Changes in Flow Density Measured Using Optical Coherence Tomography Angiography after iStent Insertion in Combination...

Area of Science:

• Ophthalmology
• Glaucoma research
• Medical imaging

Background:

• Glaucoma management often involves surgical interventions to reduce intraocular pressure (IOP).
• The trabecular micro-bypass stent (iStent) is a device used to enhance aqueous humor outflow.
• Assessing microvascular changes in the retina and optic nerve head can provide insights into glaucoma progression and treatment efficacy.

Purpose of the Study:

• To evaluate the impact of iStent implantation combined with cataract surgery on ocular blood flow density.
• To compare changes in flow density between patients receiving combined surgery and those undergoing cataract surgery alone.

Main Methods:

• Prospective study involving 48 eyes of 48 patients.
• Patients were divided into two groups: cataract surgery alone (cataract group) and cataract surgery with two iStent inject devices (iStent group).
• Intraocular pressure (IOP) and optical coherence tomography angiography (OCTA) flow density data were collected and analyzed pre- and post-operatively.

Main Results:

• The iStent group showed a statistically significant reduction in mean IOP post-surgery (18.2 mmHg to 13.2 mmHg, p < 0.001).
• The cataract group also experienced a significant IOP reduction (17.1 mmHg to 15.1 mmHg, p = 0.003).
• Significant improvements in macula and optic nerve head (ONH) flow density were observed in the iStent group (superficial macula: p = 0.002; deep macula: p = 0.034; ONH: p = 0.011), but not in the cataract group.

Conclusions:

• Cataract surgery combined with iStent implantation leads to significant improvements in macular and ONH flow density.
• Optical coherence tomography angiography (OCTA) provides a valuable noninvasive method for quantifying flow density.
• These flow density measurements may serve as a novel parameter for monitoring the success of glaucoma surgical interventions.