染料激光光斑变换模式与光凝效果的关系

以齐焦点式（ｐａｒｆｏｃａｌｔｙｐｅ）及散焦点式（ｄｅｆｏｃａｌｔｙｐｅ）染料激光的四种波长（５７７、５９０、６１０、６３０ｎｍ）分别对有色家兔视网膜及虹膜进行中等能量光凝固，然后用光学显微镜及扫描电镜观察各波长光凝组织的凝固反应，发现在相同光凝条件下，齐焦点式染料激光的光凝组织反应具有波长特性，而散焦点式染料激光则波长特性很不明显，提示照射光斑大小的变换模式不同可造成组织光凝效果的明显差异。本文就这种差异在眼组织激光治疗中的临床意义及中心过度光凝现象（ｈｏｔｓｐｏｔ）的原因进行了初步探讨。

The Relationship between Photospot Size Variation Modality of Dye Laser and Effect of Photocoagulation

The retena and iris of colored rabbits were photocoagulated by dye laser of parfocal type or defocal type with moderate amount of energy,the wavelength of which being 577,590,610 and 630nm. The effectof photocoagulation on these tissues were observed by photomicroscope and scanning electron microscope. The results showed that under the same photocoagulation condition, the photocoagulated reaction of these tissues by parfocal type dye laser had wavelength characteristics,but those of defocal type were not appar - ent . It was indicated that different photospot size vanation modality would result in significant differenceof the effect of photocoagulation. The clinical significanee of this difference in the laser therapy of eye tis-sues and the reasons of central hot spot phenomenon were preliminarily investigated.