Study of Progression of Adult Nearsightedness (SPAN)

Significant myopia progression occurs in over 40% of adults in their thirties. It has been proposed that the amount of near work performed places an individual at risk. There is also evidence that characteristics of a patient’s accommodation and vergence system may predispose them to myopic changes.

SPAN is a five-year cohort study to determine the risk factors associated with adult myopia progression. The risk factors to be evaluated include:

1. A greater proportion of time spent performing near tasks at home and at work.
2. Performing near tasks at a closer distance.
3. A higher accommodative convergence/accommodation (AC/A) ratio.
4. A higher accommodative lag.

Four hundred myopic subjects between 25 and 35 years of age have been recruited from the faculty and staff of The Ohio State University. Myopia progression is operationally defined as an increase in myopia of at least –0.75 D spherical equivalent as determined by cycloplegic auto-refraction. Subjects will be divided into progressors and non-progressors for data analysis based on this criterion.

Subjects are tested annually using the following methods:

• visual acuity
• non-cycloplegic auto-refraction and auto-keratometry
• phoria
• accommodative lag
• response AC/A ratio
• cycloplegic auto-refraction
• videophakometry
• partial coherence interferometry (axial ocular dimensions)

Participants’ near work is assessed using a novel technique known as the Experience Sampling Method. Subjects carry a portable electronic pager for two one-week periods and are paged randomly throughout the day. Each time they are paged, they dial into an automated telephone survey and report their activity at that time.

Jessica Zoz
Program Coordinator
(614) 688-5836 or send an email

Mark Bullimore, MCOptom, PhD, FAAO
Prinicpal Investigator
(614) 292-4724 or send an email

Kathleen S. Reuter, OD
Research Optometrist
(614) 688-5836 or send an email