Frequency and risk factors for pterygium in the Barbados Eye Study

The effect of cyclosporine a in pterygium surgery using fibrin glue

BACKGROUND/OBJECTIVES

To evaluate the effect of topical cyclosporine A (CsA) 0.05% in patients with pterygium surgery using fibrin glue (FG).

SUBJECTS/METHODS

Patients with primary nasal pterygium were retrospectically analyzed and categorized into two groups: Group 1 with 41 eyes from 38 patients as a control group and group 2 with 39 eyes from 36 patients who received topical CsA twice a day for 6 months. Patients were assessed for recurrence rate, tear film parameters, side effects, and complications at postoperative intervals of 1-7 days; 1st, 3rd, 6th and 12th months. The follow-up period was 1 year.

RESULTS

The two groups were age (p = 0.934) and sex (p = 0.996) matched. CsA drop was discontinued in one patient due to burning sensation and conjunctival hyperemia after 1 week. There was no statistically significant difference between the mean preoperative and postoperative 1st year Schirmer I and tear break-up time (TBUT) values in group 1 (p = 0.136; p = 0.069). Although the difference between the mean preoperative and postoperative 1st year TBUT values in group 2 was not statistically different (p = 0.249), Schirmer I results were higher postoperatively (p = 0.003). There was no statistically significant difference between preoperative Schirmer (p = 0.496), postoperative Schirmer (p = 0.661), preoperative TBUT (p = 0.240) and postoperative TBUT (p = 0.238) results of the two groups. Recurrence was observed in only one patient from group 1.

CONCLUSION

No recurrent pterygium cases were observed in group 2. Schirmer I values were higher postoperatively in group 2; thus,topical CsA treatment may improve lacrimal secretion and be effective after pterygium surgery with FG.

Myopia intervention and ultraviolet radiation related eye diseases: A narrative literature review

There has been an increased understanding of the protective effect of two or more hours in high lux light on the development and progression of myopia. The aim of myopia management is to reduce the incidence of high myopia and sight-threatening myopic complications. Equally important are the sight-threatening complications of ultraviolet radiation (UVR) on the eye and adnexal structures. This review will analyze the literature for both these epidemics to help guide public health policy. Whilst increasing childhood high lux light exposure is important, consideration of a holistic eye health policy should ensure that UV eye diseases are also prevented. The advent of ultraviolet (UV) fluorescence photography has increased our understanding that significant UV eye damage occurs in childhood, with 81% of children aged 12-15 years having signs of UV eye damage. Hence, the need to reduce myopia and protect from UV-related eye diseases needs simultaneous consideration. Advocating for eye protection is important, particularly as the natural squint reflex is disabled with dark sunglasses lenses. The pathways UV reaches the eye need to be considered and addressed to ensure that sunglasses offer optimum UV eye protection. The design of protective sunglasses that simultaneously allow high lux light exposure and protect from UVR is critical in combating both these epidemics.

Results of Fibrin Glue Applied Over the Corneal Surface Immediately After Pterygium Surgery: A Novel Pain Relief Technique

PURPOSE

The aim of this study was to compare the use of fibrin glue on the corneal epitheliectomy site at the end of pterygium surgery versus conventional eye patch regarding pain levels, need for oral analgesic medications, number of days feeling pain, and awakening due to pain after surgery.

METHODS

Forty-eight eyes of 24 patients with bilateral primary pterygium were included in this prospective, randomized, double-masked controlled trial. Each eye of the same patient was randomized to the intervention or control group. The intervention group received 2 drops of fibrin glue in the epitheliectomy site at the end of surgery and an eye patch, whereas the control group was only received an eye patch. Patients returned on the first and seventh days after surgery. Pain intensity (measured using the visual pain analog scale), need for oral analgesics, the number of days the pain lasted, and quality of sleep were assessed during follow-up visits and compared between groups. Comparison analysis accounted for sex, age, pterygium grading, and comorbidities.

RESULTS

Visual analog pain scale after surgery was significantly lower in eyes receiving fibrin glue (-1.58; 95% confidence interval: -2.84 to -0.32; P = 0.014). In addition, the intervention group presented a 73% lower chance of using oral analgesics (OR: 0.27; 95% confidence interval: 0.07-0.95; P = 0.041). No difference in the awakenings at night was noted ( P = 0.240) nor the mean days of ocular pain in the first week after surgery ( P = 0.474).

CONCLUSIONS

Fibrin glue at the end of pterygium surgery effectively reduces pain and the need for oral analgesics compared with conventional eye patching. This study is the first to describe the results of this strategy.

TFOS Lifestyle Report: Impact of environmental conditions on the ocular surface

Environmental risk factors that have an impact on the ocular surface were reviewed and associations with age and sex, race/ethnicity, geographical area, seasonality, prevalence and possible interactions between risk factors are reviewed. Environmental factors can be (a) climate-related: temperature, humidity, wind speed, altitude, dew point, ultraviolet light, and allergen or (b) outdoor and indoor pollution: gases, particulate matter, and other sources of airborne pollutants. Temperature affects ocular surface homeostasis directly and indirectly, precipitating ocular surface diseases and/or symptoms, including trachoma. Humidity is negatively associated with dry eye disease. There is little data on wind speed and dewpoint. High altitude and ultraviolet light exposure are associated with pterygium, ocular surface degenerations and neoplastic disease. Pollution is associated with dry eye disease and conjunctivitis. Primary Sjögren syndrome is associated with exposure to chemical solvents. Living within a potential zone of active volcanic eruption is associated with eye irritation. Indoor pollution, "sick" building or house can also be associated with eye irritation. Most ocular surface conditions are multifactorial, and several environmental factors may contribute to specific diseases. A systematic review was conducted to answer the following research question: "What are the associations between outdoor environment pollution and signs or symptoms of dry eye disease in humans?" Dry eye disease is associated with air pollution (from NO2) and soil pollution (from chromium), but not from air pollution from CO or PM10. Future research should adequately account for confounders, follow up over time, and report results separately for ocular surface findings, including signs and symptoms.

