Prevalence and associated factors of strabismus in former preterm and full-term infants between 4 and 10 Years of age

Gestational age, maternal smoking, neurological lesion and retinopathy predict strabismus at age 5.5 in preterm children

AIM

Prematurity is a risk factor for strabismus, but the roles of intermediate factors like retinopathy of prematurity (ROP) and neurological lesions are less understood. We aimed to identify neonatal risk factors for strabismus at age 5.5 in preterm children.

METHODS

Data were extracted from the étude épidémiologique sur les petits âges gestationnels 2 cohort, a French prospective population-based study of preterm children born in 2011 with gestational age of 34 weeks or less. Strabismus was recorded during a medical interview at 5.5 years. Using a directed acyclic graph, intermediate and confounding factors were identified. Total and direct effects of gestational age on strabismus risk were analysed using generalised estimating equation.

RESULTS

Among 2419 children assessed, 274 (52.6% male) presented strabismus at 5.5 years. The direct effect of gestational age remained significant after adjustment (p < 0.001). In the complete imputed model: maternal smoking during pregnancy (odds ratio, OR 1.8; 95% confident interval, 95% CI 1.3-2.6), neonatal severe cerebral lesions (OR 2.9, 95% CI 1.8-4.6) and severe ROP (OR 4.2, 95% CI 1.9-9.0) were independent risk factors.

CONCLUSION

Special attention is needed regarding strabismus screening at age 5.5 in preterm children, even without severe cerebral lesions and ROP. Smoking cessation during pregnancy should be encouraged.

Risk of long-term ophthalmological complications in Taiwanese preterm infants: a nationwide cohort study

OBJECTIVES

The aim was to determine whether different maturity levels and birth weights could change the risk of long-term ophthalmological complications in preterm infants.

DESIGN

This was a cohort study.

SETTING

This was a nationwide population-based study.

PARTICIPANTS

Newborns born between 2009 and 2012 were identified; newborns with congenital deformities, newborns with missing data on urban area, sex, gestational week at birth or birth weight and newborns who died before the age of 8 years were excluded.

INTERVENTIONS

Infants were divided into full-term, preterm and preterm with retinopathy of prematurity (ROP) cohorts based on their basic characteristics at birth.

PRIMARY OUTCOME MEASURES

The primary outcomes were ophthalmological complications, including strabismus, refractive error, amblyopia, cataracts and glaucoma.

RESULTS

Ultimately, 735 702 infants were included in the analysis. There were 727 403, 7165 and 1134 newborns in the full term, preterm without ROP and preterm with ROP cohorts, respectively. Premature infants, whether without ROP or with ROP, had an elevated risk of various ophthalmic complications, with adjusted ORs (aORs) ranging from 1.48 to 2.74 and 1.90 to 10.34, respectively. Extremely low birth weight contributes to an increased risk of various ophthalmic complications, with aORs ranging from 2.21 to 6.55. Moreover, a higher number of negative variables, such as preterm birth or low body weight, increased the risk of various ophthalmological complications, with the aOR falling within the range of 1.03-23.86.

CONCLUSIONS

Immaturity and low body weight were risk factors for ophthalmological complications in preterm infants. The presence of both of these two risk factors increased the risk of ophthalmological complications. Our results are essential for caregivers and health policy-makers to design comprehensive follow-up plans for preterm infants.

Prevalence of strabismus and risk factors in adults born preterm with and without retinopathy of prematurity: results from the Gutenberg Prematurity Eye study

AIM

The purpose of this study was to assess the prevalence of strabismus and nystagmus and to analyse associated factors in preterm and full-term infants in adulthood.

METHODS

The Gutenberg Prematurity Eye Study is a retrospective cohort study with a prospective ophthalmological examination of participants born preterm and full-term (aged 18-52 years). Perinatal data were carefully assessed for risk factors and comprehensive ophthalmological examinations were conducted. The association between strabismus and nystagmus was assessed by analysing 16 different perinatal and actual risk factors in multivariable analysis. Participants were grouped into full-term controls (gestational age (GA) at birth ≥37 weeks), preterm participants without retinopathy of prematurity (ROP) and GA 33-36 weeks (group 2), GA 29-32 weeks (group 3), GA ≤28 weeks (group 4), non-treated ROP (group 5) and treated ROP (group 6).

RESULTS

In total, 892 eyes of 450 preterm and full-term individuals (mean age: 28.6 years, SD: ± 8.6 years, 251 females) were included. Strabismus was observed in 2.1% (3/140), 6.6% (9/137), 17.4% (16/92), 11.1% (2/18), 27.1% (13/48) and 60% (9/15) of participants and nystagmus in 0.7% (1/140), 1.5% (2/137), 4.3% (4/92), 5.6% (1/18), 10.4% (5/48) and 26.7% (4/15) of participants in the respective groups. In the multivariable regression model, strabismus was associated with GA (OR=0.90; p=0.046), anisometropia ≥1.5 diopter (OR=3.87; p=0.003), hypermetropia ≥2 diopter (OR=9.89; p<0.001) and astigmatism ≥1.5 diopter (OR=2.73; p=0.017). Esotropia was more frequent than exotropia and hypermetropia/hypometropia. Most strabismus cases occurred within the first 10 years of life. The strongest predictor associated with nystagmus was perinatal adverse events (OR=15.8; p=0.002).

CONCLUSION

Low GA and refraction of the eye are independent risk factors for strabismus, which typically occurs in the first 10 years of life. Perinatal adverse events are the most important factors for the presence of nystagmus in adulthood.

Prematurity May Affect the Postoperative Sensory Results in Children With Strabismus

PURPOSE

To analyze the motor and sensory outcomes of strabismus surgery in children born preterm (premature group) and full-term (control group).

METHODS

The study was performed at a tertiary university hospital. Children who underwent strabismus surgery between 2012 and 2019 were retrospectively reviewed. The success of surgery, postoperative over-correction and undercorrection rates, and stereopsis and fusion test results were compared between the premature and control groups.

RESULTS

There were 70 patients in the premature group (mean gestational age: 31.25 weeks; range: 24 to 35 weeks) and 242 patients in the control group. The amounts of preoperative and postoperative deviations and overcorrection, undercorrection, and success rates were similar between the premature and control groups (P > .05). Stereopsis improved from 560 to 300 arc/sec postoperatively in the premature group (P = .066) and from 1,156 to 685 arc/sec in the control group (P < .001). The rate of fusion increased from 12.5% to 25% in the premature group (P = .50) and from 17% to 47% in the control group (P < .001). The analysis of strabismus subgroups revealed significant improvement of fusion in full-term patients (P < .001) and not in preterm patients (P = .50) with esotropia. Preoperative amount of deviation was the only risk factor for surgical success (P < .001). Age, sex, history of prematurity, and spherical equivalent refraction were not correlated with undercorrection (P > .05).

CONCLUSIONS

Regardless of the type of strabismus, although the functional results after strabismus surgery were similar in preterm and full-term patients, the gain of stereopsis and central fusion was significantly higher in full-term patients compared to preterm patients. [J Pediatr Ophthalmol Strabismus. 2024;61(4):267-272.].

Maternal Hypertensive Disorder in Pregnancy and Childhood Strabismus in Offspring

Importance

Maternal hypertensive disorder in pregnancy (HDP) might affect ocular health in offspring; however, its association with strabismus remains unclear.

Objective

To examine the association of maternal HDP with overall and type-specific strabismus in offspring.

Design, Setting, and Participants

In the Jiangsu Birth Cohort study, a population-based study in China, pregnant women were recruited from April 24, 2014, to November 30, 2018. A total of 6195 offspring had maternal HDP diagnosis information, of whom 3078 were excluded due to having no information on ocular alignment or due to having ocular diseases other than strabismus or refractive error. Offspring underwent ocular examinations at 3 years of age, completed May 21, 2022. Data were analyzed from May 28, 2022, through December 15, 2023.

