A new approach to measure interocular suppression in amblyopia and strabismus

Interocular suppression is commonly estimated by the contrast "balance point" between the eyes in individuals with amblyopia, in which the depth of suppression is defined as the increased contrast in the amblyopic eye that is perceptually matched to the fellow eye. However, this method may not be suitable for individuals with strabismus who have normal or even better contrast sensitivity in the non-fixating eye. In this study, I introduced a new approach that can be used for measuring interocular suppression for both amblyopia and strabismus without balancing contrasts between the eyes. The method consists of the following components: •The stimuli have equal contrasts in both eyes.•The percepts of objects seen monocularly and binocularly are compared.•Interocular suppression is defined as the percept of object in the amblyopic eye is suppressed when an object is presented in the fellow eye.

Lateral rectus pulley concerning the orbital wall. Area of a stereotyped bony insertion

Purpose

To examine the lateral rectus muscle pulley and its bony insertion concerning the orbital rim and periorbita.

Design

Prospective. An observational anatomic study.

Methods

Study population: Twenty postmortem orbits (10 right, 10 left) of 10 Caucasian cadavers (8 females, 2 males; age range at death, 57-100 years; median age, 79.5 years) fixed by the Thiel method.Intervention: The floor of the temporal fossa was exposed, and a bone window on the lateral wall of the orbit, posterior to the sphenozygomatic suture, was created, keeping the periorbita intact. The lateral canthus and lateral palpebral ligament were isolated and opened, and the eyelids were folded back. The frontozygomatic suture was identified, and the orbital septum opened adjacent to the orbital rim. The conjunctiva was opened at the limbus, and the lateral rectus insertion was isolated. The bone pillar containing the frontozygomatic suture and the insertion of the periorbita and the pulley was isolated and removed en bloc. The lateral rectus muscle was isolated and excised.Main outcome measures: Position of the pulley ring on the lateral rectus muscle belly and its bony attachment area in the lateral wall of the orbit.

Results

The pulley bony attachment was roughly quadrilateral with an approximate area of 90 mm2, 3 mm (mean, range 1-5 mm) posteroinferior to the frontozygomatic suture and 1 mm posterior to the orbital rim. The anterior margin of the pulley sleeve was found at 21.0 mm (median, p25-75 20.0-22.8) from the scleral insertion.

Conclusions

The lateral rectus pulley is stereotyped in its position in the muscle belly and its bony insertion, coinciding with the point of greatest adhesion of the periorbita to the anterior part of the lateral wall of the orbit.

Comparison of anterior segment optical coherence tomography and ultrasound biomicroscopy in localizing horizontal rectus muscle insertions

PURPOSE

To evaluate the viability and precision of measuring the distance from the limbus to extraocular muscle insertion using anterior segment optical coherence tomography (AS-OCT) and panoramic ultrasound biomicroscopy (UBM) before and after strabismus surgery.

METHODS

We recruited primary strabismus patients and measured the limbus-insertion distance by AS-OCT and UBM preoperatively, 2 weeks, and 1, 3, and 6 months postoperatively. Values were also measured using callipers intraoperatively before and after the planned procedures. Preoperative AS-OCT and UBM values were compared to intraoperative calliper measurements as the gold standard. Postoperative AS-OCT and UBM values were compared to the new postoperative limbus-insertion distance. The limit of agreement deemed clinically acceptable was defined as 1 mm.

RESULTS

A total of 85 horizontal muscles of 40 patients, including 48 lateral rectus muscles and 37 medial rectus muscles, were analysed. Primary muscles could be successfully detected by AS-OCT (95%) and UBM (100%). At 2 weeks and 1, 3, and 6 months postoperatively, the new rectus muscle attachment site detection rate by AS-OCT was 6%, 32%, 80%, and 89%, respectively, and that by UBM was 24%, 60%, 85%, and 93%, respectively. The Bland-Altman plots revealed better consistency in pairs of AS-OCT, UBM, and calliper measurements of primary muscles than postoperative muscles. For primary muscles, 89% of AS-OCT measurements fell within the permissible range of surgical measurements (1 mm), but this dropped to 67% at 6 months postoperatively (P < 0.001). The accuracy of UBM measurements of primary muscles was 81%, and this decreased to 59% at 6 months postoperatively (P = 0.001).

CONCLUSIONS

AS-OCT and UBM performed well in terms of imaging primary horizontal rectus muscles, but showed decreased accuracy and reproducibility in postoperative muscle measures.

Continued care and provision of glasses are necessary to improve visual and academic outcomes in children: Experience from a cluster-randomized controlled trial of school-based vision screening

OBJECTIVE

To assess the effectiveness of a kindergarten vision screening program by randomly assigning schools to receive or not receive vision screening, then following up 1.5 years later.

METHODS

Fifty high-needs elementary schools were randomly assigned to participate or not in a vision screening program for children in senior kindergarten (SK; age 5‒6 years). When the children were in Grade 2 (age 6‒7 years), vision screening was conducted at all 50 schools.

RESULTS

Contrary to expectations, screened and non-screened schools did not differ in the prevalence of suspected amblyopia in Grade 2 (8.6% vs. 7.5%, p = 0.10), nor prevalence of other visual problems such as astigmatism (45.1% vs. 47.1%, p = 0.51). There was also no difference between screened and non-screened schools in academic outcomes such as the proportion of children below grade level in reading (33% vs. 29%) or math (44% vs. 38%) (p = 0.86). However, more children were wearing glasses in screened than in non-screened schools (10.2% vs. 7.8%, p = 0.05), and more children reported their glasses as missing or broken (8.3% vs. 4.7%, p = 0.01), suggesting that SK screening had identified successfully those in need of glasses. Examination of individual results revealed that 72% of children diagnosed and treated for amblyopia in SK no longer had amblyopia in Grade 2.

CONCLUSION

The prevalence of amblyopia and other visual problems was not reduced in Grade 2 by our SK vision screening program, perhaps because of poor treatment compliance and high attrition. The results suggest that a single screening intervention is insufficient to reduce visual problems among young children. However, the data from individuals with amblyopia suggest that continuing vision care and access to glasses benefits children, especially children from lower socioeconomic class.

Intermittent Exotropia: The Effect of Alternating Occlusion Therapy on Control of Strabismus

BACKGROUND

Intermittent exotropia is a common form of pediatric strabismus characterized by intermittent misalignment of the eyes. This study investigated the clinical effectiveness of alternating occlusion therapy as a non-surgical alternative for children aged 3-10 with intermittent exotropia.

METHODS

A comprehensive review of recent research, including randomized controlled trials and case series, was conducted. These studies utilized standardized control scores to assess the impact of alternating occlusion therapy on both distance and near control of alignment.

RESULTS

The findings indicated a significant improvement in exotropia control, particularly at distance fixation, among children undergoing alternating occlusion therapy. While some variability in outcomes exists, all articles demonstrate positive responses to this noninvasive approach. Notably, the patients with poor initial control tended to benefit the most.

DISCUSSION

The potential advantages of alternating occlusion therapy are its cost-effectiveness and noninvasive nature. However, it is essential to manage patient and parental expectations and address potential drawbacks, including social stress, irritation associated with occlusion therapy and the possibility that strabismus surgery may still be needed in the future because of decompensation.

CONCLUSION

Alternating occlusion therapy is a promising option to improve exotropia control in children with intermittent exotropia. It offers a viable non-surgical strategy to delay or potentially avoid strabismus surgery, although approximately 45% of the patients might eventually still require strabismus surgery. Healthcare providers should carefully weigh the benefits and limitations of this intervention to make informed decisions through shared decision-making with the patients and their families. This review offers diverse insights into the clinical management of intermittent exotropia and provides an evidence-based alternative to surgical interventions.

Inferior Rectus Muscle Y-Split for Thyroid-Related Vertical Strabismus

Incomitant hypotropia in thyroid eye disease can be difficult to manage, especially in the presence of orthotropia with fusion in down gaze and reading position. Recessing the affected ipsilateral inferior rectus muscle may result in an undesirable downgaze diplopia secondary to a hypertropia in downgaze. Various surgical techniques have been described to manage this potential complication including asymmetric recession of both inferior rectus muscles, posterior myoscleropexy operation, and the Scott recess/resect procedure of the contralateral inferior rectus. In 2004, Hoerantner et al. introduced the y-split recession of the medial rectus muscle for near esotropic deviations. The anterior portion of muscle is split and secured in a y-shaped configuration, which reduces the muscle lever arm and helps minimize incomitance and muscle slippage. Unlike the traditional Cüppers Faden, a y-split recession results in torque reduction in all gaze positions. In addition, a y-split recession does not involve scleral passes posteriorly reducing the risk of globe perforation. We report a patient with incomitant strabismus secondary to thyroid eye disease who underwent a combination of traditional recession and y-splitting recession of the contralateral inferior rectus muscle, resulting in good functional alignment in primary gaze and in the reading position.

Long-term surgical outcome and impact on daily life activities of strabismus surgery in thyroid-associated ophthalmopathy with and without previous orbital decompression

BACKGROUNDS

To report the long-term surgical outcomes and the impact on daily life activities of strabismus surgery in patients with Thyroid Associated Orbitopathy (TAO) with and without previous orbital decompression.

