The key to success was selecting the right candidates for the initial learning curve. The stent’s indications outline the patients and situations for which the device is approved, but first cases require a bit more selectivity for any new procedure.
The ideal first patient has an eye matching one’s dominant hand (the right eye, in most cases). I looked for patients who were pseudophakic and did not require a combined phacoemulsification procedure. Their coagulation state had to be normal. The angles were all grade IV without peripheral anterior synechiae (PAS) in the superior quadrant. I also wanted patients with prominent eyes and low cheekbones.
My first few cases went well. I gave the patients a peribulbar block to make the procedure easier, but I now do most cases under topical anesthesia. I gave the patients 20 to 40 mcg of mitomycin C (MMC) in the preoperative holding area, injecting the MMC under the posterior subconjunctival space at 12 o’clock and “rolling” the medication into the superior nasal quadrant. The implant is best placed when 1 mm is in the anterior chamber, 2 mm in the intrascleral space, and 3 mm in the subconjunctival space.
The initial thought was that the implant could be placed in the superior nasal angle without the assistance of a gonioprism. While this makes the procedure slightly easier initially, I found that I was not routinely injecting the implant exactly where I wanted it to be in the angle. Sometimes I was anterior to the trabecular meshwork (TM), sometimes I was through the TM, and sometimes I was posterior to the TM.
Now, I place the implant with the help of a gonioprism and feel that I am placing the stent more routinely just anterior to the TM (the ideal position in my mind).