Table 4.
CVS prevalence and its relationship with VDT exposure, sociodemographic, refractive, environmental, and ergonomic characteristics.
| Variables | n | P | p-Value * | OR | 95% CI | p-Value ** |
|---|---|---|---|---|---|---|
| TOTAL | 81 | 74.3 | ||||
| Age (years) | ||||||
| 46–50 | 19 | 73.1 | 0.987 | 1 | ||
| 51–52 | 16 | 72.7 | 0.98 | 0.27–3.52 | 0.978 | |
| 53–55 | 23 | 76.7 | 1.21 | 0.36–4.06 | 0.757 | |
| 56–69 | 23 | 74.2 | 1.06 | 0.33–3.46 | 0.924 | |
| Sex | ||||||
| Male | 41 | 66.1 | 0.025 | 1 | ||
| Female | 40 | 85.1 | 2.93 | 1.12–7.64 | 0.028 | |
| Job category | ||||||
| TRS | 31 | 66.0 | 0.082 | 1 | ||
| AS | 50 | 80.6 | 2.15 | 0.90–5.15 | 0.085 | |
| Use of VDT at work (hours/day) | ||||||
| ≤6 | 36 | 67.9 | 0.138 | 1 | ||
| >6 | 45 | 80.4 | 1.93 | 0.81–4.64 | 0.141 | |
| Use of VDT at work (years) | ||||||
| ≤20 | 26 | 32.1 | 0.782 | 1 | ||
| 21–29 | 38 | 46.9 | 1.34 | 0.51–3.49 | 0.550 | |
| ≥30 | 17 | 21.0 | 1.44 | 0.42–4.88 | 0.560 | |
| Continuous work time at VDT (minutes) | ||||||
| ≤60 | 40 | 78.4 | 0.219 | 1 | ||
| 61–120 | 29 | 65.9 | 0.53 | 0.21–1.33 | 0.175 | |
| >120 | 12 | 85.7 | 1.65 | 0.32–8.50 | 0.549 | |
| Scheduled breaks during VDT work | ||||||
| No | 74 | 73.3 | 0.677 | 1 | ||
| Yes | 7 | 87.5 | 2.55 | 0.30–21.73 | 0.391 | |
| Total use of VDT (hours/day) | ||||||
| ≤8 | 39 | 79.6 | 0.254 | 1 | ||
| >8 | 42 | 70.0 | 0.60 | 0.25–1.45 | 0.257 | |
| Screen technology | ||||||
| LED backlight | 33 | 71.7 | 0.541 | 1 | ||
| LED | 9 | 64.3 | 0.71 | 0.20–2.52 | 0.595 | |
| LCD | 3 | 60.0 | 0.59 | 0.09–3.95 | 0.588 | |
| TFT | 34 | 81.0 | 1.67 | 0.61–4.56 | 0.314 | |
| LCD-TN | 2 | 100.0 | - | - | - | |
| Viewing distance (cm) | ||||||
| Non-altered | 69 | 75.8 | 0.417 | 1 | ||
| Altered | 12 | 66.7 | 0.64 | 0.21–1.90 | 0.419 | |
| Eye to screen angle α (°) | ||||||
| Non-altered | 81 | 74.3 | - | - | - | - |
| Altered | 0 | 0.0 | ||||
| Vision angle α′ (°) | ||||||
| Non-altered | 81 | 74.3 | - | - | - | - |
| Altered | 0 | 0.0 | ||||
| Air temperature (°C) | ||||||
| Non-altered | 67 | 74.4 | 1.000 | 1 | ||
| Altered | 14 | 73.7 | 0.96 | 0.31–2.96 | 0.945 | |
| Relative humidity (%) | ||||||
| Non-altered | 20 | 71.4 | 0.685 | 1 | ||
| Altered | 61 | 75.3 | 1.22 | 0.47–3.20 | 0.686 | |
| Illumination | ||||||
| Non-altered | 20 | 62.5 | 0.069 | 1 | ||
| Altered | 61 | 79.2 | 2.29 | 0.93–5.64 | 0.072 | |
| VDT adjustment | ||||||
| Non-altered | 44 | 72.1 | 0.557 | 1 | ||
| Altered | 37 | 77.1 | 1.30 | 0.54–3.12 | 0.557 | |
| Neck posture | ||||||
| Non-altered | 52 | 69.3 | 0.077 | 1 | ||
| Altered | 29 | 85.3 | 2.57 | 0.88–7.47 | 0.084 | |
| Ametropia | ||||||
| Emmetropia | 19 | 82.6 | 0.465 | 1 | ||
| Myopia | 41 | 74.5 | 0.62 | 0.18–2.13 | 0.444 | |
| Hyperopia | 21 | 67.7 | 0.44 | 0.12–1.65 | 0.224 | |
| Astigmatism | ||||||
| No | 54 | 70.1 | 0.121 | 1 | ||
| Yes | 27 | 84.4 | 2.30 | 0.79–6.71 | 0.128 | |
| Presbyopia | ||||||
| Moderate | 31 | 72.1 | 0.669 | 1 | ||
| Advanced | 50 | 75.8 | 1.21 | 0.51–2.89 | 0.669 |
Abbreviations: CVS: computer vision syndrome; P: prevalence; OR: odds ratio; CI: confidence interval; VDT: video display terminal; LED: Light Emitting Diode; LCD: Liquid Cristal Display; TFT: Thin Film Transistor; TN: Twisted Nematic. * Chi-square test. ** Univariate logistic regression analysis. Bold results are statistically significant. The categories of the variables are in Italic type.