METHODS

Patients who underwent strabismus surgery for TAO were retrospectively reviewed. The primary outcome was to evaluate the influence of orbital decompression on the outcomes of TAO related strabismus surgery. Surgical success was defined by the resolution of diplopia and a post-operative deviation < 10 prism diopters (PD). The secondary outcomes were the clinical features, surgical approaches, and impact on daily life activities.

RESULTS

A total of 45 patients were included in the study. The decompression surgery group (DS) included 21 patients (46.7%), whereas the non-decompression surgery group (NDS) patients were 24 (53.3%). The mean follow-up time from the last strabismus surgery was 2,8 years (range 8-200 months). Successful surgical outcome was achieved in 57,1% of patients in the DS, and 75% of patients in the NDS (p = 0,226). DS patients required almost twice the number of surgical interventions for strabismus compared to the NDS (1,95 vs. 1,16 respectively, p = 0,006), a higher number of extraocular muscles recessed in the first surgery (2,67 vs. 1,08 respectively, p < 0.001), and a lower rate of unidirectional surgery compared to NDS (23% vs. 95%, p < 0,001). At the pre-operative assessment, 71.4% of DS patients had eso-hypotropia, while no patients had this type of strabismus in the NDS group (p < 0.001). On the other hand, the hypotropia rate was 79.2% in NDS patients and only 4.8% in DS patients (p < 0.001). Moreover, 21,8% of NDS patients used prism lenses in daily life activities, compared to 42.9% of patients that used prism lenses to reduce the impairment in their daily life activities (p = 0.016).

CONCLUSIONS

The results of our study showed that DS patients required almost twice the number of strabismus surgical procedures, a higher number of extraocular muscles recessed in the first surgery, and an increased need for prism lenses to correct the residual deviation compared to the NDS, but with similar long-term surgical outcomes.

Strabismus management in retinoblastoma survivors

PURPOSE

To report the result of strabismus surgery in eye-salvaged retinoblastoma (Rb) patients.

METHODS

A retrospective case series including 18 patients with Rb and strabismus who underwent strabismus surgery after completing tumor treatment by a single pediatric ophthalmologist.

RESULTS

A total of 18 patients (10 females and 8 males) were included with a mean age of 13.3 ± 3.0 (range, 2-39) months at the time tumor presentation and 6.0 ± 1.5 (range, 4-9) years at the time of strabismus surgery. Ten (56%) patients had unilateral and 8(44%) had bilateral involvement and the most common worse eye tumor's group was D (n = 11), C (n = 4), B (n = 2) and E (n = 1). Macula was involved by the tumors in 12 (67%) patients. The tumors were managed by intravenous chemotherapy (n = 8, 47%), intra-arterial chemotherapy (n = 7, 41%) and both (n = 3, 17%). After complete treatment, the average time to strabismus surgery was 29.9 ± 20.5 (range, 12-84) months. Except for one, visual acuity was equal or less than 1.0 logMAR (≤ 20/200) in the affected eye. Seven (39%) patients had exotropia, 11(61%) had esotropia (P = 0.346) and vertical deviation was found in 8 (48%) cases. The angle of deviation was 42.0 ± 10.4 (range, 30-60) prism diopter (PD) for esotropic and 35.7 ± 7.9 (range, 25-50) PD for exotropic patients (P = 0.32) that after surgery significantly decreased to 8.5 ± 5.3 PD in esotropic cases and 5.9 ± 6.7 PD in exotropic cases (P < 0.001). The mean follow-up after surgery was 15.2 ± 2.0 (range, 10-24) months, in which, 3 (17%) patients needed a second surgery.

CONCLUSION

Strabismus surgery in treated Rb is safe and results of the surgeries are acceptable and close to the general population. There was not associated with tumor recurrence or metastasis.

Clinical and genetic studies for a cohort of patients with congenital stationary night blindness

BACKGROUND

Congenital stationary night blindness (CSNB) is an inherited retinal disorder. Most of patients have myopia. This study aims to describe the clinical and genetic characteristics of fifty-nine patients with CSNB and investigate myopic progression under genetic cause.

RESULTS

Sixty-five variants were detected in the 59 CSNB patients, including 32 novel and 33 reported variants. The most frequently involved genes were NYX, CACNA1F, and TRPM1. Myopia (96.61%, 57/59) was the most common clinical finding, followed by nystagmus (62.71%, 37/59), strabismus (52.54%, 31/59), and nyctalopia (49.15%, 29/59). An average SE of -7.73 ± 3.37 D progressed to -9.14 ± 2.09 D in NYX patients with myopia, from - 2.24 ± 1.53 D to -4.42 ± 1.43 D in those with CACNA1F, and from - 5.21 ± 2.89 D to -9.24 ± 3.16 D in those with TRPM1 during the 3-year follow-up; the TRPM1 group showed the most rapid progression.

CONCLUSIONS

High myopia and strabismus are distinct clinical features of CSNB that are helpful for diagnosis. The novel variants identified in this study will further expand the knowledge of variants in CSNB and help explore the molecular mechanisms of CSNB.

Distribution and appearance of myosin, dystrophin, and collagen IV in strabismus-affected extraocular muscle tissue compared with control tissue

OBJECTIVE

Extraocular muscles have complex development processes. The present study aimed to analyze the presence of myosin, dystrophin, and collagen IV in the strabismus-affected extraocular muscle.

METHODS

This research was an observational case-control study. Myosin, dystrophin, and collagen IV were detected by histological and immunohistochemical analyses of extraocular muscle samples from concomitant strabismus patients and controls. A semi-quantitative grading method and statistical analysis were used.

RESULTS

In the strabismus-affected extraocular muscle, morphological analysis demonstrated different-sized muscle fibers. Immature muscle fibers and an increased amount of connective tissue were also noted. Strong positive correlations were identified between myosin and collagen IV and between dystrophin and collagen IV.

CONCLUSIONS

The presence of newly formed muscle fibers, increased connective tissue, and variable diameters of skeletal striated muscle fibers indicate the decreased quality of extraocular muscles in strabismus cases. Reduced levels of myosin and dystrophin and a near absence of collagen IV in strabismus-affected skeletal striated muscle fibers characterized the muscular dystrophy of strabismus. Adjuvant therapy aimed at normalizing the metabolism of these muscles may be appropriate alongside concomitant strabismus treatment.

Clinical characteristics of acute acquired concomitant esotropia before and after the COVID-19 pandemic: a retrospective analysis

PURPOSE

This study aimed to observe the clinical characteristics of acute acquired concomitant esotropia (AACE) patients in recent five years and to examine the changes in the proportion of AACE cases before and after the COVID-19 pandemic.

METHODS

A retrospective study included 148 patients who underwent strabismus correction surgery for AACE between January 1, 2017, and December 31, 2021. The study analyzed the changing proportion of AACE cases before and after the COVID-19 pandemic and analyzed its clinical characteristics.

RESULTS

Abnormalities in the worth 4 dot examination (both distance and near) were present in 134 cases (90.54%) before surgery, while 140 cases (94.59%) showed normal results after surgery. Near stereoacuity was present in 135 cases (91.22%). The near and distance deviations were (55.01 ± 18.77) PD and (57.30 ± 17.64) PD, respectively, and there was no significant difference between the two (p = 0.279). There were significant differences in the ratio of refractive status among different age groups (p < 0.001), while no statistically significant difference was observed in the ratio of refractive status for near deviation (p = 0.085) or distance deviation (p = 0.116). The proportion of AACE cases after the COVID-19 pandemic was significantly higher than that before the COVID-19 pandemic (p = 0.042). There was no statistically significant difference in the clinical characteristics between the two groups (p > 0.05).

CONCLUSIONS

Myopia is the most common refractive status in AACE. More than half of patients had occupations that involved long hours of close work. The proportion of AACE cases increased significantly after the COVID-19 pandemic.

Trends and patterns in pediatric ophthalmology and strabismus surgeries: a decade review from a leading Portuguese university hospital

PURPOSE

Strabismus and Pediatrics Ophthalmology surgeries are pivotal in addressing early-onset visual disorders. An 11-year retrospective study at a tertiary hospital center aimed to elucidate evolving surgical trends, focusing on esotropia cases.

METHODS

The surgical records from January 2009 to January 2020 were analyzed according to the baseline diagnosis. Esotropia cases were evaluated based on the patients' deviation types, surgical techniques, and pre-operative characteristics. A total of 2050 surgeries were performed over the study period.

RESULTS

Strabismus surgery accounts for 70% of the department's surgical activity. A trend toward a decrease in esotropia surgeries and a proportional increase in exotropia surgeries was noticeable. Esotropia cases, with a median surgical age of 6 years (p25-p75, 4-10) and uniform gender distribution (females, 54.8%), predominantly involved high angular deviations. Posterior fixation sutures emerged as the preferred surgical technique for esotropia.

CONCLUSION

The study's insights, while aligning with prior European research, introduce new dimensions to the understanding of strabismus surgeries, emphasizing the significance of early interventions, evolving surgical preferences, and the challenges posed by severe deviations.

The distribution characteristics of strabismus surgery types in a tertiary hospital in the Central Plains region during the COVID-19 epidemic

OBJECTIVE

This study aimed to analyze the distribution of different types of strabismus surgery in a tertiary hospital in Central China during the three-year period of the COVID-19 pandemic.

