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Table of Contents
ORIGINAL ARTICLE
Year : 2021  |  Volume : 3  |  Issue : 1  |  Page : 38

Pterygium in Rural Andean Ecuador: Epidemiology, risk factors, and barriers to care

Sila Bal1, Sarah Marjane2, Carlos Gonzalez2, Zachary Smith2, Charlene Higgins2, Lucy Miller-Suchet2, Gil Binenbaum3
1 Partners for Andean Community Health, Connecticut; Department of Ophthalmology, Massachusetts Eye and Ear, Boston, Massachusetts, USA
2 Partners for Andean Community Health, Connecticut, USA
3 Department of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA

Date of Submission05-Aug-2021
Date of Acceptance26-Oct-2021
Date of Web Publication26-Nov-2021

Correspondence Address:
Dr. Sila Bal
Massachusetts Eye and Ear, 243 Charles Street, Boston, MA
USA
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/pajo.pajo_105_21

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  Abstract 


Background: Pterygium is an ocular surface lesion that causes chronic eye irritation and eventually, vision impairment. Pathologically, prolonged ultraviolet (UV)-induced radiation damage leads to conjunctival and limbal stem cell damage. As such, rural, high-altitude equatorial communities are at particular risk due to proximity to the sun, outdoor work, and a lack of access to eye care.
Methods: We conducted a cross-sectional study to determine the epidemiology of pterygium in the Chimborazo region of Ecuador. Adults presenting to Clinical FIBUSPAM's medical clinics for both ocular and nonocular reasons were examined by optometrists/ophthalmologists to identify pterygium. Affected patients completed a questionnaire about self-reported known risk factors, treatment, and barriers to care, and received UV-blocking sunglasses.
Results: Of 296 patients, 165 (55%) had pterygium. The mean age was 60.2 years (range 19–88), 69% were female; 63% had unilateral pterygia, and 37% had bilateral pterygia. Symptoms occurring daily included severe photophobia (36%), foreign body sensation (28%), eye pain (24%), burning (31%), and itching (28%). In addition, 40% reported concern about eye appearance. Risk factors included spending >5 h outdoors each day working (93%), smoking (8%), and alcohol (14%). For prophylaxis, while 91% routinely wore hats outdoors, only 16% used sunglasses. For treatment, 30% used eye drops, of which two-thirds were natural remedies. About 93% wanted treatment (medications or surgical removal), 78% were concerned about access to treatment, and 43% reported cost as the major concern.
Conclusions: Pterygium is highly prevalent (55%) among adults presenting for care in community health clinics in the Chimborazo Province of Ecuador. This treatable and potentially preventable cause of ocular irritation and vision loss greatly impacts the quality of life in this region. This and similar communities would benefit from improved education and outreach through care delivery models that bring affordable prevention and eye care services closer to home.

Keywords: Andean eye health, Ecuador, ocular surface, pterygium, pterygium in Ecuador


How to cite this article:
Bal S, Marjane S, Gonzalez C, Smith Z, Higgins C, Miller-Suchet L, Binenbaum G. Pterygium in Rural Andean Ecuador: Epidemiology, risk factors, and barriers to care. Pan Am J Ophthalmol 2021;3:38

How to cite this URL:
Bal S, Marjane S, Gonzalez C, Smith Z, Higgins C, Miller-Suchet L, Binenbaum G. Pterygium in Rural Andean Ecuador: Epidemiology, risk factors, and barriers to care. Pan Am J Ophthalmol [serial online] 2021 [cited 2023 Apr 1];3:38. Available from: https://www.thepajo.org/text.asp?2021/3/1/38/331326




