed increased FC in the VN and SMN (voxel-level P < 0.01; two-tailed Gaussian random field correction; cluster-level P < 0.05). There were no significant alterations in DMN FC between the two groups. FNC analysis of connections in the RSN revealed that one of the three connections in the VN was reduced, but no connectivity changes were observed in the SMN or DMN. FNC analysis of the connection between two RSNs showed that two had increased and one had a decreased connection value. CONCLUSION: The VN, SMN, and DMN are reorganized in patients with STR compared to HCs, providing novel insight into the neural substrates of STR.

Adjustable Sutures in the Treatment of Strabismus: A Report by the American Academy of Ophthalmology.

PURPOSE: To review the scientific literature that evaluates the effectiveness of adjustable sutures in the management of strabismus for adult and pediatric patients. METHODS: Literature searches were performed in the PubMed database through April 2021 with no date limitations and were restricted to publications in English. The searches identified 551 relevant citations, of which 55 were reviewed in full text. Of these, 17 articles met the inclusion criteria and were assigned a level of evidence rating by the panel methodologist. The search included all randomized controlled studies regardless of study size and cohort studies of 100 or more patients comparing the adjustable versus nonadjustable suture technique, with a focus on motor alignment outcomes or reoperation rates. RESULTS: The literature search yielded no level I studies. Of the 17 articles that met the inclusion criteria, 11 were rated level II and 6 were rated level III. Among the 12 studies that focused on motor alignment outcomes, 4 small randomized clinical trials (RCTs) did not find a statistically significant difference between groups, although they were powered to detect only very large differences. Seven of 8 nonrandomized studies found a statistically significant difference in motor alignment success in favor of the adjustable suture technique, both overall and in certain subgroups of patients. Successful motor alignment was seen in both exotropia (in 3 studies that were not limited to children) and esotropia (in 1 study of adults and 2 of children). The majority of included studies that reported on reoperation rates found the rates to be lower in patients who underwent strabismus surgery with adjustable sutures, but this finding was not uniformly demonstrated. CONCLUSIONS: Although there are no level I studies evaluating the effectiveness of adjustable sutures for strabismus surgery, the majority of nonrandomized studies that met the inclusion criteria for this assessment reported an advantage of the adjustable suture technique over the nonadjustable technique with respect to motor alignment outcomes. This finding was not uniformly demonstrated among all studies reviewed and warrants further investigation in the development and analysis of adjustable suture techniques.

Morphological change of the posterior pole following the horizontal strabismus surgery with swept source optical coherence tomography.

Extraocular muscle movement during strabismus surgery causes changes in eyeball shape. Because extraocular muscle insertion is in front of the equator, it is thought that changes due to strabismus surgery mainly occur in the anterior segment. However, changes in the posterior segment of eye may also occur, which may also result in changes in refractive error after strabismus surgery. Using a 3-dimensional reconstruction technique (en face imaging) of the swept source optical coherence tomography, we determined and quantitatively measured the posterior polar change. The deepest interface between Bruch's membrane and the choroid could be identified as the deepest point of the eyeball (DPE), and the location of the DPE relative to the optic disc and the fovea was measured. After lateral rectus muscle recession, the DPE moved away from the fovea, but after medial rectus muscle recession, the DPE moved toward the fovea. The amount of DPE movement differed by age and preoperative refractive error. Our findings suggest that the positional shift of the rectus muscle in horizontal strabismus surgery causes a structural change in the posterior segment of the eye, and the postoperative refractive changes may be related to this shift.

Unreferenced spatial localization under monocular and dichoptic viewing conditions.

Knowledge of eye position in the brain is critical for localization of objects in space. To investigate the accuracy and precision of eye position feedback in an unreferenced environment, subjects with normal ocular alignment attempted to localize briefly presented targets during monocular and dichoptic viewing. In the task, subjects' used a computer mouse to position a response disk at the remembered location of the target. Under dichoptic viewing (with red (right eye)-green (left eye) glasses), target and response disks were presented to the same or alternate eyes, leading to four conditions [green target-green response cue (LL), green-red (LR), red-green (RL), and red-red (RR)]. Time interval between target and response disks was varied and localization errors were the difference between the estimated and real positions of the target disk. Overall, the precision of spatial localization (variance across trials) became progressively worse with time. Under dichoptic viewing, localization errors were significantly greater for alternate-eye trials as compared to same-eye trials and were correlated to the average phoria of each subject. Our data suggests that during binocular dissociation, spatial localization may be achieved by combining a reliable versional efference copy signal with a proprioceptive signal that is unreliable perhaps because it is from the wrong eye or is too noisy.