Surgeons can monitor the effects of epiretinal membrane (ERM) surgery using optical coherence tomography angiography (OCT-A) to image postoperative changes in retinal vascular distortion, according to research published in BMC Ophthalmology. These changes can provide insight into the patient’s visual functioning as well, the study shows.
The investigators hypothesized that after ERM surgery, the strain on vessels would be decreased by the release of tractional forces.
They recruited 22 consecutive patients (68% women and 32% men; mean age 72.05± 8.86 years, range 57-88).who underwent standard vitrectomy for ERM and comprehensive ophthalmologic examination, including swept-source OCT-A, at Osaka University Hospital, Osaka, Japan, between May 2019 and July 2020. The patients had a mean preoperative best-corrected visual acuity (BCVA) of 0.21± 0.25 (-0.18 to 0.82) and significantly improved mean postoperative BCVA, relative to baseline, of 0.13±0.21 (-0.18 to 0.70; P =.026) at 1 month, 0.08±0.19 (-0.18 to 0.52; P =.001) at 3 months, and 0.02±0.19 (-0.18 to 0.40; P <.001) at 6 months.
The patients had 6 months of postoperative follow up. The team calculated distortion of retinal vessels using 2 parameters, the actual vessel length (VL) in the vessel section and the direct vessel branching-point distance (BD) in the nasal, temporal, and superior-inferior quadrants of the macula. They evaluated the correlation between these parameters and visual outcomes.
Postoperatively, the researchers observed significantly longer mean VL at 1, 3, and 6 months in the temporal quadrant compared with the mean baseline temporal VL (P =.006, P =.008, and P =.022, respectively). They also observed significantly shorter mean VL in nasal quadrants at 1 and 3 months (P =.046 and P =.018) compared with mean baseline nasal VL. The VLs and BDs in the superior-inferior quadrant were correlated with the mean postoperative BCVA at 1, 3, and 6 months (P =.035, P =.035, and P =.042, respectively), and postoperatively, the changes in mean VL and BCVA at 3 and 6 months showed significant associations in the nasal quadrant (P =.018 and P =.0455, respectively).
“Using OCT-A, we were able to detect changes in vascular distortion after ERM surgery,” researchers report. “The change in vessels around the macula became more linear; this was associated with visual outcomes after surgery.”
Limitations of the study included cases with simultaneous bilateral cataract surgery, a relatively small sample size, random selection of the measured vessel in each quadrant, and manual selection of vessels.
Miyazawa K, Sakimoto S, Kanai M, et al. Vascular tortuosity analysis in eyes with epiretinal membrane imaged by optical coherence tomography angiography. BMC Ophthalmol. 2022;22(1):198. doi:10.1186/s12886-022-02420-z