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.

Facial dermatosis papulosa nigra, a risk for the development of pterygium and myopia: a descriptive cross-sectional study in Ghana

Background. Dermatosis papulosa nigra (DPN) affects sun-exposed areas such as the face, neck, and trunk. The prevalence of pterygium and myopia in DPN patients in Ghana has not been studied. In this study, we examined the risk and protective factors for pterygium and myopia in DPN patients. Materials and Methods. The study involved 100 participants with facial DPN. A standard ophthalmic exam was performed using a portable slit lamp and a 3.5X magnified loop. Participants completed a closed- ended questionnaire. Logistic regression was used to summarize the level of association between DPN, myopia, and pterygium, as well as demographic factors (gender, age, occupation, family history of lesion and skin complexion). Results. 70% and 84% of participants had pterygium and myopia. Age, gender, complexion, and sun exposure were associated with pterygium and myopia (p < 0.05). Higher grade of pterygium and myopia were prevalent in the aged population. Both univariate and multivariable models highlighted that increasing age and sun exposure (outdoor) were risk factors for developing higher grade of pterygium and myopia in the DPN participants, while light skin color and male gender were respectively identified as protective factors. Conclusions. Our study is the first to examine pterygium and myopia in facial DPN patients. Most Ghanaians with facial DPN are at risk for developing pterygium and myopia.

Ocular surface squamous neoplasia in a patient following oral steroids for contralateral necrotising scleritis

A male patient in his 70s presented with left eye necrotising scleritis. His ocular history was significant for pterygium excision with mitomycin C 3 months prior in the affected eye, open-angle glaucoma, nuclear sclerosis cataract and previous sixth cranial nerve palsy. Scleral culture was negative and blood work was positive for rheumatoid factor and HLA-B27. The patient was treated for necrotising scleritis with oral doxycycline, vitamin C, ranitidine and prednisone with gradual taper over 45 days. Two months after initiating treatment, his necrotising scleritis achieved complete resolution; however, a new-onset ocular surface squamous neoplasia (OSSN) was identified at the temporal limbus of the contralateral eye. He was treated with topical interferon alpha-2b 1 million IU qid and achieved complete resolution after 4 months. The case highlights both the acute precipitation of OSSN following oral steroids and a sight-threatening complication following pterygium excision.

Evaluating the Efficacy and Safety of Different Pterygium Surgeries: A Review of the Literature

The search for the "gold standard" in the surgical treatment of pterygium has been ongoing for over two decades. Despite the development of various surgical techniques, recurrence rates range from 6.7% to 88% depending on the method used. This review discusses the latest and most commonly used methods for the surgical removal of pterygium, primarily focusing on efficacy and safety. Moreover, this review includes articles that either evaluated or compared surgical methods and clinical trials for primary and recurrent pterygium. Limited data are available on combined methods as well as on the efficacy of adjuvant treatment. The use of adjuvant intraoperative mitomycin C (MMC) and conjunctival autografting (CAU) are the two most highly recommended options, as they have the lowest rates of postoperative recurrence.

Regional features of the epidemiology of pterygium in the Republic of Bashkortostan

Background. Pterygium is ubiquitous and multifactorial; today, information on  the  prevalence of pterygium, risk factors, the relationship of its development with concomitant pathology and the type of life activity of patients in various regions of Russia is limited. All of the above led to the conduct of this epidemiological study in the Republic of Bashkortostan.

The aim of the study: to study the prevalence of pterygium, as well as to identify the relationship of risk factors for its development with the type of life activity and concomitant diseases in the urban and rural population of the Republic of Bashkortostan.

Methods. On the basis of the Ufa Research Institute of Eye Diseases, within the framework of the Ural Eye and Medical Study (UEMS) research project, a population study of people living in urban and rural regions of the Republic of Bashkortostan was carried out. The study involved 5899  people, including men – 43.7  % (2585  people), women – 56.3 % (3314 people), urban residents made 42.3 % (2491 people), rural – 57.7 % (3408 people).

Results. As a result of our study, pterygium was diagnosed in 138 people (204 eyes – 2.3 %) (95% CI: 2.0–2.7 %). One-way analysis showed a higher prevalence of pterygium associated (p˂0.10) with a number of systemic and ophthalmic parameters. However, according to the results of multivariate analysis, it was revealed that the prevalence of pterygium was significantly associated with older age (p = 0.006), rural area of residence (p = 0.001) and low educational level (p = 0.03).

Conclusion. The prevalence of pterygium in Republic of Bashkortostan according to the UEMS study was 2.3 %, or 23 people per 1000 population among people over 40 years old. The nature of the settlement influences the prevalence of pterygium in  the Republic of Bashkortostan. Pterygium was more common among older people among all respondents who took part in the study. In the study, pterygium was not a biomarker of general somatic diseases. 

Occurrence of Occult Neoplasia in Pterygium Specimens among Hispanic and Non-Hispanic Patients

PURPOSE

To determine the role of race and ethnicity in the prevalence of occult ocular surface squamous neoplasia (OSSN) in pterygium specimens.

METHODS

This retrospective study reviewed pathology reports and medical records of 504 patients who underwent pterygium surgery in South Texas. Those with clinical signs of OSSN were excluded. Clinical data including age, sex, and self-reported race and ethnicity were analyzed to determine risk factors for presence of occult OSSN in pterygium specimens.

RESULTS

There were 504 specimens; 95.8% were from patients identified as White, 1.8% from African Americans, and 2.4% from Asians. Ethnicity included Hispanic in 71% and non-Hispanic in 29%. Among all specimens, 18 (3.6%) were positive for occult OSSN. The prevalence of occult OSSN in pterygium specimens was higher in Hispanics compared to Non-Hispanics (4.8% versus 0.7%, respectively, P = 0.025). The prevalence of occult OSSN in different races included 8.3% for Asians, 3.5% for Whites, and 0% for African Americans. However, the racial difference did not reach statistical significance (P = 0.57). There were also no statistically significant differences between those with or without occult OSSN regarding age or sex.

