The cycloplegic effects of cyclopentolate and tropicamide on myopic children

Machine Learning Models for Predicting Cycloplegic Refractive Error and Myopia Status Based on Non-Cycloplegic Data in Chinese Students

Purpose

To develop and validate machine learning (ML) models for predicting cycloplegic refractive error and myopia status using noncycloplegic refractive error and biometric data.

Methods

Cross-sectional study of children aged five to 18 years who underwent biometry and autorefraction before and after cycloplegia. Myopia was defined as cycloplegic spherical equivalent refraction (SER) ≤-0.5 Diopter (D). Models were evaluated for predicting SER using R2 and mean absolute error (MAE) and myopia status using area under the receiver operating characteristic (ROC) curve (AUC). Best-performing models were further evaluated using sensitivity/specificity and comparison of observed versus predicted myopia prevalence rate overall and in each age group. Independent data sets were used for training (n = 1938) and validation (n = 1476).

Results

In the validation dataset, ML models predicted cycloplegic SER with high R2 (0.913-0.935) and low MAE (0.393-0.480 D). The AUC for predicting myopia was high (0.984-0.987). The best-performing model for SER (XGBoost) had high sensitivity and specificity (91.1% and 97.2%). Random forest (RF), the best-performing model for myopia, had high sensitivity and specificity (92.2% and 96.9%). Within each age group, difference between predicted and actual myopia prevalence was within 4%.

Conclusions

Using noncycloplegic refractive error and ocular biometric data, ML models performed well for predicting cycloplegic SER and myopia status. When measuring cycloplegic SER is not feasible, ML may provide a useful tool for estimating cycloplegic SER and myopia prevalence rate in epidemiological studies.

Translational Relevance

Using ML to predict cycloplegic refraction based on noncycloplegic data is a powerful tool for large, population-based studies of refractive error.

Tropicamide Versus Cyclopentolate for Cycloplegic Refraction in Pediatric Patients With Brown Irides: A Randomized Clinical Trial

PURPOSE

To compare the final cycloplegic refraction of tropicamide 1% and cyclopentolate 1% in children 3-16 years of age with brown irides.

DESIGN

Randomized, controlled, multicenter prospective clinical trial.

METHODS

Included patients were randomized to either cyclopentolate 1% or tropicamide 1% in the first visit with autorefraction measurements. Each subject underwent a second cycloplegic refraction using the other agent on a separate visit with a minimum of 1-week interval and a maximum of 12 weeks. We measured the change in SE (ΔSE) for each eye by deducting the SE before cycloplegia from the SE after cycloplegia.

RESULTS

A total of 185 eyes from 94 children aged 3-16 years (average= 8.79 ±3.11 years) were included. The average SE of both eyes before cycloplegia was -0.082 ± 4.8 diopters. The SE after instillation of cyclopentolate and tropicamide in both eyes was 1.07±5.2 and 0.96±5.1, respectively (P value < .001). The average ΔSE after cycloplegia was 1.15±1.2 for cyclopentolate and 1.04±1.2 for tropicamide (P value < .001). The difference between ΔSE of cyclopentolate and tropicamide was found statistically significant at 0.11±1.2 (P < .001), although clinically insignificant. The ΔSE between the 2 drops before and after cycloplegia in both eyes for all refractive error groups was clinically insignificant. The greatest effect of cyclopentolate and tropicamide was in hyperopic eyes with ΔSE of 1.54±1.4 and 1.39±1.4, respectively.

CONCLUSIONS

Tropicamide might be an effective and safe replacement for cyclopentolate in the refracting nonstrabismic pediatric population 3-16 years of age regardless of their refractive error status.

Characteristics of ciliary muscle profile in high myopes measured by swept-source anterior segment optical coherence tomography

OBJECTIVE

To characterize and compare the ciliary muscle thickness (CMT) between low and high myopes using swept-source anterior segment optical coherence tomography (AS-OCT).

METHODS

Forty visually healthy young Chinese adults aged 18-25 years were divided into two groups based on refractive errors: low myopia (n = 20, spherical-equivalent refractive error (SER) between -0.50 D to -3.00 D) and high myopia (n = 20, SER ≤ -6.00 D). Cycloplegic refractions were performed before axial length (AL) and CMT were measured using a partial coherence laser interferometer and an AS-OCT respectively. CMT was measured perpendicularly to the sclera-ciliary muscle interface at 1 mm (CMT_1), 2 mm (CMT_2), and 3 mm (CMT_3) posterior to the scleral spur, and at the location with maximal thickness (CMT_MAX).

RESULTS

High myopes demonstrated thicker CMT at 2 mm (CMT_2, p = 0.035) and 3 mm (CMT_3, p = 0.003) posterior to the scleral spur, but thinner maximal CMT (CMT_MAX, p = 0.005) than low myopes. The apical CMT_1 and CMT_MAX were also thinner in high myopes than in low myopes (both p< 0.001). CMT_MAX, apical CMT_1, and apical CMT_MAX correlated directly with SER and inversely with AL; in contrast, CMT_2 and CMT_3 showed inverse correlations with SER but direct correlations with AL.

CONCLUSION

Our findings revealed significant differences in CMT between low and high myopes, with high myopes showing thicker CMT at 2 mm and 3 mm posterior to the scleral spur, but thinner maximal CMT. These results provide new evidence of the potential structural differences in ciliary muscles during myopia development and progression.

Comparison of the new self-contained darkroom refractive screener versus table-top autorefractor and cycloplegia retinoscopy in detecting refractive error

PURPOSE

By comparing the results of the new self-contained darkroom refractive screener (YD-SX-A) versus table-top autorefractor and cycloplegic retinoscopy, to evaluate the performance of the YD-SX-A in detecting refractive error in children and adolescents and then judge whether it can be used in refractive screening.

METHODS

Cross-sectional study. 1000 participants between the ages of 6 and 18 who visited the Optometry Center of the People's Hospital of Guangxi Zhuang Autonomous Region from June to December 2022 were selected. First, participants were instructed to measure their diopter with a table-top autorefractor (Topcon KR8800) and YD-SX-A in a noncycloplegic setting. After cycloplegia, they were retinoscopy by a professional optometrist. The results measured by three methods were collected respectively. To avoid deviation, only the right eye (1000 eyes) data were used in the statistical analysis. The Bland-Altman plots were used to evaluate the agreement of diopters measured by the three methods. The receiver operating characteristic (ROC) curves was used to analysis effectiveness of detecting refractive error of YD-SX-A.

RESULTS

The average age of participants was 10.77 ± 3.00 years, including 504 boys (50.4%) and 496 girls (49.6%). When YD-SX-A and cycloplegia retinoscopy (CR) were compared in the myopia group, there was no statistical difference in spherical equivalent (SE) (P > 0.05), but there was a statistical difference in diopter spherical (DS) and diopter cylinder (DC) (P < 0.05). Comparing the diopter results of Topcon KR8800 and CR, the difference between each test value in the myopia group was statistically significant (P < 0.05). In the hyperopia group, the comparison between YD-SX-A and CR showed no statistically significant differences in the DC (P > 0.05), but there were significant differences in the SE and DS (P < 0.05). In the astigmatism group, the SE, DS, and DC were statistically different, and the DC of YD-SX-A was lower than that of CR and Topcon KR8800. Bland-Altman plots indicated that YD-SX-A has a moderate agreement with CR and Topcon KR8800. The sensitivity and specificity of YD-SX-A for detecting myopia, hyperopia and astigmatism were 90.17% and 90.32%, 97.78% and 87.88%, 84.08% and 74.26%, respectively.

CONCLUSION

This study has identified that YD-SX-A has shown good performance in both agreement and effectiveness in detecting refractive error when compared with Topcon KR8800 and CR. YD-SX-A could be a useful tool for large-scale population refractive screening.

