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Introduction

Pterygium is an elastotic degeneration of the conjunctival stroma, primarily brought on by exposure to ultraviolet (UV) light. It is a wing-shaped fibro-vascular development of conjunctiva on the superficial cornea/conjunctiva [1,2]. It is among the most prevalent conditions affecting the cornea that impair eye function [3]. Pterygium prevalence ranges from 1.1% to 53% worldwide depending on environmental factors [4-7]. A population-based study in Dhaka, Bangladesh found that the prevalence of pterygium was 3.0%. However, the study's methodology was limited, and the researchers believe that the reported figure is underestimated. Astigmatism is a visual disturbance or diminution brought on by a fibro vascular development that encroaches on the nasal or temporal cornea [8]. At first, pterygium is asymptomatic [9], but as it worsens, uneven corneal astigmatism increases and visual performance declines due to a loss of corneal transparency in the pupillary region. Pterygium is a potentially blinding condition that can have a negative impact on one's emotional, social, and financial life [10-12] and is responsible for 2.2% of all blindness cases in at least one eye [13]. Patients with pterygium frequently report experiencing redness, ocular irritation, dryness, and discomfort in their eyes [14, 15]. Although the exact cause of pterygium is unknown, some characteristics, such as working outdoors, being elderly, being male, residing in a location with increased UV radiation exposure, and having a dry and windy climate, are linked to its development [16-18].According to a study done in Blue Mountain, Australia, pterygium is significantly linked to lower skin sensitivity, sun-related skin damage, and increased pigmentation (skin and hair color) [19]. The study location is in the tropics, where there hasn't been much prior research on the frequency of pterygium, particularly on its contributing variables. In order to organize and execute frequent screening programs for prevention, early intervention, and risk factor avoidance, this study sought to ascertain the prevalence of pterygium and its contributing factors in adults. Pterygium risk factors include exposure to UV radiation, geographic latitude close to the equator, outdoor activity [20], aging, male gender [21], and dusty environments, according to several research conducted around the world [22]. Wearing brimmed hats and sunglasses with UV protection lenses is advised since UV radiation is the main risk factor for pterygium [2,9]. Depending on the stage of pterygium, the most common therapeutic options include surgery, non-steroidal anti-inflammatory eye drops, artificial tears, and refractive correction for astigmatisms [9]. Surgery for pterygiums is indicated when the cornea exhibits an atypical appearance (cosmetic issue), when it extends toward the visual axis, when it limits eye movement, when it results in astigmatism-induced visual loss, and when a patient reports pterygium expansion.

Methodology

The cross-sectional Observational study was conducted in the BNSB Zahurul Haque Eye Hospital, Faridpur from June 2022 to May 2023. A total of 60 subjects of both sexes were included in the study. Purposive sampling was done according to the availability of the patients who fulfilled the selection criteria. Face to face interview was done to collect data with a semi-structured questionnaire about risk factors and socioeconomic associations. After collection, the data were checked and cleaned, followed by editing, compiling, coding, and categorizing according to the objectives and variables to detect errors and to maintain consistency, relevancy and quality control. Statistical evaluation of the results used to be obtained via the use of a window-based computer software program devised with Statistical Packages for Social Sciences (SPSS-24).

Result

(Table 1) shows that, about 22 (36.7%) respondents’ lies between 31years to 40years and 18 (30.0%) respondents lies between 20years to 30years. Mean ± SD of the respondents was 39.5 ± 1.3 years. (Figure 1) shows that, more than half of the patient 34 (56.70%) were male and 26 (43.30%) patients were female.

Figure 1: Distribution of the patients according to sex (n=60).

Table 1: Distribution of the patients according to age (n = 60).

Age group	Frequency	%
20–30years	18	30.0
31 - 40years	22	36.7
41 - 50years	8	13.3
51 - 60years	7	11.7
>60 years	5	8.3
Total	60	100.0
Mean ± SD: 9.5 ±7.3 years

Table 2: Distribution of the patients according to marital status (n = 60).