CONCLUSIONS

A significant but low rate of occult OSSN was found in pterygium specimens. The percentage of those with OSSN in pterygium specimens was significantly greater in Hispanics compared to Non-Hispanics. As treatment and prognosis of pterygium and OSSN differ, histopathologic evaluation of all pterygium specimens is warranted.

Histopathological Rate of Ocular Surface Squamous Neoplasia in Clinically Suspected Pterygium Specimens: 10-Year Results

PURPOSE

The aim of this study was to evaluate the prevalence of histopathologically confirmed ocular surface squamous neoplasia (OSSN) in clinically diagnosed pterygium samples at a tertiary center in Northern California, over a 10-year period (2009-2019).

METHODS

A retrospective chart review of patients older than 18 years with clinically diagnosed benign pterygium requiring excision was conducted. Clinically suspected pterygia were excised using standard techniques and routinely submitted to the University of California Davis for pathologic evaluation. Demographic, clinical, surgical, and pathological information were recorded and analyzed. The prevalence rate of OSSN was calculated.

RESULTS

A total of 348 consecutive specimens were evaluated. The mean (±SD) age of the patients was 58 ± 12 years, with a near equal sex representation. A total of 57 (16%) pterygia were recurrent at initial presentation. Histopathologic results demonstrated a single case of OSSN. This patient did not have a documented history of carcinoma in other organs or any history of herpes virus, human papilloma virus, or human immunodeficiency virus infection.

CONCLUSIONS

The prevalence of histopathological OSSN in clinically suspected pterygia within our sample was approximately 0.3%. Because of shared clinical characteristics of pterygia and OSSN, a high index of suspicion and judicious use of anterior segment optical coherence tomography enable for effective preoperative diagnosis of OSSN. However, in the absence of clinical expertise or high-resolution optical coherence tomography, routine tissue pathologic examination may be warranted.

The Role of the Stromal Extracellular Matrix in the Development of Pterygium Pathology: An Update

Pterygium is a benign fibrovascular lesion of the bulbar conjunctiva with frequent involvement of the corneal limbus. Its pathogenesis has been mainly attributed to sun exposure to ultraviolet-B radiation. Obtained evidence has shown that it is a complex and multifactorial process which involves multiple mechanisms such as oxidative stress, dysregulation of cell cycle checkpoints, induction of inflammatory mediators and growth factors, angiogenic stimulation, extracellular matrix (ECM) disorders, and, most likely, viruses and hereditary changes. In this review, we aim to collect all authors’ experiences and our own, with respect to the study of fibroelastic ECM of pterygium. Collagen and elastin are intrinsic indicators of physiological and pathological states. Here, we focus on an in-depth analysis of collagen (types I and III), as well as the main constituents of elastic fibers (tropoelastin (TE), fibrillins (FBNs), and fibulins (FBLNs)) and the enzymes (lysyl oxidases (LOXs)) that carry out their assembly or crosslinking. All the studies established that changes in the fibroelastic ECM occur in pterygium, based on the following facts: An increase in the synthesis and deposition of an immature form of collagen type III, which showed the process of tissue remodeling. An increase in protein levels in most of the constituents necessary for the development of elastic fibers, except FBLN4, whose biological roles are critical in the binding of the enzyme LOX, as well as FBN1 for the development of stable elastin. There was gene overexpression of TE, FBN1, FBLN5, and LOXL1, while the expression of LOX and FBLN2 and -4 remained stable. In conclusion, collagen and elastin, as well as several constituents involved in elastic fiber assembly are overexpressed in human pterygium, thus, supporting the hypothesis that there is dysregulation in the synthesis and crosslinking of the fibroelastic component, constituting an important pathogenetic mechanism for the development of the disease.

Pterygium: an update on pathophysiology, clinical features, and management

Pterygium is a relatively common ocular surface disease. The clinical aspects and the treatment options have been studied since many years ago, but many uncertainties still exist. The core pathologic pathway and the role of heredity in the development of pterygium are still attractive fields for the researchers. The role of pterygium in corneal irregularities, in addition to the refractive properties of pterygium removal, has been increasingly recognized through numerous studies. The association between pterygium and ocular surface neoplasia is challenging the traditional beliefs regarding the safe profile of the disease. The need for a comprehensive clinical classification system has encouraged homogenization of trials and prediction of the recurrence rate of the pterygium following surgical removal. Evolving surgical methods have been associated with some complications, whose diagnosis and management are necessary for ophthalmic surgeons. According to the review, the main risk factor of pterygium progression remains to be the ultraviolet exposure. A major part of the clinical evaluation should consist of differentiating between typical and atypical pterygia, where the latter may be associated with the risk of ocular surface neoplasia. The effect of pterygium on astigmatism and the aberrations of the cornea may evoke the need for an early removal with a purpose of reducing secondary refractive error. Among the surgical methods, conjunctival or conjunctival-limbal autografting seems to be the first choice for ophthalmic surgeons because the recurrence rate following the procedure has been reported to be lower, compared with other procedures. The use of adjuvant options is supported in the literature, where intraoperative and postoperative mitomycin C has been the adjuvant treatment of choice. The efficacy and safety of anti–vascular endothelial growth factor agents and cyclosporine have been postulated; however, their exact role in the treatment of the pterygium requires further studies.

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.

Pterygium Surgery Utilizing Limbal Conjunctival Autograft and Subconjunctival Amniotic Membrane Graft in High-Risk Populations

Objective

To measure the outcomes of primary pterygium excision with a limbal conjunctival autograft when combined with the adjunctive use of a prophylactic subconjunctival graft of amniotic membrane to decrease the recurrence rate after surgery in an ethnically diverse population with a statistically higher risk for recurrence (African American, Asian, Caribbean, Asian, Latin).