Combination of orthokeratology lens with 0.01% atropine in slowing axial elongation in children with myopia: a randomized double-blinded clinical trial

BACKGROUND

To evaluate the additive effects of orthokeratology (OK) lenses and 0.01% atropine on slowing axial elongation in myopic children.

METHODS

A prospective, randomized, double-blinded, placebo-controlled trial was conducted over a 12-month period. Sixty children aged 8 to 12 years with spherical equivalent refraction from - 1.00 to -4.00 D who had been wearing OK lenses successfully for 2 months (as baseline) were randomly assigned in a 1:1 ratio to combination group (combination of OK lens and 0.01% atropine eye drops) and control group (combination of OK lens and placebo). The primary outcome was change in axial length, along with secondary outcomes including change in pupil diameter (PD) and accommodative amplitude (AMP) at 12 months (measured at 4-month intervals).

RESULTS

After 12 months, the overall axial elongation was 0.10 ± 0.14 mm and 0.20 ± 0.15 mm (p = 0.01) in the combination and control groups, respectively. The change in axial length in the two groups showed significant differences only in the first four months (median [Q1, Q3] (95% CI), -0.01 mm [-0.07, 0.05] (-0.06, 0.04) vs. 0.04 mm [0.00, 0.10] (0.02, 0.09); p = 0.04), but no difference thereafter. Multivariate linear regression analysis showed that the axial elongation was significantly slower in the combination group than in the control group (standard β = -0.10, p = 0.02). PD significantly increased by 0.45 mm [0.20, 0.68] at the 4th month visit (p < 0.001) and then remained stable in the combination group. The PD in the control group and AMP in the two groups remained stable from baseline to 12 months (all p > 0.05).

CONCLUSION

The combination therapy was more effective than the OK lens alone in slowing axial elongation after 12 months of treatment, and mainly in the first 4 months.

TRIAL REGISTRATION

The First Affiliated Hospital of Zhengzhou University, ChiCTR2000033904. Registered 16/06/2020, http://www.chictr.org.cn/login.aspx?referurl=%2flistbycreater.aspx.

Time for effective cycloplegia in patients with brown iris

We aimed to evaluate the time needed for effective cycloplegia after instillation of cyclopentolate 1% in patients with brown irides. A prospective analytical study involving 161 patients (322 eyes) with a mean (SD) age of 9.0 (3.1) years (range: 3-16 years), who attended outpatient eye clinic. All had brown irides, cyclopentolate 1% was instilled two times, 10 minutes apart, spherical equivalent (SE) was calculated using readings taken by Nidek AR-1000 autorefractometer before the first drop and at 15, 30, 45 and 60 minutes after the first drop. The time for effective cycloplegia was determined from the time point at which the 95% confidence interval of the differences between the average spherical equivalent (SE) at each point and its final value at 60 minutes was reached and remained within ±0.25 D. We found that maximum cycloplegia was reached 30 minutes after the instillation of first drop of cyclopentolate 1% in all refractive error categories (emmetropia, hyperopia and myopia) with the exception of high hyperopia subgroup (SE ≥ +6.0D) where at least 45 minutes were needed to achieve cycloplegia. Additionally no clinically significant difference in the minimum time required to achieve maximum cycloplegia was noticed in subjects under 10 years old and those aged 10 years or older with both groups needed at least 30 minutes to achieve maximum cycloplegia after the instillation of first drop of cyclopentolate 1%. In this group of patients with brown irides, most children reached maximum cycloplegia after 30 minutes of instillation of cyclopentolate 1% eye drops.

Prediction for Cycloplegic Refractive Error in Chinese School Students: Model Development and Validation

Purpose

To predict cycloplegic refractive error using measurements obtained under noncycloplegic conditions.

Method

Refractive error was measured in 5- to 18-year-old Chinese students using a NIDEK autorefractor before and after administration of 0.5% tropicamide. Spherical equivalent (SER) in diopters (D) was calculated as sphere plus half cylinder. A multivariable prediction model for cycloplegic SER was developed using data from students in Jinyun (n = 1938) and was validated using data from students in Hangzhou (n = 1498). The performance of the prediction model was evaluated using R², mean difference between predicted and measured cycloplegic SER, and sensitivity and specificity for predicting myopia (cycloplegic SER ≤ −0.5 D).

Results

Among 3436 students (mean age, 9.7 years; 51% female), the mean (SD) noncycloplegic and cycloplegic SER values were −1.12 (1.97) D and −0.20 (2.19) D, respectively. The prediction model that included demographics, noncycloplegic SER, axial length/corneal curvature radius ratio, uncorrected visual acuity (UCVA), and intraocular pressure predicted cycloplegic SER with R² of 0.93 in the development dataset and 0.92 in the validation dataset. The mean (SD) differences between predicted and measured cycloplegic SER were 0.0 (0.55) D in the development dataset and 0.06 (0.64) D in the validation dataset. In both the development and validation datasets, the combination of predicted SER and UCVA yielded high sensitivity (91.4% and 91.9%, respectively) and specificity (95.0% and 90.1%, respectively) for detecting myopia.

Conclusions

Cycloplegic refractive error can be predicted using measurements obtained under noncycloplegic conditions. The prediction model could potentially be used to correct the myopia prevalence in epidemiological studies in which administering cycloplegic agent on all participants is not feasible.

Translational Relevance

The prediction model may provide a tool for correcting the overestimation of myopia from noncycloplegic refractive error in future epidemiological studies in which administering cycloplegic agent on all participants is not feasible.

Orthokeratology Lenses Versus Administration of 0.01% Atropine Eye Drops for Axial Length Elongation in Children With Myopic Anisometropia

OBJECTIVE

To investigate the effect of orthokeratology (OK) lenses and that of 0.01% atropine eye drops on axial length (AL) elongation in children with myopic anisometropia.

METHODS

Ninety-five children with myopic anisometropia who used OK lenses (N=49) or 0.01% atropine eye drops (N=46) were enrolled in this retrospective 1-year study. For all children, the eyes with higher spherical equivalent refractive error (SER) were assigned to the H-eye subgroup, whereas the fellow eyes with lower SER were assigned to the L-eye subgroup.

RESULTS

After 1-year treatment, the mean change in the AL of H eyes and L eyes in the OK lenses group was 0.18±0.16 mm and 0.24±0.15 mm, respectively (P=0.15), and 0.28±0.20 mm and 0.25±0.18 mm, respectively (P=0.48), in the 0.01% atropine group. Multivariate regression analyses showed significant differences in AL change between H and L eyes after treatment with OK lens (P=0.03), whereas no significant difference in the 0.01% atropine (P=0.22). The change in the AL in the H-eye group was less with OK lenses than with 0.01% atropine (P=0.04), whereas there was no significant difference between the change in AL in the L-eye group between treatment with OK lens and 0.01% atropine (P=0.89).

CONCLUSIONS

In myopic anisometropic children, AL differences between 2 eyes decrease by wearing OK lenses but do not change after administration of 0.01% atropine eye drops. The increased effect of OK lenses, but not 0.01% atropine, in reducing axial elongation at 1 year in the eye with higher SER in anisometropic children warrants further investigation.

Safety and efficacy of 0.02% and 0.01% atropine on controlling myopia progression: a 2-year clinical trial

Four hundred myopic children randomly received atropine 0.02% (n = 138) or 0.01% (n = 142) in both eyes once-nightly or only wore single-vision spectacles (control group) (n = 120) for 2 years. Spherical equivalent refractive error (SER), axial length (AL), pupil diameter (PD), and amplitude of accommodation (AMP) were measured every 4 months. After 2 years, the SER changes were - 0.80 (0.52) D, - 0.93 (0.59) D and - 1.33 (0.72) D and the AL changes were 0.62 (0.29) mm, 0.72 (0.31) mm and 0.88 (0.35) mm in the 0.02% and 0.01% atropine groups and control group, respectively. There were significant differences between changes in SER and AL in the three groups (all P < 0.001). The changes in SER and AL in the 2nd year were similar to the changes in the 1st year in the three groups (all P > 0.05). From baseline to 2 years, the overall decrease in AMP and increase in PD were not significantly different in the two atropine groups, whereas the AMP and PD in the control group remained stable (all P > 0.05). 0.02% atropine had a better effect on myopia control than 0.01% atropine, and its effects on PD and AMP were similar to 0.01% atropine. 0.02% or 0.01% atropine controlled myopia progression and AL elongation synchronously and had similar effects on myopia control each year.

