Amblyopia and Strabismus Questionnaire (A&;SQ): clinical validation in a historic cohort

Background We recently developed the Amblyopia & Strabismus Questionnaire (A&SQ) to assess the quality of life in amblyopia and/or strabismus patients, and evaluated its content and criterion validity. The A&SQ was now validated clinically by correlating its outcome with past and current orthoptic parameters in a historic cohort of amblyopia and/or strabismus patients. Methods The cohort was derived from all 471 patients who were treated by occlusion therapy in the Waterland Hospital in Purmerend between 1968 and 1974 and born between 1962 and 1972. All children with insufficient visual acuity from the Waterland area had been referred to a single ophthalmologist and orthoptist. Of these, 203 were traced, and 174 filled out the A&SQ. In 137 of these, binocular vision, visual acuity, and angle of strabismus were reassessed 30–35 years after occlusion therapy. These clinical parameters were correlated with the five A&SQ domains: “distance estimation”, “visual disorientation”, “fear of losing the better eye”, “diplopia”, and “social contact and cosmetic problems”. Results The current acuity at distance of the amblyopic eye and reading acuity of the amblyopic eye correlated significantly with all five A&SQ domains (significance level P = 0.01–P = 0.05). Weaker correlations were found for binocularity. In spite of the expectation that stereopsis should strongly correlate with the domain “distance estimation”, and angle of strabismus with the domain “social contact and cosmetic problems”, the acuity of the amblyopic eye was the overall dominant parameter. Conclusions The adult acuity of the amblyopic eye seems the most important clinical determinant for quality of life in amblyopia and/or strabismus patients, even in domains of distance estimation, visual disorientation, and social contact and cosmetic problems, although intermediate determinants cannot be excluded. The study was not sponsored.     

Better prognosis for amblyopics by means of full prismatic correction after monocular treatment (author's transl)

Binocular training with full prismatic correction after the monocular therapy by occlusion brings a further improvement of the visual acuity as well as shown in a study of 29% (138 cases) of 469 selected cases with binocular problems and 43% (260 cases) of about 600 unselected cases of squint actually in treatment in the practice and orthoptic years the strength of the prisms is determined with the monocular covertest, in elder patients with the Polatest. If the amblyopia is connected with squint, an operation will only be performed after the amblyopia is improved and some degree of binocularity is reached by means of prisms. - 80% of the selected and 48% of the unselected cases reached a visual acuity of 1,0 on the amblyopic eye, including originally severe cases with eccentric fixation. In about 80% of all cases binocular single vision and stereopsis were reached. Failures were mainly due to remaining eccentric fixation, mostly connected with severe ARC, too advanced age at ting the prisms, too long intervals between controls etc.) - Finally, the importance of cooperation with an orthoptist and the social medical aspects of better chances for amblyopics are accentuated.     

Risk of strabismus and ambylopia in children with hydrocephalus

Objectives The present study was undertaken to determine the risk of strabismus and ambylopia in children who underwent operation for hydrocephalus and to compare our results with those in previous studies. Methods Full orthoptic and ophthalmological examinations, including cycloplegic refraction, were performed in all subjects. Results Ten of 25 patients (40%) were found to have manifest squint. Four of these had esotropia and six had exotropia. No paretic squint or alphabetic pattern strabismus was determined. Refraction measurements revealed amblyogenic refractive errors (significant refractive errors that cause amblyopia) in five of the 25 (20%) patients in this study. Strabismus and the risk of amblyopia were found to be significantly higher in patients who experienced shunt revision than those who had not (P<0.05). Conclusion Amblyopia, strabismus, and other acquired defects in the visual system related to hydrocephalus should be closely monitored and treated when indicated. Regular ophthalmic supervision will provide and help to maintain the best possible standard of vision in children with hydrocephalus.     

Ocular Manifestations of Autism in Ophthalmology

Abstract

Purpose: To highlight the ocular manifestations of autism spectrum disorders in a retrospective chart review of the Greater Baltimore Medical Center (GBMC) among children in the pediatric ophthalmology practice setting.

Design: Retrospective chart review. Forty-four patients diagnosed with an autism spectrum disorder (ASD) between January 2007 and October 2011 were examined by an orthoptist, orthoptic student, and a pediatric ophthalmologist.

Results: Fifty-two percent of patients with ASD at GBMC were found to have an ocular abnormality, with 41% having strabismus, 27% with significant refractive error, 7% with anisometropia, and 11% with amblyopia.

