Risk Factors for Pterygium in Ilam Province, Iran

Are Periocular and Systemic Allergy Conditions Risk Factors for Pterygium?

PURPOSE

To evaluate risk factors for pterygium and prevalence of periocular and systemic diseases among patients with pterygium.

METHODS

A retrospective case-control study was conducted among members of Clalit Health Services (CHS) in Israel, from 2001 to 2022. A total of 13,944 patients diagnosed with pterygium were included. For each case, three controls were matched among all CHS patients according to year of birth, sex, and ethnicity. Mixed models were used to assess differences in demographic characteristics, ocular and systemic diseases between the groups. Generalized estimating equation (GEE) logistic regression was used to estimate the odds ratios (OR) and adjust for confounders.

RESULTS

The average age of pterygium patients was 49 ± 17 years; 51% were male. The results showed significant associations between pterygium and risk factors of vernal kerato-conjunctivitis (OR 2.52, 95% confidence interval [CI]: [1.96-3.24]), chronic allergic conjunctivitis (OR 1.98, 95% CI: [1.65-2.39]), blepharitis (OR 1.91, 95% CI: [1.78-2.04]), chalazion (OR 1.47, 95% CI: [1.30-1.67]) and unspecified systemic allergy (OR 1.21, 95% CI [1.09-1.34]), after adjusting for rural residency status. Glaucoma (OR 0.74, 95% CI [0.64-0.85]) and smoking (OR 0.70, 95% CI [0.66-0.75]) were protective factors against pterygium.

CONCLUSION

Systemic and periocular inflammatory and allergic diseases are risk factors for pterygium.

Occupational Exposure to Solar Radiation and the Eye: A Call to Implement Health Surveillance of Outdoor Workers

Globally, hundreds of millions of outdoor workers are exposed to solar radiation (SR) for the majority of their working life. Such occupational exposure is known to induce various adverse health effects to the eyes, mainly related to its ultraviolet (UV) component. The present work is a call-to-action aimed at raising the awareness on the need of health surveillance for the prevention of the chronic ocular diseases in outdoor workers. Photo-chemical chronic damage can induce pterygium at the outer layer of the eye and cataract in the lens. Considering carcinogenic effects, rare squamous-cells tumors of the cornea and/or of the conjunctiva and the ocular melanomas are associated with UV radiation exposure. Solar UV-related eye diseases should be considered as "occupational diseases" when there is sufficient exposure in workers, but they are often not recognized, and/or frequently not reported to the national compensation authorities. Therefore, to prevent the burden of these work-related eye pathologies, an adequate risk assessment with identification of appropriate preventive measures, and a provision of periodic health surveillance to the exposed workers, in particular considering those at higher risk of exposure or with individual susceptibility, should be urgently implemented.

Epidemiologic characteristics and the change of surgical methods of pterygium and pseudopterygium from 2013 to 2019 in China: A retrospective analysis

Introduction

Pterygium is a common multifactorial external eye disease, which causes various ocular symptoms and negatively affects appearance. The aim of this study was to analyze the epidemiological characteristics and the change of surgical methods of pterygium and pseudopterygium in China from 2013 to 2019.

Materials and methods

This study was a hospital-based nationwide retrospective study to estimate the epidemiologic characteristics and the change of surgical methods of pterygium and pseudopteygium in China from 2013 to 2019. The data was extracted from the Hospital Quality Monitoring System (HQMS) database. The diagnosis was based on the tenth revision of the International Classification of Diseases (ICD-10) code.

Results

Our study included 1,007,800 pterygium and 2,681 pseudopteygium inpatients. From 2013 to 2019, the proportion of pterygium and pseudopterygium patients who underwent surgery, among all ophthalmology inpatients, increased from 3.3% in 2013 to 7.84% in 2019. The male-female ratio of surgically treated pterygium and pseudopterygium is 1:1.8 and 1.6:1 respectively. Among all age groups, the hospitalized pterygium patients who received surgery were mainly 60-69 years old, accounting for 36.53%. The pseudopterygium patients who received surgery were mostly 50-59 years old, accounting for 24.02%. Among the 31 provinces of mainland China, Yunnan Province has the highest proportion of pterygium patients treated surgically (6.40%), while Shanghai has the highest proportion of pseudopterygium patients treated surgically (12.98%). The most common occupation of participants in the study was farmer, accounting for 47.62% and 28.53%, respectively. During the study period, the application of autologous stem cell transplantation increased year by year, and became the first choice for pterygium and pseudopterygium surgery.