Effect of Cycloplegia on Refractive Error Measure in Chinese School Students

PURPOSE

To determine differences in cycloplegic vs. non-cycloplegic refractive error and factors associated with these differences in Chinese school students.

METHOD

In this cross-sectional school-based study, refractive error was measured in school students using a NIDEK autorefractor before and after administration of 0.5% tropicamide. Spherical equivalent (SER) in diopters (D) was calculated as sphere plus half cylinder. SER differences before vs. after cycloplegia were evaluated using mean, standard deviation (SD), 95% limits of agreement. Univariable and multivariable regression models were used to determine factors associated with SER differences.

RESULTS

Among 3604 students, 3450 (95.7%) provided data for analysis. Mean age (SD) was 9.7 (3.6) years. The mean SER (SD) was -1.12 (1.97) D before cycloplegia, and -0.20 (2.19) D after cycloplegia, with a mean difference of 0.92 D (95% limits of agreement: -0.93 to 2.78 D). Among 196 eyes with non-cycloplegic SER -6.0 D or worse (e.g., met high myopia definition), 71.4% had cycloplegic SER -6.0 D or worse, and among 3607 eyes with non-cycloplegic SER -0.5 D or worse (e.g., met myopia definition), 62.1% eyes had cycloplegic SER -0.5 D or worse. Cycloplegic SER was more correlated with axial length than non-cycloplegic SER (Pearson r = 0.82 vs. 0.72, p < .0001). In multivariable analysis, larger SER differences were associated with more hyperopic refractive error and smaller axial length (all p < .0001).

CONCLUSION

Non-cycloplegic refractive error overestimates myopia by approximately one diopter. This overestimation increases with more hyperopic refractive error and smaller axial length. Non-cycloplegic refractive error should not be used for evaluating pediatric myopia.

ABBREVIATIONS

BCVA = best corrected visual acuity; D = diopter; SD = standard deviation; SE = standard error; SER = spherical equivalent; CI = confidence interval.

Risk factors for rapid axial length elongation with low concentration atropine for myopia control

Three hundred and twenty-eight myopic children, randomized to use either 0.01% (N = 166) or 0.02% (N = 162) atropine were enrolled in this study. Gender, age, body mass index(BMI), parental myopia status, atropine concentration used, pupil diameter, amplitude of accommodation, spherical equivalent refractive error (SER), anterior chamber depth (ACD) and axial length (AL) were collected at baseline and 1 year after using atropine. Rapid AL elongation was defined as > 0.36 mm growth per year. Univariate analyses showed that children with rapid AL elongation tend to be younger, have a smaller BMI, use of 0.01% atropine, narrow ACD, lower SER, shorter AL, smaller change in pupil diameter between 1 year and baseline (all P < 0.05). Multivariate logistic regression analyses confirmed that rapid AL elongation was associated with children that were younger at baseline (P < 0.0001), use of 0.01% atropine (P = 0.04), a shorter baseline AL (P = 0.03) and a smaller change in pupil diameter between 1 year and baseline (P = 0.04). Younger children with shorter AL at baseline, less change in their pupil diameter with atropine treatment and using the lower of the two atropine concentrations may undergo rapid AL elongation over a 12 months myopia control treatment period.

Evolution of the Prevalence of Myopia among Taiwanese Schoolchildren: A Review of Survey Data from 1983 through 2017

PURPOSE

The aim of this study was to evaluate the changes in the prevalence of myopia in Taiwanese schoolchildren over the past few decades and to analyze the risk factors for myopia.

DESIGN

Analysis of 8 consecutive population-based myopia surveys conducted from 1983 through 2017.

PARTICIPANTS

An average of 8917 (5019-11 656) schoolchildren 3 to 18 years of age were selected using stratified systematic cluster sampling or by probability proportional to size sampling.

METHODS

All participants underwent complete ophthalmic evaluations. Three drops of 0.5% tropicamide were used to obtain the cycloplegic refractive status of each participant. Questionnaires were used to acquire participant data from the 1995, 2005, 2010, and 2016 surveys.

MAIN OUTCOME MEASURES

Prevalence of myopia (spherical equivalence of ≤-0.25 diopter [D]) and high myopia (≤-6.0 D) was assessed. Multivariate analyses of risk factors were conducted.

RESULTS

The prevalence of myopia among all age groups increased steadily. From 1983 through 2017, the weighted prevalence increased from 5.37% (95% confidence interval [CI], 3.50%-7.23%) to 25.41% (95% CI, 21.27%-29.55%) for 7-year-olds (P = 0.001 for trend) and from 30.66% (95% CI, 26.89%-34.43%) to 76.67% (95% CI, 72.94%-80.40%) for 12-year-olds (P = 0.001 for trend). The prevalence of high myopia also increased from 1.39% (95% CI, 0.43%-2.35%) to 4.26% (95% CI, 3.35%-5.17%) for 12-year-olds (P = 0.008 for trend) and from 4.37% (95% CI, 2.91%-5.82%) to 15.36% (95% CI, 13.78%-16.94%) for 15-year-olds (P = 0.039 for trend). In both the 2005 and 2016 survey samples, children who spent less than 180 minutes daily on near-work activities showed significantly lower risks for myopia developing (<60 minutes: odds ratio [OR], 0.48 and 0.56; 60-180 minutes: OR, 0.69 and 0.67). In the 2016 survey, spending more than 60 minutes daily on electronic devices was associated significantly with both myopia and high myopia (OR, 2.43 and 2.31).

CONCLUSIONS

The prevalence of myopia among schoolchildren increased rapidly from 1983 through 2017 in Taiwan. The major risk factors are older age and time spent on near-work activities. Use of electronic devices increased the amount of time spent on near-work and may increase the risk of developing myopia.

Effect of cyclopentolate versus tropicamide on anterior segment angle parameters in three refractive groups

CLINICAL RELEVANCE

Frequent clinical application of cycloplegia in clinical practice makes it essential to assess how this condition influences anterior segment angle parameters.

BACKGROUND

This study aims to compare the effects of cyclopentolate and tropicamide on anterior segment angle parameters in three adult refractive groups.

METHODS

Sixty healthy individuals were recruited and assigned into three refractive groups according to inclusion criteria. At baseline visit, anterior segment angle parameters were measured using anterior segment optical coherence tomography in the right eye. All measurements were repeated at two separate visits, one week apart, after administration of tropicamide 1% and cyclopentolate 1% at similar conditions. Main outcome measures were angle-opening distance, trabecular iris angle, trabecular iris space area and anterior chamber depth. Anterior segment angle parameters were recorded at temporal areas (180 degrees).

RESULTS

Sixty participants (29 men and 31 women, age: 27.82 ± 4.71-years) completed the experiment. Baseline mean spherical equivalents were +1.52 ± 1.20 D, -0.04 ± 0.33 D and -1.91 ± 0.91-D in hyperopic, emmetropic and myopic groups, respectively. No statistically significant differences were found between tropicamide and cyclopentolate for all angle parameters in three refractive groups. Both drops induced an increase in all parameters in three refractive groups. Analysis between refractive groups revealed that a more hyperopic refraction was associated with less trabecular iris angle, angle-opening distance and anterior chamber depth parameters in baseline, after tropicamide and cyclopentolate instillations.

