Myopia has emerged as a public health issue with the increasing prevalence of myopia in children and adolescents in China. In the clinical diagnosis and treatment of myopia, there are clinical stages and classifications, but they are not suitable for the prevention and control of myopia at the public health level. At the public health level, because there is no staging standard for myopia, there is a lack of staging prevention and control guidance for different refractive errors. Therefore, the Public Health Ophthalmology Branch of the Chinese Preventive Medicine Association organized domestic experts in relevant fields to conduct literature searches and discuss based on the research data on myopia at home and abroad, put forward the stages of public health strategies for myopia prevention and control and corresponding group prevention and control measures for each stage to reached this experts consensus. This consensus first proposes a method for assessing myopia risk, in order to predict the occurrence and development of myopia in children and adolescents; From the perspective of public health, myopia prevention and control is further divided into four stages: myopia prodromal stage, myopia development stage, high myopia stage, and pathological myopia stage. According to this consensus, myopia prevention and control technology is targeted and implemented in different stages to provide guidance for myopia prevention and control from the perspective of public health.
Humans ; Child ; Adolescent ; Public Health ; Consensus ; Myopia/epidemiology* ; Refractive Errors/epidemiology* ; Asian People ; China/epidemiology*

PURPOSE: Preoperative measurement of refractive error before LASIK or PRK is very important for good postoperative result because the measured refractive error is the basis of correction amount of operation. We analyzed the difference in spherical equivalent values of manifest refraction by operator (OMR), manifest and cycloplegic refraction by resident (RMR and RCR), noncycloplegic automated refraction (AMR). METHODS: The randomized charts of 50 patients (100 eyes) who had undergone LASIK or PRK for myopia at the Department of Ophthalmology at Samsung Medical Center between May 2000 and November 2000 were reviewed retrospectively and spherical equivalent values of preoperative OMR, RMR, RCR, and AMR by Nikon NRK-8000 autorefractor were analyzed by paired T-test. RESULTS: The mean spherical equivalent values of OMR, RMR, RCR, AMR were -5.40+/-2.10 D, -5.47+/-2.23 D, -5.36+/-2.18 D, -6.25+/-2.24 D, respectively. The spherical equivalent value of AMR was more myopic than the values of others and the bias was statistically significant. The absolute difference of spherical equivalent diopter between OMR and RMR was 0.27+/-0.27 D and that between OMR and RCR was 0.30+/-0.33 D. These two absolute difference did not show statistical significance. CONCLUSIONS: This study revealed that there was statistically significant difference in spherical equivalent diopter measured by AMR compared to those measured by OMR, RMR, or RCR. So we recommend the method of manifest and cycloplegic refraction by two ophthalmologists before LASIK or PRK for accurate measurement of refractive error.
Bias (Epidemiology) ; Humans ; Keratomileusis, Laser In Situ ; Myopia ; Ophthalmology ; Refractive Errors* ; Retrospective Studies

PURPOSE: We evaluated ocular optical components and their interrelationships in myopic Korean patients. METHODS: In this prospective observational study, 1,011 consecutive patients were recruited from a refractive surgery clinic. The best-corrected visual acuity was >20 / 20 in all patients. The refractive error, axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and vitreous chamber depth (VCD) were measured by an autorefractor and partial coherence laser interferometry (IOL Master). Central corneal thickness (CCT) was measured by ORBscan II topography. RESULTS: The refractive errors had a positive correlation with LT but negative correlations with AL, ACD, VCD, and CCT. As the axial length increased, the ACD, VCD, and CCT increased but the LT decreased. The CCT had a positive correlation with gender, refractive errors, ACD, VCD, and AL but no correlation with age. The mean CCT was increased in proportion to the increase in AL. CONCLUSIONS: In myopic Korean patients, as axial elongation progressed, the VCD and ACD deepened and the CCT thickened but the LT decreased. The CCT had a positive correlation with the degree of myopia and the AL.
Adult ; Female ; Humans ; Male ; Middle Aged ; Myopia/*epidemiology/therapy ; Prospective Studies ; Refractive Errors/*epidemiology/therapy ; Republic of Korea/epidemiology ; Visual Acuity

