Abstract
Purpose :
Accommodative therapy has been shown to improve both signs and symptoms associated with accommodative insufficiency (AI). The underlying mechanism has not yet been shown. The ciliary muscle is a multi-unit smooth muscle which may retain the ability to undergo changes in size and contractile ability. The purpose of this study was to investigate whether a change in ciliary muscle thickness (CMT) occurs in subjects with AI following accommodative therapy.
Methods :
Subjects, ages 9 to 30 years, with AI were recruited. Anterior segment optical coherence tomography was used to measure maximum ciliary thickness (CMTMAX) and ciliary muscle thickness at 1mm (CMT1), 2mm (CMT2) and 3 mm (CMT3) posterior to the scleral spur of the right eye while subjects viewed a distance target before and after therapy. Therapy consisted of 8 weeks of in-office weekly accommodative therapy (1 hour/week) with home reinforcement therapy (15 minutes/day, 5 days/week).
Results :
Subjects with AI (N = 16, mean age = 17.4 years) were enrolled and completed the therapy. CMT measurements at baseline were 776.96 ± 67.12µm at CMTMAX, 756.76 ± 66.91µm at CMT1, 554.14 ± 74.30µm at CMT2, and 335.14 ± 49.48µm at CMT3. After accommodative therapy, CMT measurements showed thickening of at least 20μm (CMTMAX: mean difference 31.54µm, p=0.012; CMT1: 28.42 µm, p=0.043, CMT2: 40.42 µm, p=0.006, CMT3: 21.59 µm, p=0.009).
Conclusions :
Accommodative therapy increased CMT in subjects with AI. The increase in muscle thickness provides a potential mechanism for the improvements in signs and symptoms seen with therapy.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.