Prevalence and associated factors for pterygium in a rural adult population (the Southern Harbin Eye Study)

TFOS Lifestyle: Impact of lifestyle challenges on the ocular surface

Many factors in the domains of mental, physical, and social health have been associated with various ocular surface diseases, with most of the focus centered on aspects of dry eye disease (DED). Regarding mental health factors, several cross-sectional studies have noted associations between depression and anxiety, and medications used to treat these disorders, and DED symptoms. Sleep disorders (both involving quality and quantity of sleep) have also been associated with DED symptoms. Under the domain of physical health, several factors have been linked to meibomian gland abnormalities, including obesity and face mask wear. Cross-sectional studies have also linked chronic pain conditions, specifically migraine, chronic pain syndrome and fibromyalgia, to DED, principally focusing on DED symptoms. A systematic review and meta-analysis reviewed available data and concluded that various chronic pain conditions increased the risk of DED (variably defined), with odds ratios ranging from 1.60 to 2.16. However, heterogeneity was noted, highlighting the need for additional studies examining the impact of chronic pain on DED signs and subtype (evaporative versus aqueous deficient). With respect to societal factors, tobacco use has been most closely linked to tear instability, cocaine to decreased corneal sensitivity, and alcohol to tear film disturbances and DED symptoms.

Prevalence and associated factors for pterygium in a Chinese rural population with type 2 diabetes in a cross-sectional study: Jiangsu Diabetic Eye Disease Study (JDEDS)

PURPOSE

To investigate the pterygium prevalence and evaluate risk factors of pterygium in rural type 2 diabetic (D2M) patients aged 50 years and above in Funing Country, Jiangsu Province, China.

METHODS

A cross-sectional ophthalmic survey was conducted in type 2 diabetes mellitus (D2M) patients aged ≥ 50 years in Funing County, Jiangsu Province, China, which was named Jiangsu Diabetic Eye Disease Study (JDEDS). All participants underwent a comprehensive questionnaire and ocular examination. Pterygium was diagnosed by slit lamp examination. The risk factors associated with pterygium were evaluated with logistic regression models.

RESULTS

The prevalence of pterygium was 22.37% (n = 427) and 95% confidence interval (CI) (20.50-24.24%) in D2M patients aged 50 years and above in JDEDS. The prevalence of pterygium was 18.32% (95% CI 15.33-21.32%) in men and 24.43% (95% CI 22.06-26.80%) in women. Women had a higher prevalence than men (p = 0.001). Multivariate analysis showed, for male participants with D2M, pterygium was independently associated with increasing age [70-79 years: OR and 95% CI 2.49(1.20-5.18), p = 0.014; ≥ 80 years: 4.84(2.04-11.47), p < 0.001], while cigarette smoking was the protective factors, especially in current smoker [OR and 95% CI 0.79(0.67-0.92); p = 0.003]. For female participants with D2M, age [60-69 years OR and 95% CI 1.68(1.07-2.62), p = 0.023; 70-79 years: 2.62(1.69-4.06), p < 0.001; ≥ 80 years:3.24(1.70-5.90), p < 0.001], hypertension [OR and 95% CI 1.40(1.05-1.87), p = 0.024], BMI 24-27.9 [OR and 95% CI 1.20(1.00-1.44), p = 0.047], higher HbA1c [(5.6-7.9) % OR and 95% CI 1.42(1.10-1.82), p = 0.006; (8.0-9.9) %: 1.32(1.10-1.58), p = 0.003] were risk factors.

CONCLUSIONS

D2M patients aged over 50 years has a high prevalence of pterygium in JDEDS. The pterygium prevalence is higher in female D2M participants. Diabetes and related factors may be risk factors of pterygium in female D2M patients. Further studies are needed to explore the gender difference in the pathogenesis of pterygium in D2M subjects.

