|Ahead of print publication
Evaluation of Variation in Tear Film Breakup Time (TBUT) in Computer Users According to Hours of Computer Usage
Abha Gahlot1, Holmes Naorem1, Divya Singh1, Monika Kapur1, Jawahar Lal Goyal1, Yogesh Arora2
1 Department of Ophthalmology, Sharda University School of Medical Sciences and Research & Sharda Hospital, Greater Noida, Uttar Pradesh, India
2 Department of Ophthalmology, Santosh Medical College, Pratap Vihar, Ghaziabad, Uttar Pradesh, India
|Date of Submission||30-Jun-2021|
|Date of Acceptance||03-Jul-2021|
|Date of Web Publication||01-Nov-2021|
Department of Ophthalmology, Sharda University School of Medical Sciences and Research & Sharda Hospital, Room No. 13 of Eye OPD, D Block, Ground Floor, Sharda Hospital, Knowledge Park 3, Greater Noida 201306, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
Background: Increased use of computers over prolonged hours leads to a decrease in tear film breakup time (TBUT), resulting in dry eye. This study was carried out to find out the variations in TBUT according to hours of daily computer usage. Methods: Computer users were grouped into five groups as group A <2 hours, group B >2 hours to ≤4 hours, group C >4 hours to ≤6 hours, group D >6 hours to ≤8 hours, and group E >8 hours according to their hours of computer exposure per day. All the participants were subjected to TBUT. Chi-squared test and analysis of variance test was used to compare mean values, find P-values, and ensuring statistical significance. Results: In our study, the mean age of the study population was 32.18 ± 5.38 years. The mean TBUT in the various groups was found to be 25.83, 21.20, 18.62, 12.40, and 9.43 seconds in the right eye and 26.05, 21.19, 18.57, 12.31, and 9.41 seconds in the left eye in groups A, B, C, D, and E, respectively. Conclusion: It seems there is significant decrease in TBUT with increasing duration of computer use per day. TBUT can be performed quickly, easily, and be used to screen and support diagnosis of dry eye.
Keywords: Computer users, dry eye, tear film breakup time (TBUT)
|How to cite this URL:|
Gahlot A, Naorem H, Singh D, Kapur M, Goyal JL, Arora Y. Evaluation of Variation in Tear Film Breakup Time (TBUT) in Computer Users According to Hours of Computer Usage. MAMC J Med Sci [Epub ahead of print] [cited 2021 Dec 3]. Available from: https://www.mamcjms.in/preprintarticle.asp?id=329761
| Introduction|| |
With technological advancement and change in lifestyle, there is increasing use of visual display devices. Nowadays, usage of computer in our daily lives is becoming ubiquitous. The reasonable prices, increased productivity, and social alterations, all have led to computers and mobile computing devices being used by a large proportion of the population. However, it has also led to an increasing number of people suffering from the ill-effects of prolonged computer use manifesting with various ocular and nonocular symptoms collectively known as computer vision syndrome (CVS).
The initial concern about the use of visual display terminals (VDTs) was centered on the radiation emitted by such devices. However, no clear evidence of any negative effects on computer users was found in most studies. There were apprehensions of adverse effects on pregnant women, which were found to be incorrect by evidence.
According to tear film and ocular surface dry-eye workshop, dry eye is a disease of multiple factors that involve tears and ocular surface leading to symptoms of discomfort, visual disturbance, and tear film instability with damage to the ocular surface. It is associated with increased osmolarity of the tear film and inflammation of the ocular surface. Patients experience symptoms such as burning, stinging, grittiness, foreign body sensation, tearing, ocular fatigue, and sensation of dryness.
Dry eyes are a common entity after prolonged computer usage and the prevalence ranges from 30.0% to 68.5%. According to the National Institute of Occupational Safety and Health, CVS affects 90.0% of the people who spend 3 hours or more a day on a computer. Severity of dry eye was directly proportionate to the duration of exposure to VDT. Associated risk factors such as smoking (62.12%), and hot, dry summer conditions (17.1%) were also observed predominantly.