Exposure

Maternal HDP, categorized into hypertension and preeclampsia or with blood pressure (BP) well controlled (systolic BP, <130; diastolic BP, <80 mm Hg) and poorly controlled (systolic BP, ≥130; diastolic BP, ≥80 mm Hg).

Main Outcomes and Measures

The primary outcome was the incidence of strabismus in offspring. Poisson generalized linear mixed models were used to estimate the association between maternal HDP and strabismus.

Results

Among the included 3117 children (mean [SD] age, 36.30 [0.74] months; 1629 boys [52.3%]), 143 (4.6%) were exposed to maternal HDP and 368 (11.8%) had strabismus. Offspring exposed to maternal HDP had an 82% increased risk of overall strabismus (relative risk [RR], 1.82 [95% CI, 1.21-2.74]), an 82% increased risk of exophoria (RR, 1.82 [95% CI, 1.11-3.00]), and a 136% increased risk of intermittent exotropia (RR, 2.36 [95% CI, 1.13-4.93]) compared with unexposed offspring. When considering the type of maternal HDP, the risk for all strabismus was high for offspring exposed to preeclampsia (RR, 2.38 [95% CI, 1.39-4.09]) compared with unexposed offspring. When considering the BP control level of maternal HDP, the risk for all strabismus was high for offspring born to mothers with HDP and poorly controlled BP (RR, 2.07 [95% CI, 1.32-3.24]) compared with unexposed offspring.

Conclusions and Relevance

These findings suggest that maternal HDP is associated with an increased risk of offspring strabismus. Early screening of strabismus might be recommended for offspring with maternal HDP. Further exploration of the underlying mechanism of the association between HDP and strabismus is warranted.

Self-Reported Findings of the Korean Intermittent Exotropia Multicenter Study Questionnaire

PURPOSE

To determine subjective symptoms and medical history of patients with intermittent exotropia in a large study population.

METHODS

The Korean Intermittent Exotropia Multicenter Study (KIEMS) is a nationwide, observational, cross-sectional, multicenter study conducted by the Korean Association for Pediatric Ophthalmology and Strabismus including 5,385 patients with intermittent exotropia. Subjective symptoms and medical history of patients with intermittent exotropia were extracted by a comprehensive survey based on a self-administered questionnaire according to the study protocol of the KIEMS.

RESULTS

The mean age of symptom onset was 5.5 years. The most common symptom reported in patients with intermittent exotropia was photophobia (52.1%), followed by diplopia at near fixation (7.3%) and distance fixation (6.2%). Preterm birth was found in 8.8%, and 4.1% had perinatal complications. A family history of strabismus was present in 14.9%, and 5.5% of patients had a family member who underwent strabismus surgery.

CONCLUSIONS

The KIEMS is one of the largest clinical studies on intermittent exotropia. Intermittent exotropia frequently caused photophobia and diplopia, and patients with a family history was not uncommon.

Retinopathy of prematurity screening: prevalence and risk factors of ophthalmic complications in non-treated preterm infants

INTRODUCTION

Retinopathy of prematurity (ROP) is a vision-threatening disease of premature infants. Practice guidelines recommend that all infants screened for ROP receive follow-up eye examinations to screen for ophthalmic complications.1 The purpose of this study was to identify risk factors for the development of strabismus, amblyopia, high refractive error, and cataracts among ROP-screened, non-treated infants.

METHODS

Retrospective single-centre study of ROP-screened, non-treated premature infants with ophthalmic follow-up. Clinical variables were screened for association with ocular findings at follow-up. Multivariable logistic regression was used to determine the risk factors associated with ocular findings.

RESULTS

309 patients were seen for follow-up at 0.97 (0.69) [mean (SD)] years after neonatal intensive care unit (NICU) discharge. Strabismus was predicted by occipitofrontal circumference (OFC) z-score at NICU discharge (OR 0.61; 95% CI [0.42, 0.88]; p = 0.008), intraventricular haemorrhage (IVH) grade III or IV (OR 3.18; 95% CI [1.18, 8.54]; p = 0.02), and exclusive formula feeding at NICU discharge (OR 2.20; 95% CI [1.07, 4.53]; p = 0.03). Significant predictors of amblyopia were OFC z-score at discharge (OR 0.55; 95% CI [0.31, 0.96]; p = 0.03) and necrotising enterocolitis (NEC) (OR 6.94; 95% CI [1.38, 35.00]; p = 0.02). NEC was a significant risk factor for high refractive error (OR 7.27; 95% CI [1.39, 37.94]; p = 0.02).

CONCLUSIONS

Among premature infants screened but not treated for ROP, severe IVH, NEC, low OFC z-score, and exclusive formula feeding at NICU discharge were risk factors for ocular morbidity. These findings affirm the value of ophthalmic follow-up for all ROP-screened infants, particularly those with the identified risk factors.

Characteristics and Trends of Strabismus Surgeries at a Tertiary Hospital Over 2 Decades - What Can Be Learned for Years to Come?

PURPOSE

To analyze characteristics and trends of strabismus surgeries in an Israeli hospital over 2 decades.

METHODS

A descriptive, retrospective study including all strabismus surgeries (666) performed during 2000-2019 at an Israeli tertiary hospital. Electronic medical records (EMRs) were directly retrieved to produce an anonymized database.

RESULTS

No trends were evident for age, sex, or ethnicity (p = .294, 0.914 and p = .167, respectively). The mean number of horizontal muscles remained stable, while an increase was noted in the mean number of muscles operated on to repair vertical strabismus (p < .0001). Among acquired cases, a 2.67-fold increase was noted in the proportion of spontaneous strabismus and a decrease of traumatic causes to a third (p < .001). An increase was noted in the proportion of exotropia among horizontal strabismus corrections (p = .022), and esotropia correction techniques distribution changed (p = .004). Reoperations comprised a third of all cases during both decades (p = .198). Reoperations were more prevalent among younger and Jewish patients (p < .001 and p = .024, respectively). Techniques to correct esotropia and exotropia differed significantly between primary surgeries and reoperations (p < .00001 each).

CONCLUSIONS

The complexity of surgical techniques increased over time. Ethnic minorities were less prone to reoperations.

Treatment rate of strabismus and amblyopia is associated with the location of pediatric ophthalmologists in the United States

PURPOSE

To determine whether the geographic density of pediatric ophthalmologists is associated with the rate of children treated for strabismus and amblyopia.

METHODS

This cross-sectional study included children treated for strabismus and amblyopia 0-17 years of age with commercial insurance who were included in the Vision and Eye Health Surveillance System. Additionally, pediatric ophthalmologists by state were determined using the American Association for Pediatric Ophthalmology and Strabismus website. Unadjusted linear regression was used to compare the geographic density of pediatric ophthalmologists and the rate of children treated for strabismus and amblyopia by state in 2016. This was repeated using multivariable linear regression, controlling for race, poverty, non-English-speaking children, and insurance coverage for children by state.

RESULTS

New York and Mississippi had the highest and lowest rates of treatment of strabismus and amblyopia, with 3.97 and 0.83 children treated per 100 children, respectively. The geographic density of pediatric ophthalmologists was associated with the rate of children treated for strabismus and amblyopia in unadjusted analyses (β = 0.62, P < 0.001). Further, the geographic density of pediatric ophthalmologists was associated with the rate of children treated for strabismus and amblyopia in adjusted analyses (β = 0.61, P < 0.001).

CONCLUSIONS

The geographic density of pediatric ophthalmologists by state was positively associated with the rate of children treated for strabismus and amblyopia.

