Hand-Held Nidek versus Table-Mounted Huvitz Autorefractors and Their Agreement with Subjective Refraction in Adults

Figures & data

Table 1 Comparison of Mean Values of Refractive Measurements Between Autorefractometers

	SE Mean ±SD	Cylinder Power Mean ±SD	J0 Mean ±SD	J45 Mean ±SD
Huvitz	−0.30±1.0	−0.84±1.0	−0.03±0.48	0.01±0.44
Nidek sitting	−0.78±0.99	−0.87±0.92	0.02±0.46	0.26±0.44
Nidek supine	−0.81±1.01	−0.87±0.9	0.04±0.46	−0.06±0.42
Subjective refraction	−0.47±0.92	−0.81±0.82	−0.02±0.45	0.01±0.43
P value	0.0001*	0.2	0.67	0.75
P1	0.0001*	0.15	0.45	0.69
P2	0.0001*	0.3	0.32	0.48
P3	0.0006*	0.81	0.94	0.98
P4	0.61	0.82	0.82	0.30
P5	0.001*	0.23	0.50	0.53
P6	0.0001*	0.33	0.31	0.56

Notes: P value compared the four group. Pairwise comparison as follows. P1: Huvitz vs Nidek stand, P2: Huvitz vs Nidek supine, P3: Huvitz vs subjective refraction, P4: Nidek stand vs Nidek supine, P5: Nidek stand vs subjective refraction, P6: Nidek supine vs subjective refraction. *P value is significant.

Abbreviations: SE, spherical equivalent; SD, standard deviation.

Table 2 Comparison of Mean Keratometric Values Between Both Devices

	Flat K Mean (SD) (Range), D	Steep K Mean (SD) (Range), D	Average K Mean (SD) (Range), D
Huvitz	43.47±1.71 (38.25:50.25)	44.20±1.86 (39.25:51.25)	43.84±1.76 (38.75:50.25)
Nidek Sitting	43.32±1.69 (37.5:50)	44.16±1.82 (39.5:50.5)	43.74±1.71 (38.88:50.13)
Nidek Supine	43.3±1.75 (36:49.75)	44.22±1.87 (39.25:51)	43.78±1.77 (37.75:50.13)
P0 value	0.58	0.93	0.83
P1	1.00	1.00	1.00
P2	1.00	1.00	1.00
P3	1.00	1.00	1.00

Notes: P0: total comparison; P1; Huvitz vs Nidek sitting; P2: Huvitz vs Nidek supine; P3: NIdek sitting vs Nidek sitting.

Abbreviations: SE, spherical equivalent; SD, standard deviation.

Table 3 Correlations Between Variables of Both Devices in Both Positions and Subjective Refraction

	Correlation (r)	P-value
Huvitz Sphere vs Subjective sphere	0.951**	0.00
Huvitz cylinder vs Subjective cylinder	0.968**	0.00
Huvitz axis vs Subjective axis	0.836**	0.00
Huvitz Sphere vs Nidek sphere sitting	0.912**	0.00
Huvitz cylinder vs Nidek cylinder sitting	0.902**	0.00
Huvitz axis vs Nidek cylinder sitting	0.507*	0.00
Huvitz Sphere vs Nidek sphere supine	0.905**	0.00
Huvitz cylinder vs Nidek cylinder supine	0.878**	0.00
Huvitz axis vs Nidek cylinder supine	0.484*	0.00
Nidek sitting Sphere vs subjective sphere	0.866**	0.00
Nidek sitting cylinder vs subjective cylinder	0.880**	0.00
Nidek sitting axis vs Nidek subjective axis	0.445*	0.00
Nidek supine Sphere vs subjective sphere	0.859**	0.00
Nidek supine cylinder vs subjective cylinder	0.850**	0.00
Nidek supine axis vs subjective axis	0.455*	0.00

Notes: **Strong correlation. *Moderate correlation.

Table 4 Differences in Mean Refractive Components Between Autorefractometers

	SE	Cylinder	J0	J45
Huvitz versus Nidek Sitting
Mean ±SD of difference	0.48±0.39	0.03±0.8	−0.05±0.65	−0.01±0.50
95% LoA	−0.29:1.24 (1.5)	−0.51:0.2 (0.7)	−1.32:1.22 (2.5)	−0.99:0.95 (1.9)
Huvitz versus Nidek supine
Mean ±SD of difference	0.51±0.43	0.03±1.0	−0.07±0.46	0.07±0.63
95% LoA	−0.34:1.36 (1.7)	−0.50:0.18 (0.7)	−1.41:1.26 (2.7)	−1.16:1.30 (2.5)
Nidek sitting versus Nidek Supine
Mean ±SD of difference	0.03±0.22	0.0±0.02	−0.02±0.66	0.08±0.62
95% LoA	−0.40:0.46 (0.9)	−0.45:0.17 (0.6)	−1.30:1.26 (2.6)	−1.13:1.29 (2.4)
Huvitz versus subjective refraction
Mean ±SD of difference	0.18±0.34	0.02±0.2	−0.01±0.13	0.0005±0.09
95% LoA	−0.49:0.84 (1.3)	−0.42:0.16 (0.6)	−0.26:0.24 (0.5)	−0.18:0.18 (0.4)
Nidek Sitting versus subjective refraction
Mean ±SD of difference	−0.31±0.48	0.03±0.8	0.04±0.62	0.02±0.50
95% LoA	−1.24:0.63 (1.9)	−0.55:0.13 (0.7)	−1.17:0.25 (1.4)	−0.96:0.99 (1.9)
Nidek supine versus subjective refraction
Mean ±SD of difference	−0.34±0.52	0.02±0.7	0.06±0.63	−0.07±0.62
95% LoA	−1.36:0.69 (2.3)	−0.43:0.12 (0.6)	−1.18:1.30 (2.5)	−1.29:1.15 (2.4)

Abbreviations: SE, spherical equivalent; SD, standard deviation; LoA, limits of agreement.

Figure 1 Bland–Altman plots of the differences in spherical equivalence (SE) between Huvitz and Nidek sitting (A), Huvitz and Nidek supine (B), and Nidek sitting and Nidek supine (C). Huvitz and subjective refraction. (D). Nidek sitting and subjective refraction (E). Nidek supine and subjective refraction (F).

Figure 2 Bland–Altman plots of the differences in J0 between Huvitz and Nidek sitting (A), Huvitz and Nidek supine (B), and Nidek sitting and Nidek supine (C). Huvitz and subjective refraction. (D). Nidek sitting and subjective refraction (E). Nidek supine and subjective refraction (F).

Figure 3 Bland–Altman plots of the differences in J45 between Huvitz and Nidek sitting (A), Huvitz and Nidek supine (B), and Nidek sitting and Nidek supine (C). Huvitz and subjective refraction. (D). Nidek sitting and subjective refraction (E). Nidek supine and subjective refraction (F).