Development of astigmatism and anisometropia in preterm children during the first 10 years of life: a population-based study

Do monocular myopia children need to wear glasses? Effects of monocular myopia on visual function and binocular balance

Objective

This study aims to compare the binocular visual functions and balance among monocular myopic adolescents and adults and binocular low myopic adolescents and explore whether monocular myopia requires glasses.

Methods

A total of 106 patients participated in this study. All patients were divided into three groups: the monocular myopia children group (Group 1 = 41 patients), the monocular myopia adult group (Group 2 = 26 patients) and the binocular low myopia children group (Group 3 = 39 patients). The refractive parameters, accommodation, stereopsis, and binocular balance were compared.

Results

The binocular refractive difference in Group 1, Group 2, and Group 3 was -1.37 ± 0.93, -1.94 ± 0.91, and -0.32 ± 0.27 D, respectively. Moreover, uncorrected visual acuity (UCVA), spherical equivalent (SE) and monocular accommodative amplitude (AA) between myopic and emmetropic eyes in Group 1 and Group 2 were significantly different (all P < 0.05). There was a significant difference in the accommodative facility (AF) between myopic and emmetropic eyes in Group 2 (t = 2.131, P = 0.043). Furthermore, significant differences were found in monocular AA (t = 6.879, P < 0.001), binocular AA (t = 5.043, P < 0.001) and binocular AF (t = -3.074, P = 0.003) between Group 1 and Group 2. The normal ratio of stereopsis according to the random dots test in Group 1 was higher than in Group 2 (χ2 = 14.596, P < 0.001). The normal ratio of dynamic stereopsis in Group 1 was lower than in Group 3 (χ2 = 13.281, P < 0.001). The normal signal-to-noise ratio of the binocular balance point in Group 1 was lower than Group 3 (χ2 = 4.755, P = 0.029).

Conclusion

First, monocular myopia could lead to accommodative dysfunction and unbalanced input of binocular visual signals, resulting in myopia progression. Second, monocular myopia may also be accompanied by stereopsis dysfunction, and long-term uncorrected monocular myopia may worsen stereopsis acuity in adulthood. In addition, patients with monocular myopia could exhibit stereopsis dysfunction at an early stage. Therefore, children with monocular myopia must wear glasses to restore binocular balance and visual functions, thereby delaying myopia progression.

Refractive state and visual acuity of children with extremely low birth weight at 3 years old in Japan

PURPOSE

To investigate the refractive status and visual acuity of 3-year-old children with extremely low birth weight (ELBW).

STUDY DESIGN

Retrospective cohort study.

METHODS

We examined 161 children born between January 2009 and December 2014. The children were divided into five groups for evaluation of visual acuity and refraction: no retinopathy of prematurity (ROP), reverse ROP, photocoagulation (PC) zone II (ZII), PC (ZI), and PC (ZI + lens-sparing vitrectomy [vit]).

RESULTS

Median (1st quartile, 3rd quartile) gestational age was 25 (24, 26) weeks. Median birth weight was 738 (588, 846) g. Spherical equivalence (SE) was +0.38 (-0.06, +0.75) diopters (D) in no ROP, +0.63 (-0.25, +1.34) D in reverse ROP, +0.38 (-0.75, +1.31) D in PC (ZII), -3.31 (-8.06, +0.16) D in PC (ZI), and -12.00 (-13.50, -4.50) D in PC (ZI+ vit) children. Best corrected visual acuity (BCVA) in log MAR was 0.15 (0.07, 0.26) in no ROP, 0.17 (0.10, 0.30) in reverse ROP, 0.22 (0.10, 0.38) in PC (ZII), 0.45 (0.22, 0.55) in PC (ZI), and 1.10 (0.82, 1.30) in PC (ZI+ vit) children. There was a significant correlation between SE and BCVA (r = -0.43, p < 0.0001).

CONCLUSION

The no ROP, reverse ROP, and PC (ZII) groups showed no significant differences in SE or BCVA, accounting for 79.5% of ELBW children. SE and BCVA in the PC (ZI) and PC (ZI+ vit) groups were worse than in the other groups. The current results reveal a correlation between SE and BCVA.

