Prevalence and Associated Factors of Pinguecula in a Rural Population in Shanghai,Eastern China

Abstract

Purpose: To determine the prevalence and associated factors of pinguecula in a rural Chinese population aged ≥50 years in Eastern China.

Methods: This cross-sectional, population-based survey included an age-stratified random sample of 1108 residents living in Lvxiang Town of Jinshan District. Participants were requested to complete a comprehensive questionnaire to collect demographic data, history of systemic diseases and lifestyle details. The presence of pinguecula on slit lamp examination was recorded. The prevalence of pinguecula and its associated factors were investigated by logistic regression models.

Results: Among 1108 eligible subjects, 959 participated in the study, with an average age of 65.1?±?9.2 years (range 50–89 years). The overall age-adjusted prevalence of pinguecula in this population was 75.57% (95% confidence interval 71.79–79.35%). Logistic regression analysis revealed that age (p?=?0.002) and working outdoors (daily sunlight exposure ≥2 hours; p?=?0.001) were independent risk factors for pinguecula. In addition, sex, education level, alcohol intake, smoking and decreased tear break-up time did not have associations with the development of pinguecula after adjusting for age and outdoor work occupations.

Conclusions: The prevalence of pinguecula was 75.57% in this Chinese population aged?≥?50 years from a coastal rural area of Shanghai, Eastern China, which was higher than the majority of previous findings. Age and working outdoors were independent risk factors for pinguecula.     

The Prevalence of Strabismus and Associated Risk Factors in a Southeastern Region of Brazil

Purpose: To determine the prevalence of strabismus and associated risk factors in southeastern Brazil. Methods: A cross-sectional, population-based study using a systematic sample from nine municipalities in a southeastern region of Brazil composed of 1852 individuals aged ≥1 and ≤12 years old was done. Visual acuity (VA), ocular alignment, and refractive error (RE) were evaluated. Strabismic individuals (strabismus group) were compared to orthotropic individuals (orthotropic group) to analyze risk factors linked to heterotropias. Results: Prevalence of strabismus was 0.81% in this population. In the strabismus group, we found 40% with hyperopia, 6.67% with astigmatism, 3.33% with myopia, 6.67% with amblyopia, and 8.33% with moderate anisometropia. In the orthotropic group, 6.85% had hyperopia, 18.12% astigmatism, 14.82% myopia, 0.19% amblyopia, and 4.37% moderate anisometropia. Conclusion: The prevalence of strabismus in southeastern Brazil was 0.81%. Strabismic individuals had more hyperopia. Amblyopia and moderate anisometropia were associated with strabismus.     

The Prevalence of Anisometropia,Amblyopia and Strabismus in Schoolchildren of Shiraz,Iran

Purpose: To determine the prevalence of amblyopia, anisometropia, and strabismus in schoolchildren of Shiraz, Iran.

Materials and Methods: A random cluster sampling was used in a cross-sectional study on schoolchildren in Shiraz. Cycloplegic refraction was performed in elementary and middle school children and high school students had non-cylcoplegic refraction. Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were recorded for each participant. Anisometropia was defined as spherical equivalent (SE) refraction difference 1.00D or more between two eyes. Amblyopia was distinguished as a reduction of BCVA to 20/30 or less in one eye or 2-line interocular optotype acuity differences in the absence of pathological causes. Cover test was performed for investigating of strabismus.

Results: Mean age of 2638 schoolchildren was 12.5 years (response rate?=?86.06%). Prevalence of anisometropia was 2.31% (95% confidence interval [CI], 1.45 to 3.16). 2.29% of schoolchildren (95% CI, 1.46 to 3.14) were amblyopic. The prevalence of amblyopia in boys and girls was 2.32% and 2.26%, respectively (p?=?0.945). Anisometropic amblyopia was found in 58.1% of the amblyopic subjects. The strabismus prevalence was 2.02% (95% CI, 1.18 to 2.85). The prevalence of exotropia and esotropia was 1.30% and 0.59%, respectively.

Conclusions: Results of this study showed that the prevalence of anisometropia, amblyopia, and strabismus are in the mid range. The etiology of amblyopia was often refractive, mostly astigmatic, and non-strabismic. Exotropia prevalence increased with age and was the most common strabismus type.     