Design

This is a retrospective, non-comparative study of post-operative outcomes.

Participants

A total of 355 patients, totaling 493 eyes, with clinically significant, primary pterygia.

Patients and Methods

Patients were enrolled into the study based on the need for pterygium surgery and if they underwent primary pterygium excision with conjunctival autograft with subconjunctival amniotic membrane placement. Patients with recurrent pterygium or those with pseudopterygium were excluded from this study. All surgeries took place at the Florida Eye Microsurgical Institute (Boynton Beach, FL) between June 2006 and October 2013 by a single surgeon (BAS). Patients were seen on post-operative day 1, 7, 30, 90, 180 and 365 to evaluate for pterygium recurrence. Pterygium recurrence is defined in this study as growth greater than 1 mm past the corneal limbus at or after 6 months.

Results

There were six cases of recurrent pterygium for a recurrence rate of 1.22% ± 0.97% (n=493, p=0.05). Follow-up ranged from 6 months to 6 years (mean 28 months).

Conclusion

Primary pterygium excision with a limbal conjunctival autograft and placement of a subconjunctival amniotic membrane graft has a low recurrence rate consistent with previously published data.

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.

Gender and ethnic differences in pterygium prevalence: an audit of remote Australian clinics

CLINICAL RELEVANCE

Developing an accurate picture of the demographic profile and refractive status of Aboriginal and non-Aboriginal individuals with pterygium will facilitate health planning and appropriate deployment of health-care resources in rural Australia.

BACKGROUND

To date, there is a paucity of reports in the literature regarding Aboriginal ocular health and refractive error. This study examines clinical data from a rural ophthalmology outreach clinic - a predominantly Aboriginal population.

METHODS

An assessment was undertaken of data of 293 patients noted to have pterygium present in at least one eye, from a sample of 2,072 individuals seen in rural northern Western Australia in 2017 by the Lions Outback Vision Visiting Optometry Service.

RESULTS

Pterygium was found in 14.1 per cent (n = 293) of patients using the Lions Outback Vision service. The mean age of those with pterygium (n = 293) was 57.1 ± 11.9-years (mean ± standard deviation); 188 were female (64.1 per cent); 260 identified as Aboriginal (88.7 per cent), 22 identified as non-Aboriginal (7.5 per cent) and 11 did not specify (3.8 per cent). There were more males than females with pterygium in the non-Aboriginal group (18.0 per cent versus 6.4 per cent); however, the reverse was true in the Aboriginal group (11.7 per cent versus 17.0 per cent). Analysis of the subjective refractive data in those with pterygium revealed an overall mean spherical equivalent value of +0.66 ± 1.28 DS. The median (interquartile range) best-corrected visual acuity was 0.0 (-0.1 to 0.0) logMAR (6/6 Snellen equivalent).

CONCLUSIONS

This paper increases our knowledge of ocular health in a remote Australian population, with an emphasis on the differences between Aboriginal and non-Aboriginal individuals, males and females.

Clinical demographics of pterygium excision and prevalence of conjunctival intraepithelial neoplasia: a 15-year review

PURPOSE

To find clinical demographics of pterygium surgery and prevalence of conjunctival intraepithelial neoplasia (CIN) in pterygium specimen.

METHODS

This is a retrospective, institutional study. The records of patients who had received pterygium excision from 2000 to 2014 were reviewed. Patients after complete ophthalmic "examinations", surgical procedures, and pathological reports were enrolled. Surgical procedures, pathology, external eye photography, prevalence of CIN in specimen, and demographic data were described.

RESULTS

Of 1787 pterygium cases, 928 were male and 859 were female. The mean age was 65.19 ± 14.21 years. Of these 1787 cases, 1435 (80.3%) cases had primary pterygium excision, while the others (n = 352; 19.7%) had pterygium excision for recurrence. Four cases presented CIN within pterygium tissue (0.22%). The mean age of pterygium patients with CIN was 57.75 ± 7.80 years. In stratified data, our patients who received primary and secondary pterygium excision were found prevalent in the eighth (28.2%) and seventh (26.1%) decade, respectively. Twelve percent of patients who underwent secondary pterygium excision had a recurrence and required another surgery. Patients requiring amniotic membrane transplantation (AMT) during primary pterygium excision were significantly younger (median, 58 years) than those (median, 67 years) without the assistance of AMT (p < 0.001). Similarly, AMT was utilized in younger patients (median, 56 years) during secondary pterygium excision, compared to those without AMT (median, 64 years) (p = 0.001).

CONCLUSION

CIN combined with pterygium is very rare. However, the possibility of the development of ocular surface squamous neoplasia in pterygium tissue should not be ignored. Meticulous pathological investigation of the surgical samples is important.

Radiation Therapy for Benign Disease: Keloids, Macular Degeneration, Orbital Pseudotumor, Pterygium, Peyronie Disease, Trigeminal Neuralgia

Although the use of ionizing radiation on malignant conditions has been well established, its application on benign conditions has not been fully accepted and has been inadequately recognized by health care providers outside of radiation therapy. Most frequently, radiation therapy in these benign conditions is used along with other treatment modalities, such as surgery, when the condition causes significant disability or could even lead to death. Radiation therapy can be helpful for inflammatory/proliferative disorders. This article discusses the present use of radiation therapy for some of the most common benign conditions.

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.

Identification of pathogenic genes of pterygium based on the Gene Expression Omnibus database

AIM

To identify the pathogenic genes in pterygium.