METHODS

A retrospective analysis was conducted on the clinical data of strabismus patients who underwent surgery and were admitted to the Department of Strabismus and Pediatric Ophthalmology at the First Affiliated Hospital of Zhengzhou University between January 2020 and December 2022.

RESULTS

A total of 3939 strabismus surgery patients were collected, including 1357 in 2020, 1451 in 2021, and 1131 in 2022. The number of surgeries decreased significantly in February 2020, August 2021, and November and December 2022. Patients aged 0-6 years accounted for 37% of the total number of strabismus surgery patientsr. The majority (60%) of all strabismus surgery patients were diagnosed with exotropia, with intermittent exotropia accounting for the highest proportion (53%). There was no statistically significant difference in the proportion of intermittent exotropia and constant exotropia during the three-year period (χ2 = 2.642, P = 0.267 and χ2 = 3.012, P = 0.221, respectively). Among patients with intermittent exotropia, insufficient convergence type was the most common form of strabismus (accounting for over 70%). Non-accommodative esotropia accounted for more than 50% of all internal strabismus cases.

CONCLUSION

During the period from 2020 to 2022, the total number of strabismus surgeries in our hospital did not show significant fluctuations, but there was a noticeable decrease in the number of surgeries during months affected by the pandemic. Exotropia accounted for the highest proportion among strabismus surgery patients. Intermittent exotropia was the most common type among patients undergoing surgery for exotropia, and the most prevalent subtype was the insufficient convergence type. The age distribution of patients varied in different months, with a concentration of surgeries for strabismus patients in the 7-12 years old age group during the months of July and August each year.

Prevalence and causes of ocular disorders and visual impairment among preterm children in Ethiopia

OBJECTIVE

The aim of this study was to determine the prevalence, causes of ocular disorders and visual impairment among preterm children previously admitted to neonatal intensive care units in Addis Ababa, Ethiopia.

METHODS AND ANALYSIS

A prospective screening survey was conducted from February to June 2019 at the paediatric eye clinic of Menelik II Hospital. Children who were preterm at birth and who attended the eye clinic were included in the study. Data on demographic and neonatal characteristics, neonatal and maternal comorbidities and ocular disorders were collected. OR and univariate analysis were used to identify predictors of ocular diseases and visual impairment.

RESULTS

There were 222 children included in the study with a mean age at presentation of 2.62 years (range 2.08-6.38 years), mean gestational age 34.11 weeks (range 30-36) weeks and mean birth weight 1941.72 g (range 953-3500 g). Nearly two-thirds had ocular disorders with refractive error (51.8%), strabismus (11.3%) and a history of retinopathy of prematurity (ROP) (7.2%) being more common. One-fourth of the children had visual impairment, and the prevalence of amblyopia was 40.1%. Uncorrected refractive errors, strabismus and ROP were causes for visual impairment.

CONCLUSION

Visual impairment and amblyopia are common in Ethiopia. There is a need to develop a screening protocol for ocular disorders for preterm children to enhance early detection and prevention of childhood visual impairment.

Impact of Vision Impairment and Ocular Morbidity and Their Treatment on Quality of Life in Children: A Systematic Review

TOPIC

This review summarizes existing evidence of the impact of vision impairment and ocular morbidity and their treatment on children's quality of life (QoL).

CLINICAL RELEVANCE

Myopia and strabismus are associated with reduced QoL among children. Surgical treatment of strabismus significantly improves affected children's QoL.

METHODS

We conducted a systematic review and meta-analysis by screening articles in any language in 9 databases published from inception through August 22, 2022, addressing the impact of vision impairment, ocular morbidity, and their treatment on QoL in children. We reported pooled standardized mean differences (SMDs) using random-effects meta-analysis models. Quality appraisal was performed using Joanna Briggs Institute and National Institutes of Health tools. This study was registered with the International Prospective Register of Systematic Reviews (identifier, CRD42021233323).

RESULTS

Our search identified 29 118 articles, 44 studies (0.15%) of which were included for analysis that included 32 318 participants from 14 countries between 2005 and 2022. Seventeen observational and 4 interventional studies concerned vision impairment, whereas 10 observational and 13 interventional studies described strabismus and other ocular morbidities. Twenty-one studies were included in the meta-analysis. The QoL scores did not differ between children with and without vision impairment (SMD, -1.04; 95% confidence interval [CI], -2.11 to 0.03; P = 0.06; 9 studies). Myopic children demonstrated significantly lower QoL scores than those with normal vision (SMD, -0.60; 95% CI, -1.09 to -0.11; P = 0.02; 7 studies). Children with strabismus showed a significantly lower QoL score compared with those without (SMD, -1.19; 95% CI, -1.66 to -0.73; P < 0.001; 7 studies). Strabismus surgery significantly improved QoL in children (SMD, 1.36; 95% CI, 0.48-2.23; P < 0.001; 7 studies). No randomized controlled trials (RCTs) concerning refractive error and QoL were identified. Among all included studies, 35 (79.5%) were scored as low to moderate quality; the remaining met all quality appraisal tools criteria.

DISCUSSION

Reduced QoL was identified in children with myopia and strabismus. Surgical correction of strabismus improves the QoL of affected children, which supports insurance coverage of strabismus surgery. Further studies, especially RCTs, investigating the impact of correction of myopia on QoL are needed.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Postoperative outcomes for unilateral congenital trochlear nerve palsy: A retrospective cohort study

PURPOSE

Congenital trochlear nerve palsy is the most common cause of vertical strabismus. The goal of this study was to investigate surgical outcomes after superior oblique tendon plication with or without inferior oblique recession in children and adults with unilateral congenital trochlear nerve palsy.

METHODS

Data and outcomes were collected in patients with a diagnosis of unilateral congenital superior oblique palsy during a retrospective single-center study conducted at the University Hospital of Tours. A reproducible, standard ophthalmological and oculomotor examination was performed pre- and postoperatively at 1 year, including presence or absence of diplopia, vertical and horizontal deviations, and compensatory head posture. Surgical success, defined as an endpoint including absence of diplopia in primary position, absence of head tilt, and vertical deviation at distance fixation<5 prism diopters (PD), was analyzed.

RESULTS

A total of fifty-seven patients (median [IQR] age of 11 years [5-42]) were analyzed. Patients experienced a significant reduction in vertical distance and near deviations (p<0.001), compensatory head tilt (p < 0.001), and diplopia after surgery (p < 0.001). Surgical success was higher in adults (17/24, 70.8%) than in children (15/33, 45.5%), although this did not reach statistical significance (p=0.0657).

CONCLUSION

This study suggests that plication of the superior oblique muscle tendon, with or without recession of the inferior oblique muscle, can be effective in treating unilateral congenital trochlear nerve palsy. Further studies are necessary to compare surgical procedures and investigate their efficacy in adults compared to children in the short and long term.

Prevalence of strabismus in premature infants in an age-related perspective

THE AIM

was to investigate the prevalence of strabismus in premature infants; to identify diagnostic indicators for predicting strabismus at the age of 3-8 years.

METHODS

The material was the data of 84 premature infants who underwent ophthalmological examination at the age of 6 months - 3 years and again - at 3-8 years. All children underwent ophthalmic examination for retinopathy of prematurity (ROP) in infancy.

RESULTS

An increase in the frequency of strabismus occurrence among preterm infants was observed in 3-8 years compared to the data from 6 months - 3 years - from 13.3% to 20.0% in children without ROP, from 5.9% to 23.5% in children with self-resolving ROP, from 22.7% to 45.5% in children with ROP after laser retinal photocoagulation. The presence of strabismus and structural changes of eye at ages 6 months - 3 years increase the risk of strabismus at ages 3-8 years, OR = 6.5 (95% CI 3.8-11.3), (p < 0.001); OR = 4.2 (95% CI 2.8-6.2), (p = 0.005). The increase in the risk of developing strabismus at ages 3-8 years is associated with the presence of anisometropia, (p = 0.047), amblyopia, (p < 0.05). Children with higher visual acuity at ages 3-8 years have a decreased risk of strabismus, (p < 0.05).

CONCLUSIONS

The frequency of strabismus occurrence among preterm infants has increased by ages 3-8 years. Strabismus, structural changes of eye at ages 6 months - 3 years increases the risk of strabismus at ages 3-8 years. Anisometropia and amblyopia increase in the risk of strabismus, higher visual acuity decreases risk of strabismus.

Orbital apex syndrome in pediatric thyroid eye disease: A case report and literature review

Thyroid eye disease is an autoimmune disorder with clinical manifestations including lid retraction, proptosis, decreased visual acuity, and strabismus, and an incidence rate of 0.79 to 6.5 cases per 100,000 children. While reports are rare, the symptoms of thyroid eye disease in children have been found to be similar to those in adults, although typically milder. A 17-year-old girl presented with diplopia and hypoesthesia of the left forehead. Other clinical symptoms included mildly reduced visual acuity, restricted ocular movement, ptosis, and lid edema of the left eye. On the basis of blood tests, including a thyroid function test, Graves' disease was diagnosed, and a complication of Graves' disease was conjectured to have caused orbital apex syndrome due to thyroid eye disease, characterized by the involvement of cranial nerves II, III, IV, and VI, and the ophthalmic division of cranial nerve V. Following steroid pulse therapy, ophthalmic symptoms improved, and the patient is currently taking the antithyroid agent methimazole. To the best of our knowledge, this is the first report to describe orbital apex syndrome in pediatric thyroid eye disease, and the presented data will contribute to the future analysis of the clinical features of atypical pediatric thyroid eye disease.

