Eye wash water flow direction study: an evaluation of the effectiveness of eye wash devices with opposite directional water flow

Figures & data

Figure 1 Eye wash study design.

Abbreviation: BCVA, best corrected visual acuity.

Table 1 Change in visual acuity compared as the change from post- to pre-wash with converging flow – the change from post- to pre-wash with diverging flow

Eye	Mean ± SD	Paired t-test
OD	0.02 ± 0.08	0.29
OS	−0.03 ± 0.10	0.17

Table 2 Corneal staining before and after eye wash use agreement tables

A Pre- vs post-staining, converging flow OD (n=20)
Pre-wash staining	Post-wash staining (%)
	1	2
1	95.0	5.0
B Pre- vs post-staining, converging flow OS (n=20)
Pre-wash staining	Post-wash staining (%)
	1	2
1	90.0	20.0
C Pre- vs post-staining, diverging flow OD (n=20)
Pre-wash staining	Post-wash staining (%)
	1	2
1	100.0	0
D Pre- vs post-staining, diverging flow OS (n=20)
Pre-wash staining	Post-wash staining (%)
	1	2
1	89.5	10.5
2	0	5.0

Table 3 Presence of fluorescein after eye wash: comparison of converging flow eye wash and diverging flow eye wash (Encon–Haws)

Eye	Mean ± SD	Paired t-test
OD	−0.42 ± 0.96	0.07
OS	−0.16 ± 0.69	0.33

Figure 2 Eye wash study questionnaire.

Table 4 Comparison of survey questions (Encon–Haws)

A Grittiness (n=18)
Encon	Haws (%)
	1	2
1	83.3	0
2	5.6	11.1
B Light sensitivity (n=19)
Encon	Haws (%)
	1	2
1	78.9	5.3
2	0	10.5
3	0	5.3
C Painfulness (n=18)
Encon	Haws (%)
	1	2
1	77.8	11.1
2	11.1	0
D Soreness (n=19)
Encon	Haws (%)
	1	2
1	47.4	15.8
2	10.5	21.1
3	0	5.3
E Blurred vision (n=19)
Encon	Haws (%)
	1	2
1	57.9	21.1
2	5.3	5.3
3	5.3	5.3

Note: The shaded cells indicate that responses were the same between both eye wash designs.

Figure 3 End-of-study eye wash questionnaire.

Figure 4 The water flow of an eye wash station with diverging water flow. This model includes a face wash flow of water above and below the eyes. The distance between the peaks of water flow are approximately 110 mm apart.

Figure 5 The water flow of an eye wash station with converging water flow. The two streams of water form one large plateau of water that will accommodate people with an inter-pupillary distance of 120 mm or less.