Experimental study of a drainage made of nitinol

One of the relevant tasks in glaucoma treatment is development of a drainage implant (microstent) and a technique for its implantation during minimally invasive surgery with the aim of forming a channel for aqueous humor outflow to maintain patients’ intraocular pressure level within the tolerable range.

We proposed a novel microstent for minimally invasive glaucoma surgery consisting of a drainage tube in the form of a self-expanding frame with dimensions significantly lower than similar devices used in clinical practice. The purpose of this work was to study the safety of the microstent made of nitinol when implanted in the eyes of experimental animals.

The study included 10 grey Chinchilla rabbits divided into two groups. The drainage implant was installed into one eye of an animal, while its second eye was used as control for evaluation of the effectiveness and safety of the microstent. The difference between the groups was conjunctival access; in the second group implantation was done through punctures, moving the knife towards the limbus area.

No inflammatory reactions were observed in cases with implantation of the stent under the conjunctiva and the limbal area. Biomicroscopy showed no differences between animal eyes. No local irritation was found according to morphological criteria.

Microstenting is a promising glaucoma treatment approach, and the present study shows prospects for its continued development and modification of the drainage implant and its delivery system.

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