Ab Interno Approach to Subconjunctival Space: First 567 Eyes Treated With New Minimally Invasive Gel Stent for Treating Glaucoma
To describe the initial 36 month results from a novel, soft and permanent, minimally invasive ab interno collagen implant used to optimize aqueous drainage to the subconjunctival space. Mean IOP, IOP change, reduction in medications, and conversions were recorded in 567 subjects, of which some have reached 36 months postop.
In this prospective, non-randomized, multi-center evaluation conducted in 13 countries with over 40 investigators, more than 500 eyes were implanted with a XEN gel stent and followed up to 36 months. During surgery, a trans-scleral gelatin stent is placed through a self-sealing corneal incision using a preloaded injector. All patients had mild, moderate, severe or refractory OAG, and 54% were solo procedures, and 46% were combined with cataract surgery. Data includes all eyes since first in human, and product development cycle included in this data set incorporates 3 inner lumen sizes of the same gel stent (140, 63, 45 um).
Mean preoperative (best-medicated) IOP for all eyes was 21.9 ± 4.2 mmHg. The mean postoperative IOPs were: 15.7 at 12 months (-29% reduction; n=175), 15.0 at 24 months (-32% reduction; n=68), and 13.2 at 36 Months (-40% reduction; n=28). At 12 months anti-glaucomatous medications were reduced by 74% from the preoperative mean of 2.7 (patients not washed out pre-surgery), by 77% at 24 months, and by 74% at 36 months. Although follow up continues, to date 23 or 4% were converted to another procedure at 12 months, 27 or 5% at 24 months, and 30 or 5% at 36 months. The results of solo and combined procedures were not significantly different.
Clinically proven subconjunctival aqueous drainage pathway combined with the minimally-invasive conjunctiva sparing approach of this new and broadly adoptable implant procedure provides a safe and effective approach to controlling IOP and reducing medications in patients with glaucoma.