Applied Forces Changed Myopia Lens Optical Performance but Not Retinal Image Quality Tested Using a Newly Designed Digital Colmascope

Figures & data

Figure 1 Birefringent pattern shown in the lens internal stress image with loose screw (A) and tight screw (B).

Table 1 Comparison and Agreement of Two Successive Measurements Obtained with the Digital Strain Viewer (N = 21)

Zone	1^st (Mean±SD)	2^nd (Mean±SD)	P^a	ICC	P^b	95% LoA of Δ	Points out of 95% LoA [n (%)]
1	58.15±30.22	57.87±30.20	0.387	0.999	<0.001	(−2.57, 3.13)	1 (4.76)
2	23.18±14.45	23.13±14.64	0.655	0.999	<0.001	(−1.02, 1.13)	2 (9.52)
3	25.37±11.83	25.66±11.86	0.534	0.984	<0.001	(−4.42, 3.83)	1 (4.76)
4	24.77±12.32	24.59±12.35	0.149	0.999	<0.001	(−0.94, 1.31)	3 (14.29)
5	36.16±21.10	35.98±21.32	0.512	0.998	<0.001	(−2.21, 2.57)	2 (9.52)
6	21.20±12.93	21.11±13.09	0.486	0.999	<0.001	(−1.08, 1.27)	2 (9.52)
7	20.85±10.65	20.67±10.66	0.065	0.999	<0.001	(−0.64, 0.99)	2 (9.52)
8	22.53±12.62	22.33±12.64	0.159	0.999	<0.001	(−1.01, 1.41)	3 (14.29)
9	22.24±12.89	22.08±13.01	0.289	0.999	<0.001	(−1.17, 1.49)	2 (9.52)

Notes: ^aPaired-samples t test. ^bF test with a true value of 0 for ICC.

Abbreviations: SD, standard deviation; ICC, Intra-class Correlation Coefficients; LoA, limits of agreement; Δ, change.

Figure 2 Bland-Altman plots of two successive measurements obtained with the digital strain viewer in nine zones.

Table 2 Description and Comparison of the Internal Stress Differences of Myopia Spectacle Lenses (N = 60)

Zone	Group	Right Lenses			Z^a,b	P	Left Lenses			Z^a,b	P	Z^a,c	P
		Median	Min	Max			Median	Min	Max
1	Loose	42.77	11.42	133.49	6.736	<0.001	58.42	20.62	223.39	6.611	<0.001	2.584	0.010
	Tight	193.26	77.97	237.21			201.68	82.77	239.87			0.029	0.977
2	Loose	18.21	8.02	49.01	6.736	<0.001	23.12	10.02	108.92	6.736	<0.001	2.400	0.016
	Tight	78.30	21.51	158.10			167.31	48.60	235.78			6.405	<0.001
3	Loose	14.30	8.14	65.74	6.736	<0.001	25.15	10.03	140.89	6.729	<0.001	5.057	<0.001
	Tight	69.15	15.60	218.01			140.31	47.98	234.75			5.867	<0.001
4	Loose	13.55	7.80	49.88	6.736	<0.001	23.48	9.79	182.66	6.736	<0.001	4.597	<0.001
	Tight	102.16	20.36	223.76			137.73	34.44	218.01			3.681	<0.001
5	Loose	25.83	7.28	88.58	6.736	<0.001	36.19	12.13	230.27	6.736	<0.001	3.018	0.003
	Tight	151.16	40.49	240.63			215.21	73.58	243.83			4.572	<0.001
6	Loose	14.74	7.35	47.79	6.736	<0.001	20.41	8.57	137.11	6.736	<0.001	3.037	0.002
	Tight	77.41	17.44	181.89			154.4	46.29	241.60			6.206	<0.001
7	Loose	12.26	7.60	51.69	6.736	<0.001	20.48	8.91	137.75	6.721	<0.001	4.608	<0.001
	Tight	65.51	14.10	204.20			124.86	42.79	237.62			5.830	<0.001
8	Loose	13.16	7.17	50.79	6.736	<0.001	21.04	8.58	194.42	6.729	<0.001	4.307	<0.001
	Tight	92.85	17.85	228.25			142.01	32.81	231.01			4.601	<0.001
9	Loose	13.95	7.20	51.68	6.736	<0.001	21.90	8.83	162.81	6.729	<0.001	3.916	<0.001
	Tight	87.25	18.53	213.14			148.52	46.99	234.22			5.602	<0.001

Notes: ^aPaired-samples Wilcoxon signed-rank test. ^bComparison of loose and tight mounting. ^cComparison of the right and left lense.

