Comparison of INTREPID® balanced and hybrid tips on anterior capsule rupture in ex vivo porcine eyes.

Phacoemulsification has emerged as the global standard for cataract surgery, and various novel methods, tools, and agents have promoted surgical efficiency and reduced complications. Conventionally, the phaco tip, which cleaves and aspirates the cataractous lens, has been mainly constructed of metal. In this study, the risk of anterior capsule rupture was evaluated under conditions of different power modes, longitudinal (Mode-L), torsional (Mode-T), or both (Mode-LT), and different aspiration powers (0 or 200 mmHg), using a traditional metal phaco tip (Group-M) or a new phaco tip with a high-strength polymer overmold on the needle edge (Group-P), which was developed to reduce the risk of capsule rupture. One hundred twenty porcine eyes were used for experiments within a setting of typical human physiological intraocular pressure. We found that Group-M showed capsule rupture with a smaller ultrasound power than did Group-P, regardless of power mode or aspiration power. In Group-M, there was no significant difference in risk of capsule rupture among power modes, however in Group-P, capsule rupture was least likely to occur with Mode-T. These results provide useful information for inexperienced ophthalmologists to improve surgical safety.

Microscopic Ophthalmic Surgery Using a Freely Movable Arm Support Robot: Basic Experiment and Clinical Experience.

INTRODUCTION: The disadvantage of conventional armrests is the difficulty to adjust their height and position during surgery. OBJECTIVES: We investigated whether a freely movable armrest (FMA) that follows the surgeon's arm is useful for reducing surgeon fatigue and arm tremors and for improving surgical accuracy. METHODS: In the basic study, a corneal suture was placed in porcine eyes with FMA (FMA group) or without FMA (non-FMA group). The suture was intended to pass through two points. Tremor was quantified using motion-tracking software when the needle was held. Subjective symptoms of arm-related fatigue were scored using a questionnaire. Suturing accuracy was compared between the groups. In the clinical study, the same surgeon performed corneal transplantation, cataract surgery, and glaucoma surgery with or without FMA. Fatigue scores from the questionnaire were then compared. RESULTS: In the basic study, hand tremor at rest was significantly improved with FMA (p < 0.0001). The subjective arm fatigue score was significantly reduced (p = 0.0465), while the subjective tremor score was also significantly improved (p = 0.0453). There were no differences in the accuracy of corneal suturing with or without FMA. In the clinical study, the total and arm-related fatigue scores during corneal transplantation and glaucoma surgery tended to improve. CONCLUSIONS: FMA is a useful tool for fixing the surgeon's arm in any position and may improve the quality of ophthalmic surgery by reducing hand tremor and fatigue.