Prevalence and Risk Factors for Trachoma in Rural Areas of Sistan-va-Baluchestan Province,Iran: A Population-Based Study

ABSTRACT

Purpose: To determine the prevalence of trachoma and risk factors associated with the disease in rural areas of the Sistan-va-Baluchestan province in Iran from 2012–2013. Population-based prevalence data for trachoma is lacking in this region.

Methods: In this population-based cross-sectional study, 80 clusters were selected using a systematic and probability proportional to size method. All participants underwent clinical eye examinations according to the World Health Organization simplified trachoma grading system. The prevalence of follicular trachoma (TF) in children aged 1–9 years and the prevalence of trachomatous trichiasis (TT) in women aged over 15 years were the most important clinical indicators of trachoma.

Results: The study surveyed 8187 individuals and analyzed 7912 participants (96.6%) including 3737 children aged 1–9 years and 4175 females >15 years. The prevalence of TF and TT in the relevant indicator groups were 0.59% (95% confidence interval, CI, 0.36–0.89%) and 0.02% (95% CI 0.00–0.13%), respectively.

Conclusion: Previously, trachoma prevalence data for this region were lacking. This study confirms that the Sistan-va-Baluchestan region is not endemic for trachoma. This has important implications for national trachoma elimination activities.     

The Prevalence of Corneal Opacity in Rural Areas in Iran: A Population-based Study

Purpose: To determine the prevalence of corneal opacity in rural areas in Iran: a population-based study

Methods: This was a cross-sectional population-based study using multi-stage cluster sampling from rural-dwellers of villages in the north and southwest of Iran. All participants underwent vision testing including measurement of visual acuity and refraction followed by slit lamp examination by an ophthalmologist through which the presence of corneal opacity was determined.

Results: The participants were 3314 people (response rate = 86.5%), and 56.3% were female. The prevalence of corneal opacity in at least one eye in the studied subjects was 1.68% (95% CI: 1.08–2.27%); 1.07% (95% CI: 0.04–3.43%) and 2.47% (95% CI: 1.49–3.43%) in women and men, respectively, and 1.45% (95% CI: 0.4–2.45%) and 1.97% (95% CI: 1.3–2.94%) in the southwest and north of the country, respectively. The prevalence of corneal opacity was related to male gender (OR = 2.06, 95% CI: 1.13–3.74) and age (OR = 1.06, 95% CI: 1.04- 1.09) but not with education level. The prevalence of visual impairment and blindness among cases with corneal opacity was 46.2% and 19.2%, respectively.

Conclusion: Given the high prevalence of corneal opacity in rural areas in Iran, it is essential to prioritize rural areas for allocation of resources and facilities for the diagnosis, screening, and necessary treatment measures.     

The Prevalence of Ptosis and Its Association with Amblyopia and Strabismus in 7-Year-Old Schoolchildren in Iran

Abstract

Purpose: To determine the prevalence of ptosis (congenital/acquired) in Iranian children aged 7 years and its relationship with amblyopia and strabismus.

Methods: Eight Iranian cities were selected for this cross-sectional study using multistage randomized cluster sampling. A number of primary schools were randomly selected in each city. All grade 1 students in each selected primary school underwent optometric examinations including the measurement of uncorrected and corrected visual acuity, cover test, and cycloplegic and non-cycloplegic refraction.

Results: Of 4614 selected students, 4106 students participated in the study (response rate?=?89%). The prevalence of ptosis (congenital/acquired) was 1.41% (95% CI 1–1.83); 0.49% (95% CI 0.26–0.72) and 0.93% (95% CI 0.59–1.26) had unilateral and bilateral ptosis, respectively. The prevalence of ptosis had no significant correlation with sex (p?=?0.810, OR?=?1.07, 95% CI 0.59–1.97). The prevalence of amblyopia was 48.28% and 0.89% in students with and without ptosis, respectively. The prevalence of tropia was significantly higher in cases with bilateral ptosis (p?<?0.001). The mean cylinder error was 1.63?±?1.72 and 0.44?±?0.60 in ptotic and non-ptotic eyes, respectively (p?<?0.001). With-the-rule (WTR) astigmatism was significantly more prevalent in students with ptosis.

Conclusion: We report the prevalence of ptosis (congenital/acquired) in children in Iran and the Middle East region for the first time. Amblyopia was considerably more prevalent in ptotic patients. We found a significant correlation between ptosis and tropia. Astigmatism, especially WTR stigmatism, was more prevalent in children with ptosis.     

