Tower microneedle minimizes vitreal reflux in intravitreal injection

Chang Yeol Lee, Yong Sung You, Sung Ho Lee, Hyungil Jung

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


Intravitreal injection is widely used for easy control of drug levels in posterior segment of the eye by injecting the drug directly with hypodermic needles. Patients, however, often experience complications from intravitreal injection due to repeated injections, increased intraocular pressure, and infection. In addition, injected drug reflux after intravitreal injection makes it challenging to maintain predetermined drug dose due to the drug loss through backward effusions. Here, we described that the Tower Microneedle can reduce initial reflux and bleb formation due to its smaller outer diameter compared to a traditional hypodermic needle. Furthermore, we use phenylephrine hydrochloride for pupil expansion and demonstrated that Tower Microneedle induced similar pupil expansions using only half the drug volume, in the same period of time, compared to the 31 Gauge hypodermic needle. Consequently, Tower Microneedle achieves the same therapeutic effect in the vitreous body using fewer drugs than a traditional hypodermic needle due to the decreased backward drug effusion. Tower Microneedle described herein holds great promise for intravitreal injection with less reflux and lower drug dosage.

Original languageEnglish
Pages (from-to)841-848
Number of pages8
JournalBiomedical Microdevices
Issue number5
Publication statusPublished - 2013 Oct

Bibliographical note

Funding Information:
Acknowledgements This study was supported by a grant of the Korean Health Technology R&D Project, Ministry for Health, Welfare, Republic of Korea (A102003) and the Public Welfare & Safety Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0020772). We would like to gratefully thank to Young Dook Byeon and INCYTO for their support.

All Science Journal Classification (ASJC) codes

  • Biomedical Engineering
  • Molecular Biology


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