Conclusion: The prevalence of strabismus, amblyopia, and anisometropia were found to be higher among patients with ASD seen at the GBMC pediatric ophthalmology practice than in the general population.     

Amblyopia in myopia in patients with strabismus and without strabismus

PURPOSE: To determine factors, which have influence on presence of strabismus among myopic patients with amblyopia. MATERIAL AND METHODS: Material covers 21 myopic patients with amblyopia, aged 6-15. All children presented have a different amount of anisometropia, 12 of them had strabismus. Authors, compared the group of patients with amblyopia and strabismus (12) with the group of patients with pure anisometropic amblyopia (9), according to the following criteria: age of presentation, best corrected visual acuity, mean refraction error of amblyopic eye, mean amount of anisometropia, percentage of patients with central fixation and binocular vision. RESULTS: Patients with strabismus presented oneself earlier than patients without squint. Best corrected visual acuity was better in patients without strabismus. Refraction error in both groups has similar value. Amount of anisometropia was slightly smaller in the group with squint. Central fixation and binocular vision were better preserved among patients without strabismus. Authors didn't find the following correlations too: correlation between amount of anisometropia and amount of amblyopia in both groups, correlation between amount of anisometropia and the amount of the deviation of squinting eye, correlation between depth of amblyopia and the amount of deviation of the squinting eye. CONCLUSION: It seems, that primary factor leading to presence of strabismus among patients with anisometropic myopia, is motor dysfunction of extraocular muscles.     

Cost-effectiveness of orthoptic screening in kindergarten: A decision-analytic model

purpose The purpose of this study was to analyze the cost-effectiveness of orthoptic screening for amblyopia in kindergarten. METHODS. A decision-analytic model was used. In this model all kindergarten children in Germany aged 3 years were examined by an orthoptist. Children with positive screening results were referred to an ophthalmologist for diagnosis. The number of newly diagnosed cases of amblyopia, amblyogenic non-obvious strabismus and amblyogenic refractive errors was used as the measure of effectiveness. Direct costs were measured form a third-party payer perspective. Data for model parameters were obtained from the literature and from own measurements in kindergartens. A base analysis was performed using median parameter values. The influence of uncertain parameters was tested in sensitivity analyses. RESULTS. According to the base analysis, the cost of one orthoptic screening test was 7.87 euro. One ophthalmologic examination cost 36.40 euro. The total cost of the screening program in all kindergartens was 3.1 million euro. A total of 4,261 new cases would be detected. The cost-effectiveness ratio was 727 euro per case detected. Sensitivity analysis showed considerable influence of the prevalence rate of target conditions and of the specificity of the orthopic examination on the cost-effectiveness ratio. CONCLUSIONS. This analysis provides information which is useful for discussion about the implementation of orthoptic screening and for planning a field study.     

Screening merits of the Lang II, Frisby, Randot, Titmus, and TNO stereo tests.

PURPOSE: Previous works show a pronounced disagreement on the reliability of stereo tests as screening tools for amblyopia and strabismus. This study's aim was to compare the ability of the Lang II, Frisby, Randot, Titmus, and TNO stereo tests to detect amblyopia and strabismus with visual acuity testing and cover testing. METHODS: A total of 1035 school children aged 12 to 13 years were examined in a field study in Monterrey, Mexico. In addition to the 5 stereo tests, the examination included visual acuity, cover testing, refraction (skiascopy), and inspection of the red reflex and posterior pole. RESULTS: Sensitivity ranged from 17% to 47% (Frisby-Titmus-Lang II-Randot-TNO, in order of occurrence). Of the 60 subjects with strabismus and/or amblyopia, only 8 subjects were identified by all 5 stereo tests. A considerable number of subjects (25), the majority of whom were amblyopic (23 subjects), were not identified by any of the tests. All stereo tests showed higher sensitivities for strabismus than for amblyopia. CONCLUSION: None of the 5 stereo tests studied is suitable for screening for amblyopia or strabismus. The results of both ocularly normal subjects and subjects with strabismus and/or amblyopia are variable, and there is no way of separating normal response from abnormal response.     