Prevalence and Risk Factors of Strabismus in a UK Multi-ethnic Birth Cohort

Purpose: To determine the prevalence, types and early-life risk factors associated with strabismus in a multi-ethnic birth cohort of children aged 4-5 years in the first year of school.

Methods: Data were collected prospectively over a 3-year period (2012-2015) from children participating in the vision screening program provided by orthoptists and carried out in schools located in the city of Bradford, UK. Prevalence of strabismus was determined for 17,018 children aged 4 to 5 years. Data linkage was undertaken for 4563 children participating in the Born in Bradford birth cohort study and the vision screening program. 4067 children had complete data and were included in the multivariable regression analyses to determine associated factors.

Results: 401/17018 (2.4%) children were found to have either a constant or an intermittent strabismus; 179/401 (45%) had an esotropic deviation, 214 (53%) an exotropic deviation, and 8 (2%) had a vertical deviation. No significant difference in the overall prevalence of strabismus was found between the white British, Pakistani, or children of other ethnic origin (P=0.41). Multivariable analysis showed that children of white British ethnicity have twice the odds of having esotropia (OR 2.4, 95% CI: 1.1, 5.3). The odds of having esotropia were highest in children with a hyperopic mean spherical equivalent (OR 2.0, 95% CI: 1.7, 2.6). There was some evidence of an interaction between ethnicity and mean spherical equivalent in children with esotropia (P=0.058).

Conclusions: Prevalence of strabismus is consistent with other population-based studies in this cohort of children aged 4-5 years. Prevalence of esotropia (constant or intermittent) is greater in the white British population, odds of esotropia increased with increasing hyperopic refractive error in both white British and Pakistani children. Exotropia (constant or intermittent) was not found to be associated with refractive error, ethnicity, or other early life factors.     

A Population-based Study of Corneal Arcus and its Risk Factors in Iran

Purpose: To determine the prevalence of corneal arcus, its risk factors, and its relationship to ocular and visual indices.

Methods: In this cross-sectional study, 300 clusters were randomly selected from Shahroud in the north of Iran, using multistage sampling. A total of 20 people were invited to participate from each cluster. After enrollment, all optometric, biometric and ophthalmic exams were conducted on site.

Results: Of 6311 people invited, 5190 (82.2%) participated in the study. The prevalence of corneal arcus was 23.3% (95% confidence interval, CI, 22.1–24.6), and 98.4% were bilateral cases. The prevalence of corneal arcus was higher in men (odds ratio, OR, 2.02, 95% CI 1.8–2.3, p?p?p?=?0.006), male sex (OR 1.30, p?=?0.001), diabetes (OR 0.7, p?p?=?0.003), outdoor activity (OR 1.4, p?=?0.006), systolic blood pressure (OR 1.01, p?=?0.012), and diastolic blood pressure (OR 0.99, p?=?0.016) were significantly correlated with corneal arcus. Including biometric components in another model, corneal thickness (OR 0.99, p?p?p?Conclusion: This study adds valuable information to the epidemiology of corneal arcus in Iran and the Middle East. In people aged over 60 years, nearly 50% of the study population had corneal arcus. Older age, male sex, smoking, and systolic hypertension were risk factors for corneal arcus. Corneal arcus was also associated with thin and flat corneas and shallow anterior chamber depth.     

Prevalence and Risk Factors for Anisometropia in the Tehran Eye Study,Iran

Purpose: To determine the prevalence of anisometropia and its determinants in a population-based sample.

Methods: In a cross-sectional population-based study, stratified cluster sampling was carried out from the population of Tehran. Respondents were transferred to a clinic for an interview and ophthalmic examinations including tests for visual acuity with and without correction, cycloplegic refraction, the slit lamp examination, fundoscopy, and lensometry. Anisometropia was defined as unequal spherical equivalent cycloplegic refractions in the two eyes.