Screen Exposure during Early Life and the Increased Risk of Astigmatism among Preschool Children: Findings from Longhua Child Cohort Study

Screen media usage has become increasingly prevalent in daily life with children being exposed to screens at an early age. This is a growing public health concern with evidence linking screen exposure to detrimental health outcomes, whereas relationship between screen exposure and the presence of astigmatism among preschoolers remains unknown, thus we aimed to resolve this issue. During the 2017 survey of the Longhua Child Cohort Study, data of 29,595 preschoolers were collected via a caregiver-reported questionnaire regarding socio-demographics, screen exposure and refraction. Cox regression models were adopted to generate adjusted prevalence ratios (APR) and 95% confidence intervals (CI) to estimate the association between early screen exposure and astigmatism. 28,029 preschoolers were included in the final analysis. After adjustment for potential confounders, screen exposure during early life was significantly associated with the increased risk of astigmatism (APR and 95% CI: 2.25, 1.76–2.88), and the greatest risk was observed in the period from birth to 1-year (APR and 95% CI: 3.10, 2.41–3.98). The risk of astigmatism increased with both the total years of exposure and the average daily duration of screen exposure. Our findings suggested that preschoolers who were exposed to screens during early life might have an increased risk of astigmatism.

Factors That Influence Refractive Changes in the First Year of Myopia Development in Premature Infants

Purpose

To study the development of refractive status from 36 weeks to one year of postmenstrual age and to identify factors that contribute to development of myopia, including gender, birth weight, gestational age, and retinopathy of prematurity (ROP).

Methods

Premature infants underwent full cycloplegic retinoscopy at 36 weeks, 38 weeks, 40 weeks, 42 weeks, 44 weeks, 46 weeks, 48 weeks, 3 months, 6 months, 9 months, and 12 months of postmenstrual age. The infants were grouped by gender, birth weight, gestational age, and the severity of ROP to evaluate the correlation with refractive status at each postmenstrual age.

Results

A total of 942 infants were recruited in this study. A total of 2716 readings were obtained. Refractive state had a hyperopic shift until 46 weeks of postmenstrual age (r = 0.42, P < 0.0001). After that, the mean spherical equivalent (SE) gradually declined (r = -0.30, P < 0.0001). Boys had lower hyperopia than girls at nine months (t = 3.10, P=0.003) and one year (t = 3.34, P=0.001) of postmenstrual age. Premature infants with ROP had a lower average SE at most of the postmenstrual ages; however, this value did not vary significantly (P > 0.05). Premature infants with severe ROP were less hyperopic than those without it at every postmenstrual age, and the average SE differed significantly at one year of postmenstrual age (t = 2.60, P=0.011). There was no significant difference between each birth weight and gestational age (P > 0.05).

Conclusions

The dioptric value of premature infants within one year was generally hyperopic. Different gender, birth weight, gestational age, and ROP did not affect the overall development of refractive status. Females may have higher hyperopia at nine months of postmenstrual age. Birth weight and gestational age had little effect on change of refractive status. Severe ROP was an important contributing factor in myopia progression, which may be related to the treatment required. Further study may be carried out to understand the mechanism behind myopia progression in premature infants, including changes in refractive system parameters and emmetropization process.

Central Corneal Thickness and Its Association with Birth Parameters in Chinese Adolescents

Purpose: To examine the distribution and determinants of central corneal thickness (CCT) including birth weight and gestational age in a school-based samples of Grade 7 students in rural China. Methods: 2346 (93.5%) grade 7 students with a mean age of 13.8 years participated in the study. CCT was measured for both eyes using the LenStar LS900. Information regarding birth weight and gestational age was retrieved from the participants' delivery records. A linear regression model was established to examine the relationship of birth weight, gestational age and other factors with CCT. Results: The mean CCT in this population was 534.7 µm and boys had a greater CCT compared with girls (P = .06). CCT was positively related to axial length (r = 0.056) while negatively related to anterior chamber depth (r = -0.076) and corneal power (r = -0.105) . In multivariate analyses, the cornea was 19.35µm thinner in individuals with low birth weight compared with those with normal. In addition, the cornea was 25.25µm thinner in prematurely born adolescents compared with full-term ones. The combined effect of birth weight and gestational age on CCT was not statistically significant (P for interaction = 0.12) Conclusions: Low birth weight and small gestational age are associated with thinner corneas in adolescence. This disparity across groups with different levels of birth parameters should be taken into account by future studies investigating CCT as risk factors or diagnostic tests for glaucoma.

Growth curves of myopia-related parameters to clinically monitor the refractive development in Chinese schoolchildren

PURPOSE

To produce a clinical model for the prediction of myopia development based on the creation of percentile curves of axial length in school-aged children from Wuhan in central China.