Discussion

This study was the first to describe the epidemiological characteristics and surgical methods of hospitalized pterygium and pseudopterygium patients in China. This study provides important information for better diagnosis, treatment and prevention of pterygium and pseudopterygium.

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.

Computer-Assisted Pterygium Screening System: A Review

Pterygium is an eye condition that causes the fibrovascular tissues to grow towards the corneal region. At the early stage, it is not a harmful condition, except for slight discomfort for the patients. However, it will start to affect the eyesight of the patient once the tissues encroach towards the corneal region, with a more serious impact if it has grown into the pupil region. Therefore, this condition needs to be identified as early as possible to halt its growth, with the use of simple eye drops and sunglasses. One of the associated risk factors for this condition is a low educational level, which explains the reason that the majority of the patients are not aware of this condition. Hence, it is important to develop an automated pterygium screening system based on simple imaging modalities such as a mobile phone camera so that it can be assessed by many people. During the early stage of automated pterygium screening system development, conventional machine learning techniques such as support vector machines and artificial neural networks are the de facto algorithms to detect the presence of pterygium tissues. However, with the arrival of the deep learning era, coupled with the availability of large training data, deep learning networks have replaced the conventional networks in screening for the pterygium condition. The deep learning networks have been successfully implemented for three major purposes, which are to classify an image regarding whether there is the presence of pterygium tissues or not, to localize the lesion tissues through object detection methodology, and to semantically segment the lesion tissues at the pixel level. This review paper summarizes the type, severity, risk factors, and existing state-of-the-art technology in automated pterygium screening systems. A few available datasets are also discussed in this paper for both classification and segmentation tasks. In conclusion, a computer-assisted pterygium screening system will benefit many people all over the world, especially in alerting them to the possibility of having this condition so that preventive actions can be advised at an early stage.

Reproductive risk factors of pterygium in postmenopausal women: a nationwide study in the Republic of Korea

This study is to elucidate the associations between female reproductive factors and pterygium. A total of 1,339,969 postmenopausal women in a retrospective cohort of Korean National Health Insurance Service data on ages 40 and above in 2009 was included. Cox proportional hazards regression was conducted to assess the hazard ratio (HR) for pterygium according to reproductive factors. Late menarche, early menopause, short reproductive period, increasing parity (≥ 2 children), breastfeeding (≥ 6 months), and no use of hormone replacement therapy (HRT) or oral contraceptive (OC) were significantly associated with risk of pterygium. In multivariate analysis, the HR for pterygium was 1.764 (95% confidence interval [CI], 1.529–2.035) for menarche age ≥ 17 years (reference: menarche age < 12 years). The HR of menopause age ≥ 55 years was 0.782 (95% CI, 0.724–0.845) (reference: menopause age < 40 years). The HR of parity ≥ 2 was 1.261 (95% CI, 1.148–1.385) (reference: nulliparity). The HR of breastfeeding ≥ 1 year was 1.663 (95% CI, 1.564–1.768) (reference: no breastfeeding). The HRs of HRT and OC use for any length of time were lower than those for the non-user groups (reference). Reproductive factors that increase estrogen exposure have protective effects against pterygium in females.

