Astigmatism In Children Research Articles

Astigmatism in Children With Epiblepharon

To study the relationship between astigmatism and epiblepharon in Taiwanese children that need surgical correction. In a retrospective case-control study, a total of 254 eyes in 134 children surgically treated for lower-lid epiblepharon were studied. A further 205 eyes in 104 children 4-7 years of age were included as controls. Data on age, sex, severity of preoperative corneal erosion, best-corrected visual acuity, and preoperative and postoperative refractive errors were recorded. The data of astigmatism were decomposed into P90 (at 90 degrees) and its oblique meridian Pobl. Nonparametric tests were used to compare the severity of astigmatism. No significant difference between age group (<4, 4-7, >7 years) in P90 was shown in children with epiblepharon. Pobl was trivial in each group of epiblepharon. Children with epiblepharon 4-7 years of age had significantly (P < 0.001) greater P90 than controls (1.12 vs. 0.47 D). P90 and Pobl were not significantly changed postoperatively. In the same individual, the eye with the more severely affected cornea had greater astigmatism (P = 0.002), even after the corneal erosion healed. Children with epiblepharon who needed surgery had greater with-the-rule astigmatism than controls. More severe corneal erosion was associated with higher astigmatism. Surgical correction of skinfold and promotion of reepithelialization did not attenuate astigmatism significantly.

Heritability of Corneal Curvature and Astigmatism

To study child-parent similarities and the heritability of corneal shape by applying a variance component model to videokeratographic data. Sixteen astigmatic (keratometric cylinder >/= 1.0 D) and 18 nonastigmatic (keratometric cylinder < 1.0 D) children, 7-14 years of age (mean age, 9.5 years), were enrolled with their parents. Corneal curvature, corneal astigmatism (axis and magnitude), asphericity, corneal uniformity index, and Rabinowitz McDonnell inferior-superior dioptric asymmetry value (I-S value), as well as spherical and astigmatic topographic patterns, were determined by a corneal topographer. Child-parent comparisons were assessed through a 1-way analysis of variance and the chi test. For corneal curvature, corneal astigmatism, and asphericity, heritability was estimated by a variance component model after adjustments were made for age and sex. Both astigmatic and nonastigmatic children showed steeper keratometric values than their parents (P < 0.05). The axis values of corneal astigmatism showed no statistically significant difference (P = 0.684) between astigmatic offspring and their parents, whereas the magnitude values were significantly higher (P < 0.001) in astigmatic children. Altogether, 68% (95% confidence interval [CI], 66%-72%) of child-parent comparisons showed the same topographic pattern between parents and their offspring. Heritability values (48%; 95% CI, 36%-57%) were statistically significant for corneal curvature (P < 0.00001) and <30% for corneal astigmatism and asphericity. The application of a variance component model to videokeratographic child-parent comparisons suggests that the genetic contribution to corneal shape affects corneal curvature rather than corneal astigmatism.

Astigmatism in unilateral coronal synostosis: Incidence and laterality

Unilateral coronal synostosis alters orbital development and can be associated with strabismus, oblique muscle dysfunction, astigmatism, and amblyopia. While the ocular effects are most dramatic on the side of the fusion, the shape of the contralateral orbit is also abnormal and the effect of these changes on bilateral visual development has not been fully described. The purpose of this study was to analyze the incidence and laterality of astigmatism in children with unilateral coronal synostosis. We retrospectively reviewed the charts of 39 consecutive patients with unilateral coronal synostosis. Recorded data included the following: patient demographics, visual acuity, cycloplegic refraction, ocular motility, procedures for craniofacial and strabismus correction, and presence and treatment of amblyopia at each visit. Twenty-one of 39 patients (54%) had 1.00 D or more astigmatism in at least one eye at their last recorded refraction. Sixteen of the 21 (76%) had aniso-astigmatism of 1.00 D or more. Of the 16, 14 (88%) had the greater degree of astigmatism in the contralateral eye. Fifteen of the 39 studied (38%) had amblyopia and, in 12 of these 15 patients (80%), the amblyopic eye was contralateral to the synostosis. Nineteen of 39 patients (49%) had greater ipsilateral fundus excyclotorsion, whereas only 1 of 39 (3%) had greater contralateral excyclotorsion. Patients with unilateral coronal synostosis are at risk for developing a greater degree of astigmatism in the eye contralateral to the synostosis. Ocular disturbances in the contralateral eye, especially anisometropic amblyopia, must be considered when treating patients with this type of craniosynostosis.