CONCLUSIONS

Topical application of cycloplegic eye drops in healthy individuals leads to small but significant changes in anterior chamber depth and anterior segment angle parameters, regardless of refractive status. Moreover, lower values of anterior chamber depth and anterior segment angle parameters in hyperopic individuals after administration of cycloplegic drops should be taken into account during biometric measurement and phakic intraocular lens implantation. Due to shorter effect and recovery time and less ocular/systemic reaction of tropicamide versus cyclopentolate, tropicamide could be a recommended cycloplegic agent for diagnostic and therapeutic procedures.

Anterior Segment Biometry During Accommodation and Effects of Cycloplegics by Swept-Source Optical Coherence Tomography

Purpose

We analyzed changes in the crystalline lens during accommodation and the effects of cycloplegics by swept-source anterior-segment optical coherence tomography (AS-OCT).

Materials and Methods

Twenty healthy volunteers (7 males and 13 females, aged 22–34 years), with no history of eye disease except for refractive errors, were recruited. Biometric parameters, including anterior chamber depth (ACD), lens thickness (LT), and anterior and posterior curvature of the lens (ACL and PCL), were measured using AS-OCT (CASIA2). The measurements were performed with or without an accommodative demand of 5.0 diopters (D). The same tests were repeated following the topical administration of 1% cyclopentolate or a compounding agent comprising 0.5% tropicamide and 0.5% phenylephrine.

Results

The AS-OCT system was capable of simultaneous visualization of all optical components of the anterior segment in a single frame. ACD, LAC, and LPC decreased and LT increased significantly during 5.0 D accommodative stimulation in both eyes. Both cyclopentolate and tropicamide/phenylephrine eyedrops led to deeper ACD, thinner LT, and flatter LAC. There were no significant differences in all lens parameters despite having 5.0 D accommodative stimulation in both eyes with cycloplegia.

Conclusion

Our results suggest that both tropicamide/phenylephrine and cyclopentolate eyedrops have enough cycloplegic effects in young adults.

Factors Affecting Pupil Reactivity After Cycloplegia in Asian Children

PURPOSE

The aim of this study was to evaluate the factors affecting cycloplegia, as determined by pupil reactivity, in Asian children.

DESIGN

Prospective observational study.

METHODS

Two-hundred sixty-eight children, aged 2 to 12 years, requiring cycloplegic refraction, were recruited. Nurses instilled 2 to 3 cycles of eye drops consisting of cyclopentolate 1%, tropicamide 0.5%, and phenylephrine 2.5%, and recorded the child's level of cooperation. Optometrists recorded pupil reactivity after the last cycle. Multivariate analysis determined factors affecting pupil reactivity including age, sex, race, number of eye drop cycles, pupil sizes before and after cycloplegia, and child's cooperation during eye drops instillation.

RESULTS

The pupils in 36 children (13.4%) were found to be still reactive. On univariate analysis, children with reactive pupils also had smaller pupils after cycloplegia (6.27 ± 1.16 mm vs 7.42 ± 0.81 mm, P < 0.001). On multiple logistic regression analysis, for every 1-mm increase in the pupil size after cycloplegic eye drop administration, the odds of having reactive pupils decreases by 65% (odds ratio = 0.35, 95% confidence interval 0.25-0.51, P ≤ 0.001). Those who were uncooperative during administration of eye drops were 3.13 times more likely to have reactive pupils (95% confidence interval 1.21-8.13, P = 0.019), whereas age (P = 0.904), sex (P = 0.355), the number of cycles of eye drops (P = 0.462), and other psychological factors were not relevant in affecting pupil reactivity.

CONCLUSIONS

Pupil reactivity, which was used as a measure of cycloplegia, was more likely to be affected by children's level of cooperation during instillation of eye drops, rather than age and sex. Two cycles of eye drops were as effective as 3 cycles in producing cycloplegia.

Comparison of cyclopentolate versus tropicamide cycloplegia: A systematic review and meta-analysis

PURPOSE

The aim of the present meta-analysis is to compare the efficacy of cyclopentolate and tropicamide in controlling accommodation during refraction.

METHODS

A comprehensive literature search was performed in PubMed, Scopus, Science direct and Ovid databases by the key words: "tropicamide"; "cyclopentolate"; "cycloplegia" and "cycloplegic" from inception to April 2016. Methodological quality of the literature was evaluated according to the Oxford Center for Evidence Based Medicine and modified Newcastle-Ottawa scale. Statistical analyses were performed using Comprehensive Meta-Analysis (version 2; Biostat Inc., USA).

RESULTS

The present meta-analysis included six studies (three randomized controlled trials and three case-control studies). Pooled standardized difference in the mean changes in the refractive error was 0.175 D [lower and upper limits: -0.089; 0.438] more plus in the cyclopentolate group compared to the tropicamide group; however, this difference was not statistically significant (p=0.194; Cochrane Q value=171.72 (p<0.05); I²=95.34%). Egger's regression intercept was -5.33 (p=0.170). Considering type of refractive errors; refractive assessment procedure and age group; although cycloplegic effect of cyclopentolate was stronger than tropicamide; however, this effect was only statistically significant in children; hyperopic patients and with retinoscopy.

CONCLUSION

We suggest that tropicamide may be considered as a viable substitute for cyclopentolate due to its rapid onset of action. Although these results should be used cautiously in infants and in patients with high hyperopia or strabismus when using tropicamide as the sole cycloplegic agent especially in situations that the findings are variable or there is no consistency between the examination results and clinical manifestations of the visual problems.

Physical activity and myopia in Danish children-The CHAMPS Eye Study

PURPOSE

To determine associations between physical activity (PA) and myopia in Danish school children and investigate the prevalence of myopia.

METHODS

This is a prospective study with longitudinal data on PA in a Danish child cohort. Physical activity (PA) was measured objectively by repeated ActiGraph accelerometer measurement four times with different intervals (1-2.5 years) at the mean ages 9.7, 11.0, 12.9 and 15.4 years. Mean intensity of PA was estimated as counts/minutes, and time spent in sedentary, light, moderate and vigorous PA was summed using defined cut-off points. The ophthalmologic examination was conducted at the mean age of 15.4 ± 0.7 years and included cycloplegic autorefraction and biometry.

RESULTS

A total of 307 children participated in the Childhood Health, Activity, and Motor Performance School (CHAMPS) Eye Study. The cycloplegic spherical equivalent (SE) was 0.30 ± 1.46 dioptres. The prevalence of myopia was 17.9% (SE ≤-0.5 dioptres). Mean axial length (AL) was 23.5 ± 0.9 mm. For all participants, the overall mean daily distribution of PA was 67.2% in sedentary, 25.6% in light, 4.4% in moderate and 2.9% in vigorous PA. Age- and sex-adjusted linear regression showed no association between PA and SE or AL. In a prospective slope analysis, there was no association between accumulated PA during the 7 years and AL or SE.

CONCLUSION

The prevalence of myopia among Danish children was 17.9%. By logistic regression and slope analysis, we found no association between PA and myopia, in this first of its kind study based on objective and repeated PA data.

Evaluating internal and ocular residual astigmatism in Chinese myopic children

PURPOSE

To investigate the nature of internal astigmatism (IA) and ocular residual astigmatism (ORA) in Chinese myopic children and to identify factors that may influence IA and ORA.

METHODS

A total of 206 eyes of 206 myopic children (97 boys and 109 girls; 10.95 ± 2.2 years) were enrolled in this cross sectional study. Total ocular astigmatism (TOA), anterior corneal astigmatism (ACA), posterior corneal astigmatism (PCA) and total corneal astigmatism (TCA) were measured directly using either a Hartmann-Shack wavefront sensor or a Pentacam. IA and ORA were calculated by Fourier vector analyses (the definitions of IA and ORA are: IA = TOA - ACA - PCA, ORA = TOA - ACA). Spearman or Pearson correlation was adopted to detect multiple factors that may influence IA and ORA, which were then predicted by linear regressions. Modified compensation factors were applied to evaluate the inter-relationship between corneal astigmatism and ORA.