Gold nanoparticles to enhance ophthalmic imaging

The use of gold nanoparticles as diagnostic tools is burgeoning, especially in the cancer community with a focus on theranostic applications to both cancer diagnosis and treatment. Gold nanoparticles have also demonstrated great potential for use in diagnostic and therapeutic approaches in ophthalmology. Although many ophthalmic imaging modalities are available, there is still a considerable unmet need, in particular for ophthalmic molecular imaging for the early detection of eye disease before morphological changes are more grossly visible. An understanding of how gold nanoparticles are leveraged in other fields could inform new ways they could be utilized in ophthalmology. In this paper, we review current ophthalmic imaging techniques and then identify optical coherence tomography (OCT) and photoacoustic imaging (PAI) as the most promising technologies amenable to the use of gold nanoparticles for molecular imaging. Within this context, the development of gold nanoparticles as OCT and PAI contrast agents are reviewed, with the most recent developments described in detail.

Prevalence of Pterygium and Associated Risk Factors in the High-Altitude Area of Ta'if City, Saudi Arabia

Background

Pterygium is an important public health problem. The prevalence rates of this disease varies widely from 1.2% to 23.4%.

Aim

To determine the prevalence rates and the associated risk factors of pterygium in the high-altitude area - Ta’if city, Saudi Arabia.

Material and method

A cross-sectional study was carried out from September 2018 till September 2019 at the ophthalmology outpatient clinics of King Abdul-Aziz Specialist Hospital, Ta’if area.

Results

Prevalence rate of pterygium in the high-altitude area, Ta’if city, Saudi Arabia was 2.4%. It is significantly higher in older patients belonging to the age group of more than 40 years. As for gender, it was significantly higher in male patients compared to females (2.6% vs. 1.9%). Pterygium prevalence was significantly higher among patients with outdoor occupations compared to indoor occupations (2.9% vs. 2.1%), and among patients with sunlight exposure during daily activities for more than 5 hours (2.6% vs. 2%) (p =< 0.05).

Conclusion

The overall incidence of pterygium in Al-Ta’if area, Saudi Arabia, was 2.4% but still lower than overall worldwide incidence (10.2%). There was an increased incidence of pterygium with age, high-altitude areas, rural areas, outdoor occupations, which is directly proportional to dose of sunlight exposure. Furthermore, smoking might be reported as a protective factor against pterygium.

Pterygium Is Related to Short Axial Length

Supplemental Digital Content is Available in the Text.

Purpose:

To test the hypothesis that pterygium presents with both refractive and anatomical changes, especially short axial length.

Methods:

A retrospective, hospital-based cross-sectional study included 521 eyes from 521 patients who were enrolled through a community survey by Shanghai Heping Eye Hospital was conducted. Patients with primary pterygium in at least 1 eye were considered the pterygium group, and those with normal eyes were considered the nonpterygium group. The prevalence and length of pterygium, refractive characteristics including spherical power, astigmatism, corneal curvature, and anatomical parameters including axial length, anterior chamber depth, endothelial cell density, and corneal thickness were compared between groups.

Results:

Five hundred twenty-one eyes of 521 patients (214 men and 307 women) with a mean age of 70.5 ± 7.6 years were included in the study. The prevalence of hyperopia (81.6%, 65.1%, P = 0.001), axial length (23.1 ± 1.2 mm, 24.2 ± 2.4 mm, P < 0.001), anterior chamber depth (2.9 ± 0.3 cm, 3.1 ± 0.4 cm, P = 0.001), flat K value (42.94 ± 2.16 diopters, 43.73 ± 1.48 diopters, P = 0.002), Kmax (51.13 ± 7.74 diopters, 47.49 ± 5.62 diopters, P < 0.001), and spherical power (0.97 ± 2.40 diopters, −0.82 ± 4.40 diopters, P < 0.001) were statistically different between the pterygium and nonpterygium groups. Age (r = −0.21, P = 0.025), corneal astigmatism (r = −0.41, P < 0.001), flat K value (r = −0.39, P < 0.001), and endothelial cell density (r = −0.33, P = 0.001) were all negatively correlated with the length of pterygium. The prevalence of pterygium and severe pterygium over 3 mm were statistically different according to the severity of hyperopia (P < 0.001) and axial length (P < 0.001). Stratified χ² analysis showed that axial length, rather than hyperopia, was a related factor to pterygium (odds ratio = 5.23, 95% confidence interval: 2.50–10.93).