Normal tear films are made up of three layers. Outer one is a lipid layer which prevents evaporation, the middle layer is made up of water with a low concentration of salt which forms the bulk (90%) of the tear film, and an innermost layer of the mucin layer which binds tear film with epithelium.
Constant working on monitors leads to quick evaporation from the surface due to inefficient blinking or changes in composition such as deficiency of mucin leading to unstable tear film. Position of monitor also plays a major role. Looking straight ahead or up instead of downward gaze reduces blink rate and decreases production of tears which leads to dry eyes. Lighting, glare, display quality, refresh rates, and radiation also contributes to dry eye.
The ocular protection index demonstrates how the TBUT and interblink interval interact to protect the corneal surface. If the amount of time between blinks is longer than TBUT, an insufficient tear film leaves the corneal epithelial cells unprotected, exacerbating the signs and symptoms of dry eyes. Generally, TBUT between 10 and 35 seconds is considered normal and less than 10 seconds is usually suspicious about tear film instability, whereas less than 5 seconds is considered as low and diagnostic of short TBUT dry eye.
Different studies have reported various prevalence rates of DES ranging from 5.5% to 37.7%. Limitations in comparisons of studies in different populations include different age distributions of the population, definitions of dry eye, and methodologies.
Eye dryness is a quite common eye disease nowadays, and it affects daily activities by decreasing the quality of life due to its symptoms. In addition, it has also become an important public health problem because of the loss of quality of life which eventually leads to decreased productivity. More studies are required in India to evaluate correlation between computer users and dry eyes. The purpose of this study was to show the variations in TBUT with long-term computer usage, which is a particularly important parameter of dry-eye disease (DED).
| Materials and Methods|| |
This cross-sectional observational noninvasive study was conducted over a period of 18 months from January 2019 to June 2020. Ethical clearance was obtained from Ethical Clearance Committee and Institutional Review Board approval was obtained in November 2018.
Inclusion criteria included patients of both sexes aged between 20 and 40 years who have been using computer for varying hours for at least past 1 year.
Exclusion criteria included patients with history of eyelid pathologies, conjunctival disorders or acute ocular infections, extra and intraocular surgeries, abnormal nasolacrimal drainage apparatus, systemic diseases such as diabetes, hypertension, collagen vascular disorders, or life-threatening systemic disease. Patients with prosthetic eyes, contact lens users, and those taking systemic medication known to cause dry eyes such as antihistaminic, anticholinergic, etc., were also excluded from the study.
About 250 people who were regular computer users were included in the study. The participants were categorized into five groups depending upon hours of computer use: group A <2 hours, group B >2 hours to ≤4 hours, group C >4 hours to ≤6 hours, group D >6 hours to ≤8 hours, and group E >8 hours.
Assessment of the patients was carried out with a detailed medical and surgical history with systematic and ophthalmologic examination according to protocol including best-corrected visual acuity and slit-lamp biomicroscopy,
Patients were then subjected to TBUT assessment.
Tear film breakup time (TBUT)
It is the time interval measured between the last blink and the appearance of the first dry spot. For TBUT, fluorescein was instilled with a fluorescein strip and after blinking a break in the tear film is visible as a dark spot under cobalt blue-filtering light. TBUT was measured three times in both eyes with a stopwatch and averaged for analysis. A TBUT of more than 10 seconds is considered a normal value. Patients were categorized as:
- >10 seconds − normal
- 5–10 seconds −suspicious
- <5 seconds − low
All patients were examined under the slit lamp and were instilled with a drop of tear substitute eye drop and an antibiotic eye drop to prevent chances of any irritation or infection.