Ethnic differences in the incidence of pterygium in a multi-ethnic Asian population: the Singapore Epidemiology of Eye Diseases Study

We evaluated the 6-year incidence and risk factors of pterygium in a multi-ethnic Asian population. Participants who attended the baseline visit of the Singapore Epidemiology of Eye Diseases Study (year 2004–2011) and returned six years later, were included in this study. Pterygium was diagnosed based on anterior segment photographs. Incident pterygium was defined as presence of pterygium at 6-year follow-up in either eye, among individuals without pterygium at baseline. Multivariable logistic regression models were used to determine factors associated with incident pterygium, adjusting for baseline age, gender, ethnicity, body mass index, occupation type, educational level, income status, smoking, alcohol consumption, presence of hypertension, diabetes and hyperlipidemia. The overall age-adjusted 6-year incidence of pterygium was 1.2% (95% confidence interval [CI] 1.0–1.6%); with Chinese (1.9%; 95% CI 1.4%-2.5%) having the highest incidence rate followed by Malays (1.4%; 95% CI 0.9%-2.1%) and Indians (0.3%; 95% CI 0.3–0.7%). In multivariable analysis, Chinese (compared with Indians; odds ratio [OR] = 4.21; 95% CI 2.12–9.35) and Malays (OR 3.22; 95% CI 1.52–7.45), male (OR 2.13; 95% CI 1.26–3.63), outdoor occupation (OR 2.33; 95% CI 1.16–4.38), and smoking (OR 0.41; 95% CI 0.16–0.87) were significantly associated with incident pterygium. Findings from this multi-ethnic Asian population provide useful information in identifying at-risk individuals for pterygium.

Fifteen-year incidence rate and risk factors of pterygium in the Southern Indian state of Andhra Pradesh

PURPOSE

To report 15-year incidence rate and associated risk factors of pterygium among people aged 30 years and above at baseline in the rural clusters of longitudinal Andhra Pradesh Eye Disease Study (APEDS III).

METHODS

The baseline APEDS I included 7771 participants of which 6447 (83%) were traced and 5395 (83.7%) were re-examined in APEDS III. To estimate the incidence of pterygium, we selected participants who were 30 years and above at baseline (4188), of which 2976 were traced and 2627 (88.3%) were examined, and based on inclusion criteria, 2290 participants were included in the study. The incidence rate of pterygium was defined as the proportion of people free of pterygium at baseline who had developed the condition at 15-year follow-up (range 13-17 years). Univariate and multivariable analyses for risk factors were undertaken.

RESULTS

The sex-adjusted incidence rate of pterygium was 25.2 per 100 person-years (95% CI 24.8 to 25.7) which was significantly higher for men than women (26.3 per 100 person-years (95% CI 25.6 to 27.0) and 24.7 (95% CI 24.1 to 25.3) respectively). At the multivariable analysis, male gender (RR: 1.35, 95% CI 1.0 to 1.83), no formal education (RR: 2.46, 95% CI 1.22 to 4.93), outdoor occupation (RR: 1.47, 95% CI 1.14 to 1.9) and lower body mass index (BMI) (<18.5) (RR: 1.25, 95% CI 1.02 to 1.55) were associated with increased risk of pterygium.

CONCLUSIONS

The overall incidence rate of pterygium was high in this rural population, especially in men and those engaged in outdoor activities, lack of formal education and with lower BMI. It is likely that greater exposure to ultraviolet light is a major contributing factor, thus warranting preventive strategies.

Prevalence and associated factors for pterygium in Han and Mongolian adults: a cross-sectional study in inner Mongolian, China

Background

To investigate the prevalence of pterygium and associated factors in Han and Mongolian adults at four survey sites in Inner Mongolia, China.

Methods

We conducted a population-based, cross-sectional study as part of the China National Health Survey (CNHS). By means of a stratified sampling method, we finally included 2651 participants of 30 years of age or older from a total of 3468 eligible residents. Factors associated with pterygium were analysed by a univariate analysis and logistic regression models.

Results

The study population included 1910 Han and 741 Mongolian adults. The mean age ± standard deviation of the study cohort was 48.93 ± 11.06 years. The overall prevalence of pterygium was 6.4% (n = 169); 1.4% (n = 38) of the cases were bilateral and 4.8% (n = 128) were unilateral. The most common grade of pterygium was Grade 2. Based on the results of the univariate analysis, eleven factors were included in a multivariate analysis. The results indicated that age (P < 0.001), outdoor occupation (P = 0.026), and time spent in rural areas (P < 0.001) were significantly associated with pterygium. Sex and ethnicity were not identified as risk factors.