METHODS

Data of 12,554 children (6054 girls and 6500 boys) were collected and analyzed for the generation of the axial length growth curves. A second data set with 226 children and three yearly successive measurements was used to verify the predictive power of the axial length growth percentile curves. Percentile curves were calculated for both gender groups and four age groups (6, 9, 12, and 15 years). The second data set was used to verify the efficacy of identifying the refractive error of the children using the axial length curves, based on their spherical refractive error from the third visit.

RESULTS

From 6 to 15 years of age, all percentiles showed a growth trend in axial length, except for the percentiles below the first quartile, which appear to stabilize after the age of 12 (- 0.10; 95%CI, - 0.36-0.16; P = 0.23 for girls; - 0.16; 95%CI, - 0.70-0.39; P = 0.34 for boys); however, the growth continued for the remaining 75% of cases. The second data set showed that the likelihood of suffering high myopia (spherical refractive error ≤- 5.00D) during adolescent years increased when axial length values were above the first quartile, for both genders.

CONCLUSIONS

The data from the current study provide a tool to observe the annual growth rates of axial length and can be considered as an approach to predict the refractive development at school ages.

Comparative study of visual dysfunctions in 6-10-year-old very preterm- and full-term-born children

PURPOSE

To compare visual dysfunction between very preterm-born (VPB) children with no retinopathy of prematurity (no-ROP) at 6-10 years of age and age- and sex-matched full-term-born controls.

METHODS

This is an observational, prospective study that included 30 children, 6-10 years of age, born ≤ 32 weeks of gestation, with no-ROP, and 30 age- and sex-matched full-term-born controls, conducted from January 2015 until August 2015. All children underwent complete ophthalmic evaluation. Main outcome measures include visual functions (best corrected visual acuity (BCVA), color vision, and stereoacuity), ocular alignment, refractive errors, and the presence of amblyopia and nystagmus.

RESULTS

Mean BCVA of the right eyes was 0.04 ± 0.08 logMAR for VPB children and 0.02 ± 0.05 logMAR for the full-term children (P = 0.075). Mean BCVA for the left eyes was 0.07 ± 0.09 logMAR for VPB children and 0.02 ± 0.05 logMAR for the full-term children (P = 0.014). Refractive errors were slightly higher though not statistically significant in VPB children compared to full-term children (P = 0.125). The incidence of myopia and hypermetropia was 16.7 and 40%, respectively, in VPB children and 10 and 23.3%, respectively, in full-term children. Anisometropia found only in VPB children with an incidence of 16.7%. Amblyopia found in 10% of VPB children compared to 3.3% in full-term children. Strabismus was found equally in 10% of each group.

CONCLUSION

VPB children with no-ROP are at an increased risk of developing decreased BCVA at least in one eye and anisometropia compared to age-matched full-term controls.

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.

Association of birth weight with corneal power in early adolescence: Results from the National Health and Nutrition Examination Survey (NHANES) 1999-2008

Purpose

To analyze the effect of birth weight on ocular morphology, refraction and visual function in early adolescents aged 12–15 years.

Material and methods

We conducted a secondary data analysis using the public use files from the National Health and Nutrition Examination Survey of the period from 1999 to 2008. Study participants aged 12 to 15 years were included with data on birth weight and ophthalmic parameters including presenting distance visual acuity, objective refraction and keratometry. Visual acuity, sphere, astigmatism in power vectors J₀ and J₄₅, corneal power and corneal astigmatism were evaluated for an association with birth weight. Linear and logistic regression with adjustment for age, sex, ethnicity, survey cycle and birth weight as independent variable were calculated.

Results

Linear regression analysis revealed an association between corneal power and birth weight (per 100g: beta = -0.04, p<0.001) in the univariate analysis, and in the model adjusted for age, sex, ethnicity and NHANES survey cycle (per 100g: beta = -0.04, p<0.001). A lower birth weight was associated with higher corneal power. We found no evidence for an association of visual acuity, sphere, spherical equivalent, J₀-vector and J₄₅-vector of astigmatism, corneal J₀- or corneal J₄₅-vector with birth weight.

Conclusion

Our data demonstrate that low BW is linked to alterations in keratometric power even in early adolescents aged 12–15 years whereas visual acuity and refractive error showed no association.

Long-term evaluation of refractive changes in eyes of preterm children: a 6-year follow-up study

PURPOSE

To investigate the longitudinal changes in refractive errors in preterm children with and without retinopathy of prematurity (ROP) in the first 6 years of life.