Concurrent adjacent strabismus surgery with glaucoma drainage device placement in childhood glaucomas

BACKGROUND

Determine outcomes of concurrent strabismus surgery with placement of a glaucoma drainage device (GDD) in children.

METHODS

Retrospective review of pediatric patients who underwent simultaneous lateral rectus (LR) muscle surgery with superotemporal GDD placement. Strabismus and GDD success were defined as residual horizontal misalignment < 10 prism diopter (PD) and intraocular pressure (IOP) < 21 mmHg, no visually devastating complications, and no additional IOP-lowering surgeries.

RESULTS

Fifteen eyes of 13 patients (69% male) underwent LR surgery (14 recessions, 1 resection) for exotropia or esotropia simultaneous with GDD placement (13 Baerveldt, 2 Ahmed) at 8.34 ± 5.26 years. Preoperative visual acuity (VA) in operative eye (0.89 ± 0.54) was worse than non-operative eye (0.23 ± 0.44, p = 0.0032). Preoperative horizontal deviation was 38.3 ± 9.4 PD and LR recession was 7.4 ± 1.1 mm. At final follow-up, VA in operative eye (0.87 ± 0.52) was unchanged from preoperative (p = 0.4062). Final IOP was significantly decreased (12.4 ± 4.7 mmHg vs. 31.1 ± 11.4 mmHg, p = 0.0001) as was number of glaucoma medications (2.7 ± 1.7 vs. 1.1 ± 1.3, p = 0.0037). Five (38%) and 9 patients (69%) met criteria for strabismus and GDD success, respectively. Two eyes required tube revision and endoscopic cyclophotocoagulation and 2 eyes had additional strabismus surgery.

CONCLUSIONS

Concurrent strabismus and GDD surgery decreased horizontal deviation and obtained IOP control. It is important to consider correction of strabismus at time of GDD placement to maximize visual development and improve cosmesis in children with glaucoma.

Relationship between strabismus associated with Angelman syndrome and orbital anomaly

PURPOSE

To investigate the relationship between the details of strabismus and orbital abnormalities determined by ocular motility tests and orbital imaging examinations in 9 cases with Angelman syndrome (AS).

STUDY DESIGN

A retrospective, clinical report.

METHODS

The 9 AS cases (mean age at initial visit: 4.6 ± 8.0 years) were confirmed by genetic diagnosis of the chromosome 15q11-13 region. In all cases, axial imaging of the orbit in the transverse plane of the horizontal extraocular muscles was obtained. The opening angle between both lateral walls of the orbit (greater wing of sphenoid) was measured as the biorbital angle, and compared with the 95% confidence interval of the orbital angle in normal children.

RESULTS

All cases had exotropia with means of the distance and near of angle 32.2 prism diopters (Δ) ± 9.7Δ and 32.8Δ ± 8.3Δ. The mean of the biorbital angle was 107.7° ± 7.6°, greater than the biorbital angle of 94.3° ± 5.1° previously reported in 129 normal children (P < 0.0001, t-test). Except for one biorbital angle of 93° in the 25-year-old patient, all the biorbital angles in the 8 children were larger than the upper 95% confidence interval in normal children. Astigmatic and hyperopic ametropic amblyopia were detected in 3 cases and 1 case, respectively.

CONCLUSIONS

The frequency of exotropia in AS is higher than previously reported, with our results strongly suggesting that the enlarged biorbital angle is related to the pathogenesis of exotropia in AS.

Eight-Year Outcomes of Bilateral Lateral Rectus Recessions versus Unilateral Recession-Resection in Childhood Basic-Type Intermittent Exotropia

PURPOSE

To report 8-year outcomes from a randomized controlled trial (RCT) comparing bilateral lateral rectus muscle recession (BLRc) with unilateral recession-resection (R&R) for childhood intermittent exotropia (IXT).

DESIGN

Eight-year follow-up of RCT cohort.

PARTICIPANTS

Of 197 randomized participants, 123 agreed to continue follow-up after the 3-year outcome visit (baseline age, 3-< 11 years; basic-type IXT, 15-40 prism diopters [Δ] by prism and alternate cover test [PACT]; baseline stereoacuity, ≤ 400 arcsec; no prior surgery).

METHODS

After the RCT primary outcome at 3 years, annual follow-up from 4 through 8 years with treatment at investigator discretion.

MAIN OUTCOME MEASURES

Suboptimal surgical outcome by 8 years after randomization, defined as any of the following at any visit: exotropia of 10 Δ or more by simultaneous prism cover test (SPCT) at distance or near, constant esotropia (ET) of 6 Δ or more by SPCT at distance or near, loss of near stereoacuity by 0.6 log arcsec or more from baseline, or reoperation. Secondary outcomes included (1) reoperation by 8 years and (2) complete or near-complete resolution at 8 years, defined as exodeviation of less than 10 Δ by SPCT and PACT at distance and near and 10 Δ or more reduction from baseline by PACT at distance and near, ET of less than 6 Δ at distance and near, no decrease in stereoacuity by 0.6 log arcsec or more from baseline, and no reoperation or nonsurgical treatment for IXT.

RESULTS

The Kaplan-Meier cumulative probability of suboptimal surgical outcome through 8 years was 68% (55 events among 101 at risk) for BLRc and 53% (42 events among 96 at risk) for R&R (difference, 15%; 95% confidence interval [CI], -2% to 32%; P = 0.08). Complete or near-complete resolution at 8 years occurred in 15% (7/46) for BLRc and 37% (16/43) for R&R (difference, -22%; 95% CI, -44% to -0.1%; P = 0.049). The cumulative probability of reoperation was 30% for BLRc and 11% for R&R (difference, 19%; 95% CI, 2%-36%; P = 0.049).

CONCLUSIONS

Despite no significant difference for the primary outcome, the 95% CI did not exclude a moderate benefit of R&R, which together with secondary outcomes suggests that unilateral R&R followed by usual care may yield better long-term outcomes than BLRc followed by usual care for basic-type childhood IXT using these surgical doses.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

"Strabismus in children" is not simple - bilateral persistent hyperplasia primary vitreous: a case report

Persistent hyperplastic primary vitreous (PHPV) is a rare congenital developmental ocular disorder caused by incomplete regression of the embryonic hyaloid vasculature; bilateral presentations are even rarer. We report a 6-year-old child with bilateral PHPV who visited our hospital for strabismus, without exhibiting leukocoria, microphthalmia, and systemic diseases. These unique characteristics distinguish our case from other cases of PHPV. It is crucial to increase awareness of congenital eye disease in children and the importance of performing fundus examination with the pupils dilated.

Molecular symmetry breaking in the Frizzled-dependent planar polarity pathway

The core planar polarity pathway consists of six proteins that form asymmetric intercellular complexes that segregate to opposite cell ends in developing tissues and specify polarized cell structures or behaviors. Within these complexes, the atypical cadherin Flamingo localizes on both sides of intercellular junctions, where it interacts homophilically in trans via its cadherin repeats, whereas the transmembrane proteins Frizzled and Strabismus localize to the opposite sides of apposing junctions. However, the molecular mechanisms underlying the formation of such asymmetric complexes are poorly understood. Using a novel tissue culture system, we determine the minimum requirements for asymmetric complex assembly in the absence of confounding feedback mechanisms. We show that complexes are intrinsically asymmetric and that an interaction of Frizzled and Flamingo in one cell with Flamingo in the neighboring cell is the key symmetry-breaking step. In contrast, Strabismus is unable to promote homophilic Flamingo trans binding and is only recruited into complexes once Frizzled has entered on the opposite side. This interaction with Strabismus requires intact intracellular loops of the seven-pass transmembrane domain of Flamingo. Once recruited, Strabismus stabilizes the intercellular complexes together with the three cytoplasmic core proteins. We propose a model whereby Flamingo exists in a closed conformation and binding of Frizzled in one cell results in a conformational change that allows its cadherin repeats to interact with a Flamingo molecule in the neighboring cell. Flamingo in the adjacent cell then undergoes a further change in the seven-pass transmembrane region that promotes the recruitment of Strabismus.

What to expect from primary inferior oblique overaction after esotropia surgery : Primary inferior oblique overaction in esotropia

BACKGROUND

Overelevation in adduction is common in patients with primary esotropia. This study evaluates the variation in ocular motility pattern in patients with primary inferior oblique (IO) muscle overaction after esotropia surgery.

METHODS

The medical records of consecutive patients who underwent surgery for infantile, partially accommodative, and basic esotropia over eleven years and had at least one year of follow-up were reviewed. Patients with primary inferior oblique muscle overaction (IOOA) presented at baseline or during follow-up were selected and divided according to the first surgery performed concurrently with horizontal rectus surgery: without IO recession (NO-recess), with unilateral IO recession (UNIL-recess), and with bilateral IO recession (BIL-recess). The success (version normalisation or at least 2 points upgrade in severity scale [0-4] in the operated eye), recurrence rates, and the evolution of the non-operated IO muscles were evaluated.

