|摘要: ||白內障在犬隻是最常見的眼科疾病之一，並且可能造成單眼甚至更常見的雙眼失明。治療白內障最有效的方式為手術移除水晶體。在獸醫，最常被選擇的手術方式為超音波乳化術合併人工水晶體植入。然而，後囊混濁為術後最常見的併發症，其發生機率為69 %至100 %，且會對視力造成影響。人類為避免後囊混濁的發生而發展出連續環形後囊撕除術。然而，目前尚未有犬隻施行連續環形後囊撕除術的相關統計。本實驗目的為評估犬隻在施行連續環形後囊撕除術後其後囊混濁發展之情形及可能的併發症。本研究包含12隻於國立中興大學獸醫學院附屬獸醫教學醫院進行超音波乳化術之犬隻，共15個眼睛，排除水晶體脫位及玻璃體混濁並排除全身系統疾病後，隨機分組為PCCC組(n=3)與no PCCC組(控制組)(n=7)，兩組皆放置人工水晶體。水晶體脫位者選擇不撕後囊、不放置人工水晶體(n=2)。有全身系統疾病如糖尿病(n=2)或術中發生併發症者如後囊破裂(n=1)則另外予以分類。術前及術後各時段觀察角膜水腫程度、眼前房混濁程度、眼壓，並比較術前及術後的差異。術後第1、2、4、8週以裂隙燈拍攝後囊混濁影像，以臨床判定及OSCA評分系統評分後囊混濁分數以比較撕除後囊、放置人工水晶體、糖尿病及後囊破裂所造成之差異。結果，施行環形後囊撕除術組術後的後囊混濁程度與控制組無顯著差異(p > 0.05)；有放置人工水晶體組術後第四週之後，後囊混濁程度持續上升有較未放置人工水晶體組嚴重的趨勢，但未達到顯著差異(p > 0.05)；臨床評分部分的術後各時段，糖尿病組有大於控制組的趨勢，但未達顯著差異(p > 0.05)；後囊破裂犬隻的後囊混濁較無後囊破裂者有較輕微的趨勢，但兩組間無顯著差異(p > 0.05)，後囊破裂犬隻後囊混濁皆以周邊為主，中心處幾乎沒有白化現象。總結而言，於犬隻單獨施行連續環形後囊撕除術無法達到完全預防後囊混濁的目的；人工水晶體的放置僅能在術後兩週內達到延緩後囊混濁的發展；糖尿病犬隻後囊混濁有較嚴重的趨勢；後囊破裂犬隻其後囊混濁僅發生於周邊區，中心區無後囊白化現象。|
Cataract is the most frequent intraocular disease and a leading cause of unilateral and more often bilateral blindness in dogs. The most and only effective treatment is surgery-extraction of diseased lens. In veterinary medicine, the method of choice in most cases is phacoemulsification and intraocular lens (IOL) implantation. However, posterior capsular opacification (PCO) is by far the most common complication following phacoemulsification and IOL implantation with the incidence of 69-100 %. PCO can decrease the visual acuity and loss of contrast sensitivity. Primary posterior continuous curvilinear capsulorhexis (PCCC) is performed to prevent this complication in human beings. Up to now, there has no any statistical report about PCCC in veterinary medicine. The aim of this study is to evaluate the efficacy of PCCC on the severity of posterior capsular opacification in dogs.
15 eyes from 12 dogs undergoing phacoemulsification cataract surgery at veterinary medical teaching hospital, National Chung Hsing University were included in this study. The subjects were randomly divided into the PCCC group (n=3) and the no PCCC group (n=7), after excluding dogs with lens luxation, opacification of vitreous, or other systemic diseases. Eyes with lens luxation were included in the group of no PCCC and no IOL (n=2). Diabetic dogs (n=2) and dogs with intraoperative complications, including rupture of posterior capsule (n=1), were defined as new groups. At all time points, including corneal edema score, flare score, and intraocular pressure were measured for each eye. Baseline values after operation were compared with the values prior to the surgery. PCO was assessed using slit lamp biomicroscopy photographs taken after maximum pupil dilation. The PCO score was quantified using PCO grading scale and the open-access systematic capsule assessment (OSCA) system at the 1, 2, 4, and 8 weeks follow-up. No significant PCO score difference between the PCCC group and no PCCC group (p > 0.05) was observed. The IOL group developed more PCO in comparison to the no IOL group at 4-8 weeks postoperatively, but the differences were not significant (p > 0.05). There was an increase in PCO formation in the diabetic group when compared to the control group, but the differences were not significant (p > 0.05). In the rupture of posterior capsule group, the PCO formation was reduced within the central region when compared to the no PCCC and no IOL group, but the differences of PCO score were not significant (p > 0.05).
Current results of the study indicate that a PCCC alone does not significantly influence the overall and central posterior capsular opacification formation in dogs. The implantation of the IOL can delay PCO formation within 2 weeks postoperatively. The PCO score is higher in diabetic dogs. In the rupture of posterior capsule group, the PCO formation was reduced within the central region.