Chiu N N, Rosenfield M
Department of Vision Sciences, State University of New York, State College of Optometry, NY 10010.
Ophthalmic Physiol Opt. 1994 Jul;14(3):290-2. doi: 10.1111/j.1475-1313.1994.tb00010.x.
Previous studies have typically assessed tonic accommodation (TA) and tonic vergence (TV) by placing subjects in total darkness. However, a recent investigation demonstrated that even under such apparently stimulus-free conditions, subjects' awareness of the proximity of the adjacent surroundings and overall room topography (i.e. surround propinquity) may still influence the accommodative response. Accordingly, the aim of the present study was to measure TA and TV while subjects (n = 34) viewed an illuminated distant target (viewing distance = 6 m) to minimize this propinquity effect. TA was measured using an objective, open-field, infrared optometer under two conditions: first, while viewing the distant target monocularly through a 0.5 mm pinhole, and second in total darkness. Additionally, TV was assessed by determining the heterophoria subjectively while subjects viewed the distant target biocularly through 0.5 mm pinholes. The mean level of TA using the pinhole technique (mean = 0.28 D) was significantly lower than that observed in total darkness (mean = 0.60 D). Furthermore, a significant positive correlation (r = 0.86) was found when comparing the difference between the two TA measurements with the level obtained in total darkness. Those subjects having apparently high levels of TA in darkness exhibited the largest propinquity effect. Thus measurements of accommodation recorded in total darkness are likely to have overestimated both the magnitude and normal range of TA. The mean level of TV was 0.58 metre angle. No significant correlation was observed between TV and either of the two TA measurements.(ABSTRACT TRUNCATED AT 250 WORDS)
以往的研究通常通过将受试者置于完全黑暗的环境中来评估张力性调节（TA）和张力性聚散（TV）。然而，最近的一项调查表明，即使在这种明显无刺激的条件下，受试者对相邻周围环境的接近程度和整个房间地形的感知（即周围接近度）仍可能影响调节反应。因此，本研究的目的是在受试者（n = 34）观看照亮的远处目标（观看距离 = 6米）时测量TA和TV，以尽量减少这种接近效应。使用客观的、开放视野的红外验光仪在两种条件下测量TA：第一，通过0.5毫米针孔单眼观看远处目标时；第二，在完全黑暗的环境中。此外，在受试者通过0.5毫米针孔双眼观看远处目标时，通过主观确定隐斜来评估TV。使用针孔技术时TA的平均水平（平均值 = 0.28 D）显著低于在完全黑暗环境中观察到的水平（平均值 = 0.60 D）。此外，将两种TA测量值之间的差异与在完全黑暗环境中获得的水平进行比较时，发现存在显著的正相关（r = 0.86）。那些在黑暗中TA水平明显较高的受试者表现出最大的接近效应。因此，在完全黑暗环境中记录的调节测量值可能高估了TA的大小和正常范围。TV的平均水平为0.58米角。在TV与两种TA测量值中的任何一个之间均未观察到显著相关性。（摘要截断于250字）
