Incidence of ocular surface squamous neoplasia in pterygium specimens.

OBJECTIVE: Pterygium and ocular surface squamous neoplasia (OSSN) have been recognized as likely related conditions and share similar risk factors such as ultraviolet radiation and chronic inflammation. The purpose of this study is to review the incidence of OSSN in pathology specimens sent as pterygium at a single tertiary centre between 2010 and 2022. METHODS: This is a retrospective chart review of patients operated on for pterygium between 2010 and 2022 at the University of Montreal Health Centre. Data collected include baseline demographics, results of pathology specimen, and clinical information for cases diagnosed as OSSN on pathology. RESULTS: A total of 1559 patients were operated on for a clinical diagnosis of pterygium between 2010 and 2022, of which 854 patients (55%) were male. A total of 1142 specimens had available pathology reports, and most of the specimens were consistent with pterygium on pathology (1105 of 1142; 97%). There was an unexpected finding of 3 cases of OSSN (3 of 1142; 0.3%). Other diagnosis besides pterygium were seen in 3% of specimens (34 of 1142), including nevus (n = 12), spheroidal degeneration (n = 3), pyogenic granuloma (n = 3), and lymphangiectasia (n = 2). The 3 cases of OSSN included an 81-year-old male of French-Canadian background, a 52-year-old male of South Asian background, and a 59-year-old female of French-Canadian background. The pathology was diagnosed as conjunctival intraepithelial neoplasia (CIN) grade 3, CIN grade 2, and CIN grade 2, respectively. CONCLUSION: The finding of OSSN in pterygium is rare in our population but can be clinically difficult to distinguish. It is important to send all pterygium specimens for pathology.

[Pterygium surgery with sutureless, glueless conjunctival graft: Preliminary study at the Centre hospitalier universitaire de Cocody in Abidjan]. / Chirurgie du ptérygion par greffe conjonctivale sans suture ni colle biologique : étude préliminaire au centre hospitalier universitaire de Cocody à Abidjan.

PURPOSE: To optimize the pterygium management by delineating the role of sutureless, glueless conjunctival graft. MATERIALS AND METHODS: This was a prospective cohort study carried out at the Centre hospitalier universitaire de Cocody between October 1st, 2021 and March 31st, 2022. It analyzed a series of 36 cases of stage I, II and III pterygium by Cornand's classification, who underwent surgery by a sutureless conjunctival graft technique without biological glue. RESULTS: Demographically, 33.3% of our study population were between 30 and 40 years of age, with a mean of 47.86 years. The patients showed a female preponderance, 53%, with a male:female ratio of 0.89. At the clinical level, 75% of our population presented for ocular redness, 84% had a nasal pterygium, and 75% were stage 2. In terms of postoperative course and appearance, we observed 80.55% graft stability, 5.56% graft retraction, 2.78% graft displacement, and 11.11% graft loss. At the conclusion of follow-up, we noted an 8.33% recurrence rate. DISCUSSION: The use of intraoperative blood ensures patient safety and postoperative comfort. This technique demonstrates satisfactory results with primary, nasal pterygia. CONCLUSION: Conjunctival autograft without sutures or biological glue might be a very promising surgical alternative in the surgical treatment of pterygium.

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.

Prevalence of co-existent neoplasia in clinically diagnosed pterygia in a UK population.

INTRODUCTION: Ocular surface squamous neoplasia (OSSN) and pterygia share risk factors and co-exist in only a minority of cases. Reported rates of OSSN in specimens sent as pterygium for histopathological analysis vary between 0% and nearly 10%, with the highest rates reported in countries with high levels of ultraviolet light exposure. As there is a paucity of data in European populations, the aim of this study was to report the prevalence of co-existent OSSN or other neoplastic disease in clinically suspected pterygium specimens sent to a specialist ophthalmic pathology service in London, United Kingdom. METHODS: We performed a retrospective review of sequential histopathology records of patients with excised tissue submitted as suspected "pterygium" between 1997 and 2021. RESULTS: In total, 2061 specimens of pterygia were received during the 24-year period, with a prevalence of neoplasia in those specimens of 0.6% (n = 12). On detailed review of the medical records of these patients, half (n = 6) had the pre-operative clinical suspicion of possible OSSN. Of those cases without clinical suspicion pre-operatively, one was diagnosed with invasive squamous cell carcinoma of the conjunctiva. CONCLUSION: In this study, rates of unexpected diagnoses are reassuringly low. These results may challenge accepted dogma, and influence future guidance for the indications for submitting non-suspicious pterygia for histopathological analysis.