Results: Of 4565 participants, cycloplegic refraction was performed in both eyes of 3519 people. The mean age of the examinees was 31.5?±?18.0 (range, 5–86) years. The mean anisometropia was 0.34 diopter (D) (95% Confidence Interval (CI): 0.31–0.37). The prevalence rates of anisometropia more than 0.5, 1.0, 1.5 and 2.0 D were 18.5% (95% CI: 17.0–19.9), 6.7% (95% CI: 5.8–7.7), 3.8% (95% CI: 3.1–4.5) and 2.6% (95% CI: 2.1–3.1). The inter-gender difference in the prevalence of anisometropia ≥ 1.0D was not statistically significant (P?=?0.952). The prevalence of anisometropia increased after the age of 45 years. Overall, 15.7% of the examinees had anisomyopia and 4.7% had anisohypermetropia equal to or more than 1.0D. Anisometropia was more prevalent among patients with cataracts, amblyopia, and pseudophakia. The prevalence rates of spherical and cylindrical anisometropia in the studied sample were 8.0% and 7.1%, respectively.

Conclusions: The prevalence of anisometropia in the population of Tehran is beyond negligible. It showed a significant increase with age. Results also indicate that myopic patients are more likely to have anisometropia.     

Refractive Error among the Elderly in Rural Southern Harbin,China

Purpose: To estimate the prevalence and associated factors of refractive errors among the elderly in a rural area of Southern Harbin, China.

Methods: Five thousand and fifty seven subjects (age ≥50 years) were enumerated for a population-based study. All participants underwent complete ophthalmic evaluation. Refraction was performed by ophthalmic personnel trained in the study procedures. Myopia was defined as spherical equivalent worse than -0.50 diopters (D) and hyperopia as spherical equivalent worse than +0.50 D. Astigmatism was defined as a cylindrical error worse than 0.75D. Association of refractive errors with age, sex, and education were analyzed.

Results: Of the 5,057 responders (91.0%), 4,979 were eligible. The mean age was 60.5 (range 50–96) years old. The prevalence of myopia was 9.5% (95% confidence interval [CI], 8.5–10.1) and of hyperopia was 8.9% (95% CI, 7.9–9.5). Astigmatism was evident in 7.6% of the subjects. Myopia, hyperopia and astigmatism increased with increasing age (p<0.001, respectively). Myopia and astigmatism were more common in males, whereas hyperopia was more common in females. We also found that prevalence of refractive error weas associated with education. Myopia was more common in those with higher degrees of education, whereas hyperopia and astigmatism were more common in those with no formal education.

Conclusions: This report has provided details of the refractive status in a rural population of Harbin. The prevalence of refractive errors in this population is lower than those reported in other regions of the world.     

Asthenopia,Associated Phoria,and Self-Selected Prism

Abstract

Purpose: The vergence position of rest (phoria) has been found to vary over time. We asked whether the vergence position of rest is correlated with discomfort on reading.

Methods: We examined 20 subjects who reported strain on prolonged reading (“asthenopes”) and 20 subjects who did not (“non-asthenopes”). The eyes were normal in all subjects. Associated phoria (AP) was determined by asking the subjects to align monocular markers in the Mallett Near Vision Unit. In addition, subjects were asked to adjust Risley prisms so that viewing appeared most relaxing while they were looking at fully fusionable pictures (self-selected prism?=?SSP). Both AP and SSP were determined at near. Each subject participated in 6 sessions. Before each session, the subjects read a text for 30 minutes. Immediately afterwards they indicated on a visual analogue scale the discomfort they had experienced during the 30 minutes.

Results: In asthenopic individuals, AP fluctuated up to 19Δ, SSP up to 20Δ. In non-asthenopic individuals, AP fluctuated up to 17Δ, SSP up to 20Δ. The correlation between AP and SSP was r?=?0.73 (p?<?0.001) in the non-asthenopes and r?=?0.81 (p?<?0.001) in the asthenopes. Neither AP nor SSP were significantly larger in the asthenopes than in the non-asthenopes. Intra-individually, among the 6 sessions, the magnitude of discomfort was not significantly correlated to AP or SSP, neither in the asthenopes nor in the non-asthenopes. Asthenopes who rated their discomfort higher did not have a larger heterophoria.

Conclusion: The lack of a significant correlation between discomfort and (horizontal) heterophoria (determined as AP or SSP), especially intra-individually among repeated measurements, does not support a causal relationship.     

