Results of dynamic visual acuity and gaze stability test in military pilots and their reference value determination

  Objective  To establish the detection method and reference values of dynamic visual acuity (DVA) and gaze stability test (GST) in military pilots.

  Methods   From January to August in 2019, 45 healthy male fighter pilots in active duty were selected as study subjects, with the age ranging from 23 to 39 years old (average age of 26.4±3.4 years). Their SVA, MPT, DVA and GST when shaking head in the axis of yaw, pitch or roll were recorded unilaterally. The difference between SVA and DVA was calculated and named as DVA Loss, and the mean values and reference ranges of SVA, MPT, DVA Loss and GST were calculated.

  Results   The mean value of SVA in 45 healthy pilots was -0.28±0.03 LogMar, and its reference range was ≤-0.23 LogMar; the mean value of MPT was 20.44±2.08 ms with its reference range of ≤23.85 ms. When shaking head in the axis of yaw, pitch or roll, the mean value of DVA Loss was all less than 0.1 LogMar, and their reference ranges were all less than 0.2 LogMar. The means of GST were all higher than 100°/s, and their reference values were all higher than the lowest velocity of DVA.

  Conclusion   This study has established the detection method and normal ranges of DVA and GST for military pilots, which provide reference for recruitment of student pilot and evaluation of vestibulo-ocular reflex in aeromedical assessment.