Ab Interno Canaloplasty in Open-angle Glaucoma Patients Combined With In Vivo Trypan Blue Aqueous Venography.

PURPOSE: To demonstrate canalogram patterns observed when trypan blue tracer is combined with oculoviscoelastic device during ab interno canaloplasty, and discuss surgical results and potential implications for diagnosis, prognosis, and treatment. METHODS: This is a retrospective small case series study. RESULTS: The authors performed this procedure on 5 patients with informed consent with 4 to 18 months of follow-up. All procedures have been complication free. The average preoperative intraocular pressure was 16.4 mm Hg with an average number of topical glaucoma medications being equal to 3.6. Postoperatively, the average intraocular pressure for the group was reduced to 13 mm Hg with a concurrent drop in the average number of topical medications used equaling 1.8. CONCLUSIONS: Currently, there are limited practical options to evaluate the patency of the aqueous outflow system in our patients. The primary purpose of this paper is to describe canalogram patterns observed during ab interno canaloplasty with trypan blue. This technique may allow us to further our understanding of the aqueous outflow system and its role in the underlying pathophysiology of glaucoma. Further research is required to evaluate the prognostic and diagnostic significance of this technique.

K-RIM (Corneal Rim) Angle Surgery Training Model.

PURPOSE: To develop an angle surgery training model for training an array of microincisional glaucoma surgery (MIGS) procedures. METHODS: We describe a method for preparing an angle surgery training model using human cadaveric corneoscleral rims. The model provides realistic tactile tissue simulation and excellent angle visualization requiring bimanual technique. Corneoscleral rims may be used multiple times and are prepared at low cost, allowing for a high volume of practice surgeries. RESULTS: This model allows for practice in bimanual surgical training using the gonioscopy lens for visualize alongside surgical tools. The in vivo surgical conditions and limited tactile feedback are recreated using human cadaveric eyes which nonhuman models fail to provide. Our model is prepared at low cost, with relative ease and also provides appropriate positioning of Schlemm canal and for high volume of practice as the canal can be used in 90-degree segments. CONCLUSIONS: Few angle surgery training models currently exist and none provide these necessary features. The model presented here aims to meet the growing demand for adequate training models required for technically advanced MIGS techniques.

Cadaver corneoscleral model for angle surgery training.

PURPOSE: To assess a new training model (Tackdriver) for new-generation microinvasive glaucoma surgeries (MIGS). SETTING: Resident training centers in Canada. DESIGN: Evaluation of technology. METHODS: Human cadaver corneoscleral rims recovered after Descemet-stripping endothelial keratoplasty or not suitable for transplantation were acquired from an eye bank. The tissue was fixated with a single tack through the center of the cornea, which was inverted in a concave fashion. A water-based medical lubricant was used for placement of a goniolens after visualization of the anterior chamber and the trabecular meshwork. Microbypass stent (iStent) insertion and gonioscopy-assisted transluminal trabeculotomy (GATT) were practiced on this model. The model was qualitatively assessed for ease of preparation, accuracy of surgical simulation, and the number and variety of MIGS procedures that can be performed. RESULTS: Efficient high-volume training was performed for microbypass stent insertion using first-generation and second-generation microbypass stents. The GATT procedure was also performed as a final step in a titratable fashion in 90-, 180-, or 270-degree segments or a complete 360-degree treatment. The model simulated bimanual angle surgery with good fidelity. CONCLUSIONS: The training model allowed for high-volume bimanual MIGS training for techniques such as microbypass stent insertion and removal as well as GATT. Preparation was relatively simple, efficient, and cost-effective compared with other models. Inverting the specimen allowed the trainee to practice MIGS techniques independent of the tissue's corneal clarity. Other MIGS techniques and angle training procedures can be adopted to this model.