To develop a method of objective simultaneous evaluation of direct accommodation (DA) and consensual accommodation (CA) of paired eyes.Methods
To assess DA and CA, eyes of 83 patients aged 7-25 with different refraction errors were examined. Objective accommodation response was measured using Binocular Open Field Auto Refracto/Keratometer WR-5100K (Grand Seiko Co., Ltd., Japan) under full correction of the existing ametropia achieved by spherical and cylinder lenses in a trial frame. A special device was used to separate the visual fields of the two eyes so that a 33 cm target could only be seen with one eye, while the fellow eye was looking at the open field with no fixation mark. In this way the DA was measured for the fixating eye and the CA for the non-fixating eye. Then the fixation mark position was switched over and the test was repeated. The difference (Δ=CA – DA) between CA and DA was calculatedResults
In all cases of hyperopia and emmetropia, consensual accommodation was equal to direct accommodation (Δ=0.02±0.03 D and 0.06±0.02 D, respectively). In low and moderate myopia, an insignificant difference was noted between CA and DA (respectively 0.16±0.04 D and 0.23±0.03 D). In high and anisometropic myopia, the difference was significant: Δ=0,27±0.04 D and 0.48±0.07 D, respectively (p<0.05).Conclusion
CA and DA did not differ in patients with hyperopia and emmetropia. Mismatch of DA and CA was found in high and anisometropic myopia. This symptom may have diagnostic and prognostic value for progressive myopia.