Family size	Frequency	%
0–3	23	38.3
4–6	29	48.3
? 7	8	13.3
Total	60	100.0

Table 3: Distribution of the patients according to family size (n=60).

Family size	Frequency	%
0–3	23	38.3
4–6	29	48.3
? 7	8	13.3
Total	60	100.0

Table 4: Distribution of the patients according to educational level (n = 60).

Educational level	Frequency	%
Illiterate	6	10.0
Primary school	23	38.3
Secondary school	21	35.0
College/university	10	16.7
Total	60	100.0

Table 5: Distribution of the patients according to Occupation (n = 60).

Occupation	Frequency	Percent
Student	7	11.7
Farmer/labor	12	20.0
Employed	17	28.3
Business	21	35.0
Others	3	5.0
Total	60	100.0

Table 6: Distribution of the patients according to sun exposure (n=60.)

Sun exposure	Frequency	%
Yes	33	55.0
No	27	45.0
Total	60	100.0

Discussion

The magnitude of pterygium varies widely from 1.1% to 53% globally. Pterygium formation's underlying mechanism is not well understood. Numerous studies have shown how exposure to ultraviolet (UV) radiation affects pterygium. Nonetheless, there have been contradictory reports on the effects of smoking, age, and gender on pterygium. Pterygium's precise pathophysiology is still unknown. Numerous studies have revealed that race is a risk factor for pterygium. Research involving two or more ethnic groups may shed additional light on how lifestyle variations or genetic predispositions affect pterygium. In this study, about 22 (36.7%) respondents lies between 31 years to 40 years and 18 (30.0%) respondents lies between 20 years to 30 years. Mean ± SD of the respondents was 39.5 ± 1.3 years. More than half of the patient 34 (56.70%) were male and 26 (43.30%) patients were female. About 39 (46.9%) were married, 8 (13.3%) were widowed, 5 (8.3%) were divorced and 8 (13.3%) were single. Nearly half of the participants 29 (48.3%) had 4–6 members in their family. Only 10 (16.7%) of the participants had completed their college/university, 23 (38.3%) had completed primary school, 21 (35.0%) had completed secondary school and 6 (10.0%) were illiterate. About 21 (35.0%) were businessman, 17 (28.3%) were employed, 12 (20.0%) were Farmer/labor and 7 (11.7%) were student. More than half 33 (55.0%) of the participants had a history of sun exposure for five and more hours per day. Indoor was the working area more than half 37 (61.7%) of the participants. About 19 (31.7%) of the participants had a history of dust exposure. Only 16 (26.7%) use sunglasses/hat for protection. Only 7 (11.7%) had a family history of pterygium. In another study, there were 400 study participants in the assessment of pterygium with a response rate of99.50%. The mean age of the study participants was 39.9 ± 9.8years. More than half 219(54.75%) of the study participants were males and slightly higher than two-third 273(68.25%) of the participants were living in rural areas. Among the study participants, almost half 206(51.50%) were married and 179(44.80%) hada family size of 4–6 children in a house. Only 114 (28.50%) of the participants could read and write as well as 164(41.00%) were merchants. More than half 212(53.00%) of the participants had a history of sun exposure for five and more hours per day. Whereas only 97(24.30%) use sunglasses/hat for protection. Besides, almost three-fourth of the study participants 294(73.40%) never use any alcohol product and only 63 (15.80%) had a family history of pterygium. The overall prevalence of pterygium among adults aged 18 years and above in Gambella town was 127(31.80%), (95% CI: 27.30, 36.30) in either eye. Most of the pterygium 101(79.53%) was located to the nasal side of the cornea and the rest 26(20.47%) was located to the temporal part of the cornea. More than half 69(54.33%) of the pterygium was unilateral and the remaining 58(45.67%) was bilateral [23]. In another study conducted in Hebei, China showed that a total of 3790 individuals (2351 Hans and1439 Manchus) met the study criteria, of which 248nwere diagnosed with pterygium (6.5%). There was no significant difference between the prevalence rates in Hans (6.2%) and Manchus (7.2%) (p=0.232). Multi variate analysis revealed that the risk factors for grade 2 or higher pterygium