Muscle recession procedures, such as those employed in strabismus surgery, can create transitory hemodynamic changes in the deep capillary plexus (DCP) and in the choriocapillaris layer (CCL), according to a study published in the Journal of the American Association for Pediatric Ophthalmology and Strabismus. Researchers report they observed the phenomenon using swept-source optical coherence tomography angiography (SS-OCT-A).
Investigators reviewed 92 eyes of 56 patients (mean age 41.1±22.7, 54% men), following strabismus surgery that involved at least 1 rectus muscle between January 2019 and December 2020. They examined hemodynamic changes in patients’ superficial retinal plexus (SCP), DCP, and CCL portions immediately after the procedure (T0), 1 day postoperative (POD1), and 30 days postoperative (POD30).
The investigation shows that the mean vascular density of the DCP was 50.20±5.57 at T0, 52.74±4.77 on POD1, and 50.92±4.58 on POD30. The mean vascular densities at the CCL were 50.72±4.80 at T0, 53.59±3.65 on POD1, and 51.39±4.64 on POD30. The participants underwent a variety of procedure types, including bilateral muscle recession (60.7%), unilateral recession (39.3%). The biological structure operated on varied as well, with 43.4% of procedures operating on the medial rectus muscle, 8.7% on the inferior rectus muscle, 38.0% on the lateral rectus muscle, 4.3% on the superior rectus muscle, 2.2% on the superior oblique muscle, and in 3.3% on the inferior oblique muscle.
The study shows statistically significant (P >.05) differences in OCT vascular density between T0 vs POD1 in the DCP and the CCL. Investigators found no significant differences in the SCP. From this, they were able to conclude that the SS-OCT-A technology can effectively detect vascular changes following muscle recession procedures.
Due to the risk of ischemia in the anterior segment of the eye following strabismus surgery, researchers are interested in changes in ocular blood flow in patients that undergo these procedures and how they can be detected. This study examined pre- and postoperative hemodynamic changes following muscle recession procedures using SS-OCT-A imaging. Results of previous studies examining hemodynamic changes following strabismus surgery are inconclusive, and only 2 prior investigations utilized OCT-A technologies.
The limitations of this study include the lack of detection of blood flow in the intermediate retinal plexus by the SS-OCT-A, including patients who underwent varying procedures, such as recession, resection, and transposition of eye musculature, and the small sample size.
Vagge A, Nucci P, Desideri LF, et al, Evaluation of macular vessel density changes after strabismus surgery using optical coherence tomography angiography. J AAPOS. Published online March 17, 2022. doi:10.1016/j.jaapos.2021.11.011.