The causal effect of obesity on concomitant exotropia: A lifecourse Mendelian randomization study

Obesity is now a significant global public health issue. Limited understanding exists regarding the association between obesity and concomitant exotropia. Our objective was to identify the causal relationship between lifecourse obesity, including birth weight, childhood body mass index (BMI), and adult BMI, and the risk of concomitant exotropia. We used a two-sample Mendelian randomization (MR) strategy to examine the causal relationship with inverse-variance weighted method as the primary MR analysis. We carried out sensitivity analyses to evaluate the accuracy and robustness of our findings. Also, we performed reverse-direction MR analysis to eliminate the possibility of reverse causality. Childhood BMI, as opposed to birth weight or adult BMI, had a significant impact on the risk of concomitant exotropia (odds ratio = 1.40, 95% confidence interval (CI): 1.08-1.81, P = .01). This significance persisted even after accounting for birth weight and adult BMI using multivariable MR analysis (odds ratio = 1.35, 95% CI: 1.04-1.75, P = .02). There was no significant heterogeneity or pleiotropy observed in sensitivity analyses (P > .05). Multivariable MR analysis further confirmed the absence of pleiotropic effects of some risk factors including prematurity, maternal smoking around birth and refractive error. Reverse causality did not affect the causal relationship (beta = -0.0244, 95% CI: -0.0545 to 0.0056, P = .11). Genetic predisposition to higher childhood BMI was found to be causally linked to an increased risk of concomitant exotropia.

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.

Wide-field digital imaging system for assessing ocular anterior segment development in very preterm infants

Purpose

This study aims to longitudinally investigate developments of the anterior segment in very preterm infants who exhibit normal retinal development outcomes by utilizing a wide-field digital imaging system.

Methods

Between June 2021 and June 2022, neonates with a birth weight of <1500 g and/or a gestational age (GA) of less than 32 weeks were included in this study. The participants underwent regular ocular examinations, including sequential evaluations of the anterior segment and the retina, at intervals of 2-5 weeks, starting from birth and continuing until they reached a corrected GA of 48 weeks. Term neonates were selected as normal controls for the study. The study recorded the weight and GA of subjects at the time of examination, as well as indicators of abnormal development in the anterior segment.

Results

A total of 48 very preterm infants with normal retinal developmental outcomes were enrolled. The control group included 59 full-term infants. Common anterior segment eye abnormalities such as persistent hyperplasia of primary vitreous, persistent pupillary membranes, iris vessels, and anterior chamber angle vessels gradually subsided with the period in very preterm infants. The vascularity of the iris was substantially higher than in term controls (P < 0.05) at term gestation. The imaging of iris vessels and anterior chamber angle vessels in very preterm infants exhibited a decline at 46 and 47 weeks, respectively, which occurred slightly later compared to term infants.

Conclusion

In very preterm infant s with normal outcomes, although the developmental process is delayed, they may form a normal anterior segment structure similar to that of full-term infants in the late stages, which is followed up by the wide-field digital imaging system.

[Ophthalmological long-term sequelae of premature birth-Persisting into adulthood : Eye development and premature birth anamnesis]

BACKGROUND

Premature birth and the postnatal occurrence of retinopathy of prematurity (ROP) are the main risk factors for reduced visual acuity and blindness in childhood and adolescence accompanied by numerous morphological ocular changes.

OBJECTIVE

It can be assumed that these alterations persist throughout life and could represent a potential risk factor for ocular diseases, although little is known to date about the long-term effects of prematurity on ocular function and morphology in adulthood.

METHODS

The aim of the present study is to review the literature on the long-term effects of prematurity and associated factors.

RESULTS

Individuals born preterm exhibit reduced visual acuity, lower visual quality of life, and steeper corneal configuration in adulthood. Furthermore, individuals with advanced ROP and need for ROP treatment are at particularly high risk for myopic refractive error, the occurrence of strabismus, and increased lens opacities with thicker lenses. Low gestational age is associated with thinner peripapillary retinal nerve fiber layer thickness as well as thicker foveal retinal thickness and more frequent occurrence of foveal hypoplasia. In addition, data from the Gutenberg Health Study showed that low birth weight as a surrogate marker for prematurity and fetal growth restriction are associated with an increased prevalence of age-related macular degeneration as well as more frequently with diabetes and consequently diabetic retinopathy.

DISCUSSION

Premature birth and associated factors lead to life-long functional and morphological ocular changes. There is evidence that this can lead to retinal diseases later in life and thus, there appear to be fetal origins for adult eye disease. This may have implications for ophthalmic controls and its intervals in adulthood.

[Ophthalmic care of adults born preterm and full-term-results from the Gutenberg Prematurity Eye Study (GPES) : Premature birth and ophthalmological care]

BACKGROUND

Prematurity and the presence of retinopathy of prematurity (ROP) increase the risk for the occurrence of amblyogenic risk factors in childhood and adolescence.

AIM

The aim of the present study was to evaluate ocular morbidities and the ophthalmological care of former preterm and full-term persons in adulthood.

MATERIAL AND METHODS

The Gutenberg prematurity eye study (GPES) is a retrospective cohort study with a prospective ophthalmological examination of individuals formerly born preterm and full term between 1969 and 2002 (now aged 18-52 years). All participants underwent a detailed ophthalmological examination and were asked about the frequency of ophthalmological care. Participants were grouped into those with normal gestational age (GA) ≥ 37 weeks (control group), preterm individuals without ROP and GA 33-36 weeks (group 2), GA 29-32 weeks (group 3), GA ≤ 28 weeks (group 4), and those with ROP without treatment (group 5) and with ROP with treatment (group 6). All participants were asked if they had an ophthalmological examination within the last 12 months.

RESULTS

In total, data from 140 term and 310 preterm adults were included in the present study. Strabismus was present in 2.1 % (3/140), 6.6 % (9/137), 17.4 % (16/92), 11.1 % (2/18), 27.1 % (13/48) and 60 % (9/15) in groups 1-6, respectively. The proportion of subjects with an ophthalmological examination within the last 12 months was highest in the groups of extremely preterm persons with and without ROP compared with the control group. Overall, 33.3 % (1/3) of the term and 57.1 % (28/49) of the preterm subjects with strabismus and 0 % (0/3) of the term and 46.9 % (15/32) of the preterm individuals with amblyopia had an ophthalmological examination within the past 12 months.

DISCUSSION

Extremely preterm adults with and without postnatal ROP showed the highest rate of eye diseases as well as the highest rate of ophthalmological check-ups within the last 12 months. This suggests that extremely preterm adults particularly with the occurrence of postnatal ROP perceive more frequent ophthalmological check-ups throughout their lives.

[Late sequelae of retinopathy of prematurity in infancy]

BACKGROUND

Retinopathy of prematurity (ROP) is one of the most frequent causes of severe visual impairment or blindness in childhood and can lead to severe late complications in children even after the initial disease has resolved.

PURPOSE

The present study summarizes possible late effects in childhood after treated and untreated ROP. A special focus is on the development of myopia, retinal detachment, as well as neurological and pulmonary development after anti-vascular endothelial growth factor (VEGF) treatment.

MATERIAL AND METHODS

This work is based on a selective literature search on late effects in childhood of treated or untreated ROP.

RESULTS

Preterm infants have an increased risk of developing high-grade myopia. Interestingly, several studies indicate that the risk of myopia is reduced following anti-VEGF treatment. With anti-VEGF treatment, however, late recurrences after initial response are possible even after several months, making long-term and frequent follow-up examinations essential. Controversy exists regarding the possible negative effects of anti-VEGF treatment on neurological and pulmonary development. After both treated and untreated ROP, rhegmatogenous, tractional or exudative retinal detachment, vitreous hemorrhage, high myopia and strabismus are possible late complications.

DISCUSSION

Children with a history of ROP with or without treatment have an increased risk for late ocular sequelae, such as high myopia, retinal detachment, vitreous hemorrhage and strabismus. A seamless transition from ROP screening to pediatric and ophthalmological follow-up care is therefore essential for timely detection and treatment of possible refractive errors, strabismus, or other amblyogenic changes.

Divergence excess and basic exotropia types of intermittent exotropia: a major review. Part 1: prevalence, classification, risk factors, natural history and clinical characteristics

INTRODUCTION

Intermittent exotropia (IXT) is a common form of strabismus. It is an outward deviation of one eye typically when viewing at distance. Symptoms include, but are not limited to double vision, eyes feeling tired, excessive blinking, and reduced quality of life. Its clinical characteristics are distinctive from other types of strabismus. This paper provides a comprehensive review of prevalence, classification, risk factors, natural history and clinical characteristics of the divergence excess and basic exotropia types of IXT.

