Accommodative lag before and after the onset of myopia

Area of Science:

• Ophthalmology
• Pediatric Optometry
• Refractive Error Research

Background:

• Myopia, or nearsightedness, is a growing global health concern.
• Understanding the factors contributing to myopia onset and progression is crucial for developing effective interventions.
• Accommodative lag, a delay in the eye's focusing response, has been investigated as a potential factor in myopia development.

Purpose of the Study:

• To investigate accommodative lag in children before, during, and after the onset of myopia.
• To compare accommodative lag in children who develop myopia with that of their emmetropic peers.

Main Methods:

• Longitudinal study of 568 children who became myopic and 539 emmetropic children from the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study.
• Annual measurement of accommodative lag using autorefractors with standardized accommodative stimuli (4D or 2D).
• Comparison of accommodative lag in myopic children to age-, gender-, and ethnicity-matched emmetropic model estimates.

Main Results:

• No significant difference in accommodative lag was found before myopia onset or during the year of onset between myopic and emmetropic children.
• A statistically significant increase in accommodative lag was observed in myopic children only after myopia onset (0.13–0.56 D).
• Ethnic variations in accommodative lag were noted, with Asian children showing the highest lag and African-American and white children the lowest.

Conclusions:

• Elevated accommodative lag is not a reliable predictor for myopia onset in children.
• Increased accommodative lag appears to be a consequence, rather than a cause, of myopia development.
• Further research is needed to understand the complex interplay between accommodation and myopia progression.