Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium.
OMFS - IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, Catholic University Leuven, Leuven, Belgium.
Acta Ophthalmol. 2021 Mar;99(2):221-226. doi: 10.1111/aos.14549. Epub 2020 Jul 23.
Fitting a customized ocular prosthesis for anophthalmic patients entails an artisanal labour-exhausting process and is standardly based on impression moulding of the socket, which may be anatomically inaccurate. The objective of the study was to design an impression-free socket mould with three-dimensional (3D) technology.
The ex vivo anophthalmic socket models included one silicone, one fresh pig cadaver head and three fresh-frozen human cadaver heads. After intra-socket application with iodine substance, five observers obtained eighteen low-dose cone beam computed tomography (CBCT) scans and one observer one high-dose CBCT scan of each model. The observers designed non-impression 3D moulds of the socket with 3D software. For the human cadaver sockets 3D geometric models of the ocular prosthesis were rendered from the 3D mould of the socket and the mirrored cornea of the contralateral eye.
The posterior surface of the 3D mould was highly accurate, with a mean absolute deviation of 0.28 mm, 0.53 mm, 0.37 mm and mean upper deviation of 0.53 mm, 0.86 mm, 1.17 mm, respectively, for the phantom, pig and human model. The intra- and interobserver repeatability and reproducibility of the 3D moulds and designs was good (<0.35 mm). The largest variation in the 3D geometric model was found at the junction of the 3D mould and mirrored cornea.
3D design of an impression-free geometric model for an ocular prosthesis with low-dose CBCT is highly accurate in ex vivo anophthalmic socket models. This novel method is a critical step towards the manufacturing of 3D printed ocular prostheses and requires validation in anophthalmic patients.
为无眼窝患者定制眼部义眼需要进行一项耗费大量人工的工作，目前标准方法是基于对眼眶进行印模，而这种方法可能存在解剖学上的不准确性。本研究旨在设计一种无印模的三维（3D）技术的眼眶模型。
离体无眼窝眼眶模型包括一个硅胶模型、一个新鲜猪头颅标本和三个新鲜冷冻的人类头颅标本。碘物质应用于眼眶内后，五位观察者对每个模型进行了 18 次低剂量锥形束计算机断层扫描（CBCT）扫描，一位观察者进行了一次高剂量 CBCT 扫描。观察者使用 3D 软件设计无印模的 3D 眼眶模型。对于人类头颅标本，从眼眶 3D 模型和对侧眼睛的镜像角膜渲染出眼部义眼的 3D 几何模型。
3D 模具的后表面高度准确，平均绝对偏差分别为 0.28mm、0.53mm、0.37mm，平均上偏差分别为 0.53mm、0.86mm、1.17mm，对于模型体、猪和人类模型。3D 模具和设计的观察者内和观察者间的重复性和可再现性良好（<0.35mm）。3D 模具和镜像角膜交界处的 3D 几何模型变化最大。
低剂量 CBCT 无印模的眼部义眼 3D 设计在离体无眼窝眼眶模型中具有高度准确性。这种新方法是制造 3D 打印眼部义眼的关键步骤，需要在无眼窝患者中进行验证。
