Sometimes you have a plan for a patient, and sometimes the patient has a plan for you.
We recently saw a 66-year-old woman with moderate primary open-angle glaucoma in the right eye and early primary open-angle glaucoma in the left eye. The patient came into our office requesting, by name, the iStent Trabecular Micro-Bypass Stent System (Glaukos).
Upon presentation, she had an average IOP of 17 mm Hg OU, with pressure spikes to the mid 20s mm Hg. She had high myopia and bilateral visually significant nuclear sclerotic cataracts. Mean central corneal thickness was in the 530s µm OU. The patient had previously undergone multiple selective laser trabeculoplasty procedures over 6 years, with two rounds of treatment in the right eye and one round of treatment in the left eye. She was using latanoprost once daily in both eyes, and she wanted to decrease her eye drop burden at the time of cataract surgery.
To control this patient’s glaucoma, we discussed placing an iStent in the eye with less severe disease (left eye) and a Hydrus Microstent (Ivantis) in the eye with more severe disease (right eye). Although now available,1 randomized controlled trial data comparing the Hydrus and iStent devices were not available at the time of treatment. In the absence of head-to-head data, this decision was made based on prior surgical experience with each device and the sense that the larger stenting extent of the Hydrus implant was more likely to result in a lower IOP, which was the goal for the more severely impacted eye.
A ‘NONINFERIORITY TRIAL’ (N = 1)
The patient underwent cataract surgery with iStent placement in the left eye, followed 2 weeks later by cataract surgery with Hydrus placement in the right eye. IOP was 17 mm Hg OS at postoperative week 5 and 13 mm Hg OD at postoperative week 7. At 8 months postoperatively, IOP was 17 mm Hg OS and 15 mm Hg OD. Off medication, the Hydrus-treated eye, which had more severe disease preoperatively and had undergone more laser treatments, achieved an IOP that was lower than baseline and the iStent-treated eye achieved baseline IOP.
Many studies have supported the effectiveness of the iStent and Hydrus devices, and both have a place in MIGS surgeons’ arsenals. Because the two devices require the cultivation of a similar skill set, a surgeon comfortable with one but inexperienced with the other should be able to diversify their offerings to cover a broader spectrum of disease without much difficulty.
With the continued proliferation of MIGS, surgeons will find it useful to be adept with multiple technologies in order to provide patients with truly customizable treatment options. Additional comparative trials are shedding light on the differences between MIGS devices. As more information becomes available, surgeons can update their decision-making processes and better tailor treatment not solely to each patient but to each eye.
1. Ahmed IIK, Fea A, Au L, et al. A prospective randomized trial comparing Hydrus and iStent microinvasive glaucoma surgery implants for standalone treatment of open-angle glaucoma: the COMPARE study. Ophthalmology. 2020;127(1):52-61.