Conclusions

Our results indicated that outdoor occupation, old age and more time spent in rural areas were risk factors for pterygium in Inner Mongolia. At the same time, town as a survey site (Hohhot and Tsining District) was a protective factor for pterygium. Ethnicity, gender, smoking, diabetes and high blood pressure are not associated with pterygium.

Pterygium Prevalence and Its Associations in a Russian Population: The Ural Eye and Medical Study

PURPOSE

To assess the prevalence of pterygia and its associations in a population in Russia.

DESIGN

Population-based cross-sectional study.

METHODS

The Ural Eye and Medical Study was performed in a rural and urban area in Ufa/Bashkortostan 1300 km east of Moscow. Out of 7328 eligible individuals aged 40+ years, 5899 (80.5%) individuals participated and underwent an ocular and systemic examination. Pterygia, defined as conjunctival extensions onto the clear cornea, were diagnosed upon slit-lamp examination and on corneal photographs.

RESULTS

Mean pterygium prevalence (per individual) was 138/5888 (2.3%; 95% confidence intervals [CI]:2.0, 2.7), with bilateral occurrence in 45 individuals (32.6% of patients with pterygium; 0.8% of study population). Pterygium prevalence increased from 0.8% (95% CI: 0.02, 1.6) in the age group from 40 to <45 years to 3.6% (95% CI: 2.1, 5.1) in the age group of 75+ years. In multivariable analysis, higher pterygium prevalence was associated with older age (P = .006; odds ratio [OR]: 1.03; 95% CI: 1.01, 1.04), rural vs urban region of habitation (P < .001; OR: 2.33; 95% CI: 1.57, 3.46), and lower level of education (P = .03; OR: 0.89; 95% CI: 0.81, 0.99), while the pterygium prevalence was statistically independent of sex (P = .34), Russian vs non-Russian ethnicity (P = .59), presence of diabetes mellitus (P = 1.00), arterial hypertension (P = .86), vegetarian vs mixed diet (P = 1.00), blood lipid concentration (P > .30), history of cardiovascular disease (P = .49), or axial length (P = .52).

CONCLUSIONS

In this rural and urban, typically multiethnic Russian study population aged 40+ years, a higher pterygium prevalence (mean: 2.3%) was correlated with older age, rural region of habitation, and lower educational level, while it was statistically independent of most other systemic or ocular parameters. A pterygium was not a biomarker for an internal medical disease.

Continuous exposure of nicotine and cotinine retards human primary pterygium cell proliferation and migration

Pterygium is a triangular-shaped hyperplastic growth, characterized by conjunctivalization, inflammation, and connective tissue remodeling. Our previous meta-analysis found that cigarette smoking is associated with a reduced risk of pterygium. Yet, the biological effect of cigarette smoke components on pterygium has not been studied. Here we reported the proliferation and migration properties of human primary pterygium cells with continuous exposure to nicotine and cotinine. Human primary pterygium cells predominantly expressed the α5, β1, and γ subunits of the nicotinic acetylcholine receptor. Continuous exposure to the mixture of 0.15 μM nicotine and 2 μM cotinine retarded pterygium cell proliferation by 16.04% (P = 0.009) and hindered their migration by 11.93% ( P = 0.039), without affecting cell apoptosis. SNAIL and α-smooth muscle actin protein expression was significantly downregulated in pterygium cells treated with 0.15 μM nicotine-2 μM cotinine mixture by 1.33- ( P = 0.036) and 1.31-fold ( P = 0.001), respectively. Besides, the 0.15 μM nicotine-2 μM cotinine mixture also reduced matrix metalloproteinase (MMP)-1 and MMP-9 expressions in pterygium cells by 1.56- ( P = 0.043) and 1.27-fold ( P = 0.012), respectively. In summary, this study revealed that continuous exposure of nicotine and cotinine inhibited human primary pterygium cell proliferation and migration in vitro by reducing epithelial-to-mesenchymal transition and MMP protein expression, partially explaining the lower incidence of pterygium in cigarette smokers.

