Physical and Physiological Changes with Presbyopia

Abstract

Purpose: To estimate the possible physical and physiological changes in the optical system of the eye related to age over 40 years in normal presbyopic persons.
Material and Methods: Sample of 20 subjects with presbyopia ages (40 – 45 years) was used as cases and other sample of 20 subjects from university student’s ages (20 – 25 years) was used for comparison. Typical measurement procedures for the two groups included: accommodation, pupil size, anterior corneal surface power, and refraction from both eyes in each subject.
Results: T-test showed significant difference between the measurements of the two groups. The estimated changes from young age to presbyopic age demonstrated the amplitude of accommodation tends to decrease 0.27 D per year, the pupil size tends to become smaller 0.033 mm per year, the refraction tends to shift toward hypermetropia 0.018 D per year, the corneal astigmatism tends to decrease 0.0083 D per year, and the cylinder of corneal astigmatism was found to change gradually from with-the-rule to against-the-rule.
Conclusion: All measurements in this study suggesting significant changes in the optical system of the eye were essentially related to age.