  Introduction Top


Pterygia are a chronic ocular surface condition secondary to abnormal fibrovascular tissue growth extending from the bulbar conjunctiva onto the cornea.[1],[2],[3] Typically diagnosed on routine eye examination, there are several environmental, lifestyle, and demographic risk factors for the development of pterygia.[2] Prolonged ultraviolet (UV) radiation is the leading environmental risk factor and is likely the result of UV-induced damage to corneal limbal stem cells.[1],[2] Supporting this hypothesis, most epidemiologic assessments have shown a large geographic variation in incidence, with countries closer to the Equator having higher rates of pterygium occurrence.[2],[3],[4] In addition to cosmetic unpleasantness, pterygia are associated with significant ocular surface irritation and as they extend further onto the cornea, will impair vision through altered tear film, induced astigmatism, epiphora, and in severe cases, obstruction of the visual axis.[5],[6],[7]

Medical therapy is typically reserved for symptomatic relief of pterygia not causing visual impairment and has not been shown to stop progression or induce reversal.[4],[5],[6] Treatment of vision loss involves surgical excision, with high rates of pterygium recurrence following simple excision.[5],[6],[7],[8] As such, adjunctive measures such as conjunctival autographs, irradiation, and topical/subtopical medications are often employed to prevent recurrence.[5],[6],[7],[8]

The prevalence of pterygium varies greatly between populations from 1.2% to 31.01% or greater in rural areas.[1],[2],[3],[4] One report describes a “pterygium zone” within 40° of latitude North or South of the Equator.[3] As a country located directly on the Equator, the people of Ecuador, especially those living in rural, mountainous communities, are particularly susceptible to the harmful effects of UV radiation and therefore the subsequent development of pterygia. There remain significant barriers to eye care in the country such as cost and lack of an ophthalmologist workforce in rural regions. However, to the best of our knowledge, no studies have assessed the prevalence of pterygium and the barriers to care in rural Ecuadorian communities.


  Methods Top


This was a cross-sectional assessment to determine the epidemiology of pterygia in the Chimborazo region of Ecuador. Participants were a convenience sample of patients seen in Fundacion Internacional Buen Samaritano Paul Martel (FIBUSPAM) clinics. FIBUSPAM is a nonprofit organization located in the high altitude (2754 m) province of Chimborazo in Ecuador that provides affordable healthcare to communities throughout the country. Adults presenting to Clinical FIBUSPAM's medical clinics for both ocular and nonocular reasons were examined by optometrists/ophthalmologists to identify pterygia in June 2019. The diagnosis was made using a portable slit-lamp or indirect ophthalmoscope to identify fibrovascular conjunctival growth onto the cornea.

A one-time 22 question survey was administered to a convenience sample of patients seen at the eye clinic who received a specific diagnosis of pterygium. Participants were solicited for enrollment in person during clinical visits. Survey questions are included in Appendix A.

Statistical analysis

The primary outcomes were the prevalence of pterygium in the sample population and the survey results surrounding self-reported known risk factors and barriers to pterygium-related care. The prevalence of pterygium was identified using descriptive statistics. Sample characteristics, including age and gender, were assessed. Descriptive statistics were used to summarize risk factors and barriers to eye care access from the survey results.


  Results Top


A total of 296 patients were screened for pterygia. Of these, 165 (55%) had pterygia. The mean age was 60.2 years (range 19–88). One hundred and fourteen (69%) were female. Of those patients with pterygia, 104 (63%) had unilateral pterygia and 53 (37%) had bilateral pterygia [Table 1].
Table 1: Demographics of patients presenting to Fundacion Internacional Buen Samaritano Paul Martel clinics found to have pterygium

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Survey results

One hundred and forty patients participated in the survey. Results showed that 36% of patients reported daily severe photophobia, 28% reported daily foreign body sensation, 24% daily eye pain, 31% daily burning, and 28% itching. In addition, 40% reported concern about eye appearance. Self-reported risk factors in individuals with pterygia included spending >5 h outdoors each day working (93%), smoking (8%), and alcohol (14%). Regarding prophylaxis, 91% of survey participants reported routinely wearing hats outdoors; however, only 16% used sunglasses. Regarding the treatment of pterygia, 30% of survey participants reported using eye drops, of which two-thirds were natural remedies. A large majority of the survey participants, 93% reported wanting medical or surgical treatment of their pterygium. The most commonly reported barriers to treatment were access to care in 78% of participants and cost for 43% of participants [Table 2].
Table 2: Survey results of patients with pterygium