RESULTS

While the mean values of IA and ORA were -0.52 DC × 94.8° and -0.63 DC × 93.0°, respectively, the percentage of ORA power over 1.00 D was as high as 28.64%. Full or under-compensation of ACA by ORA predominated in the enrolled subjects. The mean ORA J₀ and J₄₅ were -0.311 ± 0.236 and -0.032 ± 0.156 D, respectively, negatively correlated with the corresponding ACA components (J₀: r = -0.276, J₄₅: r = -0.616, p < 0.001). While age was not correlated with either IA or ORA (p > 0.1), the power of IA or ORA was correlated inversely with the axial length (IA: r = -0.193, p = 0.005; ORA: r = -0.169, p = 0.015) and positively with the spherical equivalent refraction (IA r = 0.195, p = 0.005; ORA r = 0.213, p = 0.002) and power of corneal astigmatism (IA-ACA: r = 0.302, IA-TCA: r = 0.368, ORA-ACA: r = 0.334, ORA-TCA: r = 0.293). Girls had larger IA powers than boys (0.741 ± 0.345 D vs 0.651 ± 0.340, p = 0.036).

CONCLUSIONS

Full or under-compensation of ACA by ORA is common in Chinese myopic children, and the compensation efficiency may decrease with age. Among Chinese children with myopia, a larger ORA is more prevalent with less myopia and greater corneal astigmatism.

Cycloplegic Refraction in Hyperopic Children: Effectiveness of a 0.5% Tropicamide and 0.5% Phenylephrine Addition to 1% Cyclopentolate Regimen

Purpose

To evaluate the effectiveness of a cycloplegic regimen using 0.5% tropicamide and 0.5% phenylephrine (Tropherine, Hanmi Pharm), in addition to 1% cyclopentolate, in hyperopic children.

Methods

The medical records of hyperopic patients below the age of 14 years who had undergone cycloplegic retinoscopy were retrospectively reviewed. Cycloplegic refractions were performed using one of two cycloplegic regimens. Regimen 1 was a Tropherine-added regimen comprising the administration of one drop of 1% cyclopentolate followed by two to three drops of Tropherine added at 15-minute intervals. Regimen 2 was a cyclopentolate-only regimen comprising the administration of three to four drops of 1% cyclopentolate at 15-minute intervals. The mean difference between noncycloplegic and cycloplegic refraction was compared between the two regimens.

Results

A total of 308 eyes of 308 hyperopic children were included. The mean difference (±standard deviation) in the spherical equivalent (SE) between cycloplegic and noncycloplegic refraction was significantly larger in regimen 2 than in regimen 1, with values of +1.70 ± 1.03 diopters (D) and +1.25 ± 0.89 D, respectively (p=0.001). The SE change after cycloplegia was significantly different between the two regimens only in patients aged 5 years or younger (p=0.001), particularly in those with high hyperopia with an SE ≥5 D (p=0.005) or fully accommodative esotropia (p=0.009). There was no significant difference between the two regimens in patients older than 5 years, regardless of the presence of high hyperopia or fully accommodative esotropia.

Conclusions

The Tropherine-added regimen exerted a weaker cycloplegic effect than the cyclopentolate-only regimen, particularly in children under the age of 5 years with high hyperopia or fully accommodative esotropia. However, the difference in refraction between the two regimens was small. A Tropherine-added regimen can be effective in hyperopic children, with less associated discomfort than the instillation of cyclopentolate.

Risk factors for myopia progression in second-grade primary school children in Taipei: a population-based cohort study

PURPOSE

To evaluate the 1-year progression of myopia and associated risk factors in second-grade primary school children.

METHODS

The myopia investigation study in Taipei provided semiannual visual acuity testing and cycloplegic refraction for all second-grade primary school children (mean age: 7.49 years) in Taipei who provided parental consent. A questionnaire was distributed to the participants' parents before the first and third examinations. We evaluated 1-year follow-up data for children noted to have myopia on the first examination. Multinomial logistic regression models were applied to assess risk factors associated with myopia progression. Myopia progression was categorised, based on the change in spherical equivalent (ΔSE) over 1 year, as slow (ΔSE>-0.5 dioptres (D)), moderate (-1.0 D<ΔSE≤-0.5 D) or fast (ΔSE≤-1.0 D). Of the 4214 myopic children, data were analysed for 3256 (77.3%) who completed the 1-year follow-up evaluation.

RESULTS

The baseline SE was -1.43±1.1 D. The average ΔSE was -0.42±0.85 D, with 46.96%, 28.50% and 24.54% of the study subjects showing slow, moderate and fast myopia progression, respectively. When compared with slow myopia progression, fast myopia progression was associated with a greater myopic SE at baseline (OR: 0.67, 95% CI: 0.61 to 0.72) and a shorter eye-object distance when doing near work (OR: 1.45, 95% CI: 1.18 to 1.78). More outdoor activity time and self-reported cycloplegic treatment were not associated with slow myopia progression.

CONCLUSIONS

Children with fast annual myopia progression were more myopic at baseline and had a shorter reading distance. Our study results highlight the importance of having children keep a proper reading distance.

Time of maximum cycloplegia after instillation of cyclopentolate 1% in children with brown irises

PURPOSE

We aimed to 1) determine the time of maximum cycloplegia after instillation of cyclopentolate 1% in children with brown irises, 2) evaluate the correlation between the pupillary reaction and time of maximum cycloplegia, and 3) identify any side effects of the medication.

PATIENTS AND METHODS

This was a prospective analytical study involving children aged 5 to 14 years who were attending refraction clinic. Cyclopentolate 1% was instilled three times at 10-minute intervals. The spherical equivalent, pupillary reaction, and pupillary diameter were recorded before the first drop and nine times after the last drop at 10-minute intervals. Side effects were assessed. Time of maximum cycloplegia was determined from the time point at which the 95% confidence interval of the differences between the mean spherical equivalent at each point and its final value at 110 minutes was reached and remained within the equivalence limit (±0.25 D).

RESULTS

Sixty children were enrolled in this study. Their mean age was 9.8 years (range: 5-4 years). Time of maximum cycloplegia was reached at 30 minutes after the first instillation of cyclopentolate. A poor correlation was observed between the pupillary reaction and the time of maximum cycloplegia (r=-0.07). The mean pupillary diameter at 30 minutes was 3.7±1.3 mm, and further dilation occurred thereafter. No side effects were observed.

CONCLUSION

In most children, maximum cycloplegia was reached 30 minutes after the first instillation of cyclopentolate. The absence of a pupillary reaction should not be used as an indicator of maximum cycloplegia.

The psychological impact of eyedrops administration in children

PURPOSE

To determine the psychological effects of eyedrops administration in children.

METHODS

Children requiring eyedrops for cycloplegic refraction were recruited in this cross-sectional study. Nurses administered eyedrops in 2-3 cycles spaced 5-10 minutes apart, and optometrists performed refraction 30 minutes after the last drop. Ophthalmologists, nurses, and optometrists rated the children's cooperation level at first review, after each eyedrop, at refraction, and at final review. Parents chose a personality type best describing their child, and monitored their child's anxiety using a modified Yale Preoperative Anxiety Scale (m-YPAS). Children were "uncooperative" if nurses noted significant distress during the first drop cycle.

RESULTS

A total of 298 children 2-12 years of age were included. Of these, 77 (26%) experienced pre-drop distress and 39 (13%) were uncooperative with drops. Compared to cooperative children, uncooperative children tended to be younger (2.0-4.9 years vs ≥8 years; OR, 4.11; 95% CI, 1.14-14.83; P = 0.031), male (OR, 2.55; 95% CI, 1.06-6.10; P = 0.036), have had a previous negative eyedrop experience (84.2% vs 25.3%; P < 0.001) and were more anxious (m-YPAS scores, 41.4 ± 22.0 vs 30.6 ± 12.6: P < 0.001). Children described as "demanding and aggressive" were more uncooperative than "timid and anxious" children. It took longer to instill drops (3.1 vs 1.3 minutes), and perform refraction (11.6 vs 7.2 minutes) in uncooperative children.