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.

Ocular health among industrial workers: a prevalence study of foreign body injury, refractive error, dry eye, pterygium and pingueculae.

BACKGROUND: Workplaces play a critical role in developing ocular diseases, owing to the risk of accidents. This study aimed to evaluate the ocular health of industrial workers by determining the prevalence of foreign body injury, refractive error, dry eye, and pterygium/pingueculae, as well as the factors influencing these diseases. METHODS: This study involved on-site examinations of workers from an industrial area hosting marble processing factories and metal sectors. Data such as refractive error, foreign body injury-related corneal nephelium, pterygium/pingueculae presence, and Schirmer test-assisted dry eye evaluation were all collected. RESULTS: The average age of workers was 35.78±10.05 years, with a female-to-male ratio of 20:220. The majority of workers had completed primary school (56.3%), smoked >1 cigarette/day (57.6%), and did not use any assistive devices for bodily functions (88.3%). On average, working hours/week were 55.07±8.79, and working years were 5.99±7.00. Dry eyes were found in 31 (22%), and 35 (34%) marble and metal workers, respectively (p=0.042). 11 (7.9%) marble workers and 29 (28%) metal workers had foreign body ocular injury-related corneal nephelium (p=0.0001). Furthermore, pterygium/pingueculae were revealed in 17 marble workers (12.3%) and three metal workers (3%) (p=0.009). CONCLUSIONS: Ocular health is essential, and routine ocular health screening in industrial workers, as well as workplace safety measures, should be implemented to prevent potential occupational accidents.

[Prevalence and risk factors for pterygium in six rural regions of Yunnan Province].

Objective: To investigate the prevalence and risk factors of pterygium in the rural population aged 40 years and above of 12 ethnic groups in 6 regions of Yunnan Province. Methods: This was a cross-sectional study. According to the method of multistage stratified sampling, samples of the rural population aged 40 years and above were collected from 12 ethnic groups (Han, Yi, Tibetan, Lisu, Bai, Naxi, Zhuang, Miao, Dai, Jingpo, Hani, and Lahu) in six areas (Diqing, Lijiang, Wenshan, Dehong, and Pu'er) of Yunnan Province from March 2019 to November 2019. Anterior segment examination was carried out in the target population with a hand-held slit-lamp, according to which pterygium was diagnosed, while the posterior segment of the eye was assessed by direct ophthalmoscopy. A field questionnaire survey was also conducted. A two-level model was used to study the effects of the location, nationality, sex, age, occupation, outdoor activities, smoking, and alcohol consumption on the prevalence of pterygium, with the ethnic group as the high level and the individual as the low level. Results: Among 9 617 subjects, the total prevalence rate of pterygium was 22.6%, which was adjusted to 19.6% according to the age and gender data of the Statistics Bureau of Yunnan Province. There was significant difference in prevalence of pterygium among six regions after adjusting for age and sex (χ2=146.50, P<0.001). The prevalence of pterygium was the highest in Wenshan (29.4%), followed by Chuxiong (24.4%), Diqing (17.5%), Pu'er (17.5%), Dehong (15.8%), and Lijiang (15.7%) (χ2=146.50, P<0.001). The results of the single factor analysis showed that there was statistically significant difference among different groups of age, gender, nationality, location, history of smoking, drinking, eating habits, sleeping time, continuous use of eye drops, temperature, humidity, altitude, longitude, latitude, and ultraviolet ray (P<0.05). However, the results of the multivariate analysis showed that the main risk factors of pterygium were female(OR=1.357,95%CI:1.173~1.568), advanced age(OR=1.540,95%CI:1.301~1.823), location(OR=1.713,95%CI:1.000~2.667), continuous use of eye drops(OR=1.177,95%CI:1.034~1.340), and more than 40 years of alcohol drinking(OR=1.525, 95%CI: 1.108~2.099), and the protective factor was more than 40 years of smoking(OR=0.723,95%CI:0.544~0.960). Conclusions: The prevalence of pterygium varies greatly among different regions in Yunnan Province. The main factors affecting the prevalence are sex, age, region, smoking history, and drinking history.

