Air Bubbles at the Tip of an Endolaser Probe during Microincision Vitrectomy Surgery

Objective: To investigate possible factors that could cause air bubbles at the tip of an endolaser probe and to describe a technique to remove air bubbles during microincision vitrectomy surgery (MIVS). Methods: Thirty patients (30 eyes) had 23-gauge MIVS, and endolaser photocoagulation with an endolaser probe was performed to complete panretinal photocoagulation. The primary outcome measure was the frequency for the incidence of air bubbles. In addition, experiments were performed in a bottle filled with a balanced salt solution (BSS) to evaluate possible contributing factors. Results: The frequency for the incidence of air bubbles was 3.8 ± 2.1 times/500 shots. In the bottle filled with BSS, at 59°F, the mean frequency of air bubbles from ethylene oxide-sterilized endolaser probes (2.8 ± 1.5 times per 500 shots) was significantly higher than that from new probes (0.8 ± 0.8 times per 500 shots) (Mann-Whitney Utest, P=0.032). The result was related to neither the temperature of the BSS nor the use of illumination from the illuminated endolaser (P>0.05, respectively). The air bubbles were removed by slapping the tip of the endolaser probe on the illuminator or by taking the endolaser probe out of the trocar. Conclusion: The incidence of air bubbles arising from the tip of the endolaser probe was related to the use of an ethylene oxide-sterilized endolaser probe. The effective removal of these air bubbles can be achieved by slapping the tip of the endolaser probe on the illuminator or taking the endolaser probe out of the trocar.