Prevalence and risk factors for pterygium: a cross-sectional study in Han and Manchu ethnic populations in Hebei, China

AIMS

To investigate the prevalence, ethnic differences and associated risk factors for pterygium in Han and Manchu populations aged 40-79 years in Hebei province, China.

DESIGN

Cross-sectional study, as a part of the China National Health Survey.

SETTING

Hebei province, China.

PARTICIPANTS

A multistage cluster sampling method with urbanisation level-based stratification was used to select participants for this study. A total of 4591 individuals over 40 years were recruited for this study. Inclusive criteria: (1) residents who had been living in Hebei for more than 1 year; (2) Han individuals with both parents being Han, or Manchu individuals with both parents being Manchu; (3) underwent ophthalmic examinations and (4) information in the questionnaire was complete.

MAIN OUTCOME MEASURES

Multiple logistic regression analysis was used to evaluate the association between pterygium prevalence and factors of interest.

RESULTS

A total of 3790 individuals (2351 Hans and 1439 Manchus) met the study criteria, of which 248 were diagnosed with pterygium (6.5%). There was no significant difference between the prevalence rates in Hans (6.2%) and Manchus (7.2%) (p=0.232). Multivariate analysis revealed that the risk factors for grade 2 or higher pterygium were increasing age (p<0.001) and rural residence (OR 1.83; 95% CI 1.11 to 3.02; p=0.018), while the protective factors include gender (female) (OR 0.58; 95% CI 0.37 to 0.88; p=0.011), cigarette smoking (OR 0.53; 95% CI 0.34 to 0.83; p=0.005) and myopia (OR 0.50; 95% CI 0.33 to 0.77; p=0.002). Premature menopause (OR 2.66; 95% CI 1.05 to 6.72; p=0.038) increased the risk of grade 2 or higher pterygium in females, while higher high-density lipoprotein (HDL) (OR 1.94; 95% CI 1.08 to 3.47; p=0.027) was a risk factor of grade 2 or higher pterygium in males.

CONCLUSION

The overall prevalence of pterygium in Han and Manchu population in Hebei, China was approximately 6.1%. There were no differences in the prevalence of pterygium between Hans and Manchus, and the race was not a risk factor. This is the first study to report on the positive association between premature menopause and pterygium in females and between higher HDL levels and pterygium in males.

Healing of autologous conjunctival grafts in pterygium surgery

PURPOSE

To temporally study the healing of conjunctival autografts in consecutive patients following pterygium surgery.

METHODS

A case-cohort observational study. Thirty-two eyes of 28 patients who underwent pterygium surgery were included. All eyes had pterygium excision with conjunctival autografts. Twenty-seven eyes of 24 patients underwent excision of primary pterygium while five eyes of four patients had surgery for recurrent pterygium. All grafts were attached using fibrin glue. Mitomycin-C 0.04% was used intraoperatively in 25 eyes. All eyes were followed up at 1, 2, 4, 8, 12 weeks and 6 months postoperatively. Photographs were taken at each visit to monitor graft vessels, re-perfusion and healing. Main outcome measures were graft loss; re-perfusion of grafts and appearance and resolution of oedema, transudation and haemorrhage; approximation of graft edges to host bed and changes at donor site.

RESULTS

No graft tissue was lost. In all eyes, healing of autografts started with graft swelling due to oedema and transudation followed by re-perfusion injury, which manifested as swelling, variable vessels calibre, patchy or diffuse haemorrhage occurring within first week and resolving by fourth postoperative week. Graft vessels anastomose with vessels in surrounding conjunctiva and underlying episclera to re-establish blood circulation. Retraction of graft edges from surrounding conjunctiva was uncommon with rapid epithelialization of exposed (epi)sclera.

