Abstract
Purpose :
To investigate accommodative variability (RMS) under different cue conditions in emmetropic and uncorrected hyperopic children and adults.
Methods :
Accommodative response of the right eye was measured for 1 minute intervals at 33cm using photorefraction (25Hz) in two groups: Uncorrected children (n=58, 3-9 yrs, refractive error (RE) = -0.37 to +4.91D) with age normal VA and binocular vision; Adults (n=10, 23-31 yrs, RE = -0.37 to +1.15D) and normal uncorrected VA. Three conditions were tested in random order: 1)full-cue: binocular viewing of 20/50 optotypes 2)blur-cue: monocular viewing of 20/50 optotypes 3)disparity-cue: binocular viewing of a difference of Gaussian stimulus. Mean response (cycloplegic RE + accommodation measured by photorefraction) and RMS were compared across conditions and group using 2-factor repeated measures ANOVA with post-hoc analyses (Holm-Sidek), first with all subjects and then excluding 30 children with RE greater than 1.15D to match RE to adults.
Results :
Accommodative response differed across conditions (p<0.001), but not between children and adults (p=0.779), indicating children had greater accommodative lag since the higher RE of children counted toward their response. Responses were greatest for full-cue (children 2.74±1.07D; adults 2.36±0.47D) and least for disparity-cue (children 1.69±1.03D; adults 1.76±0.73D). RMS was significantly different by condition (p<0.001) and group (p≤0.001) with no significant group x condition interaction (p=0.2). In children, RMS was different for all conditions (p≤0.019) with full-cue having least variability and disparity-cue having most (full-cue: 0.40±0.22D, blur-cue: 0.47±0.24D, disparity-cue: 0.64±0.29D). RMS was not different (p>0.05) for any comparison in the adults (full-cue: 0.19±0.04D, blur-cue: 0.20±0.05D and disparity-cue: 0.28±0.09D). When comparing subjects with matched RE, children had lower accommodative responses than adults for blur-cue and disparity-cue (p≤0.004); RMS remained higher in the sub-group of children than adults for all conditions (p≤0.022).
Conclusions :
The children (full group and sub-group) had significantly larger RMS values than adults in all conditions, even for conditions when accommodative response was similar. While adults appeared to have stable RMS irrespective of the cues present, children had increased RMS when fewer cues were available.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.