Study of binocular visual function's change after induced anisometropia of myopic patients

Objective To evaluate the effect of experimental anisometropia on binocular function of myopic patients who were over 40 years old.Methods Different power spherical lenses were added by phoroptor in 32 myopic patients with normal binocular function to induce simple myopia(+0.5 D,+1 D,+1.5 D,+2 D,+2.5 D,+3 D) anisometropia.The visual acuity,stereoscopic vision,Worth 4 dots fusional function and simultaneous vision were assessed after inducing the anisometropia.Results When the anisometropia exceeded 1.5 D,the distance vision acuity of low corrected eye decreased with increase of the amount of anisometropia(P0.01).When the anisometropia exceeded 1.5 D,the stereoscopic vision decreased(P0.01) with increase of the amount of anisometropia.When the anisometropia exceeded 1.5 D,the fusional function weakened(P0.05) with increase of the amount of anisometropia.When the anisometropia exceeded 2.0 D,the simultaneous vision weakened(P0.01) with increase of the amount of anisometropia too.Conclusion Experimental anisometropia could result in abnormal binocular visual function for middle-aged myopic patients.When the power of anisometropia exceeded 1.5 D,high class visual function declined rapidly.