METHODS

We obtained mRNA expression profiles from the Gene Expression Omnibus database (GEO) to identify differentially expressed genes (DEGs) between pterygium tissues and normal conjunctiva tissues. The Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway analysis, protein-protein interaction (PPI) network and transcription factors (TFs)-target gene regulatory network was performed to understand the function of DEGs. The expression of selected DEGs were validated by the quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

A total of 557 DEGs were identified between pterygium and normal individual. In PPI network, several genes were with high degrees such as FN1, KPNB1, DDB1, NF2 and BUB3. SSH1, PRSS23, LRP5L, MEOX1, RBM14, ABCA1, JOSD1, KRT6A and UPK1B were the most downstream genes regulated by TFs. qRT-PCR results showed that FN1, PRSS23, ABCA1, KRT6A, ECT2 and SPARC were significantly up-regulated in pterygium and MEOX1 and MMP3 were also up-regulated with no significance, which was consistent with the our integrated analysis.

CONCLUSION

The deregulated genes might be involved in the pathology of pterygium and could be used as treatment targets for pterygium.

Ocular Exposure to Particulate Matter and Development of Pterygium: A Case-Control Study

Background:

Formation of pterygium has been mainly attributed to exposure to the ultraviolet (UV) radiation. Other factors such as dry weather, wind exposure and microtrauma with dust particles, have been linked to development of pterygium.

Objective:

To determine the association between ocular exposure to particulate matter and development of pterygium.

Methods:

This case-control study was conducted in a company dedicated to the production and marketing of toilets. We included a total of 90 cases identified in November 2013 and 184 controls. The diagnosis of pterygium was based on clinical examination. Variables studied included age and job tenure of the participants. Logistic regression analysis was used to assess the effect of exposure on developing pterygium.

Results:

All study participants were male. The mean age of the cases and controls was 39.9 (SD 9.5) and 37.8 (SD 7.3) years, respectively. 115 (42%) of the participants had a job tenure of 5–8 years. The percentages of cases and controls exposed to particulate matter were 31.1% (n=28) and 30.4% (n=56), respectively (OR 1.08, 95% CI 0.61 to 1.91).

Conclusion:

We could not observe any association between ocular exposure to particulate matter and development of pterygium.

Protective effect of smoking against pterygium development in men: a nationwide longitudinal cohort study in South Korea

OBJECTIVE

The present study aimed to evaluate the association between smoking and incident pterygium in adult Korean men.

DESIGN

A retrospective nationwide longitudinal cohort.

SETTING

National Health Insurance database of South Korea.

PARTICIPANTS

This study included Korean men (age range: 40-79 years) registered in the Korea National Health Insurance Service database from 2002 through 2013. We compared HRs for pterygium between 90 547 current/past and 90 547 never-smokers via 1:1 propensity-matched analysis.

PRIMARY OUTCOME MEASURE

Incident cases of pterygium were identified from the database.

RESULTS

Pterygium developed in 5389 (6.0%) never-smokers and 3898 (4.3%) past/current smokers (P<0.001). The incidence of pterygium per 1000 person-years in never-smokers and in past/current smokers was 6.5 and 4.7, respectively (age-adjusted HR, 0.73; 95% CI, 0.70 to 0.76). This protective effect was more pronounced among current smokers than among past smokers (for current smokers: HR, 0.68; 95% CI, 0.65 to 0.71 and for past smokers: HR, 0.85; 95% CI, 0.80 to 0.90). A longer duration of smoking and higher amounts of cigarette consumption were associated with a lower incidence of pterygium.

CONCLUSIONS

Longitudinally, cigarette smoking was associated with a reduced risk of pterygium, and this protective effect was more pronounced among current smokers than among past smokers.

Comparison among adjuvant treatments for primary pterygium: a network meta-analysis

PURPOSE

Pterygium is a frequent ocular disease, where the major challenge is the high level of recurrence after its surgical removal. We performed a network meta-analysis to identify, among several adjuvant treatments for primary pterygium, which is the best to prevent recurrence.

METHODS

A search was conducted using PubMed, Scientific Electronic Library Online, Latin American and Caribbean Centre on Health Sciences and Cochrane Eyes and Vision Group Trials Register between 1993 and 2015 for randomisedclinical trials (RCTs) comparing adjuvant treatments following primary pterygium surgery.

RESULTS

24 RCTs that studied 1815 eyes of 1668 patients were included and allowed direct and indirect comparison among 14 interventions through network meta-analysis. The rank from the best to worse treatment to prevent recurrence is: conjunctival autograft + ciclosporin 0.05% eye drops, bare sclera + intraoperativemitomycin C (MMC) <0.02%, bare sclera + beta therapy (2500 cGy single dose), conjunctival autograft + beta therapy (1000 cGy single dose), bare sclera + MMC 0.02% eye drops, conjunctival autograft, bare sclera + intraoperative MMC >0.02%, bare sclera + ciclosporin 0.05% eye drops, bare sclera + intraoperative 5-fluorouracil 5%, amniotic membrane transplantation, bare sclera + intraoperative MMC 0.02%, conjunctival autograft + bevacizumab 0.05% eye drops, bare sclera + bevacizumab 0.05% eye drops and bare sclera alone.

CONCLUSION

The best adjuvant treatment to prevent recurrence after primary pterygium surgery is the association of conjunctival autograft and ciclosporin 0.05% eye drops. Bare sclera technique alone should be discontinued since it is associated with high recurrence rates.