RESULTS

One hundred and ten patients were included - 53 NO-recess, 26 UNIL-recess, and 31 BIL-recess. Medial rectus muscle posterior fixation sutures surgery (PFS) was performed in 88.2% of patients for esotropia. A recession with graded anterior transposition was the weakening IO procedure. In the NO-recess group, 28 (52.8%) patients normalised their mild IOOA after PFS surgery alone. In the UNI-recess group, the success rate was 88.5%, with 16 (61.5%) patients showing worsened IO muscle of the fellow eye, which prompted additional surgery in 10 patients. In the BIL-recess group, all 31 patients improved the adduction pattern of the operated eye for an 80.6% success rate (6 improved marginally).

CONCLUSION

Graded anterior transposition of the inferior oblique muscle effectively normalises versions. However, it's frequent for a contralateral overaction to become manifest after unilateral IO surgery.

A case of bilateral horizontal gaze palsy and concurrent esotropia

Purpose

To report a unique case of bilateral horizontal pontine gaze palsy with concurrent esotropia, surgical management, and post-operative follow-up.

Observations

A 39-year-old male presented with diplopia and a history of neurocysticercosis. He was found to have bilateral horizontal gaze palsy and concurrent esotropia, R > L. Classic bimedial rectus recess-resect surgery was done to include resection of the right lateral rectus muscle. Follow-up three months post-op demonstrates markedly improved diplopia.

Conclusion and importance

We present a recommended therapeutic approach for the rare case of concurrent bilateral horizontal gaze palsy and esotropia, which should be further evaluated in longitudinal studies.

Halil Pasha's legacy as a Turkish painter: Esotropia or pseudoesotropia in "Yaşlı Halayık"

Introduction: Esotropia is a form of strabismus, a condition characterized by the misalignment of the eyes. Specifically, esotropia refers to inward deviation of one or both eyes. It can manifest at different ages, ranging from infancy to adulthood, and can have varying degrees of severity. The false appearance of esotropia in the alignment of the visual axes is what defines pseudoesotropia. Halil Pasha was a Turkish painter known for his contributions to the art scene during the late 19th and early 20th centuries. His artistic talent, coupled with his influential position as a statesman, allowed him to leave a lasting impact on the cultural landscape of the Ottoman Empire. Methods: In the present study, artistic depictions of esotropia or pseudoesotropia in Halil Pasha's "Yaşlı Halayık" were evaluated. A comprehensive literature review on strabismus in medicine and art was conducted. Results: "Yaşlı Halayık", translated as "Old Servant Woman", is one of the iconic paintings of Turkish art. It reflects the social dynamics and lifestyle of the time, offering a glimpse into the lives of women serving in Ottoman households. When we examine this painting as a physician, the first thing we notice is the old woman's eyes. An eye misalignment in the left eye of the old servant woman is noticed. Discussion: In medical humanities, which are addressed in medical education, medicine and art intersect with different perspectives and understandings. Although the evaluation of medical scenes in artworks seems to have been first observed by an art historian, today physicians and medical students need to examine artworks more carefully and develop their observational skills. Iconodiagnosis is the medical analysis of artworks that looks for clinical signs suggestive of medical disorders and diseases. The application of iconodiagnosis in medical education is an alternative and stimulating way to exercise students' observation skills; not only the physical examination of the patient is important, but also the information obtained from their posture, clothing, general demeanour and even physical aids.

A new method based on deep learning and image processing for detection of strabismus with the Hirschberg test

Strabismus is a condition in which one or both eyes do not work in parallel or in harmony. People with strabismus have one eye looking straight ahead while the other eye looks inwards, outwards, upwards or downwards. This condition can affect both eyes. Strabismus is a common eye condition that affects about 4 % of the world's population. Tests such as Hirschberg, Cover and Krimsky are used to detect strabismus. In the Hirschberg test, a light source is held at a distance of 50 cm so that it falls on the centre of each eye. The horizontal and vertical distance between the centre of gravity of the light reflected from the cornea and the centre of the pupil indicates the degree of strabismus. In this study, deep learning and image processing algorithms are used to detect the eye, corneal reflection, iris and pupil on a patient's facial image. Based on the Hirschberg test, the horizontal and vertical shifts for both eyes were measured to determine the patient's degree of strabismus. In this way, the Hirschberg test used in strabismus screening was performed automatically by software. The correct detection of the pupil and the light reflected from the cornea by the algorithm means that the eye has been measured correctly. The software was tested on the facial images of 88 strabismic patients of different sexes and ages. 91 % of the 88 patients, or 80 patients, had their left eye measured correctly. 90 % of the 88 patients, or 79 patients, had their right eye measured correctly. The results for each eye obtained from the correct measurements were found to have an error of maximum ± 2°. This error is due to the fact that a real eye is in three-dimensional space, while the digital eye image is in two-dimensional space, and was only observed in the test results of some patients. This algorithm can be tested on patients of all ages and is not affected by morphological differences in the patients' faces. Successful results have been observed experimentally that this newly proposed method can be used in strabismus screening.

Neurological pathologies in acute acquired comitant esotropia

BACKGROUND

Acute acquired comitant esotropia (AACE) is an uncommon subtype of esotropia characterized by sudden and usually late onset of a relatively large angle of comitant esotropia with diplopia in older children and adults.

METHODS

A literature survey regarding neurological pathologies in AACE was conducted using databases (PubMed, MEDLINE, EMBASE, BioMed Central, the Cochrane Library, and Web of Science) in order to collect data for a narrative review of published reports and available literature.

RESULTS

The results of the literature survey were analyzed to provide an overview of the current knowledge of neurological pathologies in AACE. The results revealed that AACE with unclear etiologies can occur in many cases in both children and adults. Functional etiological factors for AACE were found to be due to many reasons, such as functional accommodative spasm, the excessive near work use of mobile phones/smartphones, and other digital screens. In addition, AACE was found to be associated with neurological disorders, such as astrocytoma of the corpus callosum, medulloblastoma, tumors of the brain stem or cerebellum, Arnold-Chiari malformation, cerebellar astrocytoma, Chiari 1 malformation, idiopathic intracranial hypertension, pontine glioma, cerebellar ataxia, thalamic lesions, myasthenia gravis, certain types of seizures, and hydrocephalus.

CONCLUSIONS

Previously reported cases of AACE with unknown etiologies have been reported in both children and adults. However, AACE can be associated with neurological disorders that require neuroimaging probes. The author recommends that clinicians should perform comprehensive neurological assessments to rule out neurological pathologies in AACE, especially in the presence of nystagmus or abnormal ocular and neurological indications (e.g., headache, cerebellar imbalance, weakness, nystagmus, papilloedema, clumsiness, and poor motor coordination).

Revisiting Posterior Fixation Sutures Surgery: Unveiling Novel Approaches for Primary Management of Diverse Esotropia Cases

INTRODUCTION

Strabismus, specifically esotropia, presents a significant challenge in ophthalmic surgery, while several treatment options exist. This study aims to evaluate the results of posterior fixation sutures (PFS) on the medial rectus as a primary approach for some types of esotropia.

METHODS

The medical records of consecutive patients who underwent surgery for esotropia over 11 years and had at least 1 year of follow-up were reviewed retrospectively. Patients were classified into one of three types of deviation: infantile (IE), partially accommodative (PAE) and basic (BE) esotropias. An alignment within 16 prism diopters (PD) of orthotropia was a successful outcome.

RESULTS

A total of 404 patients were included: 67 IE, 180 PAE and 157 BE. Before surgery, a deviation greater than 30 PD was present in 88.1% and 80.1%, and a deviation greater than 50 PD was present in 66.5% and 52.9% of patients (near and distance, respectively). In the BE group, PFS was the baseline surgery in a smaller number of cases (75%) compared to the other two groups (versus 86.6% [IE] and 88.3% [PAE], p = 0.002). The need for an additional procedure was significantly higher in the infantile esotropia group (44.8% vs. 18.9% and 24.8%, p < 0.001). Final surgical success was achieved in 95.3% of all patients. Orthotropia was achieved in 19.4% (IE), 29.6% (PAE) and 25.5% (BE) of cases.

CONCLUSION

PFS of the medial rectus without recession proved successful as a first-line procedure for esotropia in the subtypes of patients evaluated in this study.

A novel mutation of the RPGRIP1L gene in a Chinese boy with Joubert syndrome with oculorenal involvement

BACKGROUND

Joubert syndrome (JS) is a rare genetically heterogeneous primary ciliopathy characterized by a pathognomonic cerebellar and brainstem malformation, the "molar tooth sign", and variable organ involvement (such as eye, kidney, liver, and skeleton). Here, we present a case of JS in a Chinese boy.

CASE PRESENTATION

An 11-year-old Chinese boy presented with neonatal asphyxiation and hypoxia, strabismus, subsequent developmental delay, ataxia and end-stage kidney disease (ESKD). Routine blood tests showed severe anemia, increasing blood urea nitrogen and creatinine, elevated parathyroid hormone, hypocalcemia, hypokalemia and metabolic acidosis. Urine tests showed mild proteinuria. Ultrasound showed two small kidneys. Brain magnetic resonance imaging (MRI) showed dysplasia of the cerebellar vermis and extension of the upper cerebellar feet with the "molar tooth sign". Genetic analysis showed novel compound heterozygous mutations in the RPGRIP1L gene [p.L447fs*7(p.Leu447fsTer7) and p.G908V (p.Gly908Val)].