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  Discussion Top


We found a significantly higher rate of pterygia in the Chimborazo Province of Ecuador than previous reports in similar populations.[1],[2],[3],[4] UV radiation increases the risk of pterygia formation.[1],[2],[3],[4] Our data supports that this risk disproportionately affects individuals in mountainous equatorial regions worldwide due to long hours of outdoor performing agricultural work, limited eye care access, and decreased access to prophylactic measures such as UV eye protection.

Pterygia are a preventable and treatable cause of chronic ocular surface irritation in this community. Approximately, one-third of survey participants reported daily symptoms including severe photophobia, foreign body sensation, eye pain, burning, and itching. A large majority, 93% of survey participants spent 5 or more hours outdoors each day for work. Of these, 91% reported wearing hats but only 16% used protective eyewear. Our results highlight that interventions aimed at both education and distribution of protective eyewear may help slow, and in some cases, prevent, sun damage in these communities.

The treatment of pterygia involves interventions directed at symptom management, and in the case of vision-threatening pterygia, surgical excision.[5],[6],[7],[8] Our survey found that 93% of participants reported wanting further treatment of their pterygia. Of those, 78% were concerned about access and 43% were concerned about cost. This again underlines the need for care delivery models that bring affordable eye care services closer to home.

The strengths of this study include the large sample size and access to a sample of ocular and nonocular patients. To our knowledge, no study has examined the prevalence of pterygia in these communities and there are no reports on the self-reported known risk factors and barriers to care in these regions. This information can serve as the foundation for the development of programs that target the unique eye care needs of these communities.

There are important limitations to consider. Our sample was a convenience sample of all patients reporting to FIBUSPAM clinic. There is a potential bias from assessing the prevalence at a clinic if patients with pterygium were more likely to seek care there. However, many of the patients were seeking care for other medical reasons unrelated to pterygium. Our sample also had a high proportion of female participants, 69%. In the previous studies, men had a higher rate of pterygia, and thus our rate may actually be lower than the true prevalence in this region. Finally, our study was conducted over a narrow time period, limiting access to a more representative sample.

Pterygia represent a treatable and potentially preventable cause of chronic ocular surface irritation, and in many cases, decreased vision. In our analysis of patients presenting to clinics in the Chimborazo province which is located at 2754 meters, there was a high prevalence of pterygium. Mountainous Equatorial regions are likely at higher risk due to increased outdoor work in proximity to the sun. Despite this, there are limited resources aimed at mitigating the disproportionate risk exposure in these regions. This and similar communities would benefit from improved education and outreach surrounding eye protection through care delivery models that bring affordable prevention and eye care services closer to home.

Acknowledgments

Partners in Andean Community Health Fundacion Internacional Buen Samaritano Paul Martel.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.


  Appendix Top


Appendix A:

Pterygium Survey Questions

Survey ID #:

Age:

Gender:

Visual Acuity:

Pterygium bilateral/unilateral:

Part One: Symptoms

  1. When did you first notice that you had pterygium (please report month and year)?
  2. Have you noticed a recent change in the size of the pterygium?


