【摘要】  目的：分析白內(nèi)障術(shù)中矯正角膜散光對(duì)人工晶狀體度數(shù)預(yù)測(cè)的影響。方法：選擇老年性白內(nèi)障患者35例35眼，行上方切口超聲乳化聯(lián)合PMMA人工晶狀體植入術(shù)后角膜散光減少，測(cè)量術(shù)前和術(shù)后3mo的角膜曲率及屈光狀態(tài)。比較SRKⅡ，SRK/T，HolladayⅠ公式在使用術(shù)前和術(shù)后角膜曲率值計(jì)算的絕對(duì)預(yù)測(cè)誤差。結(jié)果：手術(shù)前后平均角膜曲率增加0.30±0.81D，角膜散光度數(shù)減少0.70±0.71D，都有統(tǒng)計(jì)學(xué)意義(P<0.05)，兩者的相關(guān)性為(r=��0.554，P<0.01)。SRKⅡ，SRK/T，HolladayⅠ使用術(shù)前角膜曲率計(jì)算的絕對(duì)預(yù)測(cè)誤差中位數(shù)分別為0.85D，0.73D，0.78D，公式間無(wú)統(tǒng)計(jì)學(xué)差異(χ2=4.474，P>0.05);使用術(shù)后角膜曲率計(jì)算則分別為0.72D,0.54D,0.46D，有統(tǒng)計(jì)學(xué)差異(χ2=7.758，P<0.05);3代公式在兩種計(jì)算方法下結(jié)果有有統(tǒng)計(jì)學(xué)差異(Z= ��2.208,��2.273，P<0.05)。結(jié)論：矯正角膜散光會(huì)引起角膜屈光度變化，導(dǎo)致人工晶狀體度數(shù)的預(yù)測(cè)誤差增大，計(jì)算公式尤其是3代公式的準(zhǔn)確性下降，有必要對(duì)公式進(jìn)行相應(yīng)調(diào)整優(yōu)化。

【關(guān)鍵詞】  角膜散光;角膜平均曲率;人工晶狀體公式核心期刊論文發(fā)表

　　　Abstract AIM: To analyse the influence of correcting corneal astigmatism on the accuracy of intraocular lens power prediction after cataract surgery.�r METHODS: Thirty�瞗ive cases of age�瞨elated cataract 35 eyes were selected, the corneal astigmatism was reduced after phacoemulsification with superior incision and PMMA intraocular lens implantation. The keratometry was measured before operation and three months postoperatively，then the absolute forecast error of SRK Ⅱ, SRK/T, Holladay Ⅰ formula with preoperative and postoperative corneal curvature were compared.RESULTS: The average corneal curvature was increased by 0.30±0.81D (t=��2.205, P<0.05)，the corneal astigmatism was decreased by 0.70±0.71D after operation(t=5.846, P<0.01)，there was correlation between them(r=��0.554, P<0.01 ).The absolute predict errors of SRKⅡ,SRK/T and Holladay Ⅰ formulas using preoperative curvature was respectively 0.85D,0.73D and 0.78D, there was no significant difference (χ2=4.474，P>0.05). The absolute predict error using postoperative curvature was respectively 0.72D,0.54D and 0.46D，SRKⅡ indicated statistical difference from other formulas (χ2=7.758，P<0.05). The third theoretical formula had statistical difference from using preoperative and postoperative curvature(Z=��2.208,��2.273，P<0.05).CONCLUSION: Correcting the corneal astigmatism may cause the changes in corneal refraction, which leads to the error of the intraocular lens prediction increase, especially the accuracy of the third generation formula decrease, so it is necessary to adjust and optimize the formula accordingly.

　 KEYWORDS：corneal astigmatism;corneal curvature;intraocular lens power formulas

　   0引言核心期刊論文發(fā)表

　　研究證實(shí)減少白內(nèi)障術(shù)后散光可以有效提高視覺質(zhì)量[1]，利用手術(shù)切口矯正術(shù)前角膜散光成為普遍采用的方法[2]，但角膜的屈光變化導(dǎo)致人工晶狀體度數(shù)的計(jì)算誤差并未受到臨床重視，我們選擇相關(guān)病例比較這種影響,現(xiàn)報(bào)告如下。

　　1對(duì)象和方法

　　1.1對(duì)象 隨機(jī)選擇2009��07/2009��12在我院行超聲乳化并人工晶狀體植入術(shù)的老年性白內(nèi)障患者35例35眼，男21例，女14例，平均年齡68.2±9.7歲，無(wú)明顯角膜病變和手術(shù)并發(fā)癥，術(shù)后角膜散光度數(shù)減少。核心期刊論文發(fā)表

　　1.2方法 使用IOLMaster校準(zhǔn)的A超(AVISO，光太公司)測(cè)量眼軸，電腦驗(yàn)光儀(KR��8800，托普康公司)測(cè)量術(shù)前和術(shù)后3mo的角膜曲率，并聯(lián)合綜合驗(yàn)光儀(CV��3000，托普康公司)確定術(shù)后驗(yàn)光結(jié)果。使用AVISO內(nèi)置SRKⅡ，SRK/T，Hoffer Q，HolladayⅠ公式分別計(jì)算絕對(duì)預(yù)測(cè)誤差(預(yù)測(cè)誤差=預(yù)測(cè)屈光度�残g(shù)后實(shí)際屈光度)。采用上方角膜緣3平面主切口，3∶00位輔助切口，連續(xù)環(huán)形撕囊，完成晶狀體超聲乳化(Millennium，博士倫公司)摘出后用5.5mm穿刺刀(愛爾康公司)擴(kuò)大角鞏膜緣切口，囊袋內(nèi)植入PMMA人工晶狀體。術(shù)后抗生素、激素滴眼1mo。

　　統(tǒng)計(jì)學(xué)分析：采用SPSS 13.0統(tǒng)計(jì)軟件包。手術(shù)前后同參數(shù)比較用配對(duì)t檢驗(yàn)，組間比較用Mann�瞁hitney檢驗(yàn)，組內(nèi)比較用Friedman檢驗(yàn)。數(shù)據(jù)結(jié)果以±s或M表示，P<0.05為差異有統(tǒng)計(jì)學(xué)意義。核心期刊論文發(fā)表
　2結(jié)果

　　2.1一般情況 眼軸為24.02±2.45mm。手術(shù)前后平均角膜曲率增加0.30±0.81D，角膜散光度數(shù)減少0.70±0.71D，都有統(tǒng)計(jì)學(xué)意義(P<0.05)，兩者的相關(guān)性為(r= ��0.554，P<0.01)。角膜散光J0變化��0.12±0.52D，J45為 ��0.21±0.58D，J45的差異有統(tǒng)計(jì)學(xué)意義(P<0.05，表1)。

　　2.2對(duì)人工晶狀體度數(shù)計(jì)算的影響 公式SRKⅡ，SRK/T，HolladayⅠ在使用術(shù)前角膜曲率計(jì)算的絕對(duì)預(yù)測(cè)誤差中位數(shù)分別為0.85D，0.73D，0.78D，公式間差異無(wú)統(tǒng)計(jì)學(xué)意義(χ2=4.474，P>0.05)