CONCLUSION

In the present study, we identified novel compound heterozygous mutations in the RPGRIP1L gene in a Chinese boy. The clinical and genetic findings of this study will expand the understanding of JS.

Acute acquired concomitant esotropia: May COVID-19 lockdowns have changed its presentation?

PURPOSE

To evaluate the effects of COVID-19 lockdown in Italy on the features of Acute Acquired Concomitant Esotropia (AACE).

SUBJECTS

Patients of the Polyclinic Hospital of Bari diagnosed with AACE between January 2018 and December 2021, subdivided in pre-lockdown group - diagnosed before March 2020 - and post-lockdown group.

METHODS

Medical records were reviewed, and statistical analysis performed. Deviation size was assessed in the 9 cardinal positions of gaze with refractive correction. Wilcoxon test for unpaired samples was used to compare data of age, near maximum deviation and best corrected visual acuity (BCVA) for each eye; Student's t test was used to compare far maximum deviation, difference far/near maximum deviation and spherical equivalent data. Fisher exact test was used to compare subtype cases (Bielschowsky vs Non-Bielschowsky) in the two groups. A p-value lower than 0.05 was considered statistically significant.The primary outcome measure was the difference in AACE subtypes between the two groups.

RESULTS

Nineteen patients were included, of which 12 males (63.2%); 7 belong to the pre-lockdown group and 12 to the post-lockdown group. The difference in types between the two groups proved to be statistically significant (p = 0.01977).The differences in the mean of age, right BCVA, right spherical equivalent and mean spherical equivalent between the two groups proved to be statistically significant (p < 0.05).

CONCLUSIONS

After the COVID-19 pandemic, the profile of the typical patient with AACE has probably changed, and now it is more probably myopic and elderly than before. Thus, we observed an increase in the Bielschowsky subtype.

Impact of strabismus and binocular dysfunctions in the developmental eye movement test and test of visual perception skills: A multicentric and retrospective study

PURPOSE

To compare the performance in the Developmental Eye Movement test (DEM) and the Test of Visual Perceptual Skills (TVPS) between three groups: individuals with strabismus and amblyopia, patients with binocular and accommodative dysfunctions, and subjects with normal binocular and accommodative function.

METHODS

A multicentric, retrospective study including 110 children aged 6-14 years old was conducted to investigate the potential impact of strabismus, amblyopia, and different binocular conditions in DEM results (adjusted time in vertical and horizontal parts) and TVPS (percentiles in the seven sub-skills).

RESULTS

No significant differences were found in the different subtests of the vertical and horizontal DEM and all the sub-skills in the TVPS between the three groups of the study. We found high variability of performance in the DEM test between participants with strabismus and amblyopia compared with binocular and accommodative problems.

CONCLUSION

DEM and TVPS scores have not been found to be influenced by the presence of strabismus with or without amblyopia, nor by binocular and accommodative dysfunctions. A slightly correlation tendency with horizontal DEM and degree of exotropia deviation was observed.

Race, Ethnicity, Insurance, and Population Density Associations with Pediatric Strabismus and Strabismic Amblyopia in the IRIS® Registry

PURPOSE

To evaluate the associations of sociodemographic factors with pediatric strabismus diagnosis and outcomes.

DESIGN

Retrospective cohort study.

PARTICIPANTS

American Academy of Ophthalmology IRIS® Registry (Intelligent Research in Sight) patients with strabismus diagnosed before the age of 10 years.

METHODS

Multivariable regression models evaluated the associations of race and ethnicity, insurance, population density, and ophthalmologist ratio with age at strabismus diagnosis, diagnosis of amblyopia, residual amblyopia, and strabismus surgery. Survival analysis evaluated the same predictors of interest with the outcome of time to strabismus surgery.

MAIN OUTCOME MEASURES

Age at strabismus diagnosis, rate of amblyopia and residual amblyopia, and rate of and time to strabismus surgery.

RESULTS

The median age at diagnosis was 5 years (interquartile range, 3-7) for 106 723 children with esotropia (ET) and 54 454 children with exotropia (XT). Amblyopia diagnosis was more likely with Medicaid insurance than commercial insurance (odds ratio [OR], 1.05 for ET; 1.25 for XT; P < 0.01), as was residual amblyopia (OR, 1.70 for ET; 1.53 for XT; P < 0.01). For XT, Black children were more likely to develop residual amblyopia than White children (OR, 1.34; P < 0.01). Children with Medicaid were more likely to undergo surgery and did so sooner after diagnosis (hazard ratio [HR], 1.23 for ET; 1.21 for XT; P < 0.01) than those with commercial insurance. Compared with White children, Black, Hispanic, and Asian children were less likely to undergo ET surgery and received surgery later (all HRs < 0.87; P < 0.01), and Hispanic and Asian children were less likely to undergo XT surgery and received surgery later (all HRs < 0.85; P < 0.01). Increasing population density and clinician ratio were associated with lower HR for ET surgery (P < 0.01).

CONCLUSIONS

Children with strabismus covered by Medicaid insurance had increased odds of amblyopia and underwent strabismus surgery sooner after diagnosis compared with children covered by commercial insurance. After adjusting for insurance status, Black, Hispanic, and Asian children were less likely to receive strabismus surgery with a longer delay between diagnosis and surgery compared with White children.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Clinical significance of CTGF and Cry61 protein in extraocular muscles of strabismic patients

PURPOSE

To investigate the relationship between clinical features and protein amounts of Cysteine-rich 61 (Cyr61/CCN1) and connective tissue growth factor (CTGF/CCN2), which are vital components and regulators of the extracellular matrix in resected muscles from strabismus surgery.

METHODS

Strabismus patients who were diagnosed with horizontal concomitant strabismus or inferior oblique overaction (IOOA) and required extraocular muscles (EOMs) resection to correct eye position were included in this study. The protein amounts were measured by enzyme-linked immunosorbent assay (ELISA) in resected EOMs. Multivariable linear regression was used to investigate the associations, adjusting for gender, age (continuous), amblyopia, and disease duration.

RESULTS

A total of 141 muscles (including 38 lateral, 81 medial rectus, and 22 inferior oblique muscles) from 128 patients were collected in this study. The amount of Cry61 and CTGF per millimeter was significantly negatively associated with deviation angle in intermittent exotropia patients (Cry61: β, - 1.44; 95%CI, - 2.79 to - 0.10, p = 0.035; CTGF: β, - 3.14; 95%CI, - 5.06 to - 1.22, p = 0.002). The same relationship was also detected in the partially accommodative and non-accommodative esotropia patients, although it was not statistically significant (Cry61: β, - 2.40; 95%CI, - 5.05 to 0.24; p = 0.073; CTGF: β, - 3.47; 95%CI, - 9.18 to 2.87; p = 0.269). The amount of Cry61 and CTGF per millimeter showed significant associations with the degree of IOOA (p < 0.05).

CONCLUSIONS

Taken together, our results demonstrated a significant relationship between deviation angle and protein amount of Cry61 and CTGF and implied that Cry61 and CTGF may play important roles in modulation of EOM contractility, which provide new insights into strabismus pathogenesis.

Changes in retinal and choroidal blood flow after one or two horizontal rectus muscle surgeries by optical coherence tomography angiography

PURPOSE

To evaluate the retinal and choroidal microvasculature after one or two horizontal rectus muscle surgeries in strabismus patients using swept-source optical coherence tomography angiography (SS-OCTA).

METHODS

30 eyes of 26 patients who underwent horizontal rectus muscle surgery were included in this study. Group A, A' and Group B , B' respectively consisted preoperative and postoperative measurements of patients who underwent one or two horizontal rectus muscle surgeries. We analyzed the vessel density (VD) of the superficial vascular complex (SVC), the deep vascular complex (DVC), the choriocapillary layer (CC), choroidal vascular index (CVI), choroidal thickness (T-Ch) and retinal nerve fiber layer thickness (T-RNFL) preoperatively, and one week postoperatively.

RESULTS

Only in the nasal sector of the perifoveal zone, the VD in SVC demonstrated a significant increase in Group A' (p = 0.027). There was a statistically significant difference in the VD changes of SVC between Group A and Group B (p = 0.043). The VD in DVC did not change significantly in the whole macular compared with the preoperative. Moreover, in both Group A' and Group B', the VD in CC showed a reduction in a single sector of the parafoveal area (p < 0.05). Group A' have increased CVI in the nasal sector of the perifoveal region (p = 0.008). In addition, the T-Ch increase in the perifoveal region was more significant in Group B' than in Group A' (p < 0.05). Group A' showed statistically significant decreases in T-RNFL in the foveal and parafoveal regions (p < 0.05).

CONCLUSION

This study revealed that the increase in choroidal thickness was more significant after two rectus muscle surgery. In addition, there were microvascular changes in sectional macular regions after strabismus surgery. OCTA is an excellent way to study the impact of strabismus surgery on the macular structure and blood flow.

Early response to intravenous methylprednisolone therapy for restrictive myopathy in patients with thyroid eye disease

PURPOSE

To report the therapeutic efficacy of intravenous methylprednisolone (IVMP) in patients with restrictive myopathy caused by thyroid eye disease (TED).

