Cutting Edge Glaucoma - Issue 2

MINIATURIZATION IN GLAUCOMA MONITORING AND TREATMENT: A REVIEW OF NEW TECHNOLOGIES THAT REQUIRE... • 55  of current intravitreously injected VEGF inhibitors used in the treatment of a number of retinal diseases. Though such an injection seems to be the smallest invasive intervention possible in oph- thalmology, the risk of an infection or other complications, though seemingly remote, cannot be completely ruled out. Another aspect is the patient’s attitude (and possibly feelings such as fear, resentment, etc.) towards receiving injections every couple of months. There can be no doubt that MIGS has not only increased the number of available procedures that can lower IOP considerably, but that it has also opened up a pathway to surgical intervention for a particular and probably large segment of the glaucoma patient population. Less-invasive pro- cedures have made surgical IOP lowering a realistic choice for patients (and their ophthalmolo- gists) who shy away from a more complex procedure such as trabeculectomy [11]. MIGS has the potential to be an attractive alternative for patients who suffer from complications and discomfort after long periods of topical glaucoma therapy [8]. A profound pressure reduction which guar- antees that the patient will no longer require antiglaucomatous eyedrops is generally not possible with MIGS. It is carried out to achieve a ‘‘safer’’ IOP level and to significantly reduce the number of medications required by the patient; in fact, a large percentage of patients require no medication following MIGS. The kind of success achievable with MIGS is illustrated by a study in which the percentage of patients with a Hydrus microstent plus cataract surgery who do not need additional IOP-lowering medications at month 24 (72.9%) was significantly higher than the corresponding percentage in patients who underwent cataract surgery alone (37.8%) [35]. Minimally invasive glaucoma surgery is an emerging field, and the fact that so far no MIGS has become anything close to a ‘‘gold standard’’ seems to indicate that none of the three differ- ent approaches is vastly superior to the other two [39]. As Anzari has rightfully pointed out, there is currently an unsatisfied demand for high-quality data and concern because there is no standardization in most of the studies published on MIGS. Furthermore, there is a lack of cost- effectiveness data and long-term data and incomplete knowledge of ideal patient selection. In a very recent systematic literature review of nine randomized controlled trials (RCTs: seven on iStent, one on Hydrus, and one on CyPass), seven non-RCTs (three on iStent, three on CyPass, and one on Hydrus), as well as 23 economic studies, Agarwal et al . came to a somewhat cau- tious conclusion. They found that these devices tend to yield higher postoperative IOP levels than other approaches [45], and that subconjunctivally placed devices were associated with a relatively high rate of postoperative hypotony. They also found limited evidence for the cost-effectiveness of MIGS [1]. Furthermore, many studies of these small implants have focused on cases receiving both an implant and cataract surgery, meaning that they lack robust evidence for the effect of MIGS alone [2]. Nevertheless, the options described in this review have the potential to considerably increase the quality and efficacy of modern-day glaucoma management. However, a deeply sobering fact about glaucoma is that despite all the recent advances made in understanding the disease, in diagnostics, and in therapy, a number of our patients still progress to blindness [21]. Much has been done, but the quest for a better approach, with the ultimate goal being to halt the disease’s progression, continues.