Influence of pupil dilation on predicted postoperative refraction and recommended IOL to obtain target postoperative refraction calculated by using third- and fourth-generation calculation formulas

Figures & data

Table 1 Clinical characteristics of the study patients (n=87)

Parameters	Meana (range)
Male, %	39.6
Age, years	72.9±7.7 (51–87)
Axial length, mm	23.94±1.51 (21.62–28.87)
Anterior chamber depth, mm	3.09±0.43 (2.01–4.90)
Lens thickness, mm	4.61±0.45 (3.44–6.28)

Note:

a Data presented are mean±SD.

Table 2 Effect of pupil dilation on axial length, anterior chamber depth, and lens thickness

Parameters	Mean,a mm		Mean difference post-minus predilation, mm	Number of eyes
	Predilation	Postdilation		Db<0	D=0	D>0
Anterior chamber depth	3.09±0.43	3.14±0.41	0.07±0.04	2 (1.2%)	2 (1.2%)	158 (97.5%)
Lens thickness	4.61±0.45	4.59±0.45	−0.02±0.02	137 (84.6%)	21 (13.0%)	4 (2.5%)

Notes: P<0.0001 for changes in anterior chamber depth and lens thickness between pre- and post-pupil dilation.

a Data presented are mean±standard deviations.

b D is the difference post- minus predilation.

Table 3 Mean absolute change in predicted postoperative refraction between pre- and post-pupil dilation in the four formulas

Formulas		Mean absolute change,a diopter
Third generation	Hoffer Q	0.0072±0.0070
	SRK/T	0.0050±0.0055
Fourth generation	Haigis	0.039±0.026
	Holladay 2	0.038±0.023

Notes: P<0.0001 for Hoffer Q or SRK/T vs Haigis or Holladay 2.

a Data presented are mean±SD.

Figure 1 Correlation plot of (A) anterior chamber depth (ACD) and (B) lens thickness (LT) between pre- and post-pupil dilation.

Figure 2 Correlation between changes in anterior chamber depth (ACD) and predicted postoperative refraction (PPR) between pre- and post-pupil dilation in the third-generation [(A) Hoffer Q and (B) SRK/T] and fourth-generation [(C) Haigis and (D) Holladay 2] formulas.

Figure 3 Correlation between changes in lens thickness (LT) and predicted postoperative refraction (PPR) between pre- and post-pupil dilation in the third-generation [(A) Hoffer Q and (B) SRK/T] and fourth-generation [(C) Haigis and (D) Holladay 2] formulas.

Table 4 Coincidence of recommended IOL power between pre- and post-pupil dilation in the four formulas

Coincidence	Number of eyes
	Third-generation formula		Fourth-generation formula
	Hoffer Q	SRK/T	Haigis	Holladay 2
Yes	161 (99.4%)	162 (100.0%)	150 (92.6%)	148 (91.4%)
No	1 (0.6%)	0 (0.0%)	12 (7.4%)	14 (8.6%)

Note: P=0.0029 for Hoffer Q vs Haigis, P=0.00076 for Hoffer Q vs Holladay 2, P=0.00040 for SRK/T vs Haigis, and P<0.0001 for SRK/T vs Holladay 2.

Abbreviation: IOL, intraocular lens.