Distribution and related factors of corneal regularity and posterior corneal astigmatism in cataract patients

Figures & data

Table 1 Demographics of study population

Parameter
Eye/patient (n)	121/121
Male/female (n)	58/63
	Mean ± SD	Range
Age (years)	67.44±10.66	38–92
AL (mm)	24.64±2.47	21.17–31.94
ACD (mm)	2.72±0.38	1.83–3.75
CCT (mm)	0.54±0.03	0.48–0.62
WTW (mm)	11.35±0.38	10.50–12.44
ATA (mm)	11.53±0.76	9.88–15.38
PCA (D)	0.31±0.17	0.05–1.09
Axial	77.65±74.40	0–179
ACA (D)	0.87±0.64	0.08–3.42
Axial	84.61±51.73	2–178
TCA (D)	0.97±0.69	0.17–3.60
Axial	86.47±45.23	1–178
KA (D)	0.84±0.67	0.04–3.90
Axial	86.69±50.93	1–179
Q value 6 mm (A)	−0.10±0.17	−0.54–0.52
Q value 6 mm (P)	−0.41±0.30	−1.91±0.17
Q value 8 mm (A)	−0.28±0.14	−0.67±0.05
Q value 8 mm (P)	−0.40±0.20	−1.19±0.16
Z31,-1 cornea	0.37±0.21	0.03–1.06
Z33,-3 cornea	0.31±0.20	0.04–0.97
Z40 cornea	0.32±0.13	−0.06–0.80
Z31,-1 CF	0.39±0.20	0.02–0.97
Z33,-3 CF	0.34±0.22	0.00–1.11
Z40 CF	0.30±0.14	−0.14–0.80
Z31,-1CB	0.09±0.05	0.02–0.26
Z33,-3CB	0.07±0.06	0.01–0.38
Z40 CB	0.02±0.03	−0.04–0.14
Total cornea RMS	1.14±0.60	0.49–3.97
Total HOA RMS	0.82±0.65	0.07–3.94
Total LOA RMS	0.69±0.28	0.32–2.00

Notes: Q value 6 mm (A) = Q value of anterior corneal surface under 6 mm pupil diameter, Q value 6 mm (P) = Q value of posterior corneal surface under 6 mm pupil diameter, Q value 8 mm (A) = Q value of anterior corneal surface under 8 mm pupil diameter, Q value 8 mm (P) = Q value of posterior corneal surface under 8 mm pupil diameter, Z31,-1 cornea = the primary coma aberration of the total cornea, Z33,-3 cornea = primary trefoil aberration of the total cornea, Z40 cornea = primary spherical aberration of the total cornea, Z31,-1 CF = primary coma aberration of the corneal front surfaces, Z33,-3 CF = primary trefoil aberration of the corneal front surfaces, Z40 CF = primary spherical aberration of the corneal front surfaces, Z31,-1 CB = primary coma aberration of the corneal back surfaces, Z33,-3 CB = primary trefoil aberration of the corneal back surfaces, Z40 CB = primary spherical aberration of the corneal back surfaces, Total cornea RMS = the total corneal aberrations, Total HOA RMS = total corneal higher-order aberrations, Total LOA RMS = total corneal lower-order aberrations.

Abbreviations: AL, axial length; KA, simulated corneal astigmatism; ACA, anterior cornea astigmatism; ACD, anterior chamber depth; AL, axial length; APV, astigmatic power vector; ATA, angle to angle distance; ATRA, ATR astigmatism; CCT, central corneal thickness; D, diopter; HOAs, higher-order aberrations; IOL, intraocular lens; K, keratometry; LOA, lower-order aberrations; PCA, posterior corneal astigmatism; RMS, root mean square; TCA, total corneal astigmatism; WTR, with-the-rule; WTRA, WTR astigmatism; WTW, horizontal corneal diameter.

Figure 1 Distribution of magnitude of PCA, ACA and TCA at 3-mm corneal diameter in cataract patients.

Abbreviations: D, diopters; PCA, posterior corneal astigmatism; ACA, anterior corneal astigmatism; TCA, total corneal astigmatism.

Figure 2 Distribution of axial of PCA at 3-mm corneal diameter.

Abbreviations: PCA, posterior corneal astigmatism; WTR, with-the-rule; ATR, against-the-rule.

Figure 3 The overall distribution of anterior, posterior, and TCA at 3-mm corneal diameter in cataract patients.

Abbreviations: PCA, posterior corneal astigmatism; ACA, anterior corneal astigmatism; TCA, total corneal astigmatism; WTR, with-the=rule; ATR, against-the-rule.

Figure 4 Positive linear correlations between the magnitude of ACA, TCA, KA and PCA.

Abbreviations: PCA, posterior corneal astigmatism; ACA, anterior corneal astigmatism; TCA, total corneal astigmatism; KA, simulated corneal astigmatism; APV, astigmatic power vector.

Figure 5 Positive linear correlations between the corneal aberration and PCA.

Abbreviations: Z4° cornea, primary spherical aberration of the total cornea; Z4° CF, primary spherical aberration of the corneal front surface; Total cornea RMS, total corneal aberrations; Total LOA RMS, total corneal lower-order aberrations; Total HOA RMS, total corneal higher-order aberrations; RMS, root mean square; APV, astigmatic power vector.

Figure 6 Positive linear correlations between the Q value (anterior) and PCA.

Abbreviations: PCA, posterior corneal astigmatism; APV, astigmatic power vector.

Figure 7 Correlations between the Q value (posterior) and PCA.

Abbreviations: PCA, posterior corneal astigmatism; APV, astigmatic power vector.

Figure 8 Correlations between Age, AL, ACD, CCT, WTW, ATA and PCA.

Abbreviations: PCA, posterior corneal astigmatism; AL, axial length; ACD, anterior chamber depth; CCT, central corneal thickness; WTW, horizontal corneal diameter; ATA, angle to angle distance; APV, astigmatic power vector.

Table S1 Correlations between PCA and influencing factors

PCA (APV)	R	R^2	P
Age	−0.172	0.030	0.059
AL	0.022	0.000	0.814
ACD	0.145	0.021	0.113
CCT	−0.042	0.002	0.649
WTW	0.082	0.007	0.373
ATA	0.004	0.000	0.961
Z3^1, −1 cornea	0.156	0.024	0.088
Z3^3, −3 cornea	0.112	0.012	0.223
Z3^1, −1 CF	0.161	0.026	0.078
Z3^3, −3 CF	0.085	0.007	0.356
Z3^1, −1 CB	0.015	0.000	0.867
Z3^3, −3 CB	−0.036	0.001	0.693
Z4° CB	−0.004	0.000	0.966
Q value (posterior 6 mm)	−0.009	0.000	0.922
Q value (posterior 8 mm)	0.029	0.001	0.754

Abbreviations: PCA, posterior corneal astigmatism; AL, axial length; ACD, anterior chamber depth; CCT, central corneal thickness; WTW, horizontal corneal diameter; ATA, angle to angle distance; APV, astigmatic power vector.