Table 4.

Demographics of presbyopia groups.

	Low add power	Moderate add power	High add power	P value∗
Number of cases	445	471	446
% of men	24.5	27.2	24.9	0.837
Age (y)	44.0 ± 5.5	49.6 ± 5.5	58.4 ± 7.4	<0.001
Spherical equivalent (D)	−3.66 ± 3.01	−3.72 ± 3.54	−2.85 ± 3.15	<0.001
Astigmatic errors (D)	0.47 ± 0.62	0.58 ± 0.66	0.69 ± 0.64	<0.001
Anisometropia (D)	0.55 ± 0.70	0.56 ± 0.99	0.63 ± 0.78	0.141
Near add power (D)	0.34 ± 0.82	1.68 ± 0.22	2.63 ± 0.98	<0.001
Intraocular pressure (mmHg)	14.6 ± 2.9	14.5 ± 2.8	14.2 ± 2.9	0.075
Tear breakup time (s)	4.12 ± 2.08	3.94 ± 1.97	3.77 ± 2.06	0.084
Corneal staining score	0.26 ± 0.57	0.27 ± 0.50	0.28 ± 0.56	0.839
Schirmer test value (mm)	14.41 ± 9.36	12.22 ± 6.90	9.44 ± 8.89	0.048
Tear strip meniscometry (mm)	3.10 ± 2.49	1.48 ± 2.49	1.53 ± 2.48	0.010

^∗Kruskal-Wallis test, except for % of men analyzed with Mann–Whitney U test.