Aventuro J A, Gaasterland D E, Buzawa D
University of Ophthalmic Consultants of Washington, DC 20016, USA.
J Glaucoma. 1998 Oct;7(5):349-52.
Contact fiberoptic laser transscleral cyclophotocoagulation (TSCPC) is an aqueous inflow-reducing surgical treatment for glaucoma. One delivery device uses a 600-microm diameter quartz glass fiberoptic with a hemispheric tip. A larger fiberoptic diameter would reduce fluence through conjunctiva and sclera. This study determined the relation of fiberoptic to ciliary body burn diameters after TSCPC with the IRIS Medical SLx diode laser system in human autopsy eyes.
Laser energy was applied with two models of delivery probe that were identical except for fiberoptic diameter (600 or 800 microm). Both had hemispheric tips, each with the hemisphere radius equal to the radius of the fiberoptic. Six fresh human autopsy eyes (three pairs) were used, each receiving eight diode laser applications at 1.75 (2 eyes) or 2.0 (4 eyes) watts for 2.5 seconds-four applications per eye with the 600-microm fiberoptic and four with the 800-microm fiberoptic. Eyes were fixed in 10% formalin then opened coronally at the equator. Inner surface burn diameters were measured parallel and perpendicular to the limbus using calipers and an operating microscope at 10x magnification.
Ciliary body burns with the 600- and 800-microm fiberoptic tips had nearly the same average diameter, range of diameter, average area, and range of areas.
The 800-microm fiber, which has a 78% larger cross-sectional area than a 600-microm fiber, reduces fluence through ocular surface tissue during diode laser TSCPC, theoretically decreasing the risk of surface bums. In this study, the larger fiber gives essentially the same size ciliary body coagulation as obtained with the 600-microm fiberoptic. This suggests that the larger fiberoptic, compared with the standard 600-microm fiberoptic, will be more safe yet equally effective for TSCPC.
接触式光纤激光经巩膜睫状体光凝术（TSCPC）是一种减少房水生成的青光眼手术治疗方法。一种输送装置使用直径为600微米的石英玻璃光纤，其尖端为半球形。较大的光纤直径会降低通过结膜和巩膜的能量密度。本研究确定了在人体尸眼上使用IRIS Medical SLx二极管激光系统进行TSCPC后，光纤直径与睫状体烧灼直径之间的关系。
使用两种输送探头模型施加激光能量，这两种探头除光纤直径（600或800微米）外完全相同。两者均具有半球形尖端，每个半球的半径等于光纤的半径。使用六只新鲜的人体尸眼（三对），每只眼睛以1.75瓦（2只眼）或2.0瓦（4只眼）的功率接受八次二极管激光照射，持续2.5秒——每只眼睛用600微米光纤照射四次，用800微米光纤照射四次。将眼睛固定在10%的福尔马林中，然后在赤道处冠状切开。使用卡尺和10倍放大倍数的手术显微镜，在与角膜缘平行和垂直的方向上测量内表面烧灼直径。
600微米和800微米光纤尖端的睫状体烧灼平均直径、直径范围、平均面积和面积范围几乎相同。
800微米光纤的横截面积比600微米光纤大78%，在二极管激光TSCPC过程中可降低通过眼表组织的能量密度，理论上降低了表面灼伤的风险。在本研究中，较大的光纤产生的睫状体凝固大小与600微米光纤基本相同。这表明，与标准的600微米光纤相比，较大的光纤在TSCPC中更安全且同样有效。
