Studio Optometrico Giovanzana, Via Cherubini 6, 20145, Milan, Italy.
The Directorate of Research, Development and Innovation Management (DMCDI), The Technical University of Cluj-Napoca, Constantin Daicoviciu St., No. 15, 400020, Cluj-Napoca, Cluj County, Romania.
Int Ophthalmol. 2020 Feb;40(2):459-465. doi: 10.1007/s10792-019-01206-5. Epub 2019 Nov 1.
We aim to improve contact lens fitting by using an innovative and simple photogrammetry imaging system to find the sagittal height (SAG) of soft contact lenses.
Eleven different types of commercially available soft contact lenses were measured, and five different lenses per package of each lens type were evaluated. The lenses were inserted in a polymethyl methacrylate cell with parallel faces containing a solution of saline and fluorescein to improve the contrast against the background. For every lens, two photographs from the top view and five photographs from the side view were taken. Using homothetic transformations, we calculated the sagittal height.
The SAG of all lenses ranged from 3450 to 3907 μm. Differences can be appreciated between SAG of different materials. Performing an ANOVA test, we confirm that the intra-packaging sagitta is reliable for every lens. Comparing the measured SAG with the calculated spherical one, we confirm that the majority of lenses, eight out of eleven, have a spherical geometry for the internal side. Finally, we are able to group the type of lenses that present similar SAG apart from the data reported on the blister.
Optical coherence tomography measurement of the eye sagitta over a given chord helped finding the first lens to fit, because matching contact lens sagitta and ocular sagitta is the key for a good fitting. In our work, we found that the majority of brands use single sphere geometry for internal surface of disposable soft contact lenses.
我们旨在通过使用创新且简单的摄影测量成像系统来提高隐形眼镜的适配度，以找到软性隐形眼镜的矢高（SAG）。
我们测量了 11 种不同类型的市售软性隐形眼镜，并对每种镜片类型的每包装中的 5 个镜片进行了评估。将镜片插入具有平行面的聚甲基丙烯酸甲酯（PMMA）单元中，其中包含盐水和荧光素溶液，以提高与背景的对比度。对每个镜片，从顶视图拍摄了两张照片，从侧视图拍摄了五张照片。使用相似变换，我们计算了矢高。
所有镜片的 SAG 范围从 3450 到 3907μm。可以看出不同材料的 SAG 存在差异。通过进行方差分析（ANOVA）测试，我们确认了每款镜片的包装内矢高是可靠的。将测量的 SAG 与计算的球面 SAG 进行比较，我们确认在 11 种镜片中，有 8 种具有内部球面几何形状。最后，我们能够根据泡罩上报告的数据将具有相似 SAG 的镜片类型分组。
对给定弦长的眼睛矢高进行光学相干断层扫描（OCT）测量有助于找到第一副适合的隐形眼镜，因为匹配隐形眼镜的矢高和眼球的矢高是良好适配的关键。在我们的工作中，我们发现大多数品牌在一次性软性隐形眼镜的内表面使用单一球面几何形状。