CONCLUSIONS

A small group of children were uncooperative with eyedrops and 26% experienced significant pre-drop anxiety. Factors such as age, sex, a previous negative eyedrop experience, and pre-drop anxiety, associated with uncooperativeness need to be considered when developing strategies to improve the eyedrops experience in children.

Study design, rationale and methods for a population-based study of myopia in schoolchildren: the Myopia Investigation study in Taipei

BACKGROUND

To describe the study design, rationale and methodology of the Myopia Investigation Study in Taipei (MIT).

DESIGN

The MIT was a city-wide, population-based cohort study.

PARTICIPANTS

Participants were grade 2 students (Fall 2013) of all 153 elementary schools in Taipei City.

METHODS

The baseline data on the risk factors for myopia development was collected by parent-administered questionnaire surveys covering demographics, medical history, parental myopia, time spent on near work and outdoor activities, reading habits and eye care-seeking behaviour. Ocular examinations focused on the measurement of visual acuity (unaided and best-corrected) and refractive status (before and after cycloplegia), which will be carried out for the eligible schoolchildren biannually for 3 years consecutively. Once myopic children are identified, case manager-led telecoaching for health-care instructions and reminders will be delivered to parents or caregivers.

MAIN OUTCOME MEASURES

To build a comprehensive database for prevalence, incidence and risk factors of early childhood myopia over a 3-year follow-up period.

RESULTS

Of all 19 374 eight-year-old schoolchildren (10 210 [52.7%] boys) eligible for the MIT, 16 486 (85.1%) responded to the questionnaire, 12 019 (62.0%) were examined during the third quarter of 2013 and 11 590 (59.8%) (6267 [52.9%] boys) completed cycloplegic autorefraction on both eyes and were enrolled for further data analysis. There was no significant difference in terms of demographics between the analysed participants and all grade 2 students in Taipei City.

CONCLUSIONS

Data from the MIT will provide population-based information concerning the prevalence, incidence and risk factors for myopia development among young schoolchildren in a metropolitan area of Taiwan.

A prospective comparison between cyclopentolate spray and drops in pediatric outpatients

PURPOSE

To determine whether children tolerate cyclopentolate 1% spray better than drops and to assess the adequacy of cycloplegia achieved by spray for objective refraction.

METHODS

The effects of cyclopentolate 1% drops and spray on distress levels were assessed prospectively using a guardian questionnaire in consecutive patients 10 years of age or younger. Distress was graded at various points during the appointment using a Likert scale of 1 to 10 (1 = no distress, 10 = severe distress). The adequacy of cycloplegia in children receiving cyclopentolate spray and the waiting times were assessed via a Likert questionnaire completed by the examining physician.

RESULTS

The guardians of 72 and 77 children who received cyclopentolate 1% drops or spray, respectively, completed the questionnaire. The children were divided in three age groups: 1 to 4 years, 5 to 7 years, and 8 to 10 years. Children 7 years or younger were significantly less distressed by administration of cyclopentolate 1% spray (P < .005). There was no statistical difference in distress levels in children older than 7 years (P = .9719). Thirteen of the 77 children who received cyclopentolate 1% spray did not have adequate cycloplegia to allow objective refraction.

CONCLUSION

The results demonstrate cyclopentolate 1% spray is less distressing at the time of administration than cyclopentolate 1% drops for children 7 years or younger. However, the cycloplegia achieved is not adequate in a high percentage of children.

Prevalence of myopia-related retinal changes among 12-18 year old Hong Kong Chinese high myopes

PURPOSE

To determine the prevalence and risk factors of myopia-related retinal changes in Hong Kong Chinese adolescents with high myopia.

METHODS

A cross-sectional study on Hong Kong Chinese teenage subjects with high myopia was conducted between January 2005 and June 2009. Subjects were recruited via newspaper advertisements, invitation letters to schools, leaflets and posters. Data collected included history related to myopia progression and retinal characteristics.

RESULTS

In total, 120 subjects (61 boys and 59 girls) were recruited. The mean age was 14.8 ± 1.6 years (range: 12-18 years). The mean SER of the eyes was -8.41 ± 1.60 D. Ninety four of the 120 adolescents were found to have a retinal change of which 0.8% were sight-threatening, 2.5% were posterior pole changes, and 61.7% were peripheral retinal changes. The five most frequent retinal changes found were optic nerve crescents (52.5%), white-without-pressure (51.7%), lattice degeneration (5.8%), microcystoid degeneration (5%) and pigmentary degeneration (4.2%). After adjusting for myopia over -8 D, age, gender, duration of myopia, family retinal history and intraocular pressure (IOP), binary logistic regressions showed that an axial length longer than 26.5 mm was a significant risk factor for peripheral retinal changes, optic nerve crescents and white-without-pressure.

CONCLUSIONS

Peripheral retinal degenerative changes and optic nerve crescent were found in a significant proportion of high myopic teenage subjects. There is increased risk of retinal changes in eyes with an axial length >26.5 mm in 12-18 year-olds.

Uncorrected visual acuity and noncycloplegic autorefraction predict significant refractive errors in Taiwanese preschool children

PURPOSE

To investigate the accuracy of uncorrected visual acuity (UCVA), stereopsis, and noncycloplegic autorefraction (NCAR) tests performed by vision-screening technicians and to determine the best referral criteria when using these methods to screen for significant refractive errors in preschool children.

DESIGN

Retrospective, case-control, and cross-sectional study.

PARTICIPANTS

We reviewed 1000 records for a population-based preschool vision-screening program. The target conditions were defined as myopia ≤-3.0 diopters (D), hyperopia ≥ 4.5 D, astigmatism ≥ 2.0 D, and anisometropia ≥ 2.0 D.

METHODS

Receiver operating characteristic (ROC) curve was used to calculate optimal referral cutoff values. The examination results obtained by the vision-screening technicians were compared with those obtained by a pediatric ophthalmologist, which were considered the gold standard.

MAIN OUTCOME MEASURES

The efficacies (sensitivity, specificity, positive predictive value, and negative predictive value) of different tests were evaluated.

RESULTS

In 7.0% (95% confidence interval [CI], 5.3-8.7) of the children, at least 1 eye showed 1 of the target conditions. If only the right eyes were considered, the prevalence of target conditions was 4.2% (95% CI, 2.9-5.5). The ROC curve analysis indicated that the NCAR cylinder test (cutoff value ≥ 0.875 D) was the best test for screening target conditions. With regard to age groups, UCVA ≤ 0.75 (Snellen equivalent) and ≤ 0.85 were the best referral criteria for ages ≤ 4 years and ≥ 5 years, respectively. Combining the UCVA test with the NCAR test (the child was referred after failing both tests) increased specificity without significantly decreasing sensitivity.

CONCLUSIONS

The UCVA and NCAR tests performed by vision-screening technicians are adequately sensitive and specific for preschool vision screening. The ROC curve analysis was used for determining the appropriate screening criteria for these tests, and combining the tests increased their accuracy. The screening criteria should be age dependent. When analyzing the test accuracy in ophthalmic problems, if the disease of interest does not symmetrically (in terms of disease severity and prevalence) involve both eyes, the prevalence based on only 1 eye should be interpreted with caution.

Development of visual acuity in preschool children as measured with Landolt C and Tumbling E charts

PURPOSE

To investigate the visual acuity development as measured by Landolt C and Tumbling E charts ("C chart" and "E chart") in preschool children.