Amblyopia in astigmatic children: Patterns of deficits

Neural changes that result from disruption of normal visual experience during development are termed amblyopia. To characterize visual deficits specific to astigmatism-related amblyopia, we compared best-corrected visual performance in 330 astigmatic and 475 non-astigmatic kindergarten through 6th grade children. Astigmatism was associated with deficits in letter, grating and vernier acuity, high and middle spatial frequency contrast sensitivity, and stereoacuity. Although grating acuity, vernier acuity, and contrast sensitivity were reduced across stimulus orientation, astigmats demonstrated orientation-dependent deficits (meridional amblyopia) only for grating acuity. Astigmatic children are at risk for deficits across a range of visual functions.

Significance of Contralateral Astigmatism in Patients with Unilateral Coronal Synostosis

Introduction: Unilateral coronal synostosis (UCS) is associated with an increased incidence of strabismus, oblique muscle dysfunction, astigmatism, and amblyopia. We analyzed the incidence and laterality of astigmatism in children with UCS to assess the impact of asymmetric orbital growth on refraction. Methods: A retrospective chart review on all UCS patients (n= 33) referred for ophthalmic consultation was performed. Laterality of the synostosis, gender, visual acuity, cycloplegic refraction, ocular motility, history of craniofacial and strabismus surgery, and presence and treatment of amblyopia was recorded.

Changes in astigmatism in children with congenital nystagmus

Astigmatism is commonly reported in children with and without nystagmus. In children less than 4 years of age the astigmatism changes from against the rule (ATR) to with the rule (WTR) astigmatism in children without nystagmus. However, little is known about children with congenital nystagmus. We compared astigmatism in children with congenital nystagmus below 4 years and above 4 years of age. Three hundred and fifty-six eyes in 178 children who satisfied the study criteria were included. The children were divided into those below 4 years of age (n of eyes = 192) and those above (n of eyes = 164). Cycloplegic refraction (with manual retinoscopy) carried out at presentation and at the last follow-up were recorded and compared. Cycloplegia was achieved using cyclopentolate eye drops. Outcome of eyes with no astigmatism at initial presentation was compared with the final refraction in both the age groups. The visual acuity at the first presentation was compared with the visual acuity at the last presentation. Average follow-up duration was 3.36+/-1.59 years. On presentation, 176 (49.44%) eyes did not have any astigmatism. We found that 26 (25.2%) out of the 103 children below 4 years of age who did not have any astigmatism on presentation developed WTR astigmatism after a mean follow-up of 3.5+/-1.5 years. (p= 0.042). In children >or=4 years of age only 7 (9.6%) children out of 73 developed WTR after a mean follow-up of 3.4+/-1.4 years. The visual acuity change was not found to be significant in the two groups. The majority (90.3%) improved or had same visual acuity in group A and 88.9% improved or had the same visual acuity in group B at the last follow-up (p= 0.77). Our incidence of WTR astigmatism in children with congenital nystagmus is similar to those previously reported series. Our data suggest that there is a significant chance that children under 4 years with congenital nystagmus may develop WTR astigmatism compared with children above 4 years of age. With the rule (WTR) astigmatism is common in children with nystagmus. Children under 4 years of age presenting with no astigmatism may acquire WTR astigmatism as they grow. The amount of astigmatism increases with age in children with nystagmus. Visual acuity, however, remains stable as the age advances.

Amblyopia in astigmatic children: Development and treatment

Amblyopia in astigmatic children: Development and treatment

Features of Hyperopic LASIK in Children

To evaluate the results of hyperopic LASIK in children and adolescents with accommodative strabismus and refractive amblyopia. The procedures were conducted by standard methods of LASIK using a Technolas 217C excimer laser (Bausch & Lomb, Rochester, NY). LASIK resolved the accommodative components of strabismus by achieving stabilization of visual acuity and decrease (or disappearance) of amblyopia degree. All patients achieved binocular vision. Excimer laser correction of hyperopia and hyperopic astigmatism in children and adolescents has the potential to correct refractive errors, improve visual function in amblyopic eyes, correct accommodative strabismus, and improve binocular vision.

