Laser Activated Flow Regulator for Glaucoma Drainage Devices

Olson, Jeffrey L.; Vélez-Montoya, Raúl; Bhandari, Ramanath

doi:10.1167/tvst.3.6.3

Cited by 7 publications

(4 citation statements)

References 31 publications

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“…Pig eyes have a relatively thick TM as well as Schlemm’s canal like segments, termed the angular aqueous plexus 32 , instead of a single lumen. They have been used to train cataract 33 and glaucoma surgeons in goniotomy 34 , trabeculectomy 12 , 35 , deep sclerectomy 36 , 37 , and tube shunt implantation 38 , but without a scoring system. Fresh pig eyes obtained from an abattoir have the additional advantages of a clear cornea and absence of human pathogens.…”

Section: Discussionmentioning

confidence: 99%

Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery

Dang

Waxman

Wang

et al. 2017

Sci Rep

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Increasing prevalence and cost of glaucoma have increased the demand for surgeons well trained in newer, microincisional surgery. These procedures occur in a highly confined space, making them difficult to learn by observation or assistance alone as is currently done. We hypothesized that our ex vivo outflow model is sensitive enough to allow computing individual learning curves to quantify progress and refine techniques. Seven trainees performed nine trabectome-mediated ab interno trabeculectomies in pig eyes (n = 63). An expert surgeon rated the procedure using an Operating Room Score (ORS). The extent of outflow beds accessed was measured with canalograms. Data was fitted using mixed effect models. ORS reached a half-maximum on an asymptote after only 2.5 eyes. Surgical time decreased by 1.4 minutes per eye in a linear fashion. The ablation arc followed an asymptotic function with a half-maximum inflection point after 5.3 eyes. Canalograms revealed that this progress did not correlate well with improvement in outflow, suggesting instead that about 30 eyes are needed for true mastery. This inexpensive pig eye model provides a safe and effective microsurgical training model and allows objective quantification of outcomes for the first time.

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Section: Discussionmentioning

confidence: 99%

Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery

Dang

Waxman

Wang

et al. 2017

Sci Rep

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“…An inexpensive training model system would be highly desirable to prepare novice surgeons and reduce the risk of complications. Pig eyes have been used before to train cataract 42 and glaucoma surgeons in goniotomy, 43 trabeculectomy, 12,44 deep sclerectomy, 45,46 and tube shunt implantation, 47 but without a scoring system. Fresh pig eyes obtained from an abattoir have the additional advantages of a clear cornea and absence of human pathogens.…”

Section: Discussionmentioning

confidence: 99%

Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery

Dang

Waxman

Wang

et al. 2017

Preprint

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Abstractplaced the eyes on a tiltable mannequin head, visualized the trabecular meshwork 23 gonioscopically through an ophthalmic microscope, and removed it by trabectome-mediated 24ablation. An expert surgeon observed, guided, and rated the procedure using an Operating 25 Room Score (ORS). The extent of accessed outflow beds was estimated with canalograms using 26 fluorescent microspheres. Data was fit using mixed effect models.

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“…10 Current commercially available shunts typically use a silicone tube with an outer diameter of 0.64 mm (23 G) and an inner diameter of 0.34 mm (30 G). Herein, we describe a second generation device with an increased lumen size: the large lumen glaucoma drainage device (LL-GDD), which has an outer diameter of 0.72 mm (22 G) and an internal diameter of 0.5 mm.…”

Section: Introductionmentioning

confidence: 99%

“…We have demonstrated in previous studies that the membrane reduces, but does not totally restrict flow when completely intact. 10 This is advantageous as it allows immediate IOP control, as well as keeping aqueous flowing through the device to prevent blockage or failure of the GDD and to prevent infection. The goals of this proof-of-concept study were to: (1) demonstrate surgical implantation; (2) prevent immediate postoperative hypotony; (3) increase flow on-demand post implantation; (4) compare flow rates to conventional drainage devices.…”

Section: Introductionmentioning

confidence: 99%

Design and performance of a large lumen glaucoma drainage device

Olson

Groman-Lupa

2016

Eye

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Purpose We report the in vivo testing of a large-lumen glaucoma drainage (LL-GDD) device equipped with a flow regulator. The device's membrane can be non-invasively opened with laser in the postoperative period to adjust aqueous flow and intraocular pressure. Methods The initial LL-GDD prototypes were constructed using 22 G silicone angiocatheters cut down to size. A 10 nm PVDF membrane was then affixed to the end using cyanoacrylate. The LL-GDD was tested first in a model eye equipped with ports for infusion and pressure measurement and in New Zealand rabbits. Results New Zealand white satin cross rabbits were used, two eyes receiving the LL-GDD and the two fellow eyes serving as the control group with no intervention performed. After the procedure, the IOP in the LL-GGD surgical group dropped an average of 5.5 mm Hg (P = 0.001), which was maintained until the membrane laser procedure at week 5 resulting in an average IOP reduction of 1.8 mm Hg. At week 7, the average IOP in the surgical group was 11 mm Hg compared with 18 mm Hg in the control group (Po0.001). A second laser procedure was done to completely open the membrane face, which resulted in an immediate drop in the average IOP of the surgical group by another 2.7 mm Hg, which was maintained until the study termination at day 55. Conclusions The large-lumen glaucoma drainage device demonstrated an ability both to prevent immediate postoperative hypotony and to allow progressively lower IOP on demand in this proof-of-concept study.

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Laser Activated Flow Regulator for Glaucoma Drainage Devices

Abstract: Initial results and evidence from this experiment will justify the initiation of in vivo animal trials with the glaucoma drainage device regulator; which brings us closer to possible human trials and the chance to significantly improve the existing technology to treat glaucoma surgically.

Cited by 7 publications

References 31 publications

Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery

Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery

Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery

Design and performance of a large lumen glaucoma drainage device

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