CONCLUSION

Conjunctival autografts in pterygium surgery follow a consistent healing pattern dominated by re-perfusion injury in early postoperative days. This produces dramatic changes in the autograft for which patients should be counselled before surgery. Conjunctival autografts are not at risk of falling off, losing epithelial cover or undergoing necrosis.

Ologen Implantation versus Conjunctival Autograft Transplantation for Treatment of Pterygium

Purpose

To evaluate the effectiveness and safety of Ologen implantation versus conjunctival autograft transplantation for primary pterygium.

Methods

A retrospective case-series analysis. Thirty-one eyes of 29 patients were included in the Ologen group and 42 eyes of 35 patients in the autograft group. The patients were followed up for 1 year and evaluated for slit-lamp biomicroscopy, intraocular pressure, and adverse events. Recurrence rate, complications, and final appearance of the cases were evaluated prospectively.

Result

At 1 year after operation, 2 eyes recurred (6.5%) in the Ologen group and 4 eyes recurred (9.52%) in the autograft group. There was no statistically significant difference between both groups (P=0.157, χ² = 3.781). There was no occurrence of serious complications. Two eyes among the 31 eyes of the Ologen group were conjunctivitis; the incidence of complications was 6.45% (2 eyes). There was conjunctivitis in 3 eyes of the autograft group, 1 eye complicated with symblepharon, and 1 eye with conjunctival granuloma; the incidence of complications was 11.90% (5 eyes), and there was no statistically significant difference between both groups (P=0.094). The conjuntiva was less vascular and inflamed at 1 month postoperatively in the Ologen group than in the autograft group.

Conclusions

Ologen transplantation was technically easier, provided short operative time compared with conjunctival autograft transplantation, and preserved healthy conjunctiva with less complication and less recurrence; it may be a new, safe, and effective alternative for improving the short-term success rate of primary surgery.

Prevalence and associated factors of pterygium among adults living in Gondar city, Northwest Ethiopia

Purpose

The aim of this study was to assess the prevalence and associated factors of pterygium among adults living in Gondar city, Northwest Ethiopia.

Methods

A cross sectional design study was carried out in 390 participants in Gondar city from April 15 to May 7, 2016. Basic ophthalmic examination was performed using portable slit lamb, 3.5x magnifying loop with torch light and a pretested and structured questionnaire was completed. The raw data has been entered into EPI INFO 3.5.1 and analyzed by SPPSS version 20. Descriptive statistics was summarized descriptive data. Logistic regression was used to summarize the predictors of pterygium. The variables with p-value less than 0.05 were considered as significant risks of pterygium.

Result

The prevalence of pterygium among study participants was 151(38.7% (95%CI; 33.8–43.8)). Among those who have pterygium, 149(98.7%) were developed pterygium on the nasal side and 15(9.9%) on temporal side of the either eye and 13(8.6%) have both. Age between 41-60(AOR = 2.20(95%CI: 1.22, 3.39)), age between 61-86(AOR = 7.97(95%CI: 2.74, 23.17)), male sex (AOR = 2.20(95%CI: 1.28, 3.82)), outdoor working area(AOR = 3.75(95%CI: 2.18, 6.46)), the use of traditional eye medication (AOR = 2.55 (95%CI: 1.04, 5.90)) and family history of pterygium (AOR = 6.68(95% CI: 2.53, 17.60)) were positively associated with pterygium whereas use of sunglass/hat (AOR = 0.40(95%CI:0.20, 0.78)) was negatively associated.

Conclusion

There is a high prevalence of pterygium in Gondar city northwest Ethiopia. Old age, male sex, outdoor working area, utilization of traditional eye medication and family history of pterygium were statistically significant predictors of pterygium. The use of sunglass/hat was protective against pterygium.

The prevalence and determinants of pterygium in rural areas

Purpose

To evaluate the prevalence of pterygium and its determinants in the underserved, rural population of Iran.

Methods

In this cross-sectional study of 3851 selected individuals, 86.5% participated in the study, and the prevalence of pterygium was evaluated in 3312 participants. A number of villages were selected from the north and south of Iran using multistage cluster sampling. Pterygium was diagnosed by the ophthalmologist using slit-lamp examination.