Development of impaired vision in mentally handicapped children

The aim of the following study was 1) to show the incidence of ophthalmic disorders in severely visually and mentally handicapped children retrospectively 2) to follow up the change in visual acuity over at least 2 years prospectively 3) to look at the effect of therapeutic concepts. 270 children of the "Blindeninstituts-stiftung Würzburg" were followed up between 1960 and 1987. ad 1) Optic atrophy was the leading cause of visual impairment (24%) followed by cataract and retinopathy of prematurity (both found in 17%), malformations of the anterior segment (12%), cortical amblyopia (8%) and refractive error (6%). Strabismus was an additional finding in 38% of the children often associated with nystagmus. Convergent and divergent strabismus had the same incidence. ad 2) Visual acuity improved in 30% of cases of cortical amblyopia, in 40% of refractive errors and in 30% of optic atrophy. In cases of cataract there was a slight improvement in 20%. In 24% of aphakia a secondary glaucoma was observed. In cases of malformations of the anterior segment and ROP the visual acuity remained stable on a low level. The cases of ROP were advanced and had not received any surgical treatment. A deterioration in vision as often seen after surgical intervention was observed in 20% of ROP. In respect of the high incidence of refractive errors and orthoptic problems in multiple handicapped children they should be seen as early as possible by an ophthalmologist. Detection of a congenital cataract soon after birth as well as complications of other disorders should help to prevent blindness. The remaining visual perception is especially important for the handicapped child to communicate and move about.     

Teller Acuity Cards Versus Clinical Judgment in the Diagnosis of Amblyopia with Strabismus

Teller acuity card testing, which is a form of the preferential-looking procedure, is a popular way of assessing visual acuity in preverbal patients. The authors suspected that the clinical judgment of a pediatric ophthalmologist is superior to the Teller acuity cards in diagnosing amblyopia when strabismus is present. Acuity card and fixation preference measurements on each eye were compared at the same clinical visit in a group of 108 strabismus patients. The authors found that the acuity cards could be used to detect amblyopia. However, the pediatric ophthalmologist was more sensitive in diagnosing amblyopia than the Teller acuity cards in the presence of strabismus.     

Review of preschool vision screening referrals in South Auckland, New Zealand

Background: Limited data are available on the causes of visual impairment in preschool children in New Zealand. We aimed to review demographic and visual parameters in children referred to the Ophthalmology Department, Manukau Super Clinic from vision screening programs in South Auckland. Methods: Retrospective medical record review of 131 children, aged three to five years, referred from community‐based vision screening programs to the Ophthalmology Department for further assessment. Medical records were reviewed to determine: the reason for referral; findings from ophthalmic assessments; treatment received; and visual acuity at the final visit. The main outcome measures were the cause of visual impairment in children referred from preschool vision screening and the visual acuity at the final follow‐up visit. Results: Thirty‐eight (29.0 per cent) children were discharged after their initial assessment as false positive referrals. Almost half (45.5 per cent) of the children were prescribed glasses for the correction of refractive error, amblyopia or strabismus. Twenty‐nine (22.1 per cent) children were diagnosed with amblyopia with an average follow‐up period of 17.5 ± 2.7 months. In general, compliance with therapy for amblyopia was poor with 48.3 per cent non‐compliant with their prescribed treatment regimen. Despite this, visual outcomes were good with an average final visual acuity in the amblyopic eye of 0.294 ± 0.231 logMAR (Snellen 6/12). Conclusions: The ‘positive predictive value’ for the Counties‐Manukau preschool vision screening program was 47.4 per cent, suggesting that the visual acuity measurements alone produce a significant number of false positive results. In children diagnosed with amblyopia, early detection and intervention showed significant improvement in vision in the amblyopic eye, with many children also showing improved binocular function.     

Test characteristics of orthoptic screening examination in 3 year old kindergarten children

AIM: To analyse the test characteristics of orthoptic screening for amblyopia or amblyogenic risk factors (target conditions) in kindergarten. METHODS: 1180 three year old children were screened by orthoptists in 121 German kindergartens. Orthoptic screening consisted of cover tests, examination of eye motility and head posture, and monocular visual acuity testing with the Lea single optotype test. Children were re-examined in kindergarten by different orthoptists after 3-6 months using a more demanding pass threshold for visual acuity. All children with at least one positive orthoptic test result or an inconclusive re-examination were referred to an ophthalmologist for diagnosis. The gold standard was set positive if a target condition was diagnosed on ophthalmological examination. It was set negative if no target condition was found upon ophthalmological examination, or if a child who screened negative or inconclusive passed the orthoptic re-examination without any positive test result. RESULTS: The gold standard was ascertained in 1114 children. 26 (2.3%) children had a "positive" gold standard. In 10.8% of the children the initial screening was "inconclusive," mostly due to lack of collaboration. Screening test sensitivity (based on conclusive results only) was 90.9% and specificity was 93.8%. CONCLUSIONS: Orthoptic vision screening of 3 year olds in kindergarten is sensitive and specific. However, owing to a substantial proportion of inconclusive screening results, rescreening of non-cooperative 3 year old children should be considered.     

