Queensland University of Technology, School of Optometry, Victoria Park Road, Kelvin Grove, QLD 4059 Brisbane, Australia.
J Biomed Opt. 2011 Jul;16(7):076012. doi: 10.1117/1.3598837.
Dry eye syndrome is one of the most commonly reported eye health conditions. Dynamic-area high-speed videokeratoscopy (DA-HSV) represents a promising alternative to the most invasive clinical methods for the assessment of the tear film surface quality (TFSQ), particularly as Placido-disk videokeratoscopy is both relatively inexpensive and widely used for corneal topography assessment. Hence, improving this technique to diagnose dry eye is of clinical significance and the aim of this work. First, a novel ray-tracing model is proposed that simulates the formation of a Placido image. This model shows the relationship between tear film topography changes and the obtained Placido image and serves as a benchmark for the assessment of indicators of the ring's regularity. Further, a novel block-feature TFSQ indicator is proposed for detecting dry eye from a series of DA-HSV measurements. The results of the new indicator evaluated on data from a retrospective clinical study, which contains 22 normal and 12 dry eyes, have shown a substantial improvement of the proposed technique to discriminate dry eye from normal tear film subjects. The best discrimination was obtained under suppressed blinking conditions. In conclusion, this work highlights the potential of the DA-HSV as a clinical tool to diagnose dry eye syndrome.
干眼症是最常见的眼部健康问题之一。动态区域高速角膜地形图（DA-HSV）代表了一种很有前途的替代方法，可以替代最具侵入性的临床方法来评估泪膜表面质量（TFSQ），特别是由于角膜地形分析中 Placido 盘角膜地形图既相对便宜又广泛使用。因此，改进这种技术来诊断干眼症具有临床意义，也是这项工作的目的。首先，提出了一种新的光线追踪模型，用于模拟 Placido 图像的形成。该模型展示了泪膜形貌变化与获得的 Placido 图像之间的关系，并作为评估环规则性指标的基准。此外，还提出了一种新的基于块特征的 TFSQ 指标，用于从一系列 DA-HSV 测量中检测干眼症。在一项包含 22 名正常和 12 名干眼症患者的回顾性临床研究数据上评估了新指标的结果，表明该技术在区分干眼症和正常泪膜方面具有显著的改进。在抑制眨眼的条件下，获得了最佳的区分效果。总之，这项工作强调了 DA-HSV 作为一种临床工具来诊断干眼症的潜力。