METHODS

Search strategies involving combination of keywords including intermittent exotropia, exotropia, divergences excess, basic exotropia, prevalence, incidence, classification, terminology, risk factor, natural history, observation, angle of deviation, control, control score, symptom, quality of life, suppression, anomalous retinal correspondence, AC/A, accommodative convergence/accommodation, accommodative convergence, convergence, accommodation, vergence, incomitance and vertical were used in Medline. All English articles from 1900/01/01 to 2020/09/01 were reviewed. The reference list of the identified article was also checked for additional relevant article. Studies focused on animal model or strabismus associated with neurologic disorder or injury were excluded.

RESULTS

The estimated prevalence of IXT in children ranges from 0.1% to 3.7%. Hypoxia at birth and being female are potential risk factors of IXT. Using validated measures of control, multicenter prospective studies showed that the rate of conversion from IXT to constant exotropia is low. The angle of deviation is the most reported outcome measure in studies of IXT. It is often used to represent the severity of the condition and has been suggested as one of the four core outcomes for studies of the surgical management of IXT. Control of exodeviation is one of the four suggested core outcomes for study of surgery of IXT and is considered the main parameter of disease severity. Several validated tools for quality of life score are available to evaluate the subjective severity of IXT.

DISCUSSION

We reviewed the prevalence, classification, risk factors, natural history and clinical characteristics of the divergence excess and basic exotropia types of IXT. Further research into these areas, especially its clinical characteristics (e.g. suppression, dual retinal correspondence), will increase our understanding of this condition and potentially lead to better management of this common form of strabismus.

Level of prematurity as a predictor for the activity of retinopathy of prematurity and strabismus

Objective: To evaluate the prevalence of strabismus in premature children after the screening for retinopathy of prematurity (ROP) and to determine whether the level of prematurity (birth weight and gestation age) can be used as a predictor for both strabismus development and disease activity. Methods: This is a retrospective study, conducted in the Clinic for Eye Disease, section for Pediatric Ophthalmology of the Clinical Centre University of Sarajevo during the period from December 2013 until January 2017. 126 patients were involved. The inclusion criteria were gestational age ≤ 34 weeks, birthweight ≤ 2000 g and performed screening test for ROP. Patients were divided into three groups: patients without ROP, patients with spontaneous regression and patients with active ROP. Results: 52.4% patients were suffering from strabismus (30.2% esotropia, 22.2% exotropia). All the patients with active ROP had esotropia (60.0%). The average birth weight and gestational age were lower in patients with strabismus (1371.3 ± 58.0 g and 29.7 ± 0.4 weeks respectively). Conclusion: Lower gestational age and birth weight of premature children showed the increased probability of strabismus development especially esotropia. Prematurity level was significantly lower in patients with active ROP compared to the rest of the patients. Abbreviations: ROP = Retinopathy of prematurity, ICROP = International Classification of Retinopathy of prematurity, BCVA = best corrected visual acuity.

Strabismus and amblyopia in Africa - a systematic review and meta-analysis

The objective of this review was to estimate the prevalence of strabismus and amblyopia in Africa. A systematic online literature search was conducted for articles on strabismus and amblyopia in Africa. Meta-analysis was performed, using the Freeman-Tukey double arcsine transformation, to estimate the prevalence of strabismus and amblyopia in Africa. Subgroup analyses were conducted according to age, gender, study year, and type of amblyopia. Meta-regression was used to evaluate the influence of predetermined factors on the prevalence of amblyopia. 8 (1 population-based & 7 school-based) and 21 (3 population-based & 18 school-based) studies on strabismus and amblyopia with sample sizes of 22,355 and 46,841, respectively, were included in the review. Overall prevalence of strabismus in Africa was estimated to be 0.8% (95% CI: 0.4% - 1.4%); exotropia was 0.2% (95% CI: 0.1% - 0.5%) and esotropia was 0.5% (95% CI: 0.1% - 1.2%). Overall prevalence of amblyopia was estimated to be 0.6% (95% CI: 0.3% - 0.9%); refractive and strabismic amblyopia were 1.1% (95% CI: 0.2% - 2.5%) and 0.4% (95% CI: 0.2% - 0.6%), respectively. Prevalence estimate of amblyopia in males was 1.8% (95% CI: 0.7% - 3.3%) and in females was 1.3% (95% CI: 0.4% - 2.6%). There was a significant association between the prevalence of amblyopia and the type of amblyopia (p = .007) and the study year (p = .006). Although there appears to be a relatively low prevalence of strabismus and amblyopia in Africa, there is a dearth of well-designed population-based studies on strabismus and amblyopia in Africa, resulting in the lack of epidemiological information on strabismus and amblyopia within the general African population. Information about the prevalence of strabismus and amblyopia across Africa can inform policy making and design and implementation of public health intervention program.

Augenärztliche Versorgung früh- und reifgeborener Personen in deren Kindheit und Jugend – eine retrospektive Sicht der Eltern

Hintergrund Das Ziel der vorliegenden Studie war die Beschreibung der augenärztlichen Versorgung in der Kindheit und Jugend früh- und reifgeborener Personen aus der retrospektiven Sicht der Eltern.

Patienten, Material und Methoden Die Gutenberg Prematurity Eye Study (GPES) ist eine retrospektive Kohortenstudie mit einer prospektiven augenärztlichen Untersuchung von früh- und reifgeborenen Personen, die zwischen 1969 und 2002 geboren wurden (aktuelles Alter 18 bis 52 Jahre). Sie schließt eine Befragung von deren Eltern zur augenärztlichen Versorgung ihrer Kinder in der Kindheit und Jugend aus der Retrospektive ein. Die Teilnehmenden und deren Eltern wurden in Personen mit normalem Gestationsalter (GA) ≥ 37 (Kontrollgruppe), Frühgeborene ohne ROP (Retinopathy of Prematurity) mit GA 33 – 36 (Gruppe 2), GA 29 – 32 (Gruppe 3), GA ≤ 28 Wochen (Gruppe 4) und solche mit ROP ohne Behandlung (Gruppe 5) und mit ROP mit Behandlung (Gruppe 6) gruppiert. Die Eltern der Teilnehmenden wurden zur augenärztlichen Versorgung und zur Zufriedenheit damit befragt.

Ergebnisse Insgesamt wurden die Daten von 57 reifgeborenen und 131 frühgeborenen Kindern und deren Eltern in die vorliegende Studie eingeschlossen. Die Eltern der Teilnehmenden gaben an, dass eine augenärztliche Untersuchung bis zum 6. Lebensjahr in den jeweiligen Gruppen 1 bis 6 bei 22/57 (38,6%), 33/58 (56,9%), 22/38 (57,9%), 3/6 (50%), 19/21 (90,5%) und 7/8 (87,5%) stattgefunden habe. Insgesamt gaben 83 – 100% der Eltern in den verschiedenen Gruppen an, dass die augenärztliche Betreuung gut gewesen sei. Einen Augenarztwechsel aufgrund von Behandlungsunzufriedenheit berichteten insgesamt 4/57 (7%), 9/58 (15,5%), 8/38 (21,1%), 1/6 (16,7%), 1/21 (4,8%) und 2/8 (25%) in den jeweiligen Gruppen.

Schlussfolgerung Die vorliegende Studie zeigt eine gute Behandlungszufriedenheit hinsichtlich der augenärztlichen Betreuung von ehemaligen frühgeborenen Personen, insbesondere Eltern von Kindern mit einer ROP bewerteten diese positiv.

Visual acuity, amblyopia, and vision-related quality of life in preterm adults with and without ROP: results from the Gutenberg prematurity eye study

Objectives

This study investigated the effects of prematurity and ROP on visual acuity and VRQoL in adults (18–52 years).