学龄前儿童弱视及斜视的调查

目的早期发现并及时治疗弱视、斜视及其他眼病,减少可预防盲及低视力。方法济南市部分幼儿园内随机检查健康3～6岁6085例学龄前儿童,检查其标准远视力、近视力、屈光、眼位、眼前节及眼底。结果3～6岁儿童远视力低常率为12．16%,近视力低常率为4．40%；弱视患病率为5．23%,其中初次发现者占86．48%；共发现斜视患儿96例,其治疗率仅为14．58%。结论近视力可作为发现患儿视力不佳的线索之一,发现后重点核实其远视力。我市3～6岁儿童的弱视斜视的漏诊漏治情况相当严重,对幼儿尽早进行眼科普查意义重大,保健预防及宣教工作亟待加强。     

Screening amblyopia of preschool children with uncorrected vision and stereopsis tests in Eastern Taiwan

AIMS OR PURPOSE: Screening for amblyopia at earliest age is important for early treatment and better prognosis. This study aimed at evaluating the validity of uncorrected distant and near visual acuity and random dot stereopsis for screening amblyopia. METHODS; In Eastern Taiwan, population-based screen tests were performed for children at age from 3 to 6 years. The tests included uncorrected distant and near visions and random dot stereopsis (300 s) test. The screen performers were registered nurses of local public health service posts. The golden standards of the tests were the results of examination by the ophthalmologists. RESULTS: Including Hans and aboriginal Taiwanese, 5232 children were included. Screened by distance visual acuity with different cutoffs and near visual acuity, 10.3, 30.3 and 8.2% children were abnormal. Screened by random dot, only 2% children were abnormal. By a senior ophthalmologist, 115 amblyopic children were diagnosed amblyopic. The sensitivities of distance visual acuity with low/high cutoff and near visual acuity were 74.7/84.8 and 49.4%, whereas that of the NTU random dot stereogram was 20.5%. Simultaneous testing of either two of the three tests improved the sensitivity. CONCLUSION: Screening for amblyopia by the local nurses using the visual acuity tests or random dot stereopsis test alone does not display a high sensitivity. Simultaneous testing of distant visual acuity and stereopsis test elevate the sensitivity and preserve the specificity.     

Preschool vision screening: negative predictive value for amblyopia

BACKGROUND/AIMS: Single optotype tests of visual acuity are widely used for preschool vision screening in order to optimise cooperation with testing. These tests may, however, underestimate the visual acuity deficit in amblyopia because they lack visual crowding. This study assessed the resultant negative predictive value (NPV) for amblyopia. METHODS: Cohort study of 936 children in the Cambridge Health District selected by date of birth. The presence of amblyopia among children who had passed preschool vision screening was determined using Snellen line acuity as the reference test. Preschool vision screening was conducted at 3.5 years of age by community orthoptists. The screening assessment comprised Sheridan-Gardiner single optotype test of visual acuity (referral criterion 6/9 or worse in either eye), cover test, ocular movements, 20(Delta) prism test, and TNO stereotest. RESULTS: The overall NPV of preschool vision screening for amblyopia was 100% (95% CI 99.4% to 100%). Most children with amblyopia were detected by the Sheridan-Gardiner single optotype test of visual acuity, but the other screening tests were necessary to prevent any false negatives. In isolation, the Sheridan-Gardiner single optotype test of visual acuity has a NPV for amblyopia of only 99.6% (95% CI 98.7% to 99.9%). CONCLUSION: Preschool vision screening using a single optotype test of visual acuity does achieve a high NPV for amblyopia, but only under certain conditions. These comprise a low threshold for referral (6/9 or worse in either eye) and the inclusion of a cover test and tests of binocular function in the screening assessment.     

