Peripheral refraction and image blur in four meridians in emmetropes and myopes

Figures & data

Figure 1 Experimental setup.

Note: C is the aberrometer.
Abbreviations: BS, beam splitter; LS, line of sight; MA, meas urement axis; S, screen; VTs, visual targets.

Table 1 Study participant’s group profiles

Total subjects (N=34)	Age (years)	Sphere (D)	Cylinder (D)
Emmetropia (n=8, from +0.50 to −0.50 D)	25.56±7.41	−0.39±0.15	−1.03±0.18
Low myopia (n=10, from −0.75 to −3.00 D)	24.43±6.54	−1.73±0.30	−0.76±0.47
Mid myopia (n=9, from −3.25 to −6.00 D)	24.28±5.23	−5.01±0.29	−1.30±0.43
High myopia (n=7, >−6.00 D)	25.17±6.02	−7.34±0.35	−0.85±0.24

Note: Data are expressed as mean ± SD.

Table 2 Summary of refraction profiles along four meridians

Meridian	M	J0	J45
Horizontal	Em. and LM: myopic PRM (0.70 D @ 30° nasal); MM and HM: hyperopic PRM, nasal VF exhibits more shift* (HM, 3.00 D @ 30° nasal; MM, 2.30 D @ 30° nasal)	Quadratic, increased ATR, nasal VF exhibits more shift*, maximum change is ~1.50 D (HM @ 30° nasal)	Linear, negative slope, variation within 0.50 D
45° Diagonal	Em. and LM: flat PRM, no significant shift; MM and HM: hyperopic PRM, inf. nasal VF exhibits more shift* (HM, ~4.00 D @ 30° IN; MM, ~3.00 D @ 30° IN)	Linear, positive slope, variation mostly within 1.00 D	Quadratic, inf. nasal VF exhibits more shift*, variation within 1.00 D
Vertical	Em.: myopic PRM (~1.00 D @ 30° superior); LM: flat PRM, no significant shift; MM and HM: hyperopic PRM, infer. VF exhibits more shift (HM, ~2.00 D @ 30° infer.; MM, ~1.00 D @ 30° infer.)	Quadratic, increased WTR, variation mostly within 1.00 D	Linear, positive slope, variation mostly within 1.00 D
135° Diagonal	Em. and LM: flat PRM, no significant shift; MM and HM: hyperopic PRM, super. nasal VF exhibits more shift (HM, ~4.00 D @ 30° SN; MM, ~1.40 D @ 30° SN)	Linear, flat slope, variation mostly within 0.50 D	Quadratic, super. nasal VF exhibits more shift*, average ~1.00 D shift @ 30° SN

Note:

* Indicates statistically significant difference (p<0.05).

Abbreviations: ATR, against the rule; Em, emmetropic; HM, high myopic; IN, inferior nasal; LM, low myopic; MM, moderate myopic; PRM, peripheral relative M; SN, superior nasal; WTR, with the rule; VF, visual field.

Figure 2 Changes of refractive components as functions of horizontal visual field angle.

Notes: (A) The Y axis shows the mean relative M, which is equal to (peripheral M – on-axis M). (B) The Y axis shows mean J₀. (C) The Y axis shows mean J₄₅. Least-square fitting was made to fit curves and lines to better show the profiles across the visual fields of each refractive component. Error bars show the SEM for each group. For clarity, symbols and error bars are staggered slightly horizontally.
Abbreviations: Em., emmetropic; HM, high myopic; LM, low myopic; MM, moderate myopic; SEM, standard error of the mean.

Figure 3 Changes of refractive components as functions of 45° diagonal visual field eccentricities.

Notes: (A) The Y axis shows mean relative M. (B) The Y axis shows mean J₀. (C) The Y axis shows mean J₄₅. Error bars show the SEM for each group. For clarity, symbols and error bars are staggered slightly horizontally.
Abbreviations: Em., emmetropic; HM, high myopic; LM, low myopic; MM, moderate myopic; SEM, standard error of the mean.

Figure 4 Changes of refractive components as functions of vertical visual field eccentricities.

Notes: (A) The Y axis shows mean relative M. (B) The Y shows mean J₀. (C) The Y axis shows mean J₄₅. Error bars show the SEM for each group. For clarity, symbols and error bars are staggered slightly horizontally.
Abbreviations: Em., emmetropic; HM, high myopic; LM, low myopic; MM, moderate myopic; SEM, standard error of the mean.

Figure 5 Changes of refractive components as functions of 135° diagonal visual field eccentricities.

Notes: (A) The Y axis shows mean relative M. (B) The Y axis shows mean J₀. (C) The Y axis shows mean J₄₅. Error bars show the SEM for each group. For clarity, symbols and error bars are staggered slightly horizontally.
Abbreviations: Em., emmetropic; HM, high myopic; LM, low myopic; MM, moderate myopic; SEM, standard error of the mean.

Figure 6 Relative SCRIB data (peripheral SCRIB – central SCRIB) fitted across 60° visual field using a triangle-based cubic interpolation method in (A) emmetropia, (B) low myopia, (C) moderate myopia and (D) high myopia.

Abbreviations: IN, inferior nasal; IT, inferior temporal; SCRIB, Sphero-Cylindrical Retinal Image Blur; SN, superior nasal; ST, superior temporal.

Figure 7 PRM patterns in different subject groups.

Note: Color patterns are only for illustration purpose to distinguish myopic, hyperopic or emmetropic PRM and not to represent the actual data.
Abbreviations: Em., emmetropic; HM, high myopic; LM, low myopic; MM, moderate myopic; PRM, peripheral relative M.