Methods

The Gutenberg Prematurity Eye Study is a retrospective cohort study with a prospective ophthalmologic examination. Preterm and full-term participants at an age from 18 to 52 years were included. Distant corrected visual acuity (DCVA) and VRQoL were assessed in participants (892 eyes of 450 individuals aged 28.6 ± 8.6 years, 251 females) grouped into full-term controls (gestational age [GA] at birth ≥37 weeks), preterm participants without ROP and GA 33–36 weeks (group 2), GA 29–32 weeks (group 3), GA ≤ 28 weeks (group 4), non-treated ROP (group 5) and treated ROP (group 6). Main outcome measures were distant corrected visual acuity (DCVA), VRQoL and prevalence of amblyopia.

Results

The DCVA of the better eye correlated (p < 0.001) with GA, birth weight, ROP, ROP treatment, and perinatal adverse events and was poorer in both ROP groups. Visual acuity of <20/200 in the better eye was observed in two participants (4.2%) in the ROP group and one person (6.7%) in the treated ROP group. The prevalence of amblyopia increased in the ROP groups. Compared to full-term controls, visual functioning VRQoL scores were lower in preterm individuals independent of ROP while socioemotional VRQoL scores were only lower in the treated ROP group.

Conclusion

Participants with postnatal ROP and its treatment showed decreased visual acuity and VRQol in adulthood, with amblyopia occurring more frequently in more preterm participants with ROP.

Study of the Biological Developmental Characteristics of the Eye in Children After Laser Surgery for the Treatment of Retinopathy of Prematurity

Objective

To observe the differences in ocular biology between premature infants who had undergone retinal laser photocoagulation (LP) for retinopathy of prematurity (ROP) and full-term infants and to investigate the relationships between these differences and the development of the refractive state.

Methods

This retrospective, cross-sectional study included 25 children (50 eyes) who had undergone laser treatment for aggressive posterior retinopathy of prematurity (AP-ROP), ROP in zone I requiring treatment, or ROP in zone II requiring treatment in the posterior pole (laser group) and 29 full-term infants (58 eyes) who had not (control group). Basic information, spherical equivalent (SE), and best corrected visual acuity (BCVA) were collected from the two groups. Their mean ages were 7.32 ± 2.85 and 7.34 ± 2.57 years, respectively (t = −0.047, P = 0.96). Ocular biology data were measured using an IOL Master 700 instrument (Carl Zeiss Meditec AG) and the data were processed using MATLAB (R2016a, Mathworks Inc.). The data markers included central corneal thickness (CCT), anterior and posterior surface corneal curvature radius (CCR), anterior chamber depth (ACD), lens thickness (LT), lens anterior surface curvature radius, lens posterior surface curvature radius, and eye axis length (AL). Optometric data were collected simultaneously and all BCVA values were converted to the logarithm of the minimum angle of resolution (LogMAR) for analysis. The data were statistically analyzed using SPSS software (V.23.0). Independent sample t-tests were used for the assessment of ocular biology and refractive indices in both groups of children and Pearson correlation coefficients were used to evaluate the correlations between age, gestational age at birth and ocular biology structural parameters. P < 0.05 was considered statistically significant.

Results

Comparisons of ocular biomarkers, refractive status, and BCVA between children in the laser and control groups showed relationships among ocular biomarkers, including the corneal-related parameters of CCT (0.54 ± 0.04 mm and 0.56 ± 0.03 mm, t = −2.116, P < 0.05), anterior surface CCR (7.53 ± 0.33 mm and 7.84 ± 0.30 mm, t = −5.063, P < 0.05), posterior surface CCR (6.75 ± 0.34 mm and 7.03 ± 0.24 mm, t = −4.864, P < 0.05); as well as those related to anterior chamber depth (ACD) were 3.24 ± 0.26 mm and 3.64 ± 0.26 mm, respectively (t = −8.065, P < 0.05), lens-related parameters (LT) were 3.80 ± 0.19 mm and 3.45 ± 0.16 mm, respectively (t = 10.514, P < 0.05); anterior lens surface curvature radius were 10.02 ± 0.93 mm and 10.52 ± 0.85 mm, respectively (t = −2.962, P < 0.05); posterior lens surface curvature radius were 5.55 ± 0.51 mm and 5.80 ± 0.36 mm, respectively (t = −2.917, P < 0.05), and ocular axis (AL) were 22.60 ± 1.42 mm and 23.45 ± 1.23 mm, respectively (t = −3.332, P < 0.05). Moreover, comparison of refractive status and BCVA between two groups of children showed an SE of −1.23 ± 3.38 D and −0.07 ± 2.00 D (t = −2.206, P < 0.05) and LogMAR (BCVA) of 0.12 ± 0.13 and 0.05 ± 0.11 (t = 3.070, P < 0.05). Analysis of the correlations between age and ocular biomarkers and refractive status of children in the laser and control groups showed correlations between age and ocular biomarkers in the two groups, in which age in the laser group was positively correlated with AL (r = 0.625, P < 0.05) but not with other biomarkers (P > 0.05). Age in the control group was negatively correlated with CCT, ACD, and AL (r = 0.303, 0.468, 0.703, P < 0.05), as well as with LT (r = −0.555, P < 0.05), with no correlation with other biomarkers (P > 0.05). Analysis of the correlation between age and refractive status of children in both groups showed that the age of children in both laser and control groups was negatively correlated with SE (r = −0.528, −0.655, P < 0.05) and LogMAR (BCVA) (r = −0.538, −0.542, P < 0.05). Analysis of the correlations between refractive status and ocular biomarkers in children in the laser and control groups showed that the refractive status in children in the laser group was negatively correlated with AL (r = −0.773, P < 0.05) but not with other biomarkers in this group (P > 0.05). The refractive status of children in the control group was negatively correlated with ACD and AL (r = −0.469, −0.734, P < 0.05), positively correlated with LT (r = 0.364, P < 0.05), and was not correlated with other biomarkers in this group (P > 0.05). Analysis of the correlations of gestational age at birth with ocular biomarkers and refractive status in children in the laser group showed a positive correlation between gestational age at birth and AL (r = 0.435, P < 0.05) but no other correlations with the other biomarkers (P > 0.05). Moreover, gestational age at birth was negatively correlated with SE (r = −0.334, P < 0.05) and LogMAR (BCVA) (r = −0.307, P < 0.05) in children in the laser group.

Conclusions

Compared to full-term infants, the development of CCT, ACD, LT, and AL was relatively delayed after ROP laser surgery, resulting in thin central corneal thickness, steep corneas, shallow anterior chambers, thicker lenses, “rounder” lens morphology, increased refractive power, and short eye axes, leading to the development of myopia. The changes in refractive status were mainly influenced by increased lens thickness. The results of this study showed that the lower the gestational age at birth, the greater the effects on emmetropization in children after ROP, and the more likely the development of myopia.

The level of prevalence and risk factors of strabismus among children and adolescents, depending on the type of settlements in the Ganja-Gazakh economic district (Azerbaijan)

BACKGROUND: Strabismus as a pathological condition complicating the visual function and affecting the behavioral functions of children is often in the center of attention of numerous studies. The presence of regional differences in the strabismus prevalence makes this problem a relevant to study issue in the regions of Azerbaijan. AIM: To assess the prevalence rate of strabismus among children depending on the settlement type. MATERIALS AND METHODS: A prospective observation of a sample of children aged 519 years was carried out; the sample size was determined taking into account the size of the margin of sampling error less than 5%. 300 children at the age 59, 1014, 1519 years (150 boys and 150 girls) in a large town (Ganja) and rural settlements of Ganja-Gazakh region (2700 children in total) have been observed. In all children, an ophthalmologic examination was performed by specialists of the mobile team of the National Ophthalmological Center named after academician Z. Aliyeva. RESULTS: Strabismus was found in children aged 5-19 years in 4.6 0.7% of cases in a large town and in 2.7 0.5% of cases in rural settlements. Significant differences of prevalence rate of strabismus by age and gender were not confirmed. CONCLUSIONS: In the region, the incidence of strabismus among children aged 519 years was 3.8 0.4%. In a large town, the risk of strabismus among children is high. In children with strabismus, refractive errors and perinatal conditions (prematurity) are often found.