Longterm oculomotor and visual function in spina bifida cystica: a population-based study

PURPOSE: To document and describe the development from birth of visual and oculomotor functions in a group of children with spina bifida cystica (myelomeningocele and myeloschisis [MMC]). The emphasis in this study is on findings at 12-14 year follow-up. METHODS: Twenty children aged 12-14 years with myelomeningocele and Chiari-related malformations were examined by an orthoptist and a paediatric ophthalmologist. A further child who did not wish to participate actively in the study is also reported. Visual acuity for near and distance, refractometer readings in cycloplegia, the presence of ocular motility disorders and nystagmus were recorded. Accommodation, convergence, colour vision and stereo acuity were assessed and the fundus and media were examined. RESULTS: Six children (29%) in the study group had subnormal vision, although no child was visually impaired. Eleven (52%) showed manifest strabismus and 17 (81%) had a significant refractive error. Near visual acuity was normal in nearly all the children, but accommodation was defective in 10. Nine children had nystagmus and two had optic atrophy. No visual field defects were found. CONCLUSIONS: The high incidence of ocular disturbances in children with spina bifida highlights the importance of regular ophthalmological investigation and follow-up.     

山东滕州市农村小学生弱视斜视及立体视锐度调查

目的 调查滕州市农村小学生的视力、立体视锐度及弱视和斜视的患病情况,并对Titmus立体视图检查法、视力检查法、Titmus立体视图联合视力检查法三种弱视筛选试验进行评价.方法 应用随机整群抽样调查方法,共抽取滕州市8所农村小学,共有小学生2742人,年龄5～14岁,平均(9.3±2.3)岁.进行Titmus立体视图、裸眼视力、眼位及眼球运动检查,对任一眼裸眼视力<1.0者进行视网膜检影验光.结果 (1)小学生视力低常率为13.83%,从7岁至13岁视力低常率呈逐渐上升趋势;视力低常的首位原因为屈光不正,弱视,其中近视占79.67%(486眼/610眼);(2)弱视患病率为1.50%.97.5%(39/40)的弱视患儿为首次被筛查出来;斜视患病率为1.72%;(3)非弱视/斜视儿童的立体视锐度5岁年龄组为60″,6岁年龄组为50″,7岁及以上年龄组均为40″;弱视患者中立体视锐度异常者占77.5%(31140),斜视患者中立体视锐度异常者占28.3%(13/46);(4)Titmus立体视图联合视力检查法筛选弱视的特异度(99.47%)及粗一致性(99.06%)最高,误诊率(0.53%)最低;其次为Titmus立体视图检查法(特异度为97.98%;粗一致性为97.59%;误诊率为2.02%);视力检查法的特异度(87.47%)及粗一致性(87.66%)最低,误诊率(12.53%)最高.结论 滕州市农村小学生视力低下的首位原因为近视;弱视和斜视是影响立体视觉发育的主要因素;Titmus立体视图联合视力检查法可提高学龄儿童弱视筛选的效率.     

Results of treatment of anisohypermetropic amblyopia without strabismus.

One hundred and two patients with anisohypermetropic amblyopia without strabismus were studied. Microstrabismus was excluded by detailed orthoptic examinations including visuscopy and Cüppers' bifoveal correspondence test. Treatment consisted in wearing correcting glasses and part-time or full-time patching of the nonamblyopic eye. In patients with dense amblyopia patching of the amblyopic eye was done and Cüppers' after-image method of pleoptic therapy was instituted as the initial procedure. When visual acuity improved sufficiently by this therapy, patching was used on the nonamblyopic eye. Sixty-five (63.7%) patients showed 2 lines or more improvement on the Snellen chart. Though young children (6 to 12 years) improved their visual acuity more often than those aged 13 to 20 years, a considerable number of patients (50.0%) in the older age group improved their visual acuity after therapy. The improvement in visual acuity was accompanied by improved stereoacuity in 49.0% of the patients. It is therefore suggested that every effort should be made to treat these patients even after the age of 12 years.     

Preschool vision screening: outcome of children referred to the hospital eye service.

