Julian Garcia-Feijoo et al. performed a European study to evaluate the safety and effectiveness in IOP lowering of a novel, ab-interno, supraciliary, minimally invasive glaucoma surgery device (MINIject DO 627) in patients with primary open-angle glaucoma uncontrolled by topical hypotensive medications.
Eight sites in 3 countries participated in a prospective interventional single-arm, multicenter European Study (STAR II). The primary endpoint was the success rate 6 months after surgery >60% (defined as a diurnal IOP ≤ 21 and > 5 mm Hg with ≥20% IOP reduction from baseline with or without glaucoma hypotensive medication).
MINIject was successfully implanted in 29 of 31 patients recruited in the study. At the 6-month follow-up visit, the primary endpoint was fulfilled, with 75.9% of patients reaching defined success. The mean IOP was reduced by 40.2% (9.9mm Hg) to 14.7 ± 6.0 mmHg. The number of IOP lowering medications was reduced by 63.4% from 2.9 ± 1.2 at baseline to 1.0 ± 1.3. Furthermore, 79.3% of the patients had mean IOP ≤ 18 mm Hg, 82.8% achieved a ≥ 20% IOP reduction, and 55.2% were medication free at 6 months.
The authors state that ab-interno supraciliary surgical implantation using MINject significantly lowers IOP by 40% at the 6-month follow-up while reducing the need for IOP lowering medication.
Interestingly MINIject implantation procedure reached a significant IOP reduction. However, there are limitations of the study which need to be considered. The study did not include a comparative group and provides with only 6 months of follow-up time. These limitations do not allow to reach conclusions about the effectiveness of this device in IOP lowering.
In addition, the authors noted on one hand complete success of 44.8% of study participants while on the other hand as many as 48.4% experienced increase in IOP after month one. Further, a number of device deficiencies were reported raising regulatory concerns in Germany.
The ITT population consisted of 29 patients, while in the PP population, 5 patients were excluded from the ITT data set resulting in 24 patients. At 6 months the primary end-point responder analysis of success >60% was successfully met and was achieved in 22 out of 29 patients while in the PP analysis this was the case in 18 out of 24 patients. One would question how this would be possible since the patients excluded from PP analysis likely had unsuccessful outcome.
Interestingly less IOP lowering was observed at one month as compared to 6 months follow-up visit. This could be at least partially explained by the fact that at one month there was a single IOP measurement (more likely at morning hours) while at 6 month visit a diurnal IOP was considered.
This study presents interesting data on the initial clinical experience with a new glaucoma surgical device. However, the study design not including comparative group, the short length of follow-up, and the limited number of patients included do not allow drawing conclusions on the IOP lowering efficacy and safety of this new device.