Results

The mean age of the study participants was 37.3 ± 21.4 years (2–93 years), and 56.3% (n = 1865) of them were women. The prevalence of pterygium was 13.11% [95%confidence interval (CI):11.75–14.47]. The prevalence of pterygium was 14.99 (95%CI:12.79–17.19) in men and 12.07 (95%CI:10.3–13.84) in women. Pterygium was not seen in children below the age of 5 years. The prevalence of pterygium increased linearly with age; the lowest and highest prevalence of pterygium was observed in the age group 5–20 years (0.19%) and 61–70 years (28.57%). Evaluation of the relationship between pterygium with age, sex, educational level, and place of living using a multiple model showed that age, living in the south of Iran, and low educational level were correlated with pterygium.

Conclusion

The prevalence of pterygium was significantly higher in Iranian villages when compared with the results of previous studies. This finding may represent the effect of a rural lifestyle and its risk factors.

Risk Factors for Pterygium in Korea: The Korean National Health and Nutrition Examination Survey V, 2010-2012

The aim of this study is to report general and age-specific risk factors for pterygium prevalence in the Korean population.This in an observational case series study.Data from total 24,812 participants (age 40 years or older) from the Korean National Health and Nutrition Examination Surveys conducted from 2010 to 2012 were retrieved. After applying exclusion criteria, data from 13,204 participants (821 with pterygium and 12,383 without) were used for univariate and multivariate analyses. General risk factors were identified and participants were grouped by decade: 40 s, 50 s, 60 s, 70 s, and 80+. Age-specific risk factors were investigated for each group.After univariate analysis, 2 multiple regression models were constructed. Model 1: age + sex + spherical equivalent (SE) + sun exposure hours + occupation (indoor vs outdoor) + residency area (rural vs urban) + education level; model 2: age + sex + SE + sun exposure hours. In model 1, older age (odds ratio [OR]: 1.05 95% confidence interval [CI]: 1.05-1.06), male gender (OR: 1.28, 95% CI: 1.01-1.61), and longer sun exposure hours (OR: 1.47, 95% CI: 1.11-1.94) were significant risk factors for pterygium prevalence whereas higher level of education (elementary school vs college, OR: 3.98, 95% CI: 2.24-7.06) and urban residency (vs rural residency, OR: 0.56, 95% CI: 0.45-0.70) were protective factors. Higher SE (OR 1.11, 95% CI: 1.03-1.19) refractive error was considered a risk factor when using model 2 for the analysis. Age-specific risk factors were different in each age group. Male gender was associated with higher pterygium prevalence in younger age groups while longer sun exposure (5+ hours/day) increased pterygium prevalence in older age groups.Previously characterized risk factors were also found in this large population study. However, we found that risk factors may vary according to the age group. Myopic eyes were found to have lower prevalence than hyperopic eyes.

Prevalence and racial differences in pterygium: a cross-sectional study in Han and Uygur adults in Xinjiang, China

PURPOSE

To understand the prevalence and associated risk factors of pterygium in Han and Uygur population in Xinjiang, China and to assess the racial differences.

METHODS

A cross-sectional study was conducted in two rural and three urban regions of Xinjiang. A multistage and stratified sampling method was used to select representative samples. Risk factors associated with pterygium were screened in logistic regression models.

RESULTS

Among 4617 participants aged 30 years and older, 2452 were Han and 2165 were Uygur Nationality adults. The overall prevalence of pterygium was 11.95% (n = 546), with 4.27% (n = 197) were bilateral and 7.56% (n = 349) were unilateral. Multivariate analysis indicated that race, age, and rural residence were significantly associated with any pterygium (P < 0.001 for all). The prevalence of pterygium (P < 0.01) in Han subjects was higher than that of Uygur subjects. Both age and rural residence were associated with any pterygium in Han and Uygur. Low education level had significant positive association with pterygium in Han population (P < 0.001).

CONCLUSIONS

Pterygium affects approximately one-ninth of Han and Uygur population. Compared with Uygur, Han ethnicity is a significant risk factor of pterygium. Our results indicated a higher prevalence of pterygium in rural areas of Xinjiang, China compared with urban cities. Age increase was also associated with presence of pterygium. Strategies are warranted to prevent the serious effects caused by pterygium.