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 incidence and prevalence of pterygium in South Korea: A 10-year population-based Korean cohort study

Although numerous population-based studies have reported the prevalences and risk factors for pterygium, information regarding the incidence of pterygium is scarce. This population-based cohort study aimed to evaluate the South Korean incidence and prevalence of pterygium. We retrospectively obtained data from a nationally representative sample of 1,116,364 South Koreans in the Korea National Health Insurance Service National Sample Cohort (NHIS-NSC). The associated sociodemographic factors were evaluated using multivariable Cox regression analysis, and the hazard ratios and confidence intervals were calculated. Pterygium was defined based on the Korean Classification of Diseases code, and surgically removed pterygium was defined as cases that required surgical removal. We identified 21,465 pterygium cases and 8,338 surgically removed pterygium cases during the study period. The overall incidences were 2.1 per 1,000 person-years for pterygium and 0.8 per 1,000 person-years for surgically removed pterygium. Among subjects who were ≥40 years old, the incidences were 4.3 per 1,000 person-years for pterygium and 1.7 per 1,000 person-years for surgically removed pterygium. The overall prevalences were 1.9% for pterygium and 0.6% for surgically removed pterygium, and the prevalences increased to 3.8% for pterygium and 1.4% for surgically removed pterygium among subjects who were ≥40 years old. The incidences of pterygium decreased according to year. The incidence and prevalence of pterygium were highest among 60–79-year-old individuals. Increasing age, female sex, and living in a relatively rural area were associated with increased risks of pterygium and surgically removed pterygium in the multivariable Cox regression analysis. Our analyses of South Korean national insurance claims data revealed a decreasing trend in the incidence of pterygium during the study period.

Evaluation of socioeconomic status as a risk factor of pterygium using the Korean National Health and Nutrition Examination Survey 2010 to 2011: A STROBE-compliant article

Pterygium is a common conjunctival disorder. The socioeconomic risk factors of pterygium have not been systematically evaluated in Korea. The study investigated risk factors of pterygium considering socioeconomic status.Participants were 9839 adults aged 19 to 74 years, who underwent ophthalmic slit-lamp examinations as part of the Korean National Health and Nutrition Examination Survey 2010 to 2011. Pterygium was diagnosed as a growth of fibrovascular tissue over the cornea. The socioeconomic risk factors were analyzed in association with the presence of pterygium. Multiple logistic regression analysis was used to evaluate the odds ratios for differences in socioeconomic status.The presence of pterygium was associated with diabetes mellitus, hypertension, metabolic syndrome, and sun exposure time (>5 h/d). The blood level of 25-hydroxyvitamin D was higher in the pterygium group than in the control group, but both groups were deficient in 25-hydroxyvitamin D compared with the normal reference level. Pterygium was almost 3 times as frequent among persons who worked outdoors, such as skilled agricultural, forestry, and fishery workers, than among those who worked indoors (odds ratio 3.061, 95% confidence interval 1.946-4.813). Low educational status and longer working hours were also significantly associated with pterygium.This study used a nationwide population-based survey conducted by the Korean Centers for Disease Control and Prevention to reveal that pterygium is associated with low socioeconomic status. Efforts should be made to reduce the risk of pterygium by changing modifiable risk factors, especially among people with low socioeconomic status.

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.

Updates on the Treatment of Pterygium

Pterygium is an ocular disease characterised by the growth of fibrovascular conjunctiva on the cornea. It occurs more often in men, at an older age, and in individuals exposed to ultraviolet radiation. Surgical treatment is the primary treatment for pterygium and there are two common procedures for pterygium excision. In the first method, the head of the pterygium is separated from the corneal surface using a surgical blade. The second method is based on avulsion. Other approaches to excising the pterygium include the use of argon laser and excimer laser. Because of a high recurrence rate, adjuvant therapies, including radiotherapy, chemotherapy, and graft procedures, are used after pterygium excision. These procedures have become the standard long-term treatments for pterygium. Radiotherapy is based on beta irradiation. Chemotherapy includes the use of mitomycin C, 5-fluorouracil, bevacizumab, and loteprednol etabonate. Graft procedures include amniotic membrane grafts and conjunctival autografts. Many surgeons believe that using mitomycin C and conjunctival autografts provides the best outcomes in terms of recurrence, cosmetics and patient satisfaction.

Five-Year Incidence and Predictors for Pterygium in a Rural Community in China: The Yunnan Minority Eye Study

PURPOSE

To determine the 5-year cumulative incidence of pterygium and its associated predictors in the Bai Chinese population in a rural community.

METHODS

This population-based study included 2133 subjects aged 50 years or older in 2010 and was repeated in 2015 with 1520 subjects (71.3%) participating in the follow-up examination. Participants with pterygium in either eye in 2010 were excluded from the analysis related to incidence. Anterior segment examination was performed without pupil dilation using a slit lamp, and pterygium was defined as a raised fleshy triangular fibrovascular tissue growth of the conjunctiva encroaching onto the clear cornea.

RESULTS

The 5-year cumulative incidence of pterygium was 6.8% [95% confidence interval (CI), 5.2-8.4] and was significantly higher in women compared with men (8.8% vs. 3.8%; P = 0.003). The age-specific incidence was 7.7%, 6.5%, and 5.6% in those aged 50-59, 60-69, 70 years, or older at the baseline, respectively. Outdoor occupation was the only predictor, which remained to be significantly associated with a higher incidence of pterygium in multivariate analysis (odds ratio = 2.52, 95% CI, 1.27-4.95). The predictive effect of outdoor occupation on incident pterygium was moderate with an area under the curve in the receiver operating characteristic analysis of 0.59 (95% CI, 0.53-0.66).

CONCLUSIONS

The incidence of pterygium in this rural cohort was higher compared to a previous report in Chinese in urban areas. The findings are important for health policy makers to project future burden of pterygium and make proper decisions on health resource allocation.

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.

Epidemiology and Associated Morbidity of Pterygium: A Large, Community-Based Case-Control Study

BACKGROUND

To evaluate the prevalence and risk factors of various conditions among patients with pterygium.

METHODS

A retrospective observational case control study of 4,037 patients who were diagnosed with pterygium in the Central District of Clalit Health Services in Israel from 2000-2009. A total of 16,054 randomly selected controls from the district HMO members. Personal, medical, and demographic information were extracted from patients' files. We calculated the prevalence of various ocular, systemic, and demographic conditions as risk factors for pterygium.

