Presence of alpha smooth muscle actin in lens epithelial cells of aphakic rabbit eyes.

Abstract

Aims-To determine whether a smooth muscle actin (a-SMA), a marker for myofibroblastic cells, is present in lens epithelial cells (LECs) in rabbit aphakic eyes. Methods-Phacoemulsification was performed in rabbit eyes, which were enucleated after surgery. Immunohistochemical methods were used to detect a-SMA in LECs.Results-Five days after surgery, the presence of a-SMA positive LECs was observed mainly around the adhesive portion of the anterior capsule margin and the posterior capsule. The posterior capsule was wrinkled at the adhesive portion. The a-SMA positive LECs were flattened with spindle-shaped cross sections. Seven days after surgery, the a-SMA positive LECs covered most ofthe central posterior capsule. They disappeared 10 days after surgery. On the other hand, the cuboidal LECs in the capsular bag were negative for a-SMA. Conclusion-The flattened LECs with spindle-shaped cross sections observed S days after cataract surgery contained a-SMA. Such LECs were distinguished biochemically from the cuboidal LECs, which lacked a-SMA. (BrJ Ophthalmol 1996;80:906-910)

Effect of Rabbit Aqueous Humor Obtained after Cataract Surgery on Collagen Gel Contraction Induced by Bovine Lens Epithelial Cells

“…After cataract surgery, the LECs that cover the inner surface of the anterior capsule except its margin exhibit a normal cuboidal appearance, while those on the posterior capsule gradually become differentiated [6,15]. These LECs do not produce capsular contraction.…”

“…The capsular contraction that follows cataract surgery occurs mainly around the margin of the anterior capsule. The LECs around the margin of the anterior capsule resemble myofibroblasts and show contractility [6,16,17]. When the anterior capsule of the rabbit [18] and rat [19,20] lens is ruptured by the Nd:YAG laser, some of the LECs around the ruptured capsule proliferate and change into myofibroblast-like cells that contribute to wound closure [18][19][20].…”

“…Specimens of aqueous humor were aspirated at the limbus with a 27-gauge needle. Following aspiration, they underwent bilateral cataract surgery using the previously described method with slight modifications [6]. In brief, an incision was made in the superior cornea and continuous circular capsulorhexis was performed.…”

“…This capsular contraction is a direct cause of visual disturbances [1], as well as being responsible for such postoperative complications as decentration of the implanted intraocular lens (IOL) [2], narrowing of the anterior capsular opening [2,3], retinal detachment [4], and postoperative hypotony [5]. Capsular contraction occurs early after cataract surgery, being noted in rabbit eyes by the 5th postoperative day [6].…”

Tavşanlarda kapsül germe halkası (KGH)’nın ve/veya intraokuler lens (İOL)’in posterior kapsüller opasifikasyona (PKO) etkisinin değerlendirilmesi

“…Lois ve ark., Çalışmada dikkati çeken bir başka bulgu da lens kapsüllerinde karşılaşılan büzüşme ve katlanmalar olmuştur. Bu konuda önceden yapılan birkaç çalışmada da lens kapsülünde postkapsüller opasifikasyonla birlikte katlanmalar olduğu bildirilmiştir (5,7,8). Çalışmada da karşılaşılan bu tip morfolojik değişiklikler literatür verileriyle uyumlu bulunmuş ve bunların özellikle bağ doku proliferasyonlarından kaynaklanabileceği düşünül-müştür.…”