Association of Birth Weight With Foveolar Thickness in Adulthood: Results From a Population-Based Study

Purpose

Low birth weight (BW) is associated with alterations of foveal shape development in childhood-leading to an increased retinal thickness of the fovea. The aim of the present study was to assess whether BW has a long-term effect on foveal retinal thickness (RT) and is still present in adulthood.

Methods

In the German population-based Gutenberg Health Study (GHS), participants were examined with spectral-domain optical coherence tomography. The association between self-reported BW and RT in the foveolar and perifoveal locations was assessed. Multivariable linear regression analyses with adjustment for potential confounders and grading of foveal hypoplasia were performed.

Results

Overall, RT measurements and self-reported BW were available for 2,539 participants (1300 female, mean age 54.5 ± 9.7 years). The absolute foveolar RT was 239.6 ± 25.8 µm, 232.2 ± 20.1 µm and 234.8 ± 21.0 µm, respectively, in the low (<2500 g), normal (2500-4000 g) and high (>4000 g) BW groups (P < 0.001). After adjustment for confounders, an association was observed between lower BW and increased foveolar thickness (B = -0.35 [95% confidence interval {CI}: -0.49; -0.20] µm/100 g; P < 0.001), whereas only a weak association with RT was observed with the nasal (P = 0.010), temporal (P = 0.011), and inferior (P = 0.021) quadrants in the 1 mm distance, with no association in the 2 mm distance to the fovea. Foveal hypoplasia grade 1 was more frequent in the low BW group (6.8%) compared to the normal (0.9%) and high BW group (1.2%).

Conclusions

This study provides evidence of an association between lower BW and increased foveolar thickness and foveal hypoplasia, indicating that prenatal growth may affect macular morphology, which in turn may persist until adulthood and predispose to retinal disease later in life.

Pattern of oculomotor and visual function in children with hydrocephalus

PURPOSE

To investigate the ocular motility disturbances, optic nerve changes, and refractive errors in children with or without surgically treated hydrocephalus.

METHODS

This retrospective study included 63 subjects diagnosed with hydrocephalus between 2007 and 2019 at the Baskent University Hospital. Full orthoptic and ophthalmic examination and brain magnetic resonance imaging were performed in all subjects.

RESULTS

The mean age of patients was 68.4±27.6 months, and the mean follow-up time was 21.3±5.2 months. Twenty-one (51.2%) patients had esotropia (ET), and 14 (34.1%) had exotropia (XT). Of the patients with ET, 9 (14.2%) had a sixth nerve palsy. Four patients (6.3%) had a fourth nerve palsy, and 1 had a superior rectus palsy. Eleven patients had manifest, and 2 latent, nystagmus. Thirteen (20.6%) patients had optic disc abnormalities. The mean BCVA was 0.4±0.2 (0.05-1.0) in the right eye and 0.5±0.2 (0.1-1.0) in the left eye. Of the 19 (30.1%) patients who had a significant refractive error, 9 (47.3%) had hyperopia. Thirty-six (57.1%) patients had ventriculoperitoneal shunt surgery, and 11 (30.5%) of them had shunt revision due to occlusion. Ocular motility disorders were found to be significantly more common in patients who underwent single shunt surgery and shunt revision than those who had no surgical procedure (P=0.041and P=0.032, respectively).

CONCLUSION

The evaluation of ocular motility disorders and visual dysfunction in hydrocephalic children can be a source of valuable information when diagnosing and following the disease.

Neuroophthalmological manifestations of congenital aqueductal stenosis

OBJECTIVE

Congenital aqueductal stenosis (CAS) is a common etiology of hydrocephalus that occurs in a subset of infants and may be linked to an increased incidence of ophthalmological abnormalities and delayed developmental milestones. Although hydrocephalus is common and widely studied, sparse literature exists on patients with isolated (no identifiable genetic link) CAS along with analysis of ophthalmological manifestations. In this study, the authors sought to describe the ophthalmological abnormalities and delayed developmental milestones of patients with isolated CAS.

METHODS

Data of patients with CAS were prospectively entered and monitored in a surgical database maintained by the Department of Neurological Surgery at Children's Hospital of Pittsburgh from January 2005 to October 2016. Patients with a family history of congenital hydrocephalus, positive testing for genetic forms of aqueductal stenosis, other congenital abnormalities suggesting an underlying genetic syndrome, and stenosis/obstruction due to secondary causes were excluded from this study. Prenatal and perinatal history, CSF diversion history, and a variety of outcomes, including ophthalmological deficits and developmental milestones, were collected and analyzed.

RESULTS

A total of 41 patients with isolated CAS were identified, with a mean follow-up duration of 6 years. Among that cohort, 26 patients (63.4%) developed neuroophthalmological complications, which were further stratified. Fourteen patients (34.1%) developed strabismus and 11 (26.8%) developed astigmatism, and 1 patient (2.4%) with papilledema was recorded. Among patients with ophthalmological abnormalities, 76.9% had delayed developmental milestones (p = 0.045).

CONCLUSIONS

Patients with CAS were found to have increased risk of ophthalmological abnormalities requiring correction, along with an increased risk of delayed developmental milestones. Importantly, there was a significant correlation between the development of ophthalmological abnormalities and delayed developmental milestones that was independent of CSF diversion history. Larger patient cohort studies are required to explore whether earlier development of hydrocephalus, as is the case in CAS, causes elevated rates of neurological and ophthalmological complications, and if earlier CSF diversion correlates with improved outcomes.

A comparison of posterior segment optical coherence tomography findings in full-term and preterm children without retinopathy of prematurity

Purpose:

Structural differences have been described in the retina of prematurely born children, including increased macular thickness caused by failed migration of the inner retina during development and retinal nerve fiber layer (RNFL) thinning related to low birth weight. The present study aimed to evaluate the differences in macular and RNFL optical coherence tomography (OCT) findings between full-term and preterm children without retinopathy of prematurity (ROP).

Methods:

Thirty-four premature (study group) and 43 full-term patients (control group)—aged 3 to 8 years—were studied. All children underwent a complete ophthalmological exam and OCT of the macula and optic nerve in both eyes to determine macular and RNFL thickness and morphology. Correlation analysis between central macular thickness, age, and visual acuity was also performed.

Results:

Central macular thickness was greater in the study group than in the control group; a difference of 14.2 μm was observed for the right eye (P = 0.002) and 12.16 μm for the left eye (P = 0.019). The thickness of the parafoveal and the perifoveal zones was consistently greater in the study group. 44.3% of eyes in the study group had mild forms of foveal hypoplasia (grades 1a and 1b) in qualitative description. No correlation between central macular thickness and visual acuity was found. There was no difference in RNFL thickness between both groups.

Conclusion:

Statistically significant structural differences were found in the macula of premature children, with a greater foveal thickness possibly reflecting retention of the inner retina during development, with no repercussion over visual acuity. RNFL thickness was similar in both groups.

Prevalence of strabismus and its risk factors among school aged children: The Hong Kong Children Eye Study

The study aims to determine the prevalence of strabismus and its risk factors among school children in Hong Kong. This is a cross-sectional study involving 6–8 year old children from different districts in Hong Kong. 4273 children received comprehensive ophthalmological examination, cycloplegic auto-refraction, best corrected visual acuity (BCVA), anterior segment examination, cover/uncover test, ocular motility, and fundus examination. Demographic information, pre- and post- natal background, parental smoking status, and family history of strabismus were obtained through questionnaires. Strabismus was found among 133 children (3.11%, 95% CI 2.59–3.63%), including 117 (2.74%) exotropia and 12 (0.28%) esotropia cases (exotropia-esotropia ratio: 9.75:1). There was no significant difference in prevalence across age (6–8 years) and gender. Multivariate analysis revealed associations of strabismus with myopia (≤ − 1.00D; OR 1.61; 95% CI 1.03–2.52; P = 0.037) hyperopia (≥ + 2.00D; OR 2.49; 95% CI 1.42–4.39; P = 0.002), astigmatism (≥ + 2.00D; OR 2.32; 95% CI 1.36–3.94; P = 0.002), and anisometropia (≥ 2.00D; OR 3.21; 95% CI 1.36–7.55; P = 0.008). Other risk factors for strabismus included maternal smoking during pregnancy (OR 4.21; 95% CI 1.80–9.81; P = 0.001), family history of strabismus (OR 6.36; 95% CI 2.78–14.50, P < 0.0001) and advanced maternal age at childbirth (> 35 years; OR 1.65; CI 1.09–2.49, P = 0.018). The prevalence of strabismus among children aged 6—8 years in Hong Kong is 3.11%. Refractive errors, family history of strabismus and maternal smoking history during pregnancy are risk factors. Early correction of refractive errors and avoidance of maternal smoking during pregnancy are potentially helpful in preventing strabismus.