PURPOSE: The aims of this study were to examine the distribution of refractive errors and clinical characteristics of strabismus in Korean patients with Down's syndrome. METHODS: A total of 41 Korean patients with Down's syndrome were screened for strabismus and refractive errors in 2009. RESULTS: A total of 41 patients with an average age of 11.9 years (range, 2 to 36 years) were screened. Eighteen patients (43.9%) had strabismus. Ten (23.4%) of 18 patients exhibited esotropia and the others had intermittent exotropia. The most frequently detected type of esotropia was acquired non-accommodative esotropia, and that of exotropia was the basic type. Fifteen patients (36.6%) had hypermetropia and 20 (48.8%) had myopia. The patients with esotropia had refractive errors of +4.89 diopters (D, +/-3.73) and the patients with exotropia had refractive errors of -0.31 D (+/-1.78). Six of ten patients with esotropia had an accommodation weakness. Twenty one patients (63.4%) had astigmatism. Eleven (28.6%) of 21 patients had anisometropia and six (14.6%) of those had clinically significant anisometropia. CONCLUSIONS: In Korean patients with Down's syndrome, esotropia was more common than exotropia and hypermetropia more common than myopia. Especially, Down's syndrome patients with esotropia generally exhibit clinically significant hyperopic errors (>+3.00 D) and evidence of under-accommodation. Thus, hypermetropia and accommodation weakness could be possible factors in esotropia when it occurs in Down's syndrome patients. Based on the results of this study, eye examinations of Down's syndrome patients should routinely include a measure of accommodation at near distances, and bifocals should be considered for those with evidence of under-accommodation.
Adolescent ; Adult ; Child ; Child, Preschool ; Down Syndrome/*complications/epidemiology ; Female ; Humans ; Incidence ; Male ; Prevalence ; Refractive Errors/complications/*epidemiology ; Republic of Korea/epidemiology ; Retrospective Studies ; Strabismus/complications/*epidemiology ; *Vision Screening ; Young Adult

INTRODUCTIONRefractive error remains one of the primary causes of visual impairment in children worldwide, and the prevalence of refractive error varies widely. The objective of this study was to determine the prevalence of refractive error and study the possible associated factors inducing refractive error among primary school children of Malay ethnicity in the suburban area of Kota Bharu, Kelantan, Malaysia.

MATERIALS AND METHODSA school-based cross-sectional study was performed from January to July 2006 by random selection on Standard 1 to Standard 6 students of 10 primary schools in the Kota Bharu district. Visual acuity assessment was measured using logMAR ETDRS chart. Positive predictive value of uncorrected visual acuity equal or worse than 20/40, was used as a cut-off point for further evaluation by automated refraction and retinoscopic refraction.

RESULTSA total of 840 students were enumerated but only 705 were examined. The prevalence of uncorrected visual impairment was seen in 54 (7.7%) children. The main cause of the uncorrected visual impairment was refractive error which contributed to 90.7% of the total, and with 7.0% prevalence for the studied population. Myopia is the most common type of refractive error among children aged 6 to 12 years with prevalence of 5.4%, followed by hyperopia at 1.0% and astigmatism at 0.6%. A significant positive correlation was noted between myopia development with increasing age (P <0.005), more hours spent on reading books (P <0.005) and background history of siblings with glasses (P <0.005) and whose parents are of higher educational level (P <0.005). Malays in suburban Kelantan (5.4%) have the lowest prevalence of myopia compared with Malays in the metropolitan cities of Kuala Lumpur (9.2%) and Singapore (22.1%).

CONCLUSIONThe ethnicity-specific prevalence rate of myopia was the lowest among Malays in Kota Bharu, followed by Kuala Lumpur, and is the highest among Singaporean Malays. Better socio-economic factors could have contributed to higher myopia rates in the cities, since the genetic background of these ethnic Malays are similar.

Child ; Cross-Sectional Studies ; Female ; Follow-Up Studies ; Humans ; Malaysia ; epidemiology ; Male ; Prevalence ; Refraction, Ocular ; Refractive Errors ; complications ; epidemiology ; physiopathology ; Retrospective Studies ; Schools ; Suburban Population ; statistics & numerical data ; Vision, Low ; epidemiology ; etiology ; physiopathology ; Visual Acuity