Prevalence and Associated Factors of Refractive Errors Among Type 2 Diabetics in Kinmen,Taiwan

Purpose: A community-based study was conducted to identify the extent of prevalence of refractive errors and their associated factors from among the Chinese type 2 diabetic population in Kinmen. Methods: A total of 547 patients (> 40 years old) with type 2 diabetes were examined with a complete eye screening tests including objective autorefraction. Spherical equivalent refractions of right eyes were reported. Data collected include age, gender, general medical information and serum biochemistry. Results: The mean refraction was ?0.83 ± 2.49 D. Prevalence rates were determined for myopia (44.1%), hyperopia (24.1%), high myopia (13.0%), and astigmatism (87.8%). Age is an important factor for all of the refractive errors. After adjustment for age, male gender and > 3 grade nuclear opacity appeared to be statistically significant factors for myopia. For hyperopia, ≥7% HbA1c was a significant associated factor, and for astigmatism, ≥200 mg/dl total cholesterol was the risk factor. Multiple linear regression showed that every increase of one year of age and one percent of HbA1c is associated with 0.04 D (p = 0.003) and 0.13D (p = 0.04) shift in hyperopia, respectively. Nuclear opacity with grade 3-4 and grade 5-6 will shift toward myopia of ?0.72D (p = 0.02) and ?5.34D (p < 0.0001) after adjustment for other risk factors. Conclusions: This study provides epidemiological data on refractive errors in a Chinese diabetic population in Kinmen, Taiwan. The myopia prevalence is higher than the reported rates in the general population. This survey further confirmed that myopia is more prevalent than hyperopia in the diabetic population. Age and blood sugar shift the refraction toward hyperopia while nuclear cataract reverses it. Correction of refractive errors in the diabetics remained a challenge as not only spectacles but medical intervention is mandatory.     

湖北省孝感市小学生视力调查及近视相关因素分析

目的：探讨学龄期儿童近视患病率与近视的影响因素,为儿童近视的防控提供理论依据。方法：横断面调查研究。于2017年6月至2019年6月,采用随机整群抽样方法抽取湖北省孝感市一年级小学生675人,对其进行视力检查与屈光状态检查以及一般情况与用眼行为问卷调查,完成每年1次数据收集,共随访3年。采用秩和检验、卡方检验与Logistic回归分析进行统计学分析。结果：3年期间小学生近视患病率逐年增高,分别为14.1%、25.6%、39.6%,差异有统计学意义（χ2=106.25,P<0.001）。3年期间小学生等效球镜度（SE）逐年降低,分别为0.25（-0.25,0.50）D、0.00（-0.50,0.25）D、-0.50 （-1.75,0.00）D,差异有统计学意义（χ2=234.819,P<0.001）。近视每年新发病率为16.0%～22.7%,近视年发病率随年龄增大而增加,差异有统计学意义（χ2=14.233,P<0.001）。早产（P=0.014）、父母近视情况（P=0.029）、每天户外活动时间（P=0.024）、每天放学后近距离学习时间（P=0.006）、家长平时是否督促孩子保护眼睛（P=0.004）、每天使用电子产品时间（P=0.013）等变量与近视发生有相关性。结论：学龄期儿童屈光状态逐年向近视方向发展,近视患病率逐年增加。早产、父母近视、长时间近距离学习以及使用电子产品是近视发生的危险因素,户外活动与家长督促孩子保护眼睛是近视发生的保护因素。     

Social Determinants and Their Impact on Visual Impairment in Southern Mexico

Abstract

Purpose: Visual impairment in disadvantaged populations in Mexico has been scarcely reported. We compared the prevalence of visual impairment and its associated risk factors in populations in rural compared to urban areas of the Mexican southern state of Chiapas.

Methods: In a population-based study, the prevalence of visual impairment in rural and urban areas of Comitan, Chiapas, was estimated. All eligible individuals aged ≥20 years living in rural areas were invited to participate; persons from urban areas were chosen randomly. Individuals were considered of indigenous (IND) origin either by self-report or if they spoke an IND language. Visual acuity (VA) and pinhole VA were measured using a tumbling E chart. VA was defined as normal (better than or equal to 20/60), moderate impairment (worse than 20/60 but better than or equal to 20/200), severe impairment (worse than 20/200 but better than or equal to 20/400), or blindness (worse than 20/400).