Clinical Spectrum of Ocular and Visual Dysfunction in Children with Periventricular Leukomalacia: A Need for an Interdisciplinary Approach

The study aimed to evaluate the ocular motility and visual and optic disc abnormalities in children diagnosed with periventricular leukomalacia (PVL). A retrospective analysis was performed on 51 consecutive children who had ophthalmic symptoms and were diagnosed with PVL by using magnetic resonance imaging. The patients were assessed for visual function, strabismus, cycloplegic refraction, fundus examination, and if appropriate, spectral-domain optical coherence tomography and visual field testing were applied. The primary outcome measures were the prevalence and visual and ocular motility dysfunctions. Mean age was 5.72 ± 2.6 years (range = 1–12), median birth weight was 2,740 g (range = 1,240–3,460), and median gestational age was 34 weeks (range = 28–38). In total, 21 patients (39.6%) had neurological deficit, 11 (21.5%) had intellectual disability, and 19 (37.2%) had no neurological symptom. In the spherical equivalent refractive error and cylinder power analysis, 10 patients had ≥3.0 D myopia, 15 had ≥3.0 D hyperopia, and eight had ≥2.50 D astigmatism. Thirteen (25.4%) children had a best-corrected visual acuity between 20/40 and 20/20 for Snellen card, while 9 (17.6%) had strabismic amblyopia and 6 (11.7%) had anisometropic amblyopia. Manifest strabismus was present in 35 patients (68.6%); of whom 12 had esotropia (23.5%), 16 had exotropia (31.3%) and 6 had vertical deviation (11.7%). Manifest or latent nystagmus was detected in 14 patients (27.4%). In 28 patients (54.9%), there was optic nerve abnormality. Two patients had hypoplastic disc, 14 had optic disc pallor, 7 had large cupping, and 5 had total optic atrophy. Six subjects underwent reliable visual field (VF) examinations, and all six had abnormal VFs, with inferior fields being most affected. Ocular motility disorders, optic nerve abnormalities, VF defects, and low visual acuity are common findings in this cohort of PVL patients and maybe the only presenting signs of the disease. The recognition of the visual disabilities and implementation of early rehabilitation may have a significant benefit in these children.

Strabismus prevalence and associated factors among pediatric patients in southern Ethiopia: a cross-sectional study

Objective

To assess the strabismus prevalence and associated factors among children aged ≤15 years.

Methods

This hospital-based cross-sectional study was conducted from March 2017 to October 2017 in the Department of Ophthalmology & Optometry, Hawassa University Comprehensive Specialized Hospital. Interviewer-administered questionnaires were used to collect relevant data and clinical examinations were performed for patient diagnosis.

Results

Overall, 582 children participated in the study (response rate, 97%). The prevalence of childhood strabismus was 17.9% [95% confidence interval: 14.6–21.1]. Additionally, 9.6%, 16.7%, and 9.6% of the children had anisometropia, amblyopia, and dense cataract, respectively. Among the 16.7% of children with amblyopia, 56.7% had strabismus; among the 22.5% of children with clinically significant refractive error, 52.7% had strabismus. Moreover, among the 9.6% of children with anisometropia, 58.9% had strabismus. The presence of amblyopia (adjusted odds ratio [95% confidence interval]: 3.9, 1.7–8.6), age <5 years (13.5 [5.0–36.1]), age 5 to 10 years (6.1 [2.3–16.3]), and clinically significant refractive error (13.3 [5.8–30.6]) were significantly associated with childhood strabismus.

Conclusions

The prevalence of strabismus was relatively high among patients in this study. Early screening for childhood strabismus is essential. A well-controlled community-based study is needed to confirm strabismus prevalence and predictors.

A retrospective survey of strabismus surgery in a tertiary eye center in northern China, 2014-2019

Background

To evaluate the distribution pattern and changes of strabismus surgery in northern China.

Methods

The records of strabismus patients at Qingdao Eye Hospital from January 2014 to December 2019 were reviewed retrospectively. The characteristics analyzed included gender, regional distribution, constituent ratio of age and type of strabismus. Changes during the periods 2014–2016 and 2017–2019 were compared and analyzed.

Results

A total of 5746 strabismus patients were recruited. The number of strabismus patients was relatively stable each year from 2014 to 2016 but gradually increased each year from 2017 to 2019. Of these, 51.7% (2968/5746) were male, and 48.3% (2778/5746) were female. The majority (89.8%, 5159/5746) of the patients were from Shandong Province. The statistical results of the constituent ratio of age showed that 32.4% (1860/5746) were 7–12 years old (primary school level). Patients under 12 years of age (preschool and primary school level) accounted for 60.0% (3447/5746) of all the patients. In terms of the types of strabismus, exotropia accounted for 63.5% (3650/5746), followed by esotropia and vertical rotational strabismus at 13.2% (758/5746) and 9.7% (555/5746), respectively. Intermittent exotropia was the most common type among the exotropia patients, accounting for 71.3% (2604/3650). Among the patients with intermittent exotropia, 62.5% (1627/2604) were children aged 4–12 years, and the basic type of intermittent exotropia was the main type. Four percent (231/5746) of the patients, of which adult patients comprised the main population, required reoperation.

Conclusions

Patients with strabismus at primary school level comprised the largest group of strabismus patients in north China. Exotropia was the most common type of strabismus, and intermittent exotropia was the most common type of exotropia. The rate of exotropia to esotropia was 5:1.

Assessment of Different Types of Strabismus Among Pediatric Patients in a Tertiary Hospital in Jeddah

Background Strabismus, also known as squint, is an ocular disorder in which the eyes do not align properly with each other when looking at an object. The estimated global prevalence of strabismus among children is between 1.3% and 5.7%. This study aimed to assess the various types of strabismus among pediatric patients in Jeddah, in the western region of Saudi Arabia. Methods The medical records of 281 patients with strabismus aged ≤18 years, who presented to the pediatric ophthalmology clinic in King Abdulaziz University Hospital between 2010 and 2019, were retrospectively reviewed. Data were analyzed using the Statistical Package for Social Sciences (SPSS; IBM Corp., Armonk, NY, USA). A p-value of 0.05 or less was considered statistically significant. Results Out of the 281 patients, 141 were (50.2%) female. The average age of the patients was 9.50 ± 4.24 years. The most common type of strabismus was esotropia (177 [63%] patients), followed by exotropia (96 [34.2%] patients), hypertropia (10 [3.6%] patients), and dissociated vertical deviation (four [1.4%] patients). Two-hundred thirty-one (82.8%) patients had bilateral strabismus. A total of 178 patients (63.3%) had no associated conditions with strabismus, whereas 103 (36.7%) had an associated condition. A significant relationship was observed between esotropia and prematurity (p = 0.024). Conclusion Esotropia was the most common type of strabismus among the patients, followed by exotropia. The results of this study showed that males were equally affected as females. We also found a significant relationship between esotropia and prematurity. Implementation of a compulsory nationwide pediatric ophthalmic screening program for children aged one, three, and five years is recommended to enable timely diagnosis of strabismus and any other refractive errors.