METHODS

We included 226 preterm children with a gestational age of ≤34 weeks: 222 eyes with no ROP, 73 eyes with mild ROP and 145 eyes with severe ROP. Longitudinal cycloplegic refraction data were collected initially and yearly thereafter until 6 years of age.

RESULTS

Eyes in the severe ROP group showed an increase in myopia values between the 1- and 3-year examinations (p = 0.005), with little change thereafter. However, the mild/no ROP group demonstrated a nonsignificant increasing myopia values throughout the 6-year follow-up (p = 0.073). Both the mild/no ROP and severe ROP groups were found to have increasing mean astigmatism values with increasing age, albeit nonsignificantly (p = 0.418, p = 0.384, respectively). Likewise, the stable mean values of anisometropia increased nonsignificantly during the first 6 years of life in both the mild/no ROP and severe ROP groups (p = 0.246, p = 0.073, respectively). Severe ROP group had higher values regarding myopia, astigmatism, and anisometropia parameters than the mild/no ROP group for all ages during the follow-up.

CONCLUSIONS

Preterm children with severe ROP should be closely monitored, and also those with mild/no ROP should be carefully followed up for not overlooking possible increases in refractive conditions.

Ocular alignment and refraction in preterm children at 1 and 6 years old

Purpose

To investigate cycloplegic refraction and ocular alignment in a population of preterm children at 1 and 6 years old.

Patients and methods

We included 261 preterm infants with a birth weight ≤1,500 g and a gestational age ≤32 weeks; there were 217 preterm infants (group 1), 28 preterm infants with mild retinopathy of prematurity (ROP) (group 2), and 16 preterm infants affected by severe ROP (group 3). Each patient underwent retinoscopy, ocular alignment assessment, and fundus examination at 1 and 6 years old.

Results

The prevalence of refractive errors and ocular alignment abnormalities at 1 year old in groups 2 and 3 compared to group 1 were, respectively (P<0.05): myopia 18% and 40.6% versus 6.9%; hyperopia 28.6% and 22% versus 39.2%; astigmatism 53.4% and 37.4% versus 53.9%; and strabismus 12.5% and 38% versus 5.3%. At 6 years old, they were, respectively (P<0.05): myopia 10.8% and 28.4% versus 7.4%; hyperopia 48.3% and 40.5% versus 62%; astigmatism 40.9% and 31.1% versus 30.6%; and strabismus 25% and 56.25% versus 11.5%.

Conclusion

At 6 years old, we observed increased rates of both hyperopia and strabismus in all groups compared to 1-year-old children. In preterm children with mild and severe ROP, we recorded increased rates of myopia and strabismus versus preterm children without ROP, and the risk of developing these disorders increased significantly with ROP severity. Astigmatism at 1 year old is not predictive of further development during growth. Patients born prematurely should be informed of the possible risks of ocular alterations due to refractive and ocular component changes.

Treatment outcomes of myopic anisometropia with 1% atropine: a pilot study

PURPOSE

To investigate the safety and efficacy of the treatment of myopic anisometropia with 1% atropine.

METHODS

Twenty-two children with myopic anisometropia were prescribed 1% solution of atropine sulfate to the more myopic eye, one drop before sleep every 3 days. Children were visited every 3 to 4 months until the degree of anisometropia was no more than 0.5 diopters (D) ("Success") or unchanged after 9 months of treatment ("No effect"). The treatment effect was assessed by comparing the interocular imbalance in refraction and axial length before and after the treatment. A detailed questionnaire about subjective symptoms in each visit and an electroretinogram in the end were administered to evaluate the side effects of this treatment.

RESULTS

The subjects were followed for 7 to 16 months. Six subjects withdrew participation on their own accord, and three were excluded because of inconstant usage of drug. Of the 13 remaining subjects, the refraction of the treated eyes decreased by 0.63 ± 0.59 D (p = 0.007), whereas that of the untreated eyes increased by -0.72 ± 0.65 D (p < 0.001). A corresponding trend was also found in the change of the axial length. Accordingly, the level of anisometropia was reduced from 1.82 ± 0.73 D to 0.47 ± 0.65 D (p < 0.001) and 10 (76.9%) of the 13 subjects were designated a "Success." One percent atropine was well tolerated by the children, and no electroretinogram abnormality was detected.

CONCLUSIONS

The results from this pilot study indicate that monocular usage of a solution of 1% atropine sulfate is an effective treatment to reduce anisometropia, although with some tolerable side effects. Nevertheless, an attenuated benefit was observed after cessation of atropine treatment. Thus, participants should be informed of a possible rebound effect before the administration of atropine for myopic anisometropia.