Continuous data are presented as means with standard deviations. Categorical data are presented as the percent frequency occurrence. The Chi-squared test and one-way analysis of variance test were used for comparisons. The evaluations were made within the 95.0% confidence interval and the P-value <0.05 was regarded as a statistically significant difference.
| Results|| |
Study was carried out in 250 computer users among which 136 were males and 114 were females. Mean age of subjects in the study was 32.18 ± 5.38 years with 103 computer users from age group 20 to 30 years and 147 computer users from age group 31 to 40 years. The mean TBUT in the various groups were found to be 25.83, 21.20, 18.62, 12.40, and 9.43 seconds in the right eye and 26.05, 21.19, 18.57, 12.31, and 9.41 seconds in the left eye in groups A, B, C, D, and E, respectively. When we compare the P-values of mean TBUT of different groups, we found it to be extremely significant with P < 0.001 [Figure 1].
|Figure 1 Graphical representation of study population depicting mean tear film breakup time in both eyes of different groups. TBUT, tear film breakup time.|
Click here to view
| Discussion|| |
The CVS is a quite common eye disease nowadays. It affects our daily activities by decreasing the quality of life due to its symptoms. In addition, it has also become an important public health problem because of the ocular morbidity that leads to decrease in productivity. More studies are required in India to evaluate correlation between computer users and dry eyes and the diagnostic value of TBUT.
In our current study, by evaluating the results of the tear breakup time, which is an important parameter of DED related to a long-term computer use, we aim to advocate the use of TBUT as a quick and reliable method of screening and aid to early diagnosis. In this study, we determine the points to be noted with regard to use of VDTs to prevent CVS.
In the present study, the mean age of study patients was 32.18 ± 5.38. The majority of patients in the study were males (54.4%). No significant association was found between TBUT with regard to age or sex. Karakus et al. also reported that there were no significant differences between patients with dry eye and controls with regard to age or sex.
The majority of participants in the current study were office workers (29.2%) and engineers (22.4%). Distribution of patients in different groups varied on the basis of their work on computers and the association was found to be statistically significant (P < 0.05). Raj et al. also reported that among computer users, majority (53.57%) were students, teachers, and engineers by profession followed by electricians, shopkeepers, and salesmen (46.42%). Ramnani et al. reported that majority of individuals were professional workers (47.6%) followed by self-employed (28.8%), students (12.4%), and field workers (11.2%). Thatte and Choudhary reported the incidence of short TBUT with exposure to VDT devices to be more in office workers (32.06%) followed by engineers.
In the present study, mean TBUT in right eye was around 25.83 ± 1.43, 21.20 ± 1.16, 18.62 ± 1.54, 12.40 ± 1.42, and 9.43 ± 1.05 seconds and in left eye was around 26.05 ± 1.51, 21.19 ± 1.12, 18.57 ± 1.59, 12.31 ± 1.62, and 9.41 ± 1.07 seconds in groups A, B, C, D, and E, respectively, and significant statistical association was found in both eyes (P < 0.001). Akkaya et al. reported that mean TBUT value was 9.15 ± 2.93 seconds in the study group and 15.80 ± 3.15 seconds in the control group, and the association was significant (P < 0.05). Thatte and Choudhary reported the incidence of dry eye detected was directly proportionate to the exposure time to VDTs. Patil et al. reported the mean TBUT in right eye to be 20.563, 16.152, and 11.514, and in left eye to be 20.250, 16.667, and 12.60 in groups A, B, and C, respectively, which was found to be significant in all compare groups.
As a preventive measure to avoid CVS, Bilton has proposed a simple term “1, 2, 10” (1–10) to describe the commonly used distances for the current electronic forms of written communication. Mobile phones at a distance of one foot (about 30 cm), two feet (about 60 cm) to two and a half feet for desktop devices and laptops, and 10 feet (about 3 m) for the television screens. Use the computer monitor in an ergonomic position − one arm distance or 40 inches away with a downward gaze of 14° or more appears to help relieve the symptoms of computer-related dry eye. This is achieved by placing the monitor so that the top line of screen is at or below eye level. Avoid screen reflections, glare from window, or overhead lights. Dust can affect clarity of screen and cause glare, so all monitors or screens should be free of dust. Avoid turning the air conditioning too high or direct draughts to the face.