Astigmatism after small-incision clear corneal cataract extraction and intraocular lens implantation in children

To investigate the magnitude of postoperative astigmatism in children having cataract extraction with intraocular lens (IOL) implantation through a 3.0 mm superior clear corneal incision. Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Indiana, USA. This retrospective chart review comprised all pediatric patients having cataract surgery with IOL implantation through a 3.0 mm clear corneal incision from 1997 to 2002. One hundred two eyes of 75 patients were included. All refractions were performed manually by an experienced pediatric ophthalmologist. The mean postoperative retinoscopic cylinder in all patients was 0.63 diopter (D) (range 0.0 to 4.50 D) at 1 month, 0.40 D (range 0.0 to 1.75 D) at 6 months, and 0.51 D (range 0.0 to 2.50 D) at 1 year. Patients aged 0 to 36 months at the time of surgery had a mean postoperative cylinder of 0.22 D at 1 month, 0.03 D at 6 months, and 0.21 D at 1 year. Patients between 36 months and 6 years of age at surgery had a mean refractive cylinder of 0.50 D, 0.38 D, and 0.75 D, respectively. Patients older than 6 years at surgery had a mean refractive cylinder of 0.94 D, 0.75 D, and 0.76 D, respectively. Small-incision clear corneal cataract extraction with IOL implantation in children led to minimal postoperative astigmatism that remained stable over time. Less astigmatism was observed in children having surgery before they were 36 months old.

Treatment of astigmatism-related amblyopia in 3- to 5-year-old children

Best-corrected acuity was measured for vertical and horizontal gratings and for Lea Symbols ® recognition acuity in 3- to 5-year-old children with high astigmatism and in non-astigmatic children. There was significant amblyopia among astigmatic children at baseline. There was no evidence that eyeglass correction of astigmatism resulted in a reduction in amblyopia over a 4-month average treatment duration (although vision in astigmatic children was significantly improved immediately upon eyeglass correction, indicating that eyeglass correction did provide a visual benefit). Treatment outcome results are discussed in terms of both methodological issues and theoretical implications.

Relationship between the axis and degree of high astigmatism and obliquity of palpebral fissure.

To investigate a possible relationship between the slanting of palpebral fissures and the magnitude and axis of astigmatism in children with astigmatism. Cross-sectional study at a referral center of 53 children with astigmatism of more than +1.50 D in at least 1 eye. Visual acuity testing, cycloplegic refraction, slit-lamp biomicroscopy, and ophthalmoscopy were done on every patient. Corneal topography was obtained in 40 cooperative patients. External photographs of the midface were taken in 45 children. The degree of slanting of the palpebral fissures was evaluated based on the photographs. The statistical analysis tool used was repeated measures analysis of variance. Patients in whom photographic analysis was not available were excluded from the part of the statistical analysis dealing with eyelid slant. Palpebral fissure slant (P =.013) and gender (P =.0005) were highly correlated with the obliquity of cylinder axis. There was a possible correlation between gender and eyelid slant (P =.0594), with females having slightly larger degrees of upward palpebral fissure slanting and male more downward slanting of their fissures compared to published angles in an age-matched population. We found a statistically significant correlation between the degree of total astigmatism and a larger abnormal slant (P =.0192) and between the axis and magnitude of corneal astigmatism and abnormal slant (P =.0092). Higher degrees of eyelid slant (> 8 degrees or < -4 degrees ) increased the risk of high cylinder magnitude (> 3.00 D) by an odds ratio of 4.17 (95% CI: 1.03, 19.95). Children with astigmatism with large degrees of slanting of their palpebral fissures are at higher risk for high astigmatism (> 3.00 D). The axis of the astigmatism is highly correlated with the slanting of the palpebral fissure.

Relationship between the axis and degree of high astigmatism and obliquity of palpebral fissure

Purpose To investigate a possible relationship between the slanting of palpebral fissures and the magnitude and axis of astigmatism in children with astigmatism. Methods Cross-sectional study at a referral center of 53 children with astigmatism of more than +1.50 D in at least 1 eye. Visual acuity testing, cycloplegic refraction, slit-lamp biomicroscopy, and ophthalmoscopy were done on every patient. Corneal topography was obtained in 40 cooperative patients. External photographs of the midface were taken in 45 children. The degree of slanting of the palpebral fissures was evaluated based on the photographs. The statistical analysis tool used was repeated measures analysis of variance. Patients in whom photographic analysis was not available were excluded from the part of the statistical analysis dealing with eyelid slant. Results Palpebral fissure slant ( P = .013) and gender ( P = .0005) were highly correlated with the obliquity of cylinder axis. There was a possible correlation between gender and eyelid slant ( P = .0594), with females having slightly larger degrees of upward palpebral fissure slanting and male more downward slanting of their fissures compared to published angles in an age-matched population. We found a statistically significant correlation between the degree of total astigmatism and a larger abnormal slant ( P = .0192) and between the axis and magnitude of corneal astigmatism and abnormal slant ( P = .0092). Higher degrees of eyelid slant (> 8° or < −4°) increased the risk of high cylinder magnitude (> 3.00 D) by an odds ratio of 4.17 (95% CI: 1.03, 19.95). Conclusions Children with astigmatism with large degrees of slanting of their palpebral fissures are at higher risk for high astigmatism (> 3.00 D). The axis of the astigmatism is highly correlated with the slanting of the palpebral fissure.