Astigmatism and biometric optic components of diode laser-treated threshold retinopathy of prematurity at 9 years of age

PURPOSE

To assess the prevalence of astigmatism and its relationship with biometric optic components in preterm school children with diode laser-treated threshold retinopathy of prematurity (ROP).

METHODS

A prospective, cross-sectional study in which cycloplegic keratometry, refraction, and ultrasound biometric measurement of optic components were performed on 24 consecutive preterm children with diode laser-treated threshold ROP at the age of 9 years. The study results were compared with data on 1021 age-matched full-term control children from a national survey.

RESULTS

The laser-treated eyes had a mean astigmatism of 3.47 D, with a mean spherical equivalent of -4.49 D. Of the 46 eyes studied, 98% of eyes showed astigmatism ≥0.5 D and 50% had high astigmatism (>3.0 D). Most astigmatic eyes (97.7%) showed with-the-rule astigmatism, with the mean plus cylinder axis at 89.30(o). Further correlation analysis showed the astigmatism in refraction was highly correlated with the corneal astigmatism (r=0.921, P<0.001) and the vertical corneal curvature (r=0.405, P=0.005). There was significantly steeper vertical corneal curvature (P=0.003) and flatter horizontal corneal curvature (P=0.031) in eyes with laser-treated ROP when compared with age-matched full-term controls. The eyes with laser-treated ROP also show significantly thicker lens (3.93 mm) and shallower anterior chamber depth (ACD; 2.92 mm) than full-term controls (P<0.001).

CONCLUSIONS

There is significantly higher prevalence and greater magnitude of astigmatism in eyes with laser-treated threshold ROP compared with full-term controls. The steeper vertical corneal curvature component contributes to the increased astigmatism in eyes with laser-treated ROP.

Anisometropia in children from infancy to 15 years

PURPOSE

To investigate anisometropia in children from age 6 months to 15 years.

METHODS

Children with refractions at 6 months (n = 1120), 5 years (n = 395), and 12 to 15 years (n = 312) were included in this study. All children were refracted in the laboratory by noncycloplegic retinoscopy. Myopes had spherical equivalent refraction (SER) of the less ametropic eye of less than -0.50 D, hyperopes had SER of the less ametropic eye greater than or equal to 1.00 D, and emmetropes had SER of the less ametropic eye from -0.50 to +1.00 D.

RESULTS

The mean difference in refraction between the two eyes was similar at 6 months (0.11 D) and 5 years (0.15 D), increasing to 0.28 D at 12 to 15 years. Using a cutoff of 1.00 D SER for anisometropia, the prevalence was 1.96%, 1.27%, and 5.77% at 6 months, 5 years, and 12 to 15 years, respectively. At 12 to 15 years, the prevalence of anisometropia in the myopes was 9.64% and in the hyperopes was 13.64%, both significantly higher than that in the emmetropes (3.38%, P < 0.05). The degree of anisometropia at 12 to 15 years was significantly associated with the refractive error of the less ametropic eye at 12 to 15 years, with and without adjustment for relevant covariates (P < 0.05). Infants with significant astigmatism (cylinder power ≥ 1.00 D in one or both eyes) have an increased risk of anisometropia (P < 0.05).

CONCLUSIONS

The prevalence of anisometropia increases between 5 and 15 years, when some children's eyes grow longer and become myopic. However, anisometropia was found to accompany both myopia and hyperopia, suggesting that other mechanisms in addition to excessive eye growth may exist for anisometropia development, especially in hyperopia.

Ocular growth and morbidity in preterm children without retinopathy of prematurity

PURPOSE

To investigate ocular growth and morbidity in both preschool and school-aged children born prematurely without retinopathy of prematurity (ROP).

METHODS

This population-based study was carried out in 26 children, 5-7 years of age, born prematurely without ROP. All children underwent a full ocular examination, including corrected visual acuity, cycloplegic refractive errors, color vision, ocular alignment, and anterior and posterior segment examinations. Anterior chamber depth, lens thickness, vitreous length, and total axial length were measured.

RESULTS

There was no correlation between the degree of prematurity and visual acuity or refractive state. Two (7.7%) subjects had strabismus, two (7.7%) had amblyopia, and four (15%) had anisometropia. Total axial length was significantly correlated with both gestational age at birth (r=0.822, P<0.001) and birth weight (r=0.569, P=0.003). Similarly, vitreous length was also significantly correlated with gestational age (r=0.744, P<0.001) and birth weight (r=0.553, P=0.004).