It seems that the prevalence of dry eye is increasing in the era of the Internet. Thus, as ophthalmologists will probably encounter an increasing number of dry-eye patients in their daily practice, they should be familiar with quick, reliable, and less invasive diagnostic tests to manage the disease successfully.
| Conclusion|| |
We live today in the era of technological advancement; use of computer and other VDTs has become a necessity in our daily lives, leading to an increased incidence of CVS. Ophthalmologists will have to face the challenge of prevention, early diagnosis, and proper management of the ever-increasing load of patients suffering from CVS. TBUT may hold good diagnostic accuracy and can detect early dry eye changes in computer users. TBUT is affected significantly among computer users, which shows that tear film becomes unstable with prolonged usage of computers. This type of study helps in finding actual correlation of dry eye with use of computers and assessing the relation of severity of dry eye with duration of computer use. TBUT can be safely regarded as a tool for early recognition of dry eye for early intervention and can be performed easily and used to support the diagnosis of dry eye which will help in preventing the loss of work productivity and vision-related quality of life in computer users.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Bali J, Neeraj N, Bali RT. Computer vision syndrome: a review. Comm Article 2014;2:61-8.
Lakhotia S. The dry eye syndrome. Opthalmol Today 2001;2:65-6.
Apostol S, Filip M, Dragne C, Filip A. Dry eye syndrome. Etiological and therapeutic aspects. Oftalmologia 2003;59:28-31.
Harrison WW, Begley CG, Liu H, Chen M, Garcia M, Smith JA. Menisci and fullness of the blink in dry eye. Optom Vis Sci 2008;85:706-14.
Thatte S, Choudhary R. The prevalence of dry eye in young individuals exposed to visual display terminal. Clin Ophthalmol J 2020;1:1004.
Koslowe KC, Hadas W, Biner-Kaplan M. The blink frequency relationship between reading from a computer screen and reading from a printed page. Optom Vis Dev 2011;42:168.
Ousler GW 3rd, Hagberg KW, Schindelar M, Welch D, Abelson MB. The ocular protection index. Cornea 2008;27:509-13.
Guo B, Lu P, Chen X, Zhang W, Chen R. Prevalence of dry eye disease in Mongolians at high altitude in China: the Henan eye study. Ophthalmic Epidemiol 2010;17:234-41.
Ranasinghe P, Wathurapatha WS, Perera YS et al.
Computer vision syndrome among computer office workers in a developing country: an evaluation of prevalence and risk factors. BMC Res Notes 2016;9:150.
Karakus S, Agrawal D, Hindman HB, Henrich C, Ramulu PY, Akpek EK. Effects of prolonged reading on dry eye. Ophthalmology 2018;125:1500-5.
Raj A, Dhasmana R, Bahadur H. Evaluation of impact of computer usage on various tear parameters in normal healthy tertiary hospital based population in Uttarakhand, India. Int J Community Med Public Health 2016;3:3130-4.
Ramnani P, Laad S, Singh H et al.
To quantify severity of dry eye disease in an adult population. JEBMH 2019;6:2448-51.
Akkaya S, Atakan T, Acikalin B, Aksoy S, Ozkurt Y. Effects of long-term computer use on eye dryness. North Clin Istanb 2018;5:319-22.
Patil SD, Trivedi HR, Parekh NV, Jethva JJ. Evaluation of dry eye in computer users. Int J Community Med Public Health 2016;3:3403-7.
Bilton N. I Live in the Future and Here is How it Works? New York: Crown Business; 2010. p. 1-293.
Sheedy JE. The bottom line on fixing computer-related vision and eye problem. J Am Optom Ass 1996;67:512-7.