Figure 3 Lens zone numbering method of the mounted spectacle from the digital strain viewer image in a different mounting state (interior view). The tested lens was divided into nine zones by three concentric circles and two intersecting lines. The diameters of the concentric circles are 3, 6, and 9 mm. The angle between the two lines is 90°. The medians of the internal lens stress in the different zones are placed inside the brackets below the zone number. (A) Loose mounting. (B) Tight mounting.

Figure 4 Box plots of the internal lens stress distribution in the different zones. Statistically significant differences between the different zones after the post hoc tests are marked with lines and asterisks. (A) Vertically arranged zones. (B) Horizontally arranged zones. * P<0.05.

Table 3 Comparisons of the Central Residual Refractive Errors and Visual Image Quality Parameters of the Corrected Eyes Between Loose- and Tight-Mounted Spectacles (N = 60)

Parameter	Right Lenses								Left Lenses
	Loose Mounted			Tight Mounted			Z^a	P	Loose Mounted			Tight Mounted			Z^a	P
	Median	Min	Max	Median	Min	Max			Median	Min	Max	Median	Min	Max
Sphere (D)	−0.25	−1.25	3.50	−0.25	−1.75	2.00	−0.761	0.446	−0.50	−3.00	3.25	−0.25	−1.50	3.25	−1.550	0.121
Cylinder (D)	−0.25	−5.25	0.00	−0.25	−2.50	0.00	−1.872	0.061	−0.25	−5.25	0.00	−0.25	−9.50	0.00	−0.395	0.693
J0 (D)	0.00	−2.10	1.99	0.00	−1.19	0.68	−0.589	0.556	0.00	−2.38	0.42	0.00	−1.74	1.80	−0.155	0.877
J45 (D)	0.00	−1.47	1.71	0.00	−0.87	1.05	−0.058	0.954	0.00	−0.74	1.65	0.00	−1.80	4.70	−0.424	0.671
MSE (D)	−0.50	−2.63	1.25	−0.50	−2.00	0.75	−0.434	0.664	−0.63	−3.00	0.63	−0.63	−2.50	1.50	−0.752	0.452
MTF	30.35	15.20	108.00	33.05	2.90	97.40	−0.736	0.462	30.60	11.50	116.70	29.00	12.10	88.40	−0.368	0.713
Strehl Ratio	0.01	0.00	0.27	0.01	0.00	0.34	−1.727	0.084	0.01	0.00	0.49	0.01	0.00	0.24	−0.244	0.807
3rd-order RMS	0.15	0.03	1.90	0.16	0.03	4.44	−0.788	0.431	0.18	0.02	1.24	0.18	0.03	2.02	−1.104	0.269
4th-order RMS	0.09	0.03	0.86	0.08	0.01	1.03	−0.687	0.492	0.08	0.03	0.85	0.08	0.04	3.19	−1.620	0.105
Total HOA	0.20	0.06	2.09	0.18	0.04	4.55	−0.883	0.377	0.20	0.04	1.43	0.19	0.07	3.45	−1.244	0.213
Combined coma	0.06	0.01	0.30	0.05	0.00	0.60	−0.314	0.754	0.05	0.00	0.30	0.06	0.01	1.50	−0.985	0.325
Horizontal coma	−0.01	0.30	0.08	−0.01	−0.34	0.10	−0.247	0.805	−0.01	−0.27	0.22	−0.02	−1.43	0.55	−1.302	0.193
Vertical coma	−0.01	−0.10	0.15	−0.02	−0.50	0.11	−0.684	0.494	0.00	−0.14	0.23	0.01	−0.44	0.17	−0.422	0.673
Combined trefoil	0.15	0.03	1.90	0.16	0.03	4.44	−0.788	0.431	0.18	0.02	1.24	0.18	0.03	2.02	−1.104	0.269
Spherical aberration	0.00	−0.25	0.22	−0.01	−0.22	0.32	−0.654	0.513	−0.01	−0.50	0.11	−0.01	−0.91	0.99	−0.005	0.996

Note: ^aPaired-samples Wilcoxon signed-rank test.