Institute of Applied Computer Science, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany.
Invest Ophthalmol Vis Sci. 2014 Feb 4;55(2):759-66. doi: 10.1167/iovs.13-12162.
After cataract surgery, the ability to accommodate is lost. For this reason, a mechatronic IOL is being developed at the moment: The Artificial Accommodation System. This device requires an easily measureable indicator of the distance of the observed object to determine the demand of accommodation. As the pupil constricts with near vision, pupil size might be such an indicator. Our research focused on whether the pupil can control an artificial lens.
A study with 14 healthy subjects aged between 24 and 64 years was conducted. An artificial lens with variable refractive power was mounted in front of one eye. In this eye, natural accommodation was greatly reduced or absent due to presbyopia, pseudophakia, or iatrogenic cycloplegia. The lens' refractive power was changed in a computer-controlled manner depending on changes in the pupil diameter of the second eye, which could not see the fixation stimulus. The subject's task was to get a clear focused image of the target in different distances.
The lens can be controlled by the pupil intuitively (P < 1.8 × 10(-18)). Without prior knowledge, 11/14 subjects passed the first trial, and 31/41 trials were successful. Only one subject was not able to control the lens at all. Most subjects comprehended instantly how to use the unfamiliar lens control to bring a target into focus.
This study emphasizes the plasticity of the visual control system. Positioning accuracy was acceptable, but the control must be optimized to facilitate maintaining a defined refractive power.
白内障手术后，调节能力丧失。出于这个原因，目前正在开发一种机电一体的人工晶状体：人工调节系统。该设备需要一个易于测量的观察目标距离指标来确定调节需求。由于瞳孔随近距视力收缩，瞳孔大小可能就是这样一个指标。我们的研究集中在瞳孔是否可以控制人工晶状体。
对 14 名年龄在 24 至 64 岁之间的健康受试者进行了一项研究。在一只眼睛前面安装了具有可变屈光力的人工晶状体。由于远视、白内障或医源性睫状肌麻痹，该眼的自然调节能力大大降低或丧失。透镜的屈光力由第二只眼睛瞳孔直径的变化以计算机控制的方式改变，第二只眼睛无法看到固定刺激。受试者的任务是在不同距离使目标清晰聚焦。
可以直观地通过瞳孔控制透镜（P < 1.8 × 10(-18))。无需事先了解，14 名受试者中的 11 名通过了第一次试验，41 次试验中有 31 次成功。只有一名受试者根本无法控制镜片。大多数受试者立即理解如何使用不熟悉的镜片控制将目标聚焦。
这项研究强调了视觉控制系统的可塑性。定位精度可以接受，但必须对控制进行优化，以方便维持定义的屈光力。