METHODS

Visual acuity measurements of healthy children ages 3-6 years who had been evaluated with the use of E charts (during kindergarten screening) and C charts (in a hospital setting) from 2005 to 2007 were studied. Inclusion criteria were hyperopia <4.5 D, myopia <3.0 D, astigmatism <2.0 D, and anisometropia <2.0 D. The best-corrected visual acuity (BCVA) in each group was analyzed.

RESULTS

There were 821 children in the E chart group and 212 in the C chart group (mean age, 5 years). The mean BCVA improved from between age 3-4 years and age 5-6 years in both groups (P < 0.001). Children in the C chart group had significantly greater astigmatism compared with those in the E chart group (0.66 D ± 0.47 vs 0.28 D ± 0.39; P < 0.001). The BCVA obtained by E chart was greater than that obtained by C chart at age 3-4 years (logMAR 0.0246 ± 0.0646 vs 0.1158 ± 0.1462, P < 0.001), but not at age 5-6 years.

CONCLUSIONS

When children reach 5-6 years of age, visual acuity values obtained by C and E charts approach those observed in adults. In younger patients, the E chart obtains a greater visual acuity score than the C chart. Thus, thresholds for normal visual acuity in preschool children ages 3-6 years should be both age specific and test specific.

Astigmatism in preschool children in Taiwan

PURPOSE

To elucidate the prevalence of astigmatism and its corneal component, the association between the amount of astigmatism and its axis, and the association between the axis of astigmatism and body mass index (BMI) in Taiwanese preschool children.

METHODS

In this population-based study we analyzed 2 data sets, one obtained by retrospective review of vision-screening data and another obtained in a prospective observational study. Each study collected data for age, sex, and refraction status. Autokeratometry, height, and weight measurements were obtained only in the observational study. Astigmatism was classified as with-the-rule, against-the-rule, or oblique.

RESULTS

The prevalence of astigmatism was unassociated with age or sex in both data sets. The retrospective study (1,094 subjects; mean age, 5 years; range, 2.19-7.32 years) revealed that 13.3% of the subjects had astigmatism > or = 1.00 D, and most of them had with-the-rule astigmatism; 4.0% had high astigmatism (>1.50 D). Children with with-the-rule astigmatism had greater mean cylinder power than those with against-the-rule or oblique astigmatism. In the prospective study (190 subjects; mean age, 5.65 years; range, 3.79-6.68 years) astigmatism correlated with its corneal component. Preschoolers with with-the-rule astigmatism and with-the-rule corneal astigmatism had greater BMI and heavier weight than those with against-the-rule or oblique type.

CONCLUSIONS

Astigmatism is common in Taiwanese preschool children. The predominant types are with-the-rule and oblique astigmatism. Most patients with high astigmatism and high corneal astigmatism have with-the-rule type. High BMI or weight is associated with with-the-rule astigmatism and with with-the-rule corneal astigmatism.

The visual status of children ages 3 to 6 years in the vision screening program in Taiwan

PURPOSE

To investigate the current status of myopia, amblyopia, and strabismus of preschoolers in Taiwan.

METHODS

The records of a vision screening performed in 2005 at 4 preschools by a tertiary referral medical center in Kaohsiung, Taiwan were reviewed. Cycloplegic refraction, visual acuity by E chart, stereopsis by Titmus and National Taiwan University tests, and ocular alignment were analyzed.

RESULTS

Most (97.7%) of the children (n = 618) were able to perform visual acuity testing. There was good correlation between the results of cycloplegic spherical equivalent obtained by autorefraction and by retinoscopy (r = 0.934, p < 0.001). The prevalence of amblyopia was about 5%. A trend was found between amblyopia morbidity and the 4 age groups when a single criterion (best-corrected visual acuity <0.7) was used for all ages (decreased amblyopia incidence with increased age; p = 0.028, chi(2) test for trend). The prevalence of myopia was 3.0%, 4.2%, 4.7%, and 12.2% at ages 3, 4, 5, and 6 years, respectively. There was a trend of increased myopia with increased age (p = 0.021, chi(2) test for trend).

CONCLUSIONS

The prevalence of myopia in children ages 3 to 6 years in Taiwan was high compared with the prevalence in other countries. Criteria for amblyopia based on age difference and on the types of visual acuity test are recommended.

Cycloplegic effect of 0.5% tropicamide and 0.5% phenylephrine mixed eye drops: objective assessment in Japanese schoolchildren with myopia

PURPOSE

To evaluate the cycloplegic effect of mixed eye drops containing 0.5% tropicamide and 0.5% phenylephrine in myopic children, and to determine whether their efficacy was associated with their clinical characteristics.

METHODS

Eighty-one myopic children (age, mean +/- SD, 11.0 +/- 1.5 years; mean spherical equivalent refractive error, -4.27 +/- 1.41 D; range, -1.57 to -8.66 D) were recruited. One drop of Mydrin-P was administered to each eye twice, with an interval of 5 min between. Twenty-five minutes after the second drop, accommodative responses were measured with an open-view autorefractometer, while the subject was encouraged to accommodate by binocularly looking at a Maltese cross located at a distance of 33 cm. The difference between the refractive reading and that obtained with a Maltese cross at 500 cm was regarded as residual accommodation (RA). The repeatability of this measurement was also evaluated.

RESULTS

The mean RA was 0.21 +/- 0.29 D (range, -0.31 to 0.99 D). There was no association in RA between the right and left eyes, between RA and age, or between RA and sex, but RA was weakly correlated with refractive error (r = 0.274, P = 0.019). The intersubject difference found in RA can be explained mostly by the extent of repeatability (+/-0.71 D).

CONCLUSION

The insignificant magnitude of RA indicated that the mixed eye drop is an acceptable and useful cycloplegic agent in Japanese schoolchildren with a wide range of myopic refractive errors.

The Study of Progression of Adult Nearsightedness (SPAN): design and baseline characteristics

PURPOSE

The Study of Progression of Adult Nearsightedness (SPAN) is a 5-year observational study to determine the risk factors associated with adult myopia progression. Candidate risk factors include: a high proportion of time spent performing near tasks, performing near tasks at a close distance, high accommodative convergence/accommodation (AC/A) ratio, and high accommodative lag.

METHODS

Subjects between 25 and 35 years of age, with at least -0.50 D spherical equivalent of myopia (cycloplegic autorefraction), were recruited from the faculty and staff of The Ohio State University. Progression is defined as an increase in myopia of at least -0.75 D spherical equivalent as determined by cycloplegic autorefraction. Annual testing includes visual acuity, noncycloplegic autorefraction and autokeratometry, phoria, accommodative lag, response AC/A ratio, cycloplegic autorefraction, videophakometry, ultrasound, and partial coherence interferometry (IOLMaster). Participants' near activities were assessed using the experience sampling method (ESM). Subjects carried a pager for two 1-week periods and were paged randomly throughout the day. Each time they were paged, they dialed into an automated telephone survey and reported their visual activity at that time. From these responses, the proportion of time spent performing near work was estimated.

RESULTS

Three-hundred ninety-six subjects were enrolled in SPAN. The mean (+/- standard deviation) age at baseline was 30.7 +/- 3.5 years, 66% were female, 80% were white, 11% were black, and 8% were Asian/Pacific Islander. The mean level of myopia (spherical equivalent) was -3.54 +/- 1.77 D, the mean axial length by IOLMaster was 24.6 +/- 1.1 mm, and subjects were 1.7 +/- 4.0 Delta exophoric. Refractive error was associated with the number of myopic parents (F = 3.83, p = 0.023), and the number of myopic parents was associated with the age of myopia onset (chi2 = 13.78, p = 0.001). In a multivariate analysis, onset of myopia (early vs. late) still had a significant effect on degree of myopia (F = 115.1, p < 0.001), but the number of myopic parents was no longer significant (F = 0.65, p = 0.52). For the ESM, the most frequently reported visual task was computer use (mean, 18.9%; range, 0-60.0%) and, overall, subjects reported near work activity 34.1% of the time (range, 0-67.3%).