The association of sun exposure, ultraviolet radiation effects and other risk factors for pterygium (the SURE RISK for pterygium study) in geographically diverse adult (≥40 years) rural populations of India -3rd report of the ICMR-EYE SEE study group.

PURPOSE: To determine the prevalence and risk factors for pterygium in geographically diverse regions of India. METHODS: A population-based, cross-sectional multicentric study was conducted in adults aged ≥40 years in plains, hilly and coastal regions of India. All participants underwent a detailed questionnaire-based assessment for sun exposure, usage of sun protective measures, exposure to indoor smoke, and smoking. Detailed ocular and systemic examinations were performed. Pterygium was diagnosed and graded clinically by slit-lamp examination. Association of pterygium with sociodemographic, ophthalmological, and systemic parameters was assessed. Physical environmental parameters for the study period were estimated. RESULTS: Of the 12,021 eligible subjects, 9735 (81% response rate) participated in the study. The prevalence of pterygium in any eye was 13.2% (95% CI: 12.5%-13.9%), and bilateral pterygium was 6.7% (95% CI: 6.2-7.2). The prevalence increased with age (<0.001) irrespective of sex and was highest in those aged 60-69 years (15.8%). The prevalence was highest in coastal (20.3%), followed by plains (11.2%) and hilly regions (9.1%). On multi-logistic regression, pterygium was positively associated with coastal location (P<0.001), illiteracy (P = 0.037), increasing lifetime sun exposure (P<0.001), and negatively associated with BMI ≥25 kg/m2 (P = 0.009). CONCLUSION: Pterygium prevalence is high in the rural Indian population. The association of pterygium with several potentially modifiable risk factors reflects its multifactorial etiology and provides targets for preventive measures.

Environmental exposures to lead, cadmium, and mercury and pterygium in Korean adults.

Pterygium, one of the most common eye disorders, is an abnormal fibrovascular proliferation extending from the conjunctiva to the cornea. The mechanism of development in pterygium has not been fully elucidated; however, oxidative stress is suggested to be one of the major causes. Heavy metals such as lead (Pb), cadmium (Cd), and mercury (Hg) enter the human body and induce oxidative stress. However, no study has investigated the association of these heavy metals with pterygium. Therefore, this study aimed to evaluate the associations of environmental exposures to Pb, Cd, and Hg with pterygium in the Korean general adults. We analyzed data from 6,587 adults (≥ 20 years of age) who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011. Pterygium was diagnosed as the presence of a wing-shaped fibrovascular growth. The exposures of Pb, Cd, and Hg were estimated by measuring blood concentrations. The prevalence of pterygium in this study population was 4.0% (348 subjects). After adjusting for potential confounders, the Pb level in blood was found to have a significant dose-dependent association with pterygium (p for trend = 0.001), and its highest quintile (vs. the lowest) had an odds ratio (OR) of 2.22 (95% CI: 1.30, 3.78) for pterygium. The Hg level in blood in the second quintile (vs. the lowest) had an OR of 1.64 (95% CI: 1.04, 2.59) for pterygium. In conclusion, this study suggests that environmental exposures to Pb and Hg in the Korean general adults may be related to the development of pterygium.

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 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 ocular surface squamous neoplasia were excluded. Clinical data including age, sex, and self-reported race and ethnicity were analyzed to determine risk factors for presence of occult ocular surface squamous neoplasia 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 70.8% and non-Hispanic in 29.2%. Among all specimens, 18 (3.6%) were positive for occult ocular surface squamous neoplasia. The prevalence of occult ocular surface squamous neoplasia in pterygium specimens was higher in Hispanics compared to non-Hispanics (4.8% vs. 0.7%, respectively, p = .025). The prevalence of occult ocular surface squamous neoplasia 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 = .57). There were also no statistically significant differences between those with or without occult ocular surface squamous neoplasia regarding age or sex. CONCLUSIONS: A significant but low rate of occult ocular surface squamous neoplasia was found in pterygium specimens. The percentage of those with ocular surface squamous neoplasia in pterygium specimens was significantly greater in Hispanics compared to non-Hispanics. As treatment and prognosis of pterygium and ocular surface squamous neoplasia differ, histopathologic evaluation of all pterygium specimens is warranted.