Results: Data on VA were obtained from 969 persons (610 rural, 359 urban) whose mean age was 43.3 years (standard deviation 15.6 years). Prevalence of moderate visual impairment was higher in rural (10.2%, 95% confidence interval, CI, 7.2–14.2%) than urban (3.9%, 95% CI 1.9–7.9%) areas (p?<?0.001). Persons with moderate visual impairment were older and less educated (both p?<?0.001). Rural individuals aged 50 years and older had 4.4 times (95% CI 1.8–11.3, p?=?0.002) the likelihood of having moderate visual impairment compared with urban persons.

Conclusion: Unfavorable socioeconomic conditions were associated with higher prevalence of moderate visual impairment in rural compared with urban populations in Mexico.     

The Prevalence of Amblyopia in 7-year-old Schoolchildren in Iran

Purpose: To determine the prevalence of amblyopia in schoolchildren aged 7 years in Iran, its relation with refractive errors, and its determinants.

Methods: In this cross-sectional study, cluster sampling was done from elementary school students in 7 cities in Iran. In all schools, an optometrist conducted all tests, including measurement of uncorrected and corrected visual acuity, cycloplegic refraction, and cover test. In this study, amblyopia was defined as best corrected visual acuity 20/30 or less or a 2-line interocular optotype acuity difference with no pathology.

Results: Of the 4157 students selected for the study, 3675 participated and final analyses were done with data from 3547 children. The prevalence of amblyopia was 1.88% (95% CI: 1.24–2.52) (n?=?63). The prevalence was 1.91% (95% CI: 0.85–2.97) in boys and 1.85% (95% CI: 1.12–2.58) in girls (p?=?0.92). Among these cases, 60.30% (n?=?38) were unilateral. Also, 61.9% were strabismic, 27.0% were anisometropic, 9.5% were isometropic, and one case (1.6%) was due to congenital cataracts. Amblyopic individuals were more hypermetropic and the mean cylinder error was significantly higher.

Conclusion: Necessary attention should be paid to amblyopia, although its prevalence in Iran is mid-range when compared with other countries. Amblyopia is more common in hyperopic and astigmatic individuals and therefore it is important to pay more attention to this refractive error during childhood. Since strabismus is the most common cause of amblyopia in Iran, children need to be checked for strabismus before the age of 5 years.     

山东省龙口市7～18岁中小学生近视患病率调查分析

目的：调查研究山东省龙口市7～18岁中小学生近视患病率情况,为近视防控提供科学依据。

方法：采用横断面随机整群抽样的方法于2015-01/12对山东省龙口市7～18岁在校学生以学校为抽样单位进行近视情况的调查,共抽取学校58所,有效抽样61 036人。按地域分为城市、城乡结合部及农村3类地区。由相关工作人员在全程质量控制下采用标准对数视力表检查受检者双眼裸眼视力,采用自动验光仪(TOPCON-RM8900)在非散瞳情况下行电脑验光检查。采用Microsoft Excel工作表建立数据库,SPSS 21.0软件进行统计学分析。

结果：2015年龙口市7～18岁中小学生的总体近视患病率为49.81%,11～12岁时总体近视患病率增幅最快,13岁时轻度近视患病率最高。男性和女性总体近视患病率分别为46.41%、53.39%,女性总体近视患病率高于男性。城市、城乡结合部及农村地区学生总体近视患病率分别为55.18%、49.75%、44.47%,城市学生总体近视患病率明显高于城乡结合部及农村地区。总体近视患病率与年龄呈正相关(r_s=0.943,P<0.05),即总体近视患病率随年龄的增长而逐渐升高。

