The Dry Eye Zone

Rebecca's Blog

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Study: Long-acting liposomal corneal anaesthetics

I know that corneal pain patients won't need any extra encouragement to click on this link! This is such a hot button in the dry eye world right now... pain, corneal pain, corneal neuropathic pain, corneal neuralgia, question marks about whether your pain is from dryness or not, questions about whether you really ought to be using all those pain meds, so many questions. It's a hard place to be and we need all the promising news we can get, especially about research work being done that might result in something SAFE and EFFECTIVE to help people improve their quality of life.

Anyway, this one caught my eye....

The big question of course is, we all know anesthetizing the cornea is dangerous because pain signals are the key way we keep our eyes safe from 'assault'. Nothing about that in this abstract, just too early I suppose. Keen to see what they come up with down the road.

Biomaterials. 2018 Aug 9;181:372-377. doi: 10.1016/j.biomaterials.2018.07.054.
Long-acting liposomal corneal anesthetics.
Zhan C, Santamaria CM, Wang W, McAlvin JB, Kohane DS.

Abstract
Eye drops producing long-acting ocular anesthesia would be desirable for corneal pain management. Here we present liposome-based formulations to achieve very long ocular anesthetic effect after a single eye drop instillation. The liposomes were functionalized with succinyl-Concanavalin A (sConA-Lip), which can bind corneal glycan moieties, to significantly prolong the dwell time of liposomes on the cornea. sConA-Lip were loaded with tetrodotoxin and dexmedetomidine (sConA-Lip/TD), and provided sustained release for both. A single topical instillation of sConA-Lip/TD on the cornea could achieve 105 min of complete analgesia and 608 min of partial analgesia, which was significantly longer than analgesia with proparacaine, tetrodotoxin/dexmedetomidine solution or unmodified liposomes containing tetrodotoxin and dexmedetomidine. sConA-Lip/TD were not cytotoxic in vitro to human corneal limbal epithelial cells or corneal keratocytes. Topical administration of sConA-Lip/TD provided prolonged corneal anesthesia without delaying corneal wound healing. Such a formulation may be useful for the management of acute surgical and nonsurgical corneal pain, or for treatment of other ocular surface diseases.