Comparison of Pterygium Recurrence Rates Between Attending Physicians and Supervised Trainee Residents.

PURPOSE: To compare the recurrence rates after pterygium surgery performed by supervised trainee residents and attending physicians. METHODS: This retrospective study included pterygium surgeries performed by trainee residents and attending physicians in an academic institution in South Texas in the years 2008 to 2019. All residents performed surgeries under direct supervision of an attending physician. Only primary pterygium cases with a minimum postoperative follow-up of 6 months were included. Patients' demographics, primary surgeon, use of conjunctival autograft (CAU) or amniotic membrane graft (AMG), recurrence of pterygium, follow-up length, and complications were recorded. RESULTS: This study included 240 eyes of 229 patients with a mean age of 55.6 ± 12.3 years (range, 28-91 years). Of these eyes, 100 surgeries were performed by attending physicians (including 87 with CAU and 13 with AMG) and 140 surgeries by trainee residents (including 119 with CAU and 21 with AMG). There were no significant differences between the 2 groups of patients regarding age, sex, and surgical technique (CAU vs. AMG). Patients were followed up for an average of 19.8 ± 15.2 months. No statistically significant differences were found in comparing the rate of pterygium recurrence between attending physicians and residents when using CAU (6.8% vs. 10.0%, respectively; P = 0.42) and AMG (69.2% vs. 47.6%, respectively; P = 0.22). Moreover, there were no significant differences in other postoperative complications between the groups. CONCLUSIONS: Pterygium recurrence rates were similar between attending physicians and supervised trainee residents. Thus, acceptable outcomes can be expected when pterygium surgery is performed by a supervised ophthalmology resident.

Hydroxychloroquine treatment on SARS-CoV-2 receptor ACE2, TMPRSS2 and NRP1 expression in human primary pterygium and conjunctival cells.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen for coronavirus disease 2019 (COVID-19) pandemic. Its infection depends on the binding of spike protein to the host cell receptor angiotensin-converting enzyme 2 (ACE2), type II transmembrane serine protease (TMPRSS2) and neuropilin-1 (NRP1). Hydroxychloroquine has been applied as one of the COVID-19 treatment strategies. Here we aimed to evaluate hydroxychloroquine treatment on SARS-CoV-2 receptor expression in human primary pterygium and conjunctival cells and its potential influences. Expression of ACE2, TMPRSS2 and NRP1 proteins were found in the epithelial layer of both primary pterygium and conjunctiva tissues as well as in their isolated fibroblasts. High concentration of hydroxychloroquine treatment significantly reduced the viability of both primary pterygium and conjunctival cells. ACE2 protein expression was significantly decreased in both pterygium and conjunctival cells after hydroxychloroquine treatment. Hydroxychloroquine also reduced NRP1 protein expression in conjunctival cells. In contrast, TMPRSS2 protein expression showed slightly increased in conjunctival cells. Notably, ROS production and SOD2 expression was significantly elevated in both pterygium and conjunctival cells after hydroxychloroquine treatment. In summary, this study revealed the reduction of ACE2 and NRP1 expression by hydroxychloroquine in human primary pterygium and conjunctival fibroblasts; yet with the increase in TMPRSS2 expression and oxidative stress and decrease in cell viability. Implementation of hydroxychloroquine for COVID-19 treatment should be carefully considered with its potential side effects and in combination with TMPRSS2 inhibitor.

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.

Prevalence of Human Papillomavirus Genotypes in Pterygia from Thai Individuals.

