探討遮蔽劑輔助準分子雷射角膜切除術治療角膜不規則表面之效果

The Masking Agents for Treatment of Corneal Surface Irregularities with Excimer Laser Phototherapeutic Keratectomy

蘇娟儀(Chuan-Yi Su)

指導教授 ： 王惠珠 教授 ； 林昌平 教授

高雄醫學大學/醫學院/醫學研究所/碩士(2003年)

摘要

研究目的：本實驗之研究目的，在於探討利用準分子雷射角膜切除術（PTK）所使用遮蔽劑對角膜不規則表面之矯正效果，以及遮蔽劑之物理性質測定、臨床使用之觀察，並探討和矯正效果之關聯。
研究材料及方法：本實驗研究6種遮蔽劑及3種素材所形成之標準化不規則表面，6種遮蔽劑包括0.9% Saline solution、0.3% Methylcellulose、1% Methylcellulose、Tear Naturale®、1% Sodium hyaluronate 及Collagen。3種素材包括黑色相片紙、PMMA板及豬眼球角膜，在此3種素材上製造標準化之不規則表面。觀察記錄遮蔽劑在準分子雷射下之變化，並比較6種遮蔽劑輔助準分子雷射角膜切除術於3種素材上去除不規則表面之效果。
研究結果：實際觀察顯示0.9% Saline solution、0.3% Methylcellulose、1% Methylcellulose、Tear Naturale，在準分子雷射中不論在任何素材上均容易產生氣泡，影響PTK之進行。直接觀察去除黑色相片之不規則表面之效果，6種遮蔽劑之效果都不理想，殘留表面皆不均勻。以剖面儀測量6種遮蔽劑使用於去除PMMA板不規則表面（n = 6），不使用遮蔽劑粗糙度平均值Ra為 13.94 ±0.63 μm，與標準不規則表面（Ra = 14.98 ±0.64 μm）比較下，沒有去除不規則表面之效果（p = 0.127），0.9% Saline solution之Ra值為10.34 ±0.49 μm、0.3% Methylcellulose之Ra值為10.87 ±1.11 μm、1% Methylcellulose之Ra值為9.52 ±2.19 μm、Tear Naturale之Ra值為10.06 ±1.42 μm、1% Sodium hyaluronate之Ra值為7.39 ±1.78 μm 、Collagen之Ra值為8.72 ±1.09 μm，顯示6種遮蔽劑雖然皆有去除不規則表面之效果（p <0.05），但殘餘之表面和原本未經處理之PMMA板之粗糙度（Ra值0.04 ±0.01 μm）相比則顯示仍粗糙（p < 0.05）。對於豬眼球角膜不規則表面，利用掃描式電子顯微鏡比較6種遮蔽劑之效果（n = 6），將表面平滑程度分程Grade I 最不平滑、Grade II 不平滑、Grade III平滑，在6種遮蔽劑中以Collagen 之效果最好：有1個Grade II及5個Grade III，其次是1% Sodium hyaluronate：有2個Grade II及4個Grade III，其餘之遮蔽劑則不佳。
結論：黑色相片紙模式容易觀察雷射下之變化，但有雷射發數之限制；PMMA板模式容易數據化，但為平面式且雷射切削率與角膜組織有差別；豬眼球模式則是最佳之in vitro模式，也是最可以信賴之模式，Collagen於本研究當中，是準分子雷射角膜切除術去除豬角膜不規則表面時所使用的遮蔽劑中，可以形成最平滑表面的遮蔽劑。

關鍵字

遮蔽劑 ； 準分子雷射角膜切除術 ； 角膜不規則表面

並列摘要

Purpose: The purpose of this study is to evaluate the different kinds of masking agents and to evaluate the smoothing effects of phototherapeutic keratectomy (PTK) using masking agents.
Materials and Methods: Six kinds of masking agents, including 0.9% Saline solution, 0.3% Methylcellulose, 1% Methylcellulose, Tear Naturale®（0.1% Dextran 70 with 0.3% Hydroxypropyl methycellulose）, 1% Sodium hyaluronate, and collagen were studied. A model of an irregular surface was developed on the black photograph, the PMMA plate and enucleated pig cornea. The smoothing effects of masking agents were evaluated via observation, profilometry, and scanning electron microscopy.
Results: There were much bubbles appeared in the 0.9% saline solution, 0.3% methylcellulose, 1% methylcellulose and Tear Naturale during excimer laser photoablation. Profilometry showed the average roughness Ra of PMMA plate treated without and with 6 masking agents（n = 6）: Standard irregular surface 14.98 ±0.64， PTK without masking agent 13.94 ±0.6，0.9% Saline solution 10.34 ±0.49, 0.3% Methylcellulose 10.87 ±1.11, 1% Methylcellulose 9.52 ±2.19, Tear Naturale 10.06 ±1.42, 1% Sodium hyaluronate 7.39 ±1.78 , Collagen 8.72 ±1.09. There was no effect of PTK without masking agent in removing irregular PMMA surface (p = 0.127). There was incompletely smoothing effect of PTK with 6 masking agents. Scanning electron microscopy demonstrated the smoothness of pig cornea as grade I: very irregular, grade II: irregular, grade III: smooth （n = 6）. The corneas treated with collagen （grade II :1, grade III:5）and 1% sodium hyaluronate（grade II:2, grade III: 4）had smoother surface.
Conclusion: Black photograph paper could offer directly observable model for excimer laser photoablation. PMMA plate could offer numberable data of roughness. Pig cornea was the best model in vitro. Collagen has the potential as a masking agent in the treatment of corneal surface irregularities.

並列關鍵字

Masking agents ； Phototherapeutic keratectomy ； Corneal surface irregularities

參考文獻

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