Prevalence of ocular morbidity among industrial workers of Eastern Nepal

INTRODUCTION

Ocular morbidity was defined as the spectrum of eye diseases, which include both visually impairing and non-visual impairing ocular conditions.^[1] Worldwide, there are 246 million individuals with impaired vision, and 39 million among them are blind.^[2] The majority of vision impairments, approximately 80%, can be prevented, treated, or cured. In developing nations, where ocular morbidities pose a significant public health challenge, around 90% of the global blind population resides.^[3] Occupational eye disorders represent a complex group of traumatic injuries, harmful exposures, undiagnosed ocular diseases, eyestrain, fatigue, and other miscellaneous ocular complaints.^[4] The industrial work environment has given rise to issues with detrimental effects on ocular health, leading to diseases, visual impairment, and blindness. These outcomes stem from the prevalent industrial hazards within the work environment. Industrial and occupational factors significantly contribute to morbidity rates, causing suffering for workers and their families. This scenario adds to the overall societal burden by causing lost productivity and increased reliance on medical and welfare services.^[5] Various factors, including socioeconomic variables such as age, gender, type of occupation, income level, and the duration spent working in a particular environment, can influence ocular morbidity. In addition, the provision of eye protection against the hazards prevalent in the work environment plays a crucial role in determining the impact on ocular health.^[6] These hazards can have adverse effects on workers’ health, particularly on their eyes, which are vulnerable to injury and diseases.

The prevalence of ocular morbidities in India is consistently reported as high, ranging from 20% to 90%, according to various studies.^[7-10] A study from Eastern Nepal found that about 90.7% of morbid conditions were related to injuries during working hours.^[11] Work-related ocular injuries were reported between 35% and 60% in different studies, including Nepal.^[12-17] The prevalence of uncorrected refractive errors and uncorrected presbyopia has been reported at various rates, between 6% to 45% in several studies.^[11,18-20] In several studies, 1–8% of industrial workers, men and 0.4–3% of women have color vision defects.^[21,22] Awareness of ocular safety and utilization of ocular safety devices during work and workplace reported to be very low which increases the ocular morbidity.^{[1,5,13,15,16,21-24]}

However, there is limited research on the prevalence of ocular morbidity and its associated factors in industrial workers. The purpose of this study was to assess the prevalence of ocular morbidity and its association with industrial workers in Koshi Province, Nepal.

MATERIALS AND METHODS

A cross-sectional study was carried out in four different industries: the sugar industry, dairy industry, soap industry, and jute industry of Biratnagar Municipality in Koshi Province, Nepal. All the participant were underwent comprehensive optometric examination between March to June 2023. A total of 359 workers were enrolled, and the purposive sampling technique was used. The study was conducted in collaboration with the outreach team of Biratnagar Eye Hospital (BEH), Biratnagar. A Memorandum of Understanding was signed between the industries and the BEH outreach team to conduct the eye screening program, in which the purpose of the study was also explained to them. Appointments were scheduled to do the eye screening, and the workers were advised to bring their previous ocular examination card if they had on the day of screening. Ethical clearance was taken from the Institutional Review Committee (78/A) of the BEH and the study adhered to the Tenets of the Declaration of Helsinki. To conduct the study, all consenting participants were included in the study. The data were collected using a defined clinical proforma and well-structured schedule. A pretesting was done on thirty workers of the pharmaceutical industry and tools were modified.

The clinical proforma and schedule contain data on sociodemographic characteristics, workplace characteristics, history of ocular injury, ocular complaints, use of protective eye devices, and barriers to the use of protective devices. The data were collected through face-to-face interviews by the principal investigator.

All the ocular examination was performed by an optometrist and the test were carried out during the day of eye screening at the scheduled industry. Assessment of uncorrected visual acuity and best-corrected visual acuity (BCVA) for each eye was assessed using the E-optotype of the Snellen chart, which was placed at a 6 m distance from the participant. Visual acuity in the better eye of 6/6–6/12 was considered normal, 6/18–6/60 was classified as visual impairments, and <6/60– 3/60 was classified as severe visual impairments.^[2] Objective and subjective (Dry) refraction was performed on all of them who needed distance and near spectacles corrections and spectacles were prescribed accordingly. External eye examination and anterior segments examination were performed using a pen torch, and posterior segments were examined by direct ophthalmoscope where lens status and posterior part of the eye was examined and documented, and then, diagnosis was made accordingly.