结论：山东省龙口市2015年中小学生近视患病率较高,且随年龄的增长而逐渐升高,女性高于男性,城市高于城乡结合部及农村地区。     

Prevalence of refractive errors among schoolchildren in Shiraz,Iran

Purpose: To determine the prevalence of refractive errors in Shiraz schoolchildren by age and gender. Methods: For this cross‐sectional study, random cluster sampling was carried out from students of the 2008–2009 academic year. After the initial interview, ophthalmic examinations including tests of visual acuity, non‐cycloplegic and cycloplegic refraction and binocular vision were performed. Myopia was defined as a spherical equivalent ≤?0.50 dioptre (D), hyperopia as ≥+2.0 D, and astigmatism as a cylinder refraction ≥0.75 D. All values for school grade and gender were directly standardized based on the total student population in the 2008–2009 school year. Results: A total of 2130 students were sampled, of which 1872 participated in the study (response rate = 87.88%). The prevalence of uncorrected, best‐corrected, presenting and spectacle corrected visual acuity of 6/12 or worse in the better eye was 6.46%, 0%, 1.49% and 0.9%, respectively. The prevalence rates of myopia, hyperopia and astigmatism were 4.35% (95% confidence interval [CI]: 2.89–5.82%), 5.04% (95% CI: 3.50–6.58%), and 11.27% (95% CI: 9.81–12.74%), respectively. Anisometropia was detected in 2.58% of schoolchildren. The prevalence of hyperopia significantly decreased with age (P = 0.021). Conclusions: Compared with other reported rates, the prevalence of myopia in the schoolchildren of Shiraz is similar to that in most places excluding East Asian countries, and that of hyperopia is in the mid range.     

Prevalence of and Risk Factors for Pterygia in a Rural Northern Chinese Population

Purpose: To determine the prevalence of and associated risk factors for pterygia development in a high-latitude-dwelling Northern Chinese population.

Methods: A prospective population-based survey was conducted between November 2008 and July 2009. A stratified, clustered, randomized sampling procedure was used to select 8445 subjects, aged ≥18 years, all with diagnosed, graded pterygia. Risk factors associated with the occurrence of pterygia were evaluated according to logistic regression models.

Results: A total of 8445 residents (aged 18–94 years) from the Heilongjiang Province, China, participated in the study. Of these, 208 (2.5%) had at least one diagnosed pterygium. The prevalence of bilateral pterygia was 1.2% (95% confidence interval, CI, 1.0–1.4%). According to multivariable analysis, pterygia were significantly more likely to occur in persons aged 70–94 years than in those aged 18–39 years (odds ratio, OR, 29.0, 95% CI 13.6–61.6, p?<?0.01). Pterygia were significantly associated with male sex (OR 1.9, 95% CI 1.4–2.6, p?<?0.01) and outdoor work (OR 1.8, 95% CI 1.2-2.6, p?<?0.01). Multivariable analysis indicated that pterygia were not associated with smoking status (OR 1.0, 95% CI 0.8–1.4) or alcohol intake (OR 1.0, 95% CI 0.7–1.4, p?>?0.05).

Conclusions: This study details the occurrence of and risk factors for pterygia in a Chinese population residing in a rural, high-latitude, cold-climate area of Northern China. The primary risk factors for pterygia were age, male sex, and outdoor work.     

Prevalence and Associated Risk Indicators of Retinopathy in a Rural Bangladeshi Population with and without Diabetes

Abstract

Purpose: To determine the prevalence of retinopathy among people with normal and abnormal glucose metabolism in a remote rural community of Bangladesh, and to identify the associated risk indicators for developing retinopathy in this population.

Methods: A population-based cross-sectional study was conducted through screening in camp settings, which included a total of 836 participants (468 male and 368 female) aged 30 years or over. Retinopathy was determined by fundus photography. Anthropometric measures (body mass index and waist-to-hip ratio), oral glucose tolerance, glycosylated hemoglobin (HbA₁c), blood pressure, lipid profile, serum creatinine and urine albumin creatinine ratio (UACR) were measured. Logistic regression analysis was used with adjustment for potential confounders.

Results: The overall prevalence of retinopathy was 5.4% (95% confidence interval, CI, 3.9–6.9). The prevalence rates of retinopathy among diabetic, impaired glucose regulation and non-diabetic subjects were 21.6%, 13% and 3.5%, respectively. Adjusted odds ratios for retinopathy were 2.53 (95% CI 1.52–5.41) for abnormal glucose metabolism and 1.98 (95% CI 1.17–5.63), 1.74 (95% CI 1.09–3.02) and 1.63 (95% CI 1.08–3.12) for hypertension, HbA₁c and UACR, respectively. Additionally, age, body mass index, triglyceride and total cholesterol were also found to be significant independent risk indicators for the occurrence of retinopathy in this population.

Conclusion: A high prevalence of retinopathy was observed in this rural Bangladeshi population. In addition to blood glucose control for diabetes, screening for hypertension, obesity, hyperlipidemia and proteinuria as well as adequate treatment of these risk indicators may prevent retinopathy in rural Bangladeshi populations.