摘要
在台灣，因汽機車盛行，使得眼眶骨折(orbital blow-out fracture)的發生率居高不下，而眼眶骨折常導致病人有複視(diplopia)、眼球內陷(enophthalmos)、眼位不正(dystopia)等等功能失常和影響外觀的狀況。在受傷初期由於軟組織的瘀青腫脹和張眼困難，使得臨床醫師不易在短時間評估受傷的嚴重程度，以做為手術適應症的參考。臨床上常以未受傷側的顱顏結構，做為治療受傷側治療的參考，然而手術前的預測和手術後的結果仍然存在著誤差，甚至產生併發症。電腦斷層(computed tomography)影像的呈現頗為精密，然目前無客觀的臨床或影像指標，可以做為診斷或治療上的可靠參考。因此本研究利用電腦斷層立體重組(CT 3-D reformation)技術，建構眼球、眼窩及顏面顱骨的三維模型，並設計可以用於表達眼部結構相關性的幾何數學參數，表達並量化正常人眼窩及其周遭顱顏骨頭的幾何結構，來呈現眼球、軟組織和眼眶骨的立體空間關係，瞭解正常人眼眶的解剖特性及探討左右眼眶的對稱性，期望能確認眼眶骨整形手術前評估的正確性。本分析法在蒐集足夠案例樣本後，希望能建立台灣人的顱顏和眼部結構的幾何參數資料庫，期望能以客觀數據建立診斷準則和嚴重程度的分類，來做為手術與否及術式選擇的參考依據。
關鍵詞：眼眶、眼眶骨折、眼球內陷、電腦斷層
Abstract
In Taiwan, orbital blow-out fractures are frequent due to popularity of motorcycle traffic accident. The recognized sequelae of orbital blow-out fracture include enophthalmos, diplopia from extraocular muscle dysfunction (entrapment, ischemia, hemorrhage, or nerve injury), dystopia and disfiguring facial contours. There are still many clinical issues needed to be resolved. At early stage of orbital trauma, severe swelling and ecchymosis of orbital structures makes the diagnosis and indications for reconstructive surgery difficult. The orbital and facial structure of non-injured side is always as the reference in reconstructive surgery of the injured side. Although computed tomography (CT) evaluation is popular, the clear data with objective clinical examination combined with imaging study is still lack as the results making the orbital reconstruction controversial. Therefore we first reform the three-dimensional (3D) orbital CT model and set some mathematic geometric parameters to define the relationship of eyeball and orbital structure. By using 3-D CT reformation, structures in the orbital cavity including the eyeball, soft tissues and bony walls can be segmented from the sequential CT images, and then the algorithms of computer graphics can be implemented for 3D model reconstruction. In this study, we investigate the anatomic characteristics and investigate the symmetry of normal orbits. The associated database for Taiwanese can be established while enough cases can be collected and measured. In the future, we hope the system can be applied for the prediction of surgical results, facilitate the surgical procedures and improve the quality of reconstructive orbital surgery.
Keyword: Orbita, Orbital Fracture, Enophthalmos, Computed Tomography