Astigmatic axis and amblyopia in childhood.

This study is part of a larger project whose aim is to evaluate the relationship between refractive errors and amblyopia. In an earlier study, we showed that there is a substantial increase in the prevalence of amblyopia among children with oblique astigmatism. To further evaluate this relationship, we examined children with astigmatisms of 1 dioptre or more and varying directions of the astigmatic axes. Two groups of astigmatic children, with oblique and orthogonal astigmatism, respectively, were selected for the study at 1 year of age via a general health screening programme. The most emmetropic axis was identified in each child and used in the study. Visual acuity (VA) was tested when the children were between 4 and 4.5 years of age. The presence of amblyopia, defined as difference in VA between the eyes of 0.1 log unit or more, and any increase in acuity following occlusion therapy were noted. The angle of the astigmatic axis strongly relates to the risk of developing amblyopia. Axes +/- 15 degrees from the main axes did not affect the risk of amblyopia but oblique astigmatism significantly increased the risk of developing amblyopia (p = 0.0024). The results accord with earlier findings that oblique astigmatism increases the risk of developing amblyopia.

Três anos pós-LASIK em crianças anisométropes de 8 a 15 anos de idade

PURPOSE: To determine the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK), three years after surgery, to correct high myopia or high myopic astigmatism in children with high anisometropia in whom conventional treatments had failed. METHODS: Nine eyes of 9 patients, 3 boys and 6 girls with a mean age of 11.5 years (range, 8 to 15 years) underwent LASIK using the Chiron Technolas 217 excimer laser. Minimum follow-up was 36 months. RESULTS: Three years after LASIK, uncorrected visual acuity improved by at least five Snellen lines in all eyes; five eyes (55.5%) were 20/50 or better without correction. Six eyes (66.6%), were 20/50 or better with correction and five eyes (55.5%) improved at least 1 line in the best spectacle corrected visual acuity (BSCVA). Due to amblyopia, no eye had uncorrected visual acuity of 20/20 or better. The mean spherical refraction equivalent decreased from -7.66 (± 3.75) D to -1.02 (± 1.26) D, and mean preoperative astigmatism decreased from -3.11 (± 2.09) D to -0.75 (± 0.25) D. Highest anisometropia was 1.5 D. CONCLUSION: Three years after surgery, LASIK seems to be a safe and effective option for the correction of high anisometropia in children from 8 to 15 years old, in whom conventional therapy had failed. The natural change in refraction related to maturation did not affect the use of appropriate spectacle correction.

Amblyopia in astigmatic preschool children

Best-corrected acuity was measured for vertical and horizontal gratings and for recognition acuity optotypes (Lea Symbols) in a group of three- to five-year-old children with a high prevalence of astigmatism. Results showed meridional amblyopia (MA) among children with simple/compound myopic or mixed astigmatism, due to reduced acuity for horizontal gratings. Children with simple/compound hyperopic astigmatism showed no MA, but did show reduced acuity for both grating orientations. Reduced best-corrected recognition acuity was shown by both myopic/mixed and hyperopic astigmats. These results suggest that optical correction of astigmatism should be provided prior to age three to five years, to prevent development of amblyopia.