were increasing age (p<0.001) and rural residence (OR 1.83; 95% CI 1.11 to 3.02; p=0.018), while the protective factors include gender (female) (OR 0.58;95% CI 0.37 to 0.88; p=0.011), cigarette smoking (OR0.53; 95% CI 0.34 to 0.83; p=0.005) and myopia (OR 0.50;95% CI 0.33 to 0.77; p=0.002). Premature menopause (OR2.66; 95% CI 1.05 to 6.72; p=0.038) increased the risk of grade 2 or higher pterygium in females, while higher high-density lipoprotein (HDL) (OR 1.94; 95% CI 1.08 to 3.47; p=0.027) was a risk factor of grade 2 or higher pterygium in males [24]. A possible reason behind our high finding could be it is carried out in a hot, dry, and dusty environment with low latitude that might contribute to the occurrence of pterygium [25,26]. Furthermore, different geographical areas nearer to the equator (tropical area) have greater exposure to ultraviolet-B that intern contributes to the occurrence of pterygium [10,20]. The proportion of pterygium in this study is similar to other studies done in Southwest, Japan (30.8%) [10], China (33.98%) [25]. although these countries are located in different geographical areas, the possible reason might be all studies were carried out with similar study design. On the other side, the proportion of pterygium in this study is lower than other studies done in Northwest Ethiopia (38.7%) [8].This might due to geographical, latitudinal, economic, and environmental variations that contribute to the occurrence of the disease [20, 27]. The other possible reason could due to the age groups included in the studies. Adults aged 18years and above were included in this study but, the study done in Gondar, Ethiopia includes adult’s age greater than 20 years that might contribute to the occurrence of the pterygium [4,19,21]. Those adults who were exposed to sunlight five hours and above were 6.86 times more likely to develop pterygium than those who were not exposed (AOR = 6.86 (95% CI: 4.00,11.79). This is in line with studies done in South Korea [28], Australia [5], India [30], Koladiba Ethiopia [27]. Although it is difficult to quantify the true amount of one’s exposure to sunlight with ultraviolet radiation, many studies had shown that outdoor workers have a higher risk of the development of pterygium [2, 28]. Even though some amount of ultraviolent is important for our body, exposure for five hours and more for acute or long time could cause disorders in skin, conjunctiva, cornea, and lens [2, 20]. Lots of controversies are raised regarding the association of gender and pterygium in different kinds of literature. This study showed that being male was 2.10 times more likely to develop pterygium as compared to females. This result is supported by studies done in Ethiopia [8], Australia [5], China [1, 26], Japan [12], Malaya Indonesia [29], and Central India [20]. Males spent most of their time in outdoor activities in most African countries including Ethiopia. This might intern expose them to develop pterygium [8]. Whereas a study in South Korea [24] showed that being female was associated with pterygium. In contrast, studies in Japan, China [4,30], and Iran [34] indicated that there were no significant differences in the association of gender and pterygium. Cultural differences, differences in ethnicity, and varied environmental factors could affect the exposure status of males and females for pterygium [21]. On the other side, adults who wore sunglass/hat were 62% less likely to develop pterygium as compared to those who did not wear sunglass/hat. This is consistent with studies done in Gondar, Ethiopia [8], and Benin City, Nigeria. A possible reason could be wearing hat/protective sunglasses might reduce the exposure status from UV light and dust particles that might also reduce the development of pterygium [5].

Risk Factors and Socio-Economic Associations of Pterygium: A Cross-Sectional Study Download PDF

Journal Name : SunText Review of Medical & Clinical Research

Abstract

Introduction

Methodology

Result

Discussion

Conclusion

References

Working area	Frequency	%
Outdoor	23	38.3
Indoor	37	61.7
Total	60	100.0

Dust exposure	Frequency	%
Yes	19	31.7
No	41	68.3
Total	60	100.0