PURPOSE: Our study provides epidemiologic data on the prevalence of refractive errors in all age group ≥5 years in Korea. METHODS: In 2008 to 2012, a total of 33,355 participants aged ≥5 years underwent ophthalmologic examinations. Using the right eye, myopia was defined as a spherical equivalent (SE) less than -0.5 or -1.0 diopters (D) in subjects aged 19 years and older or as an SE less than -0.75 or -1.25 D in subjects aged 5 to 18 years according to non-cycloplegic refraction. Other refractive errors were defined as follows: high myopia as an SE less than -6.0 D; hyperopia as an SE larger than +0.5 D; and astigmatism as a cylindrical error less than -1.0 D. The prevalence and risk factors of myopia were evaluated. RESULTS: Prevalence rates with a 95% confidence interval were determined for myopia (SE <-0.5 D, 51.9% [51.2 to 52.7]; SE <-1.0 D, 39.6% [38.8 to 40.3]), high myopia (5.0% [4.7 to 5.3]), hyperopia (13.4% [12.9 to 13.9]), and astigmatism (31.2% [30.5 to 32.0]). The prevalence of myopia demonstrated a nonlinear distribution with the highest peak between the ages of 19 and 29 years. The prevalence of hyperopia decreased with age in subjects aged 39 years or younger and then increased with age in subjects aged 40 years or older. The prevalence of astigmatism gradually increased with age. Education was associated with all refractive errors; myopia was more prevalent and hyperopia and astigmatism were less prevalent in the highly educated groups. CONCLUSIONS: In young generations, the prevalence of myopia in Korea was much higher compared to the white or black populations in Western countries and is consistent with the high prevalence found in most other Asian countries. The overall prevalence of hyperopia was much lower compared to that of the white Western population. Age and education level were significant predictive factors associated with all kinds of refractive errors.
Adolescent ; Adult ; Age Distribution ; Aged ; Child ; Child, Preschool ; Cross-Sectional Studies ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; *Nutrition Surveys ; Prevalence ; Refractive Errors/*epidemiology/physiopathology ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Factors ; Visual Acuity/*physiology ; Young Adult

PURPOSE: To investigate normative angle kappa data and to examine whether correlations exist between angle kappa and ocular biometric measurements (e.g., refractive error, axial length) and demographic features in Koreans. METHODS: Data from 436 eyes (213 males and 223 females) were analyzed in this study. The angle kappa was measured using Orbscan II. We used ocular biometric measurements, including refractive spherical equivalent, interpupillary distance and axial length, to investigate the correlations between angle kappa and ocular biometry. The IOL Master ver. 5.02 was used to obtain axial length. RESULTS: The mean patient age was 57.5 +/- 12.0 years in males and 59.4 +/- 12.4 years in females (p = 0.11). Angle kappa averaged 4.70 +/- 2.70 degrees in men and 4.89 +/- 2.14 degrees in women (p = 0.48). Axial length and spherical equivalent were correlated with angle kappa (r = -0.342 and r = 0.197, respectively). The correlation between axial length and spherical equivalent had a negative correlation (r = -0.540, p < 0.001). CONCLUSIONS: Angle kappa increased with spherical equivalent and age. Thus, careful manipulation should be considered in older and hyperopic patients when planning refractive or strabismus surgery.
Anterior Chamber/*pathology ; *Axial Length, Eye ; Diagnostic Techniques, Ophthalmological/*instrumentation ; Equipment Design ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Morbidity/trends ; Refractive Errors/*diagnosis/epidemiology ; Republic of Korea/epidemiology ; Retrospective Studies

This study was performed to compare the incidence of posterior capsular opacity (PCO) and refractive errors between hydrophilic (ACR6D, Corneal (R) ) and hydrophobic (MA60BM, AcrySof (R) ) acrylic intraocular lenses (IOLs) over a 3-year follow-up after phacoemulsification surgery. The patients with AcrySof (R) implanted in one eye and Corneal (R) in the other eye were categorized as Group 1 (n=28), while those with one or both eyes implanted with IOLs of the same kind were categorized as Group 2 (AcrySof (R), n=90; Corneal (R), n=95). Refractive errors were evaluated at 3 months and 3 years postoperatively. The incidence of visually significant PCO was investigated 3 years postoperatively. Postoperative refractive values at 3 months were not significantly different between the two groups. However, refractive values at 3 years were significantly different between two IOLs in both groups [AcrySof (R) -0.37 +/- 0.43D, Corneal (R) -0.62 +/- 0.58D in Group 1 (p=0.04) ; AcrySof (R) -0.38 +/- 0.52, Corneal (R) -0.68 +/- 0.54 in Group 2 (p< 0.01) ]. The incidence of visually significant PCO was 14% and 32% in Group 1, and 13% and 28% in Group 2, for the AcrySof (R) and Corneal (R) implants, respectively. The incidence of visually significant PCO of hydrophilic acrylic IOLs was higher than that of hydrophobic acrylic IOLs in the 3-year follow-up. The postoperative 3-year refractive value of Corneal (R) showed myopic shift.
*Acrylic Resins ; Aged ; Cataract/*epidemiology/etiology ; Comparative Study ; Female ; Follow-Up Studies ; Humans ; Hydrophobicity ; Incidence ; Lens Capsule, Crystalline/*pathology ; Lens Implantation, Intraocular ; *Lenses, Intraocular ; Male ; Middle Aged ; Phacoemulsification ; *Postoperative Complications ; Refractive Errors/*epidemiology/etiology