RESULTS

The average age of pterygium patients was 58.4 ± 14 years; 56.9% were male. A significant tendency to develop pterygium was found among individuals of lower socioeconomic status (p < 0.001) and in populations living in rural areas (p < 0.001). A logistic regression model adjusted to marital status, socio-economic class, and area of living was performed. The following conditions were significantly associated with pterygium: blepharitis (OR = 1.71; 99.9% CI: 1.53-1.93), chalazia (OR = 1.46; 99.9% CI: (1.19-1.78)), anxiety (OR = 1.14, 99.9% CI: 0.98-1.33), and G6PD deficiency (OR = 1.85; 99.9% CI: 1.11-3.07). Schizophrenia (OR 0.31; 99.9% CI: 0.19-0.50) and smoking (OR 0.82; 99.9% CI: 0.76-0.89) were significantly less prevalent among pterygium patients.

CONCLUSIONS

Pterygium etiology is multifactorial. Some demographic, systemic, and periocular conditions are significantly more prevalent and some are less prevalent among pterygium patients. Better understanding of the pathophysiological association between those diseases and pterygium may help in its prevention and treatment.

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 risk factors for pterygium in rural older adults in Shandong Province of China: a cross-sectional study

To investigate the prevalence and risk factors for pterygium in rural older adults in Shandong Province, eastern China, a population-based, cross-sectional study was performed from April to July 2008. By means of cluster random sampling methods, a total of 19,583 people aged 50 years or above were randomly selected from four rural counties. Out of 19,583 people, 1,767 residents were excluded mainly because they were migrant workers when this study was performed. Finally, 17,816 (90.98%) people were included as eligible subjects. They received a comprehensive eye examination and a structured questionnaire voluntarily. Patients with pterygium were defined as having pterygium at the time of survey or pterygium surgery had been performed. 1,876 people were diagnosed as pterygium, either unilateral (1,083) or bilateral (793), which is equivalent to a prevalence of 10.53% (95% CI, 10.08–10.98). The multivariate logistic regression analysis showed that pterygium was independently associated with older age, areas, outdoor time, educational level, and use of hat and/or sunglasses. The prevalence of pterygium increased with age and hours spent under sunshine per day. Meanwhile, the higher the educational level and the more use of hat and/or sunglasses, the lower the pterygium prevalence.

Prevalence of sun exposure and its associated factors in southern Brazil: a population-based study

BACKGROUND

Sunlight exposure is responsible for a large number of dermatological diseases.

OBJECTIVE

We estimated the prevalence of sunlight exposure and its associated factors in adults from southern Brazil in a cross-sectional, population-based study.

METHODS

We investigated a representative sample of individuals aged ≥ 20 years (n=3,136). Sunlight exposure and its associated factors were evaluated in two distinct situations: at leisure time and at work. The time period investigated ranged from December 2004 to March 2005, comprising 120 days of the highest ultraviolet index in the urban area of the city of Pelotas, in southern Brazil. The participants were asked about sunlight exposure for at least 20 minutes between 10 A.M. and 4 P.M. The analysis was stratified by sex, and sunlight exposure was grouped into five categories.

RESULTS

Among the 3,136 participants, prevalence of sunlight exposure at the beach was 32.8% (95% CI, 30.3 - 35.2) and 26.3% (95% CI, 24.2 28.3) among men and women, respectively. The prevalence at work was 39.8% (95% CI, 37.2 - 42.4) among men and 10.5% (95% CI, 9.1 - 12.0) among women. Age was inversely associated with sunlight exposure. Family income and achieved schooling were positively associated with sunlight exposure at leisure time and inversely associated with sunglight exposure at work. Self-reported skin color was not associated. Knowledge of any friend or relative who has been affected by skin cancer was positively associated with sunlight exposure among men at work.

CONCLUSION

Despite the media campaigns on the harmful effects of excessive sunlight exposure, we found a high prevalence of sunlight exposure during a period of high ultraviolet index.

The prevalence of pterygium in Alkhobar: A hospital-based study

Objective:

To analyze the epidemiology of pterygium in a hospital-based population in Alkhobar, which is located in the eastern province of Saudi Arabia.

Materials and Methods:

This was a retrospective, non-randomized, and consecutive case study. Out of 88,666 patients who were seen in the ophthalmology clinic between January 1995 through the end of December 2010, 116 patients were diagnosed with advanced pterygium. The medical records of these patients were evaluated.

Results:

The overall prevalence of pterygium was found to be 0.074%. There was no significant difference by either gender, side, or by laterality (P > 0.05). A significant increase was noticed in the prevalence of pterygium with increasing age and nasal location (P < 0.05).

Conclusion:

The overall prevalence rate of pterygium in Alkhobar is low when compared with results reported from other areas of the world.

Risk factors associated with pterygium and its subtypes in Korea: the Korean National Health and Nutrition Examination Survey 2008-2010

PURPOSE

To assess the sociodemographic and health-related risk factors associated with pterygium and its subtypes in Korea.

METHODS

From 2008 to 2010, a total of 14,920 randomly selected national representative participants of the Korean National Health and Nutrition Examination Survey underwent additional ophthalmologic examinations by the Korean Ophthalmologic Society. The risk factors for pterygium in general or according to subtype (atrophic, intermediate, and fleshy) were identified using multivariate logistic regression analysis.

RESULTS

The prevalence of pterygium was 6.7% (95% confidence interval, 5.9-7.5) in subjects aged 30 years or older. Older age, male sex, lower educational level, rural habitation, nonsmoking, and sun exposure were independent risk factors for pterygium. Among subjects with pterygium, older age, male sex, lower educational level, and nonsmoking were independent risk factors for all types of pterygium. Sun exposure for >5 h/d was the independent risk factor for the severe pterygium subtype.

CONCLUSIONS

Socioeconomic disparities in pterygium development exist. Proper ocular examination and education to avoid excessive sun exposure would be helpful in reducing disease risk.