CONCLUSIONS

This study showed that although the globe gets longer as gestational age approaches term and as birth weight increases, this condition does not result in any significant refractive error. According to the literature, the prevalence of strabismus, amblyopia, and anisometropia may be higher in preterm children without ROP than in age-matched, normally delivered children.

Astigmatism in the Early Treatment for Retinopathy Of Prematurity Study: findings to 3 years of age

PURPOSE

To examine the prevalence of astigmatism (> or =1.00 diopter [D]) and high astigmatism (> or =2.00 D) at 6 and 9 months corrected age and 2 and 3 years postnatal age, in preterm children with birth weight of less than 1251 g in whom high-risk prethreshold retinopathy of prematurity (ROP) developed and who participated in the Early Treatment for Retinopathy of Prematurity (ETROP) Study.

DESIGN

Randomized, controlled clinical trial.

PARTICIPANTS

Four hundred one infants in whom prethreshold ROP developed in one or both eyes and who were randomized after they were determined to have a high risk (> or =15%) of poor structural outcome without treatment using the Risk Management of Retinopathy of Prematurity (RM-ROP2) program. Refractive error was measured by cycloplegic retinoscopy. Eyes with additional retinal, glaucoma, or cataract surgery were excluded.

INTERVENTION

Eyes were randomized to receive laser photocoagulation at high-risk prethreshold ROP (early treated [ET]) or to be conventionally managed (CM), receiving treatment only if threshold ROP developed.

MAIN OUTCOME MEASURES

Astigmatism and high astigmatism at each visit. Astigmatism was classified as with-the-rule (WTR; 75 degrees -105 degrees ), against-the-rule (ATR; 0 degrees -15 degrees and 165 degrees -180 degrees ), or oblique (OBL; 16 degrees -74 degrees and 106 degrees -164 degrees ).

RESULTS

The prevalence of astigmatism in ET and CM eyes was similar at each test age. For both groups, there was an increase in prevalence of astigmatism from approximately 32% at 6 months to approximately 42% by 3 years, mostly occurring between 6 and 9 months. Among eyes that could be refracted, astigmatism was not influenced by zone of acute-phase ROP, presence of plus disease, or retinal residua of ROP. Eyes with astigmatism and high astigmatism most often had WTR astigmatism.

CONCLUSIONS

By age 3 years, nearly 43% of eyes treated at high-risk prethreshold ROP developed astigmatism of > or =1.00 D and nearly 20% had astigmatism of > or =2.00 D. Presence of astigmatism was not influenced by timing of treatment of acute-phase ROP or by characteristics of acute-phase or cicatricial ROP. These findings reinforce the need for follow-up eye examinations in infants with high-risk prethreshold ROP.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Long-term follow-up of visual functions in prematurely born children--a prospective population-based study up to 10 years of age

INTRODUCTION

Prematurely born children have an increased risk of ophthalmologic problems. There is still no consensus on how they should be followed. The purpose of this study was to evaluate predictive factors for problems in premature children at ten years of age and to discuss follow-up recommendations.

MATERIALS AND METHODS

One hundred ninety-nine children with a birth weight of 1500 g or less were screened for retinopathy of prematurity (ROP) in the neonatal period and thereafter ophthalmologically examined at 6 months, 1.5, 2.5, 3.5, and 10 years of age. "Visual dysfunction" at ten years of age was defined as visual acuity > or =0.1 logMAR and/or strabismus and/or subnormal contrast sensitivity. Multiple regression analyses were used to evaluate risk factors at an early age, which could predict problems at ten years of age.

RESULTS

Twenty-five percent of the cohort had visual dysfunction at ten years of age. Neurological complications, cryotreated ROP, anisometropia, and astigmatism were risk factors. The sensitivity was 75.5%, and the specificity 80.7% for the detection of visual dysfunction at ten years of age when all children with neurological complications, cryotreated ROP, strabismus, anisometropia > or =1 diopters (D) at 2.5 years, and astigmatism > or =2 D at 2.5 years were included in further follow-up.

CONCLUSIONS

Repeated ophthalmologic follow-up of prematurely born children should be performed in those with treated ROP and/or neurological conditions. For a third group without such problems, at least one follow-up is recommended. Such an examination also provides a good opportunity to identify neurological problems that warrant further ophthalmologic follow-up.