    1. No
    2. Yes, it has grown over the past 6 months
    3. Yes, it has grown over the past 2 years
    4. I do not know if it has grown


  3. Do you have increased sensitivity to bright light?


    1. No sensitivity to bright light
    2. Some sensitivity to bright light
    3. A lot of sensitivity to bright light


  4. Does it feel like there is something rubbing against your eye on most days?


    1. No rubbing sensation
    2. Some rubbing sensation
    3. A lot of rubbing sensation


  5. Do you worry about the appearance of your eyes?


    1. I do not worry about my appearance
    2. I worry about my appearance a little
    3. I worry about my appearance a lot


  6. Do you notice redness of your eyes on most days?


    1. No redness
    2. Some redness
    3. A lot of redness


  7. Do you have eye pain most days?


    1. No pain
    2. Some pain
    3. A lot of pain


  8. Do your eyes burn most days?


    1. No burning
    2. Some burning
    3. A lot of burning


  9. Do your eyes itch most days?


    1. No itching
    2. Some itching
    3. A lot of itching


Part Two: Risk Factors

  1. Do you use sunglasses?


    1. Yes, most of the time
    2. Yes, some of the time
    3. No


  2. How long have you been using sunglasses?


    1. Less than 1 year
    2. 5 years or less
    3. Greater than 5 years


  3. Do you use a sun hat when you are outside?


    1. Yes, most of the time
    2. Yes, some of the time
    3. No


  4. How much time do you spend outside on an average day?


    1. Less than 5 h
    2. More than 5 h


  5. Do you work?


    1. Yes


      1. If yes, does your job require you to be outside for most of the day?


      1. Yes
      2. No


    2. No


  6. Do you live in the city or outside of the city?


    1. City
    2. Outside of the city


  7. Do you smoke cigarettes?


    1. Yes
    2. No


  8. Do you drink more than 1 alcoholic drink a day?


    1. Yes
    2. No


Part Three: Treatment and Barriers to Care

  1. Do you use any eye drops for your pterygium?


    1. Yes


      1. If yes, which eye drops?


    2. No


  2. Have you ever had surgical removal of your pterygium?


    1. Yes


      1. When was the surgery and what type of surgery was performed?
      2. How soon after the surgery did you notice the pterygium come back?


    2. No


  3. Do you want treatment for your pterygium?


    1. Yes, I would like treatment


      1. If yes, go to questions 4 and 5


    2. No, I do not want treatment


  4. Are you concerned about getting treatment for your pterygium?


    1. Yes, I am concerned
    2. No, I am able to get treatment


  5. What is your major concern related to treatment?


    1. Cost of surgery
    2. Fear of surgery
    3. Unable to get to the clinic
    4. Do not have time for the surgery


Preguntas de la Encuesta sobre el Pterigión

ID de la Encuesta #:

Edad:

Genero:

Agudeza Visual:

Pterigión bilateral/unilateral:

Parte Uno: Síntomas

  1. Hace cuánto tiempo notaste que tenías un pterigión (en meses)?
  2. Has notado un cambio reciente en el tamaño del pterigión?