METHODS

The present prospective uncontrolled study comprised 28 patients with TED and restrictive myopathy who presented with diplopia that had developed within 6 months before their visit. All patients were treated with IVMP for 12 weeks. Deviation angle, limitation of extraocular muscle (EOM) movement, binocular single vision score, Hess score, clinical activity score (CAS), modified NOSPECS score, exophthalmometric value, and the size of EOMs on computed tomography were evaluated. The patients were divided into two groups: those whose deviation angle had decreased or remained unchanged 6 months after treatment (group 1; n = 17) and those whose deviation angle had increased in that time (group 2; n = 11).

RESULTS

The mean CAS of the whole cohort significantly decreased from baseline to 1 month and 3 months after treatment (P = 0.03 and P = 0.02, respectively). The mean deviation angle significantly increased from baseline to 1, 3, and 6 months (P = 0.01, P < 0.01, and P < 0.01, respectively). The deviation angle decreased in 10 (36%), remained constant in seven (25%), and increased in 11 (39%) of the 28 patients. When groups 1 and 2 were compared, no single variable was identified as a cause of deviation angle deterioration (P > 0.05).

CONCLUSIONS

When treating patients with TED who have restrictive myopathy, physicians should be aware that some patients show worsening of the strabismus angle despite inflammation control with IVMP therapy. Uncontrolled fibrosis can result in motility deterioration.

Clinical features of Helveston syndrome and discussion of individualized surgical design

Background

Reasonable personalized surgical design can achieve good treatment results for Helveston syndrome in one surgery, reducing the psychological and economic burden on patients. This article aims to explore the clinical characteristics of Helveston syndrome and the clinical effectiveness and feasibility of individualized surgical design.

Methods

In this retrospective case series study, 28 patients who underwent strabismus correction for Helveston syndrome at the Affiliated Hospital of Yunnan University from June 2018 to December 2020 with complete follow-up data were enrolled. Preoperatively, all patients received standard assessment of vision, intraocular pressure, slit lamp, fundus and refractive status, excluding other eye diseases, as well as detailed special examination of strabismus. These patients were divided into two groups according to the surgical modality: the horizontal muscle surgery alone group and the horizontal muscle surgery combined with superior oblique muscle surgery (combined surgery) group. We used SPSS software for data analysis and compared the postoperative eye position, eye movement, success rate, and reoperation rate between these two groups. Clinical measurement data were compared and analyzed with Fisher's exact test for count data, the t-test for normally distributed measurement data, and the Mann-Whitney U test for non-normally distributed measurement data. P<0.05 was considered statistically significant.

Results

This study included a total of 28 patients with Helveston syndrome, including 20 males and 8 females. The average age at the time of surgery is 12.04 ± 8.67 years (range, 4-43 years). The postoperative A-pattern degree was significantly greater in the group undergoing horizontal muscle surgery alone [6.23±1.31 prism diopters (PD); range, 0-10 PD] than in the group undergoing combined surgery (0.53±0.32 PD; range, 0-4 PD; P=0.002). Superior oblique muscle overactivity was significantly reduced in the combined surgery group (0.20±0.11+; range, 0-1+) compared to the horizontal muscle surgery alone group (1.31±0.26+; range, 0-2+; P=0.002). However, there was no significant difference in success rate or reoperation rate between the two groups. Additionally, after combining the recession of the superior rectus muscle with the horizontal muscle, the number of A-pattern degrees was greatly reduced.

Conclusions

Helveston syndrome can be improved using a personalized surgical design according to the degree of external strabismus A-pattern, superior oblique muscle overaction, and dissociated vertical deviation (DVD) degree, which improves the success rate of single surgery.

Role of Abelson Helper Integration Site 1, Nebulin, and Paired Box 3 Genes in the Development of Nonsyndromic Strabismus in a Series of Iranian Families: Sequence Analysis and Systematic Review of the Genetics of Nonsyndromic Strabismus

Purpose

To look for causative genetic mutations in a series of Iranian families with strabismus. In addition, we systematically reviewed all the published articles regarding the role of genetic variations in primary and nonsyndromic comitant strabismus.

Methods

Four families with a history of multiple cases of primary and nonsyndromic comitant strabismus were enrolled in this study. Polymerase chain reaction and Sanger sequencing of exons 23, 11, and 3 of the Abelson helper integration site 1 (AHI1), nebulin (NEB), and paired box 3 (PAX3) genes were performed, respectively. One offspring of a consanguineous marriage underwent whole-exome sequencing (WES) to look for possible causative variants. To conduct a systematic review, we thoroughly searched PubMed, Scopus, and ISI Web of Knowledge extracting relevant publications, released by April 2021.

Results

We examined four Iranian strabismus pedigrees with multiple affected offspring in different generations. Among these 17 participants, 10 family members had strabismus and 7 were healthy. Sanger sequencing did not reveal a causative mutation. Therefore, to further investigate, one affected offspring was chosen for WES. The WES study demonstrated two possible variants in MYO5B and DHODH genes. These genetic variants showed high allele frequency in our population and are thought to be polymorphisms in our series of Iranian families.

Conclusions

We demonstrated that mutations in AHI1, NEB, and PAX3 genes were not common in a series of Iranian patients with familial strabismus. Moreover, by performing WES, we revealed that two variants of uncertain significance as possible causative variants for strabismus are not related to this disease in our population.

[High-dose medialis recession in latent nystagmus]

BACKGROUND

Large muscle recessions reduce anomalous head turn (AHT) in infantile nystagmus syndrome (INS). Their quantitative effect to reduce AHT in fusion maldevelopment nystagmus syndrome (FMNS) is unknown.

AIM OF THE STUDY

To evaluate the reduction of AHT by large medial rectus muscle recession in patients with FMNS.

METHODS

We analyzed data of 12 patients with pure FMNS who received large medial rectus muscle recessions on the sound eye or only eye between 2014 and 2019. Medians and ranges (min-max) were: age at surgery 14 years (3-43 years); decimal BCVA sound eye/fellow eye 0.56 (0.4-1.0)/0.01 (0-0.4); AHT at 5 m/0.3 m fixation distance 35° (15-45°)/20° (0-45°); amount of recession 13 mm (11.5-15 mm); follow-up 13 (4-39) months.

RESULTS

At the final visit, AHT at 5 m/0.3 m was 10° (0-20°/0-15°). The individual reduction of AHT at 5 m amounted to 25° (8-35°) without any overcorrection. The available visual field of functionally monocular patients increased correspondingly. Slight overcorrection at 0.3 m occurred in 2 cases. Adduction of the sound eye was limited to 25e-40°). BCVA and anomalous head posture in vertical and frontal planes did not improve.

CONCLUSION

Large medial rectus muscle recession on the sound eye improves AHT in FMNS by a similar amount compared to INS and the available visual field of functionally monocular patients.

Evaluation of fixation characteristics in amblyopia using microperimetry

PURPOSE

To evaluate fixation characteristics in amblyopia using macular analyzer integrity assessment (MAIA) microperimetry and to investigate the factors affecting fixation stability.

METHODS

This prospective, cross-sectional study enrolled a total of 58 amblyopic patients who were between 8 and 55 years old. Average threshold macular sensitivity (AT) and fixation characteristics were assessed using MAIA microperimetry. Two Bivariate contour ellipse area (BCEA) fixation indices (63% and 95% proportional values) and the percentage of fixation points within 1° and 2° from the fovea (P1 and P2) were used to assess fixation stability. Non-amblyopic fellow eyes were used as the control group for comparison.

RESULTS

AT and fixation stability indices (P1, P2, BCEA 63%, BCEA 95%) were worse in the amblyopic eyes than in the fellow eyes (p < 0.05, for all indices). There was a moderate positive correlation between best corrected visual acuity (BCVA), and AT, and P2, and a moderate negative correlation between BCVA, and BCEA indices. 48% of the eyes were eccentrically fixating (the percentage was 25% in the anisometropic group, 52% in the strabismic group, and 69% in the combined group) and 32% in the non-amblyopic eye (p = 0.052). The preferred fixation eccentricity in amblyopic eyes was significantly greater than the non-amblyopic eyes (p = 0.004), and there was a negative correlation between preferred fixation eccentricity and BCVA (p = 0.012, r = - 0.327).

CONCLUSIONS

Our data showed a decrease in fixation stability, a positive correlation between fixation stability and BCVA, and a negative correlation between preferred fixation eccentricity and BCVA in amblyopic eyes.

Unilateral four muscle surgery for extra-large monocular exotropia

INTRODUCTION

Recurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD).

METHODS

Retrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position.

RESULTS

Twelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9 ± 15.1 (range 35-80; median 60 PD) to 3.3 ± 5.5 (range 0-16; median 0 PD) postoperatively (p < 0.005). Two of 3 patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92%% of the patients had an exodeviation of 10 PD or less (range 0-16 PD median 0 PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured -0.6 ± 1 (0 to -3) and adduction -0.4 ± 0.7 (0 to -2).

CONCLUSION

Weakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations.

The effect of strabismus surgery performed by preserving the anterior ciliary vessels on the choroid in pediatric patients

BACKGROUND

Horizontal strabismus surgery is one of the most common eye operations. Many studies have shown that strabismus surgery has an effect on choroidal thicknesses. This study aimed to evaluate choroidal changes after the anterior ciliary vessels (ACV) conservation surgery using Enhanced Depth Imaging-Optical coherence tomography (EDI-OCT).

