Purpose: To report the development and clinical findings of a universal trans-punctal lacrimal microendoscope design.
Methods: In this study, we examined a unique and original "2-bend" (i.e., double-angle) rigid lacrimal microendoscope designed for universal applications for anatomical variations. The shape of endoscope was initially evaluated in 6 lacrimal systems of cadavers (4 Caucasian-cadaver lacrimal systems and 2 Asian-cadaver lacrimal systems). Second, a prospective clinical study involving 45 consecutive cases of nasolacrimal duct obstruction in Japanese patients was conducted to compare the facility and ease of use between the conventional single-bend type and our original 2-bend type trans-punctal lacrimal microendoscope for examination of the lacrimal drainage system.
Results: The findings in the cadaver study revealed that original 2-bend lacrimal microendoscope, which was designed double-angled 20°-30° at 10 and 30 mm from the tip of the scope, could more easily used to insert and image all lacrimal systems, while the conventional single-bent lacrimal microendoscope was difficult to insert in subset of patients with a prominent nasal process of the frontal bone. In the clinical trial, our findings showed that 26.7% of lacrimal systems could not be passed using the conventional single-bend design, while using the 2-bend design, all cases could successfully be investigated.
Conclusions: The original 2-bend-design microendoscope was found to be effective and valuable for universal use in examination and evaluation of the lacrimal passage.