Abstract
Purpose: :
To investigate the relationship between high frequency component (HFC) of accommodative microfluctuations and amount of exophoria.
Methods: :
The AutoRefractor Speedy–K® & soft program MF–1 (Righton) modified to allow high–speed recording of refraction was used to measure the HFC and static objective accommodation. Accommodation levels ranged from –0.5D to 3.0D in 0.5D steps. The waveforms of the accommodative microfluctuations were analyzed by Fast Fourier Transform. Thirty two eyes of 16 subjects (aged 21–25 years; mean 22.2±1.6) took part in this study. Eighteen eyes were low exophoria group (eye position: –4.2±4.7 Δ), 6 eyes were high exophoria group (eye position: –15.3±5.7 Δ) and 8 eyes were orthophoria group (eye position: 0±0 Δ).
Results: :
For an accommodative stimulus 1.0 and 3.0 D, the HFC in high exophoria group were statistically more than orthophoria and low exophoria groups (p<0.05, Scheffé test). There is no statistically significant correlation between the accommodative response and the amount of exophoria for all accommodative stimuli.
Conclusions: :
The results suggest that convergence accommodation put a strain to ciliary muscle in higher exophoria, resulting higher exophoria has influenced on HFC.
Keywords: ciliary muscle • refraction • vergence