- 學位論文
有晶體式人工水晶體植入後長期併發症追蹤與危險性分析
Long Term Follow Up and Risk Analysis After Implantation of Phakic Intraocular Lens
摘要
有晶體式人工水晶體是目前被證實可有效矯正高度近視的產品，其為保留病人原有的水晶體情況下植入人工水晶體，彷如將隱形眼鏡植入眼球內，以矯正其近視度數，當人工水晶體植入後，病人可以不再依賴眼鏡或隱形眼鏡就獲得高品質的視力。而散光矯治型有晶體式人工水晶體亦可同時改善近視與散光等屈光不正之問題。 有晶體式人工水晶體可分為虹膜固定式的有晶體式人工水晶體與後房有晶體式人工水晶體，本研究主要聚焦於虹膜固定式有晶體式人工水晶體。有晶體式人工水晶體置入病人後可能會造成一些後遺症，與其種類有高度的相關。虹膜固定式可能會造成角膜內皮細胞損失、慢性虹彩炎、鏡片位移或是瞳孔阻滯性青光眼，其中最常見也最重要的，便是植入晶體後的角膜內皮細胞損失。 目前研究指出，造成術後內皮細胞損失率增加的危險因子，最重要的是前房深度，而自從前方光學同調儀 (AS-OCT)應用在偵測有晶體式人工水晶體的精確位置後，可靠的解像力讓人工水晶體與角膜內皮之間的距離更準確地被測量，也因此更精準的危險因子逐漸被提出；角膜內皮與人工水晶體邊緣的距離(edge distance)逐漸被認為是最精確判斷有晶體式人工水晶體植入後，內皮細胞損失的危險因子。然而，臨床上，縱使病患擁有足夠的前房深度與角膜晶體距離，嚴重的慢性角膜內皮損失仍然可能發生，因此除了角膜與人工水晶體距離之外，仍然有其他危險因子可能會影響長期的角膜內皮損失。 本研究挑選2種虹膜固定式晶體式人工水晶體 (“歐斯提克”阿提申人工水晶體Artisan、“歐斯提克”阿提菲克斯人工水晶體Artiflex、)進行臨床效益風險評估分析研究。針對植入Artiflex與Artisan鏡片病人的詳細眼科檢查，並且尋找有晶體式人工水晶體植入後造成角膜內皮細胞損失的危險因子。 本研究收集黃維仁醫師與胡芳蓉醫師手術的虹膜固定式有晶體式人工水晶體植入病人，在施術醫師的協助下，將病人召回進行眼科檢查，包含一般檢查、角膜內皮細胞數、AS-OCT、角膜生物動力學等。並且對照術前的資料進行內皮細胞損失的統計分析，並進行危險因子的分析。 本研究為橫斷性觀察性研究(cross-sectional observational study)，共計納入104位病人，205隻眼睛，平均距離手術的時間是4.56±2.42年，依照距手術的時間長短，將病人分為短期( <3年)、中期(3-6年)、長期( >6年)三組。三組病患的內皮細胞年平均損失率分別為4.34±4.10%、2.39±1.60%、2.16±1.51%。我們進一步將各組細分為高年平均損失率與低年平均損失率兩組，並且進行兩組間的危險性因子分析。 我們的研究發現了幾項造成長期內皮細胞損失的危險因子。中期與長期的病人，高年平均損失率的病人，其角膜-晶體距離是比較短的，中期與長期的高損失率病人的數值分別是1.04 ±0.18 and 1.05±0.11 mm，相對的低損失率的病人數值分別是1.24 ±0.21 and 1.23±0.17 mm (兩者的p<0.05)，而在短期的病人，兩者的角膜-晶體距離並沒有太大的差別，高損失率組與低損失率組分別為1.18±0.17 mm 與1.24±0.21mm (p=0.44)。因此我們發現角膜與人工水晶體的距離過短會造成長期的內皮細胞損失率增加。 本研究也發現角膜的軟硬度會影響有晶體式人工水晶體植入後，長期的角膜內皮細胞損失。中期與長期的病人，高年平均損失率的病人，其角膜生物動力學，包含角膜遲滯係數(corneal hysteresis，CH)與角膜阻抗係數(corneal resistant factor，CRF)，皆低於低損失率的病人。長期組中高損失率的病人，其平均CH與CRF分別是8.99 ± 1.09mmHg與8.42 ± 1.04 mmHg，而低損失率的病人，其CH與CRF則是9.82 ± 1.68mmHg與10.02 ± 1.52mmHg (p皆為0.016)；中期的高損失率的病人，其平均CH與CRF分別是8.99 ± 1.09 mmHg與 8.91 ± 1.1mmHg，相對的低損失率病人，其CH與CRF則分別是10.10 ±1.47mmHg與10.04 ±1.78mmHg (p為0.02與0.04)；而短期組的高損失率病人，其CH與CRF亦呈現較低的情形，惟統計上呈現邊界顯著的狀況。 本研究另外針對角膜周邊內皮細胞密度與中心內皮細胞密度進行比較，其中心與上、下、鼻、顳側的角膜內皮細胞密度，分別為2549.50±408.62 cells/mm2、1983.48±585.81 cells/mm2、2508.18±489.97 cells/mm2、2151,54±498.22 cells/mm2、2311.81±441.44 cells/mm2，我們發現除了下方的密度與中心並無差異之外，上方、鼻側、顳側的角膜內皮細胞，皆明顯低於中心部位，並且達到統計上顯著的差異。比較其原因，上方因為是手術進出的位置，因此密度最低，鼻側的角膜-水晶體平均距離最短，因此是密度次低的位置。由周邊內皮細胞密度可得知，術中造成的角膜內皮細胞損失，與角膜-水晶體距離皆為影響術後內皮細胞損失的重要因素。除此之外，若我們只檢查中心部位內皮細胞密度，整體角膜術後的內皮細胞損失可能會被低估。 本研究確立了角膜與有晶體式人工水晶體邊緣的最小距離以及角膜軟硬度，是影響有晶體式人工水晶體植入後長期角膜內皮細胞損失之重要危險因子。另外，本研究亦是第一個針對有晶體式人工水晶體直入後，周邊角膜內皮細胞密度進行研究之先驅研究，希望能提供未來施行有晶體式人工水晶體的醫師與病患避免嚴重角膜內皮細胞損失之可能。
並列摘要
Phakic intraocular lens (pIOLs) implantation is an alternative for laser refractive surgery, which is mostly performed in the high myopic eyes. The toric pIOLs can also correct astigmatism as well as myopia, and the efficacy has already been highly accepted. The pIOLs includes the iris-fixated pIOL and the posterior chamber implantable contact lens (ICL), and we focused on iris-fixated pIOLs in this study. There are still some severe complications reported. The commonly reported complications of the iris-fixated pIOLs include loss of endothelial cells, chronic iritis, pupillary block syndrome, or IOL dislocation. Among all the complications, endothelial cell loss is one of the most concerned complications. Several risk factors causing EC loss after