PURPOSE: Pterygium, a common ocular growth, has an unknown pathogenesis and aetiology. Environmental factors such as ultraviolet light, genetic factors and viral infections may be implicated in the development of pterygia. Human papillomavirus (HPV), an oncogenic virus, has previous been detected in individuals with pterygia. The aim of this study was to assess the prevalence of HPV genotypes in pterygia from Thai individuals. METHODS: DNA was extracted from 389 pterygia. HPV was detected by nested PCR and HPV genotyping was conducted using reverse hybridization. The DNA sequences of HPV-L1 genes were analyzed. RESULTS: HPV was detected in only 6.8% (25/389) of pterygia from Thai individuals. The majority (16/25, 64%) of strains were genotyped as HPV-16 and the remainder (9/25, 36%) could not be typed. Four pterygia showed evidence of coinfection by HPV-16 and either HPV-18 (2/25, 8%) or HPV-58 (2/25, 8%). Nine of 11 samples showed the same HPV-16 L1 gene sequence that was identical to a HPV-16 reference sequence in GenBank. The remaining two samples each bore silent single nucleotide mutations (T1078G and T1081A) that did not result in amino acid changes. CONCLUSION: HPV, especially HPV-16, may be one of the pathogens causing pterygia in Thai individuals. Genotyping data suggested that HPV-16 from pterygia may be similar in sequence to HPV-16 causing cervical cancer.

Association between outpatient visits for pterygium and air pollution in Hangzhou, China.

Air pollution could be a risk factor for the development of pterygium. This study aimed to investigate the potential associations between outpatient visits for pterygium and air pollutants. Using a time-stratified case-crossover design, the data of 3017 outpatients with pterygium visiting an eye center in Hangzhou, China, and the air pollution data of the Environmental Protection Department of Zhejiang Province between July 1, 2014, and November 30, 2019, were examined. The relationships between the air pollutants nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone, and fine particulate matter (PM) with median aerometric diameter <2.5 µm (PM2.5) and <10 µm (PM10) and outpatient visits for primary pterygium were assessed using single- and multiple-pollutant models. Significant associations between outpatient visits for pterygium and air pollutants (PM2.5, PM10, SO2, and NO2) were observed. Younger patients were found to be more sensitive to air pollution. Interestingly, the younger female patients with pterygium were more vulnerable to PM2.5 exposure during the warm season, while the younger male patients with pterygium were more sensitive to NO2 during the cold season. Significant effects were also observed between the pterygium outpatients and PM2.5 (odds ratio [OR] = 1.06, P = 0.02), PM10 (OR = 1.04, P = 0.01), and SO2 (OR = 1.26, P = 0.01) during the warm season, as well as NO2 (OR = 1.06, P = 0.01) during the cold season. Our study provides evidence that outpatient visits for pterygium are positively associated with increases in the air pollutants PM2.5, PM10, SO2, and NO2, revealing the important role of air pollution in the occurrence and development of pterygium.

Correlation between the presumed pterygium with dry eye and with systemic and ocular risk factors.

OBJECTIVE: To estimate the epidemiology of the pterygium and its correlation with dry eye symptoms and with the potential systemic and ocular predictors. METHODS: This study is a population-based, cross-sectional study in which random visits were made to the 600 households of 600 participants of age ≥40 years in Ribeirão Preto-SP (n=420) and Cassia dos Coqueiros-SP (n=180) in Brazil. The participants were subjected to a structured interview with a detailed questionnaire to collect information on demography and the potential risk factors. Next, random participants with pterygium (n=63) or not (n=110) were evaluated for the ocular surface changes. RESULTS: The frequency of pterygium in Ribeirão Preto was 21% (15.7% among women and 32.1% among men; p=0.0002). In Cássia dos Coqueiros, the corresponding frequency was 19.4% (17.3% among women and 25.5% among men; p=0.28). The mean age of the affected individuals was higher than that of the unaffected ones (65.6 ± 10.5 years vs. 61.2 ± 12.0 years, p=0.02). A positive correlation was noted between pterygium and any prior radiotherapy and chemotherapy (p<0.0001, for both). A higher score on corneal fluorescein and conjunctival lissamine green staining was asso ciated with pterygium (p=0.0003 and 0.0001, respectively). CONCLUSION: We noted a high frequency of pterygium in two Brazilian adult populations, mainly among the men and elderly. Ocular surface damage and a previous history of radiotherapy and/or chemotherapy were found to be associated with pterygium.