Comparison of the Efficiency of the Botulinum Toxin for the Treatment of Esotropia in Children with and without Neurological Disease and/or Prematurity

OBJECTIVE

To compare the effect of botulinum toxin injection for the management of esotropia in patients with and without neurological disease and/or prematurity.

METHODS

A single-center, retrospective, nonrandomized controlled study was performed on botulinum toxin in 87 children divided into two groups: study group of esotropia in 56 children with neurological disease and/or prematurity and, control group of 31 healthy children with infantile esotropia. All patients were followed for at least 24 months after injection. Success was defined as motor alignment with 10^Δ of orthotropia after single bilateral botulinum injection.

RESULTS

Mean age at treatment was similar in both groups (15.5 vs 14.8 months; p = .555). Mean pretreatment deviation was similar in both groups (50.8^Δ vs 50^Δ; p = .855). The success rate was better in the control group (61.2% vs 51.7%, p = .265) at 24 months after injection, but the change in the mean angle of deviation was not statistically significant between the groups at 12 and 24 months after injection (p = .264 and p = .547, respectively). Multivariate regression analysis showed that pretreatment angle of deviation and presence of retinopathy of prematurity were significant predictors at 12 months after injection (p = .0001 and p = .004, respectively), while pretreatment angle of deviation was found to be a predictor at 24 months after injection (p = .0001).

CONCLUSIONS

Decreased angle of deviation and absence of retinopathy of prematurity were associated with a better result. There was no difference in motor alignment of esotropia in children with and without neurological disease and/or prematurity. In these patients, botulinum injection may be used as an alternative to surgery.

Motor skills in children with strabismus

PURPOSE

To assess the extent to which strabismus in children was associated with motor difficulties and to examine which parameters of strabismus were most closely associated with motor development.

METHODS

The motor skills of children who were suffering from strabismus, were tested binocularly using the Movement Assessment Battery for Children, Second Edition (MABC-2) and compared with the motor performance of monocularly tested healthy controls without any ophthalmologic disease.

RESULTS

A total of 40 children with strabismus (mean, 7.25 ± 3.83 years; 19 females) and 18 controls (mean age, 8.33 ± 5.42 years; 6 females) were tested. According to the MABC-2 test, of the 40, 19 had no motor disability, and 21 were at risk of or already presented significant motor disabilities. Results of the MABC-2 were significantly lower for strabismic children without binocularity compared to those with binocularity (P = 0.002). Lack of binocularity was associated with significantly lower performance for static balance (P = 0.003) as well as for catching tasks (P = 0.042).

CONCLUSIONS

Lack of binocularity and stereopsis in children is associated with significant motor skills impairment, in particular for static balance and catching tasks. These results should be confirmed with a larger sample, including older patients, to assess the compensation mechanisms that develop with age and the actual effects of strabismus on overall motor performance.

Maternal smoking during pregnancy and the risk of strabismus in offspring: a meta-analysis

The effect of maternal smoking during pregnancy on strabismus in offspring remains unclear. We conducted a meta-analysis to summarize epidemiological evidences on the association between maternal smoking during pregnancy and the risk of offspring strabismus. Eligible studies were searched from the PubMed, Ovid, Embase and CNKI databases up to May 2018. The qualities of included articles were assessed with the Newcastle-Ottawa Scale and the assessment scale recommended by the Agency for Healthcare Research and Quality. Odds ratios (ORs) corresponding with its 95% confidence intervals (CIs) were pooled to estimate the effects of maternal cigarette smoking on the risk of offspring strabismus. Subgroup analyses and meta-regression were performed to explore the potential sources of heterogeneity. The Begg's test and Egger's test were used to assess the publication bias. Eleven articles involving 4,833 patients with strabismus were included. The pooled OR showed that maternal smoking during pregnancy was significantly associated with strabismus in offspring (OR = 1.46, 95% CI = 1.32-1.60). Compared with less than 10 cigarettes per day (OR = 1.17, 95% CI = 1.06-1.29), maternal smoking 10 cigarettes or more per day during pregnancy significantly increased the risk of offspring strabismus (OR = 1.79, 95% CI = 1.39-2.31). The risk of developing esotropia and exotropia for smoking pregnant women, respectively, increased by 65% (OR = 1.65, 95% CI = 1.31-2.09 and OR = 1.65, 95% CI = 1.24-2.19) than those who did not smoke during pregnancy. Additionally, the increased risk of maternity smoking associated with offspring strabismus was stable across all subgroup analyses. Overall, maternal smoking during pregnancy was associated with a significantly increased risk of offspring strabismus and the result was persistent in subgroup analyses, suggesting the importance in changing smoking habit or smoking cessation for women who are pregnant or preparing to.

Correlation of morphological parameters and visual acuity with neurological development in former preterm children aged 4-10 years

PURPOSE

The objective of this study was to investigate the relationship between visual acuity, peripapillary retinal nerve fibre layer (pRNFL), retinal thickness at the fovea and other factors with the neurologic status of former preterm children.

METHODS

In this cross-sectional hospital based study in a maximum care tertiary centre, detailed anthropometric and ophthalmological data of former preterm children ranging from 4 to 10 years of age with a gestational age (GA) ≤32 weeks were assessed. Analyses of the correlation between pRNFL and foveal thickness, as well as visual acuity (VA) parameters at 4-10 years of age, with neurological development were evaluated at 2 years of age by Bayley Scales II of Infant Development, including Psychomotor Developmental Index (PDI) and Mental Developmental Index (MDI).

RESULTS

Data were available for 106 former preterm children. Univariate analysis revealed a correlation between PDI with pRNFL thickness (B = 0.43; p = 0.013), VA (B = -29.2; p < 0.001), GA (B = 2.7; p = 0.002), retinopathy of prematurity (ROP; B = -16.3; p < 0.001) and intraventricular haemorrhages (IVH; B = -22.9; p < 0.001) but not with strabismus or foveal thickness. In the multivariable analysis, the association remained for visual acuity and IVH, but not for pRNFL thickness or ROP. Mental Developmental Index (MDI) was associated with visual acuity (B = -34.3; p = 0.001), GA (B = 2.53; p = 0.02) and IVH (B = -15.4; p = 0.02), the latter also in the multivariable analysis.

CONCLUSION

This study revealed an association between PDI at 2 years of age and lower visual acuity later in childhood. However, there was no correlation between retinal morphology and neurologic outcome in former preterm children after adjusting for several potential confounders.

Association of low birth weight with myopic refractive error and lower visual acuity in adulthood: results from the population-based Gutenberg Health Study (GHS)

Purpose

Low birth weight (BW) is linked to impaired organ development in childhood, including altered ocular morphological and functional development. The aim of this study was to evaluate whether low BW has long-term effects on visual acuity and refraction in adulthood.

Methods

The Gutenberg Health Study is a population-based, observational cohort study in Germany, including 15 010 participants aged between 35 and 74 years. These participants were divided into three different BW groups (low: <2500 g; normal: between 2500 and 4000 g; and high: >4000 g). Best-corrected visual acuity and objective refraction were examined. We used multivariable linear regression models with adjustment for age, sex, socioeconomic status and self-reported glaucoma, age-related macular degeneration, corneal disease and cataract to assess associations between BW and the main outcome measures, best-corrected visual acuity, spherical equivalent and astigmatism.

Results

Overall, 8369 participants reported their BW. In a multivariable analysis, an association for low BW with spherical equivalent (B=−0.28 per dioptre, P=0.005) and best-corrected visual acuity (B=0.02 logarithm of the minimum angle of resolution, P=0.006) compared with normal BW was observed. For participants with high BW, an association was observed with spherical equivalent (B=0.29 per dioptre, P<0.001), while none with visual acuity.

Conclusions

Our data demonstrated that low BW is linked to visual acuity and refractive long-term outcomes long after childhood. Individuals with low BW are more likely to have lower visual acuity and a higher myopic refractive error in adulthood. Adults with high BW are more likely to have a more hyperopic refractive error.