    1. Si, ha crecido en los últimos 6 meses.
    2. Si, ha crecido en los últimos 2 años.
    3. No sé si ha crecido


  3. Tienes una mayor sensibilidad a la luz?


    1. Ninguna sensibilidad a la luz
    2. Un poco de sensibilidad a la luz
    3. Mucha sensibilidad a la luz


  4. Sientes que hay algo que rasca en sus ojos?


    1. No siento nada
    2. Siento un poco
    3. Siento mucho


  5. Te preocupas con la apariencia de tus ojos?


    1. No me preocupo
    2. Me preocupo un poco
    3. Me preocupo mucho


  6. Notas enrojecimiento de sus ojos en la mayoría de los días?


    1. Ningún enrojecimiento
    2. Un poco de enrojecimiento
    3. Mucho enrojecimiento


  7. Tienes dolor en sus ojos la mayoría de los días?


    1. Ningún dolor
    2. Algún dolor
    3. Mucho dolor


  8. Tienes ardor en sus ojos la mayoría de los días?


    1. Ningún ardor
    2. Algún ardor
    3. Mucho ardor


  9. Tienes comezón relacionado a su pterigión?


    1. Ningún comezón
    2. Algún comezón
    3. Mucho comezón


Parte Dos: Factores de Riesgo

  1. Usas lentes oscuros?


    1. Si
    2. No


  2. A cuánto tiempo usas lentes oscuros?


    1. Menos de un años
    2. Entre 1-5 años
    3. Más de 5 años


  3. Usas un sombrero cuando estas en el sol?


    1. Sí, la mayoría de los días
    2. Sí, algunos días
    3. No


  4. Cuanto tiempo por día pasas afuera?


    1. Menos de 5 horas
    2. Más de 5 horas


  5. Trabajas?


    1. Si


      1. En caso afirmativo, su trabajo requiere que pases la mayoría del día afuera?


      1. Si
      2. No


    2. No


  6. Vives en la ciudad o en el campo?


    1. Ciudad
    2. Campo


  7. Fumas cigarrillos?


    1. Si
    2. No


  8. Bebes más que una bebida alcohólica por día?


    1. Si
    2. No


Parte Tres: Barreras al Tratamiento

  1. Usas gotas para su pterigión?


    1. Si


      1. En caso afirmativo, cuáles?


    2. No


  2. Alguna vez le hicieron la cirugía para remover el pterigión?


    1. Si


      1. Cuando fue la cirugía e que tipo fue hecho?
      2. Cuanto tiempo después de la cirugía notaste que volvió el pterigión?


    2. No


  3. Quieres tratamiento para tu pterigión?


    1. Si, quiero tratamiento


      1. En caso afirmativo continúe a las preguntas 4 y 5


    2. No quiero tratamiento


  4. Estas preocupado sobre el tratamiento del pterigión?


    1. Si estoy preocupado
    2. No tengo preocupaciones sobre el tratamiento


  5. Cuál es su mayor preocupación con el tratamiento?


  1. Precio de la cirugía
  2. Miedo de la cirugía
  3. Dificultades con llegar a la clínica
  4. No tengo tiempo para la cirugía




 
  References Top

1.
Rezvan F, Khabazkhoob M, Hooshmand E, Yekta A, Saatchi M, Hashemi H. Prevalence and risk factors of pterygium: A systematic review and meta-analysis. Surv Ophthalmol 2018;63:719-35.  Back to cited text no. 1
    
2.
Ang LP, Chua JL, Tan DT. Current concepts and techniques in pterygium treatment. Curr Opin Ophthalmol 2007;18:308-13.  Back to cited text no. 2
    
3.
Luthra R, Nemesure BB, Wu SY, Xie SH, Leske MC; Barbados Eye Studies Group. Frequency and risk factors for pterygium in the Barbados eye study. Arch Ophthalmol 2001;119:1827-32.  Back to cited text no. 3
    
4.
Liang QF, Xu L, Jin XY, You QS, Yang XH, Cui TT. Epidemiology of pterygium in aged rural population of Beijing, China. Chin Med J (Engl) 2010;123:1699-701.  Back to cited text no. 4
    
5.
Kim KW, Kim JC. Current approaches and future directions in the management of pterygium. Int J Ophthalmol. 2018;11(5):709-711. Published 2018 May 18. doi:10.18240/ijo.2018.05.01.  Back to cited text no. 5
    
6.
Clearfield E, Muthappan V, Wang X, Kuo IC. Conjunctival autograft for pterygium. Cochrane Database Syst Rev 2016;2:CD011349.  Back to cited text no. 6
    
7.
Küçükerdönmez C, Akova YA, Altinörs DD. Comparison of conjunctival autograft with amniotic membrane transplantation for pterygium surgery: Surgical and cosmetic outcome. Cornea 2007;26:407-13.  Back to cited text no. 7
    
8.
Chen PP, Ariyasu RG, Kaza V, LaBree LD, McDonnell PJ. A randomized trial comparing mitomycin C and conjunctival autograft after excision of primary pterygium. Am J Ophthalmol 1995;120:151-60.  Back to cited text no. 8
    



 
 
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