Visual function assessments such as color vision were assessed with an Ishihara pseudo isochromatic (38 plates) chart at 75 cm, contrast sensitivity with a Hiding Heidi card at 40 cm, and stereopsis measurement was also done using Titmus fly stereo acuity chart at 40 cm after refraction with BCVA for distance and near.

RESULTS

A total of 365 industrial workers from four different industries were presented on the day of the eye examination. Among them, six workers did not provide their consent to participate in the study, resulting in non-responses. Among them 321, (89%) were male and 38 ,(11%) were female with the mean age of 43.72 ± 10.18. The majority of them were from 40 to 49 years of age group 135 (37.6%); regarding education levels, the majority of workers had completed primary education 137 (38%). In terms of income, the mean monthly income of the workers was NRs. 22072.42 ± 10090.94. The majority of workers received a monthly income within the range of NRs. 10,000–15,000, which were 117 (32.6%) [Table 1].

There was a reduction in visual impairment after best corrections from 9.2% to 5.8% [Table 2]. Overall, the prevalence of ocular morbidity among the workers was 80.50%. The highest ocular morbidity was seen in the sugar industry 98 (89.9%). Presbyopia 166 (46.23%) was the most common ocular morbidity among all industries [Table 3]. The history of ocular injuries among all the industrial workers was 115 (32%), and the majority of them had superficial conjunctiva or corneal foreign body 88 (76.39%). Moreover, the main source of ocular injury was dust/dirt 66 (57.39%). Most of the workers visited the eye clinic/hospital 220 (61.3%) for their treatment after the ocular injury [Table 4]. There was no significant between association ocular injury with age, gender, occupation but significant association with monthly income ,nature of work and use of ocular safety devices[Table 5]. The most of workers were from the production 141 (39.3%), with a mean work experience was of 12.29 years. Awareness of the use of ocular safety devices was 272 (75.8%), but only 69 (19.2%) workers used ocular safety devices, and unavailability was a major reason 190 (52.9%) for not using ocular safety devices. Only 6 (1.7%) of workers had received training on the use of ocular safety devices.

DISCUSSION

We assessed ocular morbidity and its associated factors among industrial workers and found a high prevalence of ocular morbidity. In this study, the majority were male; similar findings were found in other studies among industrial workers, welders, and sawmills.^[6,11,12] Industrial work is naturally physically demanding jobs, and this could be a reason for the male dominance of the field.

The mean age of our study participants was 43.72 years, and the largest age group was 40–49 years. A similar finding was reported in other studies^{[12,15,25,26]} regarding education level; the majority of workers had completed primary education, and a similar result was reported by a study done in Nepal.^[12] This is because the workers were mainly from the production department and labor.

The mean monthly income of workers was NRs. 22072.42. The majority of workers received a monthly income within the range of NRs. 10,000–15,000. This study shows that the wages are not given according to the wages of Nepal law.^[27] It might be due to difference in working hours and wages in the private sector, which are not given according to Nepal law.

The present study showed overall prevalence rate of ocular morbidity was 80.50%, which was higher than the other studies done in Nepal.^[12,25] workers and 32.1% in rubber industry workers.^[25] In our study, the majority of workers were presbyopia; similar findings were reported in a study done in Goa.^[25] The reason might be the age of workers were more than 40 years and above.

The prevalence of ocular injury was 32%, and the most common ocular injury was superficial conjunctiva or corneal foreign bodies. Jute industry workers had a high rate of ocular injury, which might be due to tiny dust and dirt particles in the surrounding atmosphere. On the other hand, a study from Malaysia presented a notably higher prevalence of ocular injury, reaching 66.20% among workers.^[28]

In our study, we found that 19% of workers were aware of and using ocular safety devices. Out of them, the majority of workers used goggles as ocular safety devices. The main reason for not using any ocular safety devices was due to the unavailability of devices, and only 2% had received training on the use of ocular safety devices. Whereas, another study finding showed that 47.7% of workers used one or more types of PPE.^[12]

This study gave insight into the current situation of industrial workers, which will be helpful for policymakers. There is a need to increase awareness about the use of ocular safety devices and regular eye health examinations. Further research will be needed on a large population at the provincial level to generalize the findings.

CONCLUSION

The research highlights a significant prevalence of ocular morbidity among industrial workers, with presbyopia emerging as the most common ocular disorder.