Ultraviolet damage to the eye revisited: eye-sun protection factor (E-SPF®), a new ultraviolet protection label for eyewear

Ultraviolet (UV) radiation potentially damages the skin, the immune system, and structures of the eye. A useful UV sun protection for the skin has been established. Since a remarkable body of evidence shows an association between UV radiation and damage to structures of the eye, eye protection is important, but a reliable and practical tool to assess and compare the UV-protective properties of lenses has been lacking. Among the general lay public, misconceptions on eye-sun protection have been identified. For example, sun protection is mainly ascribed to sunglasses, but less so to clear lenses. Skin malignancies in the periorbital region are frequent, but usual topical skin protection does not include the lids. Recent research utilized exact dosimetry and demonstrated relevant differences in UV burden to the eye and skin at a given ambient irradiation. Chronic UV effects on the cornea and lens are cumulative, so effective UV protection of the eyes is important for all age groups and should be used systematically. Protection of children's eyes is especially important, because UV transmittance is higher at a very young age, allowing higher levels of UV radiation to reach the crystalline lens and even the retina. Sunglasses as well as clear lenses (plano and prescription) effectively reduce transmittance of UV radiation. However, an important share of the UV burden to the eye is explained by back reflection of radiation from lenses to the eye. UV radiation incident from an angle of 135°-150° behind a lens wearer is reflected from the back side of lenses. The usual antireflective coatings considerably increase reflection of UV radiation. To provide reliable labeling of the protective potential of lenses, an eye-sun protection factor (E-SPF®) has been developed. It integrates UV transmission as well as UV reflectance of lenses. The E-SPF® compares well with established skin-sun protection factors and provides clear messages to eye health care providers and to lay consumers.

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.

Geographical prevalence and risk factors for pterygium: a systematic review and meta-analysis

OBJECTIVE

Pterygium is considered to be a proliferative overgrowth of bulbar conjunctiva that can induce significant astigmatism and cause visual impairment; this is the first meta-analysis to investigate the pooled prevalence and risk factors for pterygium in the global world.

DESIGN

A systematic review and meta-analysis of population-based studies.

SETTING

International.

PARTICIPANTS

A total of 20 studies with 900 545 samples were included.

PRIMARY OUTCOME MEASURE

The pooled prevalence and risk factors for pterygium.

RESULTS

20 studies were included. The pooled prevalence of pterygium was 10.2% (95% CI 6.3% to 16.1%). The pooled prevalence among men was higher than that among women (14.5% vs 13.6%). The proportion of participants with unilateral cases of pterygium was higher than that of participants with bilateral cases of pterygium. We found a trend that the higher pooled prevalence of pterygium was associated with decreasing geographical latitude and age in the world. The pooled OR was 2.32 (95% CI 1.66 to 3.23) for the male gender and 1.76 (95% CI 1.55 to 2.00) for outdoor activity, respectively.

CONCLUSIONS

The pooled prevalence of pterygium was relatively high, especially for low latitude regions and the elderly. There were many modifiable risk factors associated with pterygium to which healthcare providers should pay more attention.

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

PURPOSE

To estimate the prevalence of pterygium and identify associated risk factors in a Southern Harbin population at low altitude in a cold climate.

METHODS

A prospective population-based survey was conducted in 2006. A stratified, clustered, randomized sampling procedure was used to select 5057 subjects aged 50 years and older. Pterygia were diagnosed and graded, and the association between pterygium and astigmatism was investigated. Risk factors associated with pterygium were evaluated with logistic regression models.

RESULTS

A total of 5057 persons aged 50 to 96 years (91.0% of the eligible population) who were residents of Southern Harbin, Heilongjiang Province, China, participated in the study, and 323 (6.4%) had at least 1 pterygium. The prevalence of pterygium in the unilateral and bilateral eyes of the participants was 3.7% and 2.6%, respectively. The presence of a pterygium was significantly associated with the presence of astigmatism (cylinder ≥ ± 0.5 diopters, P < 0.001). Pterygium was independently associated with male sex (odds ratio 1.73; 95% confidence interval, 1.37-2.19) and smoking (odds ratio 1.90; 95% confidence interval, 1.51-2.35) (P < 0.001).

CONCLUSIONS

This study details pterygium in a rural population of Harbin at low altitude in a cold climate. The prevalence of pterygium in the population is lower than that reported in other regions of the world. The primary causative factors were related to male sex and smoking, the latter of which is easily preventable. Public health schemes to address this serious health issue are urgently needed.

Conjunctivochalasis is the precursor to pterygium

Pterygium is a fibrovascular proliferative condition of the ocular surface with no known pathological mechanism. This condition affects vision due to dry eyes, astigmatism or physical occlusion of the visual axis for severe cases. The only definitive treatment for this condition is surgical excision. Interestingly, it is a lesion that may be related to UV radiation and elaboration of proteases. Conjunctivochalasis is a dry eye related condition that is exemplified by excessive conjunctiva or the mucous membrane of the front of the eye around the cornea. Both pterygium and conjunctivochalasis are associated with elaboration of matrix metalloproteinases as well as inflammatory cytokines. We propose that under specific conditions, conjunctivochalasis in the nasal part of the conjunctiva can progress to pterygium. The progression of conjunctivochalasis to pterygium may be related to special kinds of oxidative or inflammatory damage that affects only the part of the loose conjunctival tissue adjacent to the cornea. Protease expressed may then breakdown the conjunctival and corneal epithelium causing the head of pterygium to be very adherent to the cornea. This explains the fact that surgically excised pterygium tissue has stromal tissue enclosed by epithelia on both surfaces. In addition, it explains the existence of a surgical plane when an instrument is passed under the neck of the pterygium tissue but not at the apex. The implications of this hypothesis are first, treatment should be directed to the protection of conjunctivochalasis before it transforms to pterygium. This may be achieved by anti-inflammatory measures, anti-protease treatment, or preventing the triggering of the changes at the head of pterygium, such as avoidance of sunlight. Second, during resection of pterygium, it may not be necessary to resect the pterygium too extensively away from the cornea, since this effectively removes relatively normal conjunctiva.