Active-fluidics versus gravity-fluidics in uncomplicated cataract surgery: using optical coherence tomography angiography to estimate early changes in macular and optic disc microcirculation

TL;DR

This study compares two cataract surgery techniques using OCTA to assess early effects on retinal and optic disc blood flow, finding that one method better preserves microcirculation.

Contribution

The study introduces OCTA as a tool to detect early microcirculation changes in cataract surgery and identifies AFS as a potentially safer technique for preserving retinal vasculature.

Findings

The GFS group showed significantly lower macular vessel density at 24 hours post-surgery compared to the AFS group.

Seven days after surgery, the GFS group had higher retinal nerve fiber layer thickness and lower vessel density in specific quadrants compared to the AFS group.

The AFS system appears to better protect retinal and optic disc microcirculation during cataract surgery.

Abstract

To compare, using optical coherence tomography angiography (OCTA), the earliest changes and damages to macular and optic disc microcirculation after active-fluidics system (AFS) and gravity-fluidics system (GFS) procedures in uncomplicated cataract surgery.

We included 42 eyes affected by uncomplicated cataracts and divided them into two groups: 21 eyes were randomly assigned to an AFS group and 21 eyes were randomly assigned to a GFS group. Expert examiners performed OCTA 30 ± 10 min before surgery (T0), 30 ± 8 min after surgery (T1), 24 ± 2 h after surgery (T2) and 7 days after surgery (T3).

No significant differences at T1 were detected between the groups. At T2, eyes in the GFS group exhibited a whole macula deep capillary plexus vessel density of 37.9 ± 5.8%, which was significantly lower than that of the eyes in the AFS group (42.2 ± 5.7%; p = 0.048). At T3, eyes in the GFS group exhibited a significantly higher retinal nerve fibre layer thickness in the nasal (p = 0.020) and inferior (p = 0.045) quadrant, and a significantly lower peripapillary vessel density in the inferior quadrant of the papilla (p = 0.036) compared with eyes in the AFS group.

The AFS procedure appears to protect macular and optic disc microcirculation during phacoemulsification, and it may represent a more prudent approach, particularly in cases that require specific care to preserve residual peripapillary and macular vasculature (e.g., diabetic or glaucomatous eyes).

The active-fluidics system reduces intraoperative intraocular pressure fluctuations, that can affect retinal and optic nerve vasculature

The active-fluidics system reduces intraoperative intraocular pressure fluctuations, that can affect retinal and optic nerve vasculature

In both AFS and GFS groups, macular thickness showed a transient increase in the immediate postoperative period, accompanied by a decrease in DCP VD in both groups. It remained persistently higher in GFS-group, in parallel with a rebound increase in DCP VD with values at 7 days that were higher that baseline values.Seven days after surgery eyes from GFS group showed a significantly higher RNFLT in the nasal and inferior quadrant, and a significantly lower RCP VD in the inferior quadrant compared to eyes in AFS group.We postulated a mechanism of ischemia and reperfusion accompanied by intraretinal oedema involving both the papillary region and the macular region in GFS group.

In both AFS and GFS groups, macular thickness showed a transient increase in the immediate postoperative period, accompanied by a decrease in DCP VD in both groups. It remained persistently higher in GFS-group, in parallel with a rebound increase in DCP VD with values at 7 days that were higher that baseline values.

Seven days after surgery eyes from GFS group showed a significantly higher RNFLT in the nasal and inferior quadrant, and a significantly lower RCP VD in the inferior quadrant compared to eyes in AFS group.

We postulated a mechanism of ischemia and reperfusion accompanied by intraretinal oedema involving both the papillary region and the macular region in GFS group.

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