iris-fixated pIOLs implantation were identified. Previous studies revealed a negative correlation between anterior chamber depth (ACD) and EC loss. Furthermore, the endothelial-IOL distance (E-IOL distance), especially the edge distance, has been considered as a more accurate risk factor since anterior chamber optical conherence tomography (AS-OCT) started being applied to visualize the iris-fixated pIOL in the anterior chamber. However, even though we strictly select the patients by their ACD depth and E-IOL distance, we still noticed severe long-term EC loss in some patients. The purpose of this study is to evaluate the long-term postoperative safety of iris-fixated pIOLs, including complications and risk factors analysis for adverse effects. This is a cross-sectional observational study. We included the patients receiving two kinds of iris-fixated pIOLs, Artisan and Artiflex. All the patients received the operation in National Taiwan University Hospital (NTUH) and in Ray Guard Eye Clinic. We recalled the patients to NTUH for generally ocular examinations. We also examined central and peripheral endothelial cell density (ECD), corneal biomechanical properties (CBP), and endothelial-IOL distances. According to the examination data and pre-operative chart records, we obtained the ECD loss after iris-fixated pIOL implantation. We divided all the cases into 3 groups according to the duration since implantation of iris-fixated pIOLs (< 3 years, 3-6 years, and > 6 years as short-term, mid-term, and long-term groups). The risk factors associated with loss of endothelial cell density after implantation of iris-fixated pIOL in these 3 groups were analyzed. One hundred and four patients (205 eyes) who received implantation of iris-fixated pIOL were examined. The mean duration between examination and the operation is 4.56±2.42 years. In the mid-term and long-term groups, the average minimal endothelial-IOL edge distances are 1.04 ±0.18 and 1.05±0.11 mm in the high annual ECD loss subgroup, whereas those are 1.24 ±0.21 and 1.23±0.17 mm respectively in the low annual ECD loss subgroup (both P<.05). We also analyzed the correlation between EC loss and CBP. Both CH and CRF showed marginal difference between the 2 subgroups in the short-term group. In the mid-term and long-term groups, the CH and CRF were both significantly lower in the high ECD loss rate subgroups. In the mid-term group, the average CH in the high and low loss rate subgroups were 8.99 ± 1.09 mmHg and10.10 ±1.47 mmHg (P =0.02). In the long-term group, the mean CH in the two subgroups were 8.08 ± 0.97 mmHg and 9.82 ± 1.68 mmHg (P =0.016). Since peripheral ECD is significantly lower than the central ECD in the superior, nasal, and temporal quadrants, we assume that the edge E-IOL distance and the intraoperative loss of ECD may be important factors of the final EC loss. Furthermore, we could underestimate the total EC loss if we only measured the central endothelial cell density. In conclusion, low minimal edge distance and low CBP are important risk factors contributing to the higher annual loss rate after the iris-fixated pIOLs implantation. Long term follow-up of ECD are recommended for those patients with risk factors.