METHODS

This study included 41 eyes of 26 pediatric patients that were diagnosed with esotropia and underwent surgery with the standard procedure and 38 eyes of 25 pediatric patients treated with ACV preservation. Preoperative and postoperative refraction error measurements, biomicroscopic examinations, intraocular pressure measurements, dilated fundus control, and strabismus examinations were performed, and the best corrected visual acuity was determined. The patients were operated on under general anesthesia by the same surgeon using two different procedures: the standard procedure (Group 1) and by preserving the ACV (Group 2). Using EDI-OCT, choroidal measurements were performed preoperatively, on postoperative week 1, month 1, and month 3.

RESULTS

The preoperative and postoperative choroidal thickness measurements of the patients in Group 1 decreased in all regions postoperatively (p<0.05) especially at week 1 and month 1, but approached the preoperative values at the third -month evaluations (p>0.05). In Group 2, there was no statistically significant difference in the choroidal measurements between the preoperative ​​and postoperative week 1, month 1, and month 3 values (p>0.05).

CONCLUSIONS

ACV preservation is recommended to prevent choroidal changes occurring in the early period after horizontal strabismus surgery.

Characteristics and differences of strabismus surgeries performed in private versus public settings: a national multicenter study

PURPOSE

To investigate and compare the demographics, diagnoses, and surgical procedure types of strabismus repair in public and private hospitals in Israel in order to highlight possible disparities between them.

METHODS

Retrospective descriptive study included all strabismus surgeries in seven private hospitals, compared with two large public university-affiliated hospitals from June 2016 to June 2021. Electronic medical records were directly retrieved to produce an anonymized database.

RESULTS

During the study period 2420 operations were performed. Patients who underwent strabismus surgery in public hospitals were older and had shorter procedures (p < 0.001 and p = 0.004, respectively). The median number of operated muscles and the prevalence of bilateral procedures were higher in private hospitals (p < 0.001 and p < 0.001, respectively). Surgery for common strabismus, especially esotropia, was more prevalent in private (p < 0.001), whereas surgery for vertical strabismus, cranial nerve palsies and complex syndromes were performed more often in public hospitals (p < 0.001, p = 0.008, and p < 0.001, respectively). Rectus recession and inferior oblique (IO) anteriorization were more predominant in private hospitals (p = 0.002 and p < 0.001, respectively), while recuts advancement and IO myectomies were more prevalent in public ones (p = 0.001 and p < 0.001, respectively). Reoperations were far more common in public hospitals (27.2% vs 6.2%, p < 0.0001). This was true across most age groups.

CONCLUSIONS

Candidates for strabismus surgery in private hospitals in Israel are often younger, with more common diagnoses, and are usually referred for simpler procedures.

[Management of binocular diplopia in the department of ophthalmic emergencies at the Regional University Hospital of Tours]

OBJECTIVES

To describe the etiologies of binocular diplopia for patients presenting to the ophthalmologic emergency department of the Regional University Center Hospital (CHRU) of Tours.

METHODS

This is a retrospective study of the medical records of patients who presented with binocular diplopia in the ophthalmic emergency department of the CHRU of Tours between January 1st and December 31st, 2019. Binocular diplopia was classified as paralytic or non-paralytic according to the ocular motility examination.

RESULTS

One hundred twelve patients were included. The median age was 61 years. Internal referral from other hospital services represented 44.6% of the patients. On ophthalmological examination, 73.2% had paralytic diplopia, 13.4% non-paralytic diplopia and 13.4% normal examination. Neuroimaging was performed in 88.3% of cases, with 75.7% of patients receiving it on the same day. Oculomotor nerve palsy was the most frequent cause of diplopia in 58.9%, the majority represented by abducens nerve palsy (60.6%). The most frequent etiology of binocular diplopia was ischemic, with microvascular damage in 26.8% of cases and stroke in 10.7% of cases.

CONCLUSION

Among patients assessed in an ophthalmological emergency department setting, one in ten patients had stroke. It is essential to inform patients of the urgent nature of ophthalmological evaluation in the case of acute binocular diplopia. Urgent neurovascular management is also mandatory and should be based on the clinical description provided by the ophthalmologist. Neuroimaging should be performed as soon as possible, based on the ophthalmologic and neurological findings.

Minimal Invasive Procedures in Strabismus Surgery: A Narrative Review

Purpose

To review the principles and different techniques of minimally invasive procedures in strabismus surgery.

Methods

This is a narrative review on minimally invasive procedures in strabismus surgery including general aspects and different new modifications on conventional strabismus surgery. We reviewed 24 articles published between 1993 and 2020.

Results

Minimal invasive procedures could be categorized into two subsets: one which minimizes conjunctival opening size and another which minimizes the muscle manipulations. Different conjunctival approaches have been introduced, such as Cul-de-sac and minimally invasive strabismus surgery incisions. Furthermore, there are different techniques for extraocular muscle weakening, strengthening, and transposition, such as mini-tenotomy, plication, mini-plication, Nishida, and modified Nishida procedures. Moreover, there are some techniques for handling strabismus in heavy eyes with high myopia and using adjustable sutures for strabismus correction.

Conclusions

Minimally invasive procedures in strabismus surgery consist of surgical procedures that minimize tissue disruption, speed up rehabilitation, and often ultimate better outcomes. These techniques could be replaced traditional methods to reduce conjunctival and lid swelling in the direct postoperative period.

Surgical training with phantoms in strabismus surgery

BACKGROUND AND PURPOSE

Simulation in surgical learning responds to ethical and pragmatic needs. Our purpose is to describe the effects on surgical skills of conducting a surgical training workshop on strabismus surgery with phantoms. Concern for patient safety makes it necessary to consider the use of simulators (virtual and three-dimensional physical) and animal models that allow the applicant to safely practice the procedures before facing a real case.

MATERIAL AND METHODS

Realization of a workshop with previous theoretical content and real practice with phantoms designed to simulate strabismus surgery (eyeball, 6 muscles, conjunctiva, eyelid and tenon capsule inserted in the skull) of real anatomical dimensions. Satisfaction survey and subjective evaluation of learning by the student and the expert tutor according to the Kirkpatrick evaluation model.

RESULTS

Total, 100% of the 26 students attending two courses (15 students in one course and 11 students in another course) and 100% of the 3 tutors who participated in both courses completed the survey. 20 were resident doctors and 20 specialists in ophthalmology. The overall satisfaction of the students was 8.2 (±0.68).

CONCLUSIONS

According to the results of the Kirkpatrick training actions evaluation survey, the perception of students and tutors is that training with phantoms in strabismus surgery can help improve the skills necessary for safe and independent practice. The ultimate goal being to improve patient safety.

Congenital Aniridia and Ocular motility

PURPOSE

To study the frequency and types of strabismus in congenital aniridia, the presence of associated nystagmus, foveal hypoplasia, and congenital cataracts.

DESIGN

Prospective, single-center cohort study.

METHODS

A review was conducted of 379 medical records of congenital aniridia patients who had a follow-up at the Necker-Enfants malades University Hospital between 2006 and 2022; the target age was between 12 months and 30 years. Ophthalmologic and orthoptic assessments according to age were performed. Strabismus was further analyzed according to the type of aniridia, foveal hypoplasia, and laterality of congenital cataract.

RESULTS

Strabismus was diagnosed in 150 patients; 73 were included in the study (28 males [38%] and 45 females [62%]), with a mean age of 11.02 years. The mean follow-up was 24 months. Thirty-six (49.3%) presented with familial aniridia, and 37 (50.7%) presented with sporadic aniridia. Thirty-six (49.3%) were diagnosed with esotropia, 37 (50.7%) had exotropia. Nystagmus was detected in 70 patients (96%). Thirty-nine (53.4%) suffered from congenital cataract, 10 unilateral (25.7%) and 29 bilateral (74.3%). Foveal hypoplasia was found in 73 cases (100%); esotropia was predominant in all grades. PAX6 mutation was found in 56 patients (77%).

CONCLUSION

Strabismus is one of the clinical signs of congenital aniridia. The laterality of congenital cataracts seems to affect the type of strabismus. The grade of foveal hypoplasia has little impact on strabismus but is prevalent for nystagmus. Foveal hypoplasia affects optical focus, which is essential for binocularity; this could explain the poor binocular adjustment leading to strabismus without exotropia or esotropia predominance.

Translation and transcultural adaptation of the AS-20 scale to measure quality of life in adults with strabismus in Colombia, a pilot study

BACKGROUND

Strabismus generates a negative psychosocial impact on adult patients, affecting aspects such as self-perception and quality of life. There is no scale in Colombian Spanish that measures these impacts.

OBJECTIVE

To carry out the translation and cross-cultural adaptation of the AS-20 instrument into Colombian Spanish.

MATERIALS AND METHODS

Pilot test of a cross-sectional Study for the translation, reverse translation, and cross-cultural the AS-20 instrument from its original language, English, to Colombian Spanish, in adult patients with strabismus in Bogotá, Colombia.

RESULTS

16 patients were assessed. The age range was between 18 and 68 years with a mean age of 41 years. The scale was answered in an average time of 10.62min. Difficulty was reported in three individuals for understanding two items (questions 8 and 14), which were resolved.

CONCLUSION

The translation and pilot test of AS-20 scale into Colombian Spanish was carried out, identifying and solving translational difficulties. Is the first step in the cross-cultural adaptation process. Based on the results, the validation and cross-cultural adaptation can be completed in a future study.