Relaxation of postoperative astigmatism after lens implantation through a 6.25 mm scleral wound in children

Purpose: To investigate the evolution of postoperative astigmatism in children having cataract extraction with intraocular lens (IOL) implantation through a 6.25 mm superior scleral tunnel wound. Setting: A university clinical practice. Methods: A retrospective chart review of all pediatric patients having cataract extraction and IOL implantation in the practice of 1 surgeon from 1995 to 2000 was performed. Statistical comparisons were performed using the Student t test for nonpaired data. Results: Ten eyes of 9 children were included. Six cataracts were due to corneal or corneoscleral lacerations, 3 were idiopathic, and 1 occurred after blunt trauma. Eight eyes could not be refracted preoperatively because of mature cataract. The mean cylindrical correction of all refractions performed 1 to 15 days after surgery (n = 6) was 6.71 diopters (D) ± 1.63 (SD); of those performed at 16 to 30 days (n = 6), 2.71 ± 2.09 D; and of those performed at 31 to 45 days (n = 7), 1.93 ± 1.48 D. The mean spherical equivalent of the final (dispensed) refraction was -0.21 ± 1.79 D; the mean cylindrical correction of this refraction was 1.13 ± 0.79 D. The difference between the cylindrical correction of the final prescription and the corneal astigmatism in fellow eyes was not statistically significant ( P = .29). Conclusions: Relaxation of large amounts of suture-induced astigmatism occurs in children having cataract extraction. Surgeons should not hesitate to secure scleral wounds meticulously in children for fear of a permanent undesirable refractive outcome.

Promoção da saúde ocular na escola: percepções de professores sobre erros de refração

Objetivo: Identificar percepcoes de professores do sistema publico de ensino, em relacao aos erros de refracao manifestados na idade escolar, a fim de subsidiar programas de treinamento para docentes, visando a deteccao e posterior assistencia a problemas oftalmicos de escolares. Metodos: Estudo transversal em populacao de professores de primeira serie do ensino fundamental, de todas as escolas publicas da regiao sul do municipio de Sao Paulo. Aplicou-se questionario estruturado com base em estudo exploratorio. Resultados: Foi obtida uma populacao de 545 sujeitos, distribuidos em 120 escolas. A populacao apresentou media de idade de 37,8 anos e media de tempo de magisterio de 13,2 anos. A maioria (67,4%) nao recebeu orientacao sobre saude ocular nos ultimos tres anos. Os professores distinguiram mais corretamente os sinais de miopia (70,8%) do que os de hipermetropia (42,9%) e astigmatismo (40,9%). Proporcao significativa (48,5%) apontou sinais e comportamentos indicativos da presenca de miopia no escolar; 40,9% apontaram dificuldades na leitura e na escrita, para a crianca hipermetrope sem correcao optica. Na crianca astigmata as manifestacoes mais mencionadas foram vista embacada (45,4%) e desinteresse por atividades que exigem esforco visual (40,9%). Os professores classificaram todos os erros de refracao como agravos muito graves. Conclusao: Foram evidenciados conhecimentos distorcidos e/ou insuficientes entre professores do ensino fundamental, a respeito de erros de refracao manifestados na idade escolar.

Myopia in children born premature or with low birth weight.

To evaluate the association of myopia or astigmatism in children without retinopathy of prematurity (ROP) born premature or with low birth weight. This cross-sectional study was conducted in Singapore where 527 children from three kindergartens aged 2 to 7 years without a history of ROP were recruited. Information on birth weight and gestational age at birth was obtained from a personal booklet and the refractive error in spherical equivalents was measured using distance photoretinoscopy. The data was analysed with univariate analysis and logistic regression models. There was no difference in the prevalence of myopia in children born premature or with low birth weight. There was also no difference in astigmatism in children born premature or with low birth weight. This study shows no relationship between astigmatism or myopia with prematurity or low birth weight in children born without retinopathy of prematurity.

5 a longitudinal study of a population based sample of astigmatic children. 1. Refraction and amblyopia

5 a longitudinal study of a population based sample of astigmatic children. 1. Refraction and amblyopia

A longitudinal study of a population based sample of astigmatic children: II. The changeability of anisometropia

The variability of anisometropi in a sample of 310 children with astigmatism at the age of 1 year was longitudinally studied during a 3-year period between 1 and 4 years of age. The prevalence of anisometropia of 1 D or more at each year level was rather stable. When individual cases were examined we found that between the first and the last test session 19 of the 33 children with anisometropia at the first test session had become non-anisometropic and were substituted with 14 new cases which were non-anisometropic at the age of 1 year. In general, less than half of the cases, at all levels of anisometropia, remained anisometropic throughout the whole test period. We also found that children with anisometropia persisting through the whole test period were at considerable risk, about one out of four, of developing amblyopia. There was no simple relationship, however, between anisometropia at a certain age level between 1 and 4 years and amblyopia and/or strabismus. Non-persisting anisometropia in an emmetropizing eye is in most cases a benign sign and not connected with an increased risk for developing amblyopia.