Purpose:
To create a defocus curve of emerging presbyopic patients of various age groups.
Setting:
Single site private practice in Sioux Falls, South Dakota.
Design:
This was a non-randomized, prospective study. All subjects were enrolled from healthy volunteers.
Methods:
Subjects aged 37-9, 40-42, 43-45 and 46-48 that have 20/20 best-corrected distance visual acuity (BCDVA) were included. Binocular visual acuity at different defocus steps ranging from +0.5 D to -3 D was measured in each age group. Defocus curves were generated from the mean logMAR visual acuities at each defocus step, by age group.
Results:
Of the 60 subjects, 23.3% of subjects were between the ages of 37-39, 26.7% were between the ages of 40-42, 25% of subjects were between ages 43-45, and 25% were between the ages of 46-48. Visual acuity significantly decreased from plano to -3 D defocus steps in all groups (p < 0.0002, p = 0, p = 0 and p = 0). The 46-48-year-old group had worse visual acuity compared to the other three groups from the -1.0 to -2.0 D defocus steps (p = 0.037, p = 0.022 and 0.017, respectively). Starting at a near point of 40cm, the 37-39 group had the best logMAR vision and the 46-48 group had the worst vision (p = 0.001).
Conclusion:
The defocus curves of emerging presbyopic individuals demonstrate a decreasing visual acuity at near defocus steps that decreases with age. Defocus curves at different age ranges can help doctors explain various presbyopia treatment options in terms of near point capabilities at various ages.