Conclusions:

We conclude from our study that the prevalence of pterygium is related to small eye size. SDF-1/CXCR4 signaling may play a vital role in pterygium and shorter axial length. Further study focused on SDF-1/CXCR4 signaling will be needed.

Prevalence and Associated Factors of Pterygium Among Adults Living in Kolla Diba Town, Northwest Ethiopia

Background

Pterygium is a disfiguring disease that can potentially lead to blindness. It is more common in warm, windy and dry climates of tropical and sub-tropical regions of Africa. Globally, the prevalence ranging from 0.07% to 53%. Studies conducted on the prevalence of pterygium in developing countries were limited with a wider discrepancy between them. In this study, we aimed to assess the prevalence of pterygium and its associated factors among adults in Kolla Diba town.

Methods

A community-based cross-sectional study was done in Kolla Diba town from May 30-June 16, 2019. A systematic random sampling technique was used to select 627 study participants. The basic ophthalmic examination was performed using portable slit lamp, 3x magnifying loop with torch light and a pretested structured questionnaire was completed. The data entered into EPI INFO version 7 and analyzed using SPSS version 20. Descriptive statistics and binary logistic regression analysis were employed. P-values of <0.05 were considered statistically significant.

Results

A total of 605 study participants were involved with a response rate of 96.5%. Among them, 317 (52.4%) participants were males. The mean age of the respondents was 38.18 ± 15.56 with a range of (18–95) in years. The overall prevalence of pterygium was 112 (18.5% (95% CI (15.6–21.7)). Being widowed (AOR = 7.32 (95% CI: 2.88, 18.57)), outdoor occupation (AOR = 2.50 (95% CI: 1.46, 4.29)), sun exposure (AOR = 2.38 (95% CI: 1.28, 4.43)), wind exposure (AOR = 1.97 (95% CI: 1.04, 3.72)), alcohol drinking (AOR = 2.26 (95% CI: 1.48, 4.63)), and severe blepharitis (AOR = 2.45 (95% CI: 1.48, 4.05)) had statistically significant positive association with pterygium.

Conclusion

The prevalence of pterygium was relatively higher. Being widowed, outdoor occupation, sun exposure, wind exposure, alcohol drinking, and severe blepharitis were significantly associated with the development of pterygium.

Serum Fibroblast Growth Factor 21 in Patients with and without Pterygia

Purpose

Pterygium is a common fibro-vascular-related eye disease. The fibroblast growth factor 21 (FGF21) helps reduce neovascularization. Previous studies have shown that the serum level of FGF21 correlates with vascular eye diseases such as diabetic retinopathy and retinopathy of prematurity. In this study, the serum FGF21 is compared in patients with and without pterygium.

Methods

This descriptive-analytical cross-sectional study examines individuals with pterygium who visited the Ophthalmology Clinic of Khatam-al-Anbia Hospital in Mashhad, Iran, during 2017–2018. Control subjects were selected from healthy people without pterygium disease. Patients with a history of acute illness, chronic liver and kidney disease, diabetes, cancer, malnutrition and drug use, women who were pregnant or breastfeeding, and subjects who were taking anticonvulsants or glucocorticoids were excluded as these may affect insulin and glycosuria levels. Sixty people (30 in each group) were chosen using the convenient sampling method. Intravenous blood samples were taken from all patients. After preparing the patients, the freeze was checked using the enzyme-linked immunosorbent assay (ELISA) method after samples had been taken. Data were analyzed by SPSS using an independent t-test, Mann–Whitney, Chi-square, Kruskal–Wallis, and Kolmogorov–Smirnov tests (α = 0.05).

Results

The serum FGF21 levels were 319.09 ± 246.93 pg/ml and 608.88 ± 449.81 pg/ml (P = 0.005) in the pterygium group and control subjects, respectively. The average serum FGF21 was 281.55 ± 40.74 pg/ml in males and 361.375 ± 10.298 pg/ml in females in the pterygium group. The difference was not statistically significant (P = 0.19)

Conclusion

Our study showed that FGF21 levels were lower in patients with pterygium than the control subjects to a statistically significant level.

