tailieunhanh - Cataract and Refractive Surgery (part 6)

Các mục tiêu chung là giảm mức năng lượng cho việc cắt giảm lamellar và bên, và giảm vị trí và phân tách dòng. Năng lượng tại chỗ và bên cắt giảm nên được giảm cho đến khi nâng nắp gặp phải sức đề kháng quá mức. | 86 The Femtosecond Laser a New Tool for Refractive and Corneal Surgery 7 Fig. Stromal interface following flap creation with the femtosecond laser. a demonstrates a smoother stromal interface produced with a spot energy of mJ a spot separation of 11 mm and a line sepa- ration of 9 mm. b shows a rougher stromal interface when the spot energy is raised to mJ while the spot and line separations are unchanged. ence with each laser accrues the parameters can be refined to optimize the intraoperative performance of each system as well as the postoperative surgical results. General goals are to decrease energy levels for the lamellar and side cuts and to reduce the spot and line separations. The spot and side cut energies should be reduced until flap lifting encounters excessive resistance. Spot separations can be decreased until the procedure length becomes prohibitively long. Adequate adjustment of these parameters will eliminate postoperative inflammation and minimize resistance to flap lifting while maintaining a smooth ablation surface Fig. . while the surgeon supports the suction ring. As the lens assembly is lowered onto the cornea the area of contact between the lens and corneal surface can be viewed on the laser s video monitor. Centration is maintained with the joystick as the applanated surface area increases until it fills the entire suction ring. When adequate applanation is achieved a green light on the video monitor notifies the surgeon. To complete the docking procedure the surgeon releases the clip on the suction ring which reduces its inner diameter causing it to firmly grip the applanation lens. Further refinements in docking can be achieved by squeezing the suction ring to release its grip Surgical Technique During LASIK flap creation globe stability is achieved using a disposable suction ring attached to a spring-loaded syringe. The system results in relatively low intraocular pressures during flap creation approximately 35 .