Study Of 24-Hour Intraocular Pressure Fluctuations After Trabecular Surgery With Istent Inject® W Implantation Using A Contact Lens Sensor.

To evaluate the effect of trabecular surgery with iStent inject® W implantation on 24-hour intraocular pressure (IOP) fluctuations in patients with open-angle glaucoma, as measured by a contact lens sensor (CLS). Specifically, the study aimed to quantify changes in circadian IOP fluctuation patterns assessed by cosinor and biphasic amplitudes before and after surgery, and to determine whether iStent implantation reduces the magnitude of IOP variability over a 24-hour period in addition to lowering mean IOP and reducing the need for topical hypotensive medication.

Prospective controlled pre-post interventional study conducted at a two tertiary referral Spanish hospitals. The study follows the tenets of the Declaration of Helsinki and complies with European Medical Device Regulation (EU 2017/745).

Thirteen  adult patients with primary open-angle glaucoma (POAG) requiring cataract surgery and trabecular surgery with implantation of the iStent inject® W were included. All patients underwent twenty-four-hour IOP-related pattern using the SENSIMED Triggerfish® CLS system one month before surgery and three months after surgery. The primary endpoint was the amplitude of the cosine and biphasic curve (mVeq), representing 24-hour IOP-related fluctuation magnitude. Secondary parameters included acrophase timing, nocturnal pattern classification (high nocturnal, low nocturnal, or absence of pattern), number of peaks (>90 mVeq), and sleep-to-wake slopes. Goldmann applanation tonometry (GAT) was performed before and after each CLS session.

Mean IOP (mmHg) before surgery was 16.3±3.0 mmHg and 14.5±3 after surgery with iStent (p-value 0.1084). The number of preoperative hypotensive medications was 2.38±0.51 and decreased to 0.0 after surgery (p-value 0.0012). Mean preoperative cosinor amplitude was 145.83±42.00 mVeq and decreased to 117.80±63.97 mVeq after surgery (p-value 0.0827). Mean preoperative biphasic amplitude was 163.27±44.23 and decreased to 128.63±60.12 after surgery (p-value 0.0208).

Glaucoma surgery with iStent inject W showed a reduction in 24-hour IOP fluctuations. Further studies are needed to confirm these results; however, this reduction in IOP fluctuations could be an important factor in controlling glaucoma progression with this trabecular surgery, in addition to lowering IOP.