Bilateral Double-headed Recurrent Pterygium: A Case Presentation and Literature Review

Pterygium is a frequent corneal disease characterized by growing of fibrovascular tissue from the bulbar conjunctiva onto the cornea. Although the causes of pterygium are not obvious, sun exposure is closely correlated with its development. Pterygium, especially double-headed pterygium is mostly seen in warm climate and in individuals who work outdoors. A minority of pterygium is double-headed (both temporal and nasal origins). Bilateral recurrent double-headed pterygium is a very rare condition. Here, we reported a 35-year-old male patient with bilateral recurrent double-headed pterygium. A brief review about the recent literature concerning the etiology, associated risk factors, operation types and management of patients with recurrent pterygium was also discussed. The patient was a field worker, smoker and had a family history of pterygium. There was no ocular surgery history except pterygium surgery 15 years ago in both eyes. A successful pterygium excision was performed under local anesthesia with the vertical split conjunctival autograft transplantation (CAT) in both temporal and nasal parts of the right eye (randomly) for cosmetic disfigurement and avoidance of recurrence. The pathological report was consistent with pterygium. At postoperative first week, first and 1.5^th month visits, conjunctival autografts were in place and stable. No complications such as infection, corneal thinning or graft dislocation were seen. The patient was satisfied with his right eye and demanded the same surgery for his left eye. We suggest vertical split simultaneous CAT as a safe and useful surgical method for the treatment of recurrent double-headed pterygium; however, longer follow-up is required to confirm the outcome.

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.

Solar Radiation Exposure and Outdoor Work: An Underestimated Occupational Risk

A considerably high number of outdoor workers worldwide are constantly exposed for the majority of their working life to solar radiation (SR); this exposure is known to induce various adverse health effects, mainly related to its ultraviolet (UV) component. The skin and the eye are the principal target organs for both acute and long-term exposure. Actinic keratosis, non-melanoma skin cancers, and malignant melanoma are the main long-term adverse skin effects, whereas in the eye pterygium, cataracts, and according to an increasing body of evidence, macular degeneration may be induced. Despite this, SR exposure risk is currently undervalued, if not neglected, as an occupational risk factor for outdoor workers. SR exposure is influenced by various environmental and individual factors, and occupation is one of the most relevant. For a better understanding of this risk and for the development of more effective prevention strategies, one of the main problems is the lack of available and adequate methods to estimate SR worker exposure, especially long-term exposure. The main aims of this review were to provide a comprehensive overview of SR exposure risk of outdoor workers, including the UV exposure levels and the main methods recently proposed for short-term and cumulative exposure, and to provide an update of knowledge on the main adverse eye and skin effects. Finally, we also outline here preventive interventions to reduce occupational risk.

Occupational Exposure to Solar Radiation at Different Latitudes and Pterygium: A Systematic Review of the Last 10 Years of Scientific Literature

Pterygium is a chronic eye disease: among its recognized risk factors there is long-term exposure to ultraviolet (UV) radiation. The Sun is the main source of UV exposure: according to the World Health Organization, the Population Attributable Fraction of pterygium due to solar radiation (SR) is 42–74%. Outdoor work can deeply influence the eye exposure to solar UV rays, but, despite this, pterygium is currently not adequately considered as a possible occupational disease in this working category, at least in Europe. For this reason, we performed a systematic review of the scientific literature published in the last ten years (2008–2017) considering the role of outdoor work as a risk factor for pterygium, in order to give new support for the prevention of this UV related disease in workers. We identified 29 relevant papers. Our results show that pterygium prevalence highly increased with latitude and mean annual UV index, and outdoor work is one of the most relevant risk factors, as well as age and male sex, both in high risk and in moderate risk World areas considering the environmental UV levels. Accordingly, pterygium occurring in outdoor workers should be considered an occupational disease. Moreover, our findings clearly support the need of further research on more effective prevention of the occupational risk related to long-term solar radiation exposure of the eye.