CONCLUSIONS

The design of SPAN and the baseline characteristics of the cohort have been described. Parental history of myopia is related to the degree of myopia at baseline, but this effect is mediated by the age of onset of myopia.

Comparison of tropicamide and cyclopentolate for cycloplegic refractions in myopic adult refractive surgery patients

PURPOSE

To compare tropicamide 1%, a shorter-acting cycloplegic agent, with cyclopentolate 1% for cycloplegic refractions in adult refractive surgery patients.

SETTING

Navy Refractive Surgery Center, Ophthalmology, Naval Medical Center, San Diego, California.

METHODS

The study was prospective, single center, with randomized sequencing of cycloplegic agent; each patient received both agents. Thirty consecutive myopic adult refractive surgery patients (mean age 35.4 years) participated. A complete preoperative examination, including cycloplegic refraction, was obtained twice, 1 week apart. The patient and the examiner were masked to the medication. Main outcome measures included cycloplegic and manifest refractions, best corrected distance acuity, near-point accommodation, pupil diameters, and subjective appraisal of experience with cycloplegic agents.

RESULTS

Twenty-eight of 30 patients completed both examinations. Both eyes were measured, but comparisons were limited to right and left eyes, independently. No statistically significant difference was found between the tropicamide and cyclopentolate cycloplegic refractions (mean difference in MSE +/- SD, OD=0.054 +/- 0.214 diopters (D), t=1.33, P=.10; OS=0.054 +/- 0.253 D, t=1.12, P=.14). Five eyes of 3 patients had a difference of 0.50 D or greater between the 2 agents; less myopia with cyclopentolate. Near-point testing revealed less residual accommodation with cyclopentolate (difference in MSE, OD=-0.27 +/- 0.51 D, t=2.68, P=.006; OS=-0.32 +/- 0.49 D, t=3.46, P=.001). Subjectively, 24 of 28 (86%) patients preferred tropicamide, 1 (4%) preferred cyclopentolate, and 3 (10%) had no preference.

CONCLUSIONS

There was no statistically significant difference in mean cycloplegic refractions. Cyclopentolate was more effective than tropicamide in reducing accommodative amplitude in adult myopes (near-point testing). Patients strongly preferred tropicamide.

Comparative study on the safety and efficacy of different cycloplegic agents in children with darkly pigmented irides

BACKGROUND

The ideal cycloplegic drug that is safe, effective and convenient in children is not yet available. This study aimed to evaluate the safety and efficacy of three cycloplegic regimens in hyperopic children with pigmented irides. The responses to cycloplegia in different age groups and presence of strabismus were also compared.

METHODS

Tropicamide 0.5% and phenylephrine 0.5% (regimen I), tropicamide 1.0% and cyclopentolate 1.0% (regimen II), and atropine 1.0% (regimen III) were evaluated in 25 children using a crossover study design. Cycloplegic refractions were assessed.

RESULTS

The mean age of the children was 5.7 +/- 2.0 years (range 2.5-10.8 years). Six (24.0%) of them had strabismus. The spherical equivalent (SE) refraction for regimens I, II and III were +5.11 +/- 2.04 D, +5.29 +/- 1.89 D and +5.71 +/- 1.90 D, respectively, and were significant different from the manifest SE (+3.95 +/- 2.17 D) (P < 0.001). There was no statistical difference between regimen I and II in children without strabismus (P = 0.258) or aged older than 5 years (P > 0.050).

CONCLUSION

In older children, regimen I was as effective as regimen II and can be used to avoid cyclopentolate toxicity.

Topical mydriatic and cycloplegic spray for Chinese children

PURPOSE

To assess the efficacy and tolerance of mydriatic and cycloplegic spray versus drops for Chinese children.

METHODS

The effects of the spray (cyclopentolate 0.25%, phenylephrine 0.625%, and tropicamide 0.5%) and the drops (cyclopentolate 1%, phenylephrine 0.5%, and tropicamide 0.5%) were evaluated in 29 children (58 eyes) in two separate sessions. There was a 1-week period between the applications of the spray and the drops. Dilated pupil size and refraction after cycloplegia were the primary outcome variables used to assess the efficacy. A subjective discomfort score was used to assess acceptance of the spray and the drops.

RESULTS

The mean age of the study population was 4.33 +/- 1.39 years (range, 3 to 8 years). The mean pupil size was 6.9 mm for the spray and 6.6 mm for the drops. The spray appeared to be slightly more effective than the drops, with a mean difference of 0.3 mm that was statistically significant (P = .001, two-tailed t test). No statistically significant difference in cycloplegic response was found between the spray and the drops (P = .535, two-tailed t test). Administration of the spray caused less discomfort than did administration of the drops (P < .001, Wilcoxon signed-rank test).

CONCLUSIONS

The spray system appears to be clinically equivalent to the drops for achieving effective pupil dilation and cycloplegia, even in a population with dark irides such as ours. Tolerability and acceptance improved because the spray was applied to the closed eyelids.

Measurement of refractive error in Native American preschoolers: validity and reproducibility of autorefraction

PURPOSE

To examine (1) reproducibility of cycloplegic retinoscopy (C-RNS), cycloplegic autorefraction (C-Autoref), and noncycloplegic autorefraction (NC-Autoref), and (2) validity of C-Autoref and NC-Autoref compared with C-RNS in preschoolers with astigmatism.

METHODS

Subjects were 36 Native American preschoolers. Three measurements of right eye refractive error were obtained with each of three methods: C-RNS (by three different retinoscopists), C-Autoref, and NC-Autoref (Nikon Retinomax K+). Vector methods (vector dioptric distance, VDD) were used in the analyses.

RESULTS

Mean reproducibility was 0.41 D (SD = 0.18) for C-RNS, 0.25 D (SD = 0.17) for C-Autoref, and 0.37 D (SD = 0.21) for NC-Autoref. Mean agreement between C-Autoref and C-RNS ranged from 0.51 to 0.61 VDD (SD = 0.24 to 0.35), and ranged from 1.66 to 1.74 VDD (SD = 1.11 to 1.25) for agreement between NC-Autoref and C-RNS. Mean bias was -0.07 +0.21 x 149 and -1.33 +0.34 x 178 for C-Autoref and NC-Autoref, respectively.

CONCLUSIONS

C-Autoref provided reliable and valid measurements of refractive error in young children. NC-Autoref measurements were reliable within subjects, but there was large variability in validity among subjects.

Development of refraction and strabismus

In the past year, as in recent years, most of the research on the development of refraction has focused on the following: 1) mechanisms whereby the eye can maintain coordinated growth to achieve emmetropia and 2) disruptions of emmetropization resulting in myopia or hyperopia. Preterm children and those with Down syndrome have higher refractive errors than other children, suggesting a failure of emmetropization. One of the most intriguing studies of the past year and one certain to lead to follow-up studies reported that ambient room illumination at night in a child's first two years is associated with a higher prevalence of myopia than sleeping in darkness. Reports on the development of hyperopia showed that it is axial in nature, similar to myopia. The effects of spectacle interventions to correct refractive errors are still being debated, with recent evidence from children suggesting that lenses do not exacerbate myopia. Analyses of risk factors and numerous new screening procedures detect patients with strabismus for referral at a variety of sensitivity and specificity levels. Hyperopia and high AC/A ratios are most clearly associated as causal agents for esotropia and intermittent exotropia. However, the action of even these simple mechanisms is confounded by abnormal binocular fusion mechanisms and the inability of optical correction to align the eyes of many patients. Asymmetric optokinetic nystagmus, latent nystagmus, and dissociated vertical deviation appear to be linked to infantile esotropia from before its onset. But the way the mechanisms underlying these oculomotor anomalies are causally related to the onset of infantile esotropia remains a mystery.