AIMS: To assess the outcome of children referred to the hospital eye service (HES) from an orthoptist based preschool vision screening programme. METHODS: A retrospective study was conducted of children referred from screening during a 2 year period. Children were screened by community orthoptists at 3 1/2 years of age. The main outcome measures were (1) HES findings for children referred from screening, and (2) visual outcome for amblyopic children after completion of treatment. RESULTS: The attendance rate at screening was 79.3% (6794 children): 348 children (5.1% of those screened) were referred to the HES. The HES findings were refractive error (32.9%), amblyopia (29.9%), false positive referral (20.1%), strabismus (13.2%), and other ocular disorders (3.9%). The positive predictive value of screening was 79.9%. Screening detected 48 children with straight eyed amblyopia and 43 children with strabismic amblyopia. A visual acuity of 6/9 or better in the amblyopic eye was achieved by 87.2% of straight eyed amblyopes and 64.3% of strabismic amblyopes (chi 2 = 5.27, p = 0.02). Residual amblyopia of 6/24 or worse occurred in only 5.6% of amblyopic children. CONCLUSION: Most amblyopic children detected by preschool vision screening achieve a good visual outcome with treatment. While treatment earlier in the sensitive period might be expected to give improved results, it remains to be demonstrated that preschool screening results in a better outcome than screening at school entry. Preschool vision screening also detects a significant number of children without amblyopia who have reduced vision due to refractive errors. This group of children must be included in any analysis of the cost effectiveness of preschool vision screening.     

Original papers: Prevalence of amblyogenic diseases in a preschool population sample of Valladolid, Spain

Objectives: Amblyopia is the leading cause of monocular vision loss in people under 40 years, and especially in children. The purpose of the present investigation is to determine the prevalence of amblyopia and ocular pathology, specially the most common causes of amblyopia, in a population of 3-to 6-year-old children. Patients and methods: From a total of 8167 children, a geographically defined population of 3-to 6-year-old children, 2000 were randomly selected, and 1179 (58.9%) examined. Ophthalmologic examination included: Personal and familial history, visual acuity, extraocular motility, cover test at near distance, cycloplegic refraction with autorefractometer and fundus eye examination. Amblyopia was considered when corrected visual acuity was < 0.5 with Marquez optotypes and difference in visual acuity of 0.2 or more between eyes. Pathology considered as amblyogenic were strabismus, visual acuity asymmetry and anisometropia. Results: The family history showed amblyopia in 249 (21.1%), strabismus in 227 (19.2%), and refractive errors in 808 (65.5%). Cover test was positive in 78 children (6.7%). A visual acuity difference of 0.2 or more between eyes was present in 88 (7.5%) children, and anisometropia over 1.5 diopters (in spherical equivalent) was present in 17 (1.4%) subjects. One hundred and twenty-two (10.35%) children did not achieve a normal visual acuity: visual acuity in the better eye was less than 0.5 in 55 children under 5 years and less than 0.6 in 67 children over 5 years. The prevalence of amblyopia was 7.5%. Conclusions: The data support the importance of early detection and treatment of amblyopia and the need for visual screening at an early age.     

Change in vision disorders among Hong Kong preschoolers in 10 years

Background: To determine the change in refractive error and the prevalence of amblyopia and strabismus among preschool children in Hong Kong over a period of 10 years. Design: Two cross‐sectional population‐based studies conducted in 1996 to 1997 (part A) and 2006 to 2007 (part B) Participants: Children attending randomly selected kindergarten participated in the study. Methods: Ocular alignment, visual acuity, cover and uncover tests, cycloplegic refraction, slit‐lamp and fundi examination were performed under a standardized testing environment. Main Outcome Measures: The prevalence of amblyopia (best‐corrected visual acuity ≤6/12 in one or both eyes, or a bilateral difference of ≥2 best‐corrected visual acuity lines), strabismus and significant refractive error (hyperopia ≥+2.50 D; myopia ≥?1.00 D; astigmatism ≥2.00 D) among preschool children. Results: Of the 601 children in part A of the study, reduced visual acuity was presented in 3.8%; whereas strabismus was found in 1.8%. The commonest type of refractive error was astigmatism in 6.3% of children, followed by hyperopia (5.8%) and myopia (2.3%). Among 823 children in part B, reduced visual acuity was presented in 2.7% of children, and strabismus was found in 1.7%. The commonest type of refractive error was myopia (6.3%), followed by astigmatism (5.7%) and hyperopia (5.1%). The percentage of children having myopia has significantly increased (P = 0.001). Conclusion: A significant increase in myopia has been noted in Hong Kong preschoolers. Visual screening programmes may need to be tailored to correspond to the local population and be adjusted accordingly from time to time.