Abstract
Abstract: :
Purpose: To study the use of micro–probes through 1.0 mm corneal incisions in laser photolysis cataract extraction. Background: Laser photolysis cataract extraction makes use of a bimanual surgical technique; separation of the laser photolysis probe from the irrigation hand–piece allows nuclear emulsification via two small corneal incisions. Previously, 1.4 mm paracentesis ports were required. However, recent development of a micro–probe has allowed for cataract removal via two 1.0 mm incisions. The goal of this study was to determine the energy needed to perform photolysis using the micro–probes. Methods: Data was collected from surgical patients who underwent laser photolysis cataract extraction by a single surgeon during two different sessions. In one session, the larger probes were used via 1.4 mm corneal incisions, and in the other, small probes were introduced via 1.0 mm incisions. Data collected included number of laser shots used during photolysis. Statistical analysis was performed using the student’s t–test. Results: 10 patients underwent laser photolysis in each group. The average number of laser shots used with the micro–probe was 88 (st dev 37), and the average number of laser shots used with the larger probe was 42 (st dev 18). This difference reached statistical significance as calculated using the student’s t–test (p=0.003). The maximum energy delivered per laser pulse is 10 mJ; therefore the average energy delivered using the micro–probe was roughly twice as much (8.8 J) as that delivered using the larger probe (4.2 J). Conclusions: The development of the laser photolysis micro–probe allows cataract extraction to now be performed via two 1.0 mm corneal incisions. The surgical advantages of these smaller instruments include less wound leakage and better anterior chamber stability. Other advantages include the diminished risk of infection and surgically–induced astigmatism. This study shows that the amount of laser energy needed is significantly higher using the micro–probes versus the traditional laser probes. However, the amount of total energy used still remains well below that needed for ultrasound phacoemulsification.
Keywords: cataract • laser