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.

The ocular benefits of estrogen replacement therapy: a population-based study in postmenopausal Korean women

Purpose

To elucidate the prevalence of cataract, glaucoma, pterygia, and diabetic retinopathy among Korean postmenopausal women with or without estrogen replacement therapy (ERT).

Methods

A cross-sectional, nationally representative sample from the 4th Korea National Health and Nutrition Examination Survey (KNHANES IV) (2007–2009) was used. Participants were interviewed for the determination of socioeconomic and gynecologic factors. Each woman also underwent an ophthalmologic examination and provided a blood sample for risk factor assessment.

Results

Of 3968 postmenopausal women enrolled, 3390 had never received estrogen, and 578 were undergoing estrogen treatment. After adjusting for age, diabetes, hypertension, high cholesterol levels, and high low-density lipoprotein levels, the prevalence of anterior polar cataract, retinal nerve fiber layer (RNFL) defect, and flesh pterygium was higher in the non-ERT group (OR, 3.24; 95% CI, 1.12–9.35, OR 1.70; 95% CI, 1.04–2.78, OR 3.725; 95% CI, 1.21–11.45, respectively). Further, the prevalence of atrophic pterygium was lower in the non-ERT group compared to that in the ERT group (OR, 0.21, 95% CI, 0.07–0.63).

Conclusions

These data suggest that ERT has a protective effect against the development of anterior polar cataract, flesh pterygium, and RNFL defect.

Prevalence and associated factors for pterygium in rural agrarian central India. The central India eye and medical study

Purpose

To evaluate the prevalence of pterygia and associated factors in a rural population in a mostly undeveloped agrarian region.

Methods

The Central India Eye and Medical Study is a population-based study performed in a rural region of Central India. The study comprised 4711 subjects (aged 30+ years). A detailed ophthalmic and medical examination was performed. A pterygium was diagnosed during the slit lamp examination and confirmed on corneal photographs. It was defined as a fleshy fibrovascular growth, crossing the limbus and typically seen on the nasal, and sometimes temporal, conjunctiva.

Results

A pterygium was detected in 798 eyes (prevalence rate: 8.47±0.29%) of 608 (12.91±0.49%) subjects. Bilateral pterygia were present in 190 subjects (4.0% of study population). Pterygia prevalence increased from 6.7±0.8% in the age group 30-39 years, to 13.5±1.2% in the age group 50-59 years, to 25.3±2.1% in the age group 70-79 years. Prevalence of pterygia was associated with older age (P<0.001; regression coefficient B: 0.02; odds ratio (OR): 1.02; 95%CI: 1.01, 1.03), male gender (P<0.001;B:-0.73;OR: .48;95%CI:0.39,0.61), lower level of education (P<0.001;B:-0.30;OR:0.74;95%CI:0.69,0.80), lower body height (P=0.001;B:-0.02;OR:0.98;95%CI:0.97,0.99), and higher cylindrical refractive error (P<0.001;B:0.23;OR:1.26;95%CI:1.18,1.34). If the education level was dropped, the number of hours spent with vigorous activity outdoors (P=0.001;B:0.001;OR:1.001;95%CI:1.000,1.0001) was significantly associated with the prevalence of pterygia, in addition to older age (P<0.001;B:0.03;OR:1.03;95%CI:1.03,1.04), male gender (P<0.001;B:-0.49;OR:0.62;95%CI:0.49,0.77), lower body height (P=0.005;B:-0.02;OR:0.98;95%CI:0.97,0.99), and higher cylindrical refractive error (P<0.001;B:0.23;OR:1.25;95%CI:1.18,1.34).

Conclusions

Pterygium prevalence in rural Central India is about 13% among adult Indians aged 30+ years. Older age, male gender, lower educational level, lower body height and more time spent outdoors with vigorous work were associated factors. Since the living conditions in the study location were mostly untouched by modern developments, the results may show the prevalence and associations of pterygia without major medical or technologic influences.