Velez FG, et al. - Experts ascertained the use of iris optic coherence tomography angiography (OCT-A) for patients undergoing strabismus surgery and who are at risk for anterior segment ischemia (ASI). Iris vessel filling defects when present were determined by OCT-A. Moreover, qualitative vessel density values that can be compared preoperatively and postoperatively were given by OCT-A. Nonetheless, the clinical relevance of small differences remained unknown. While only 10 eyes were evaluated, and experts could not determine the generalizability of these findings as such, findings suggested the probability of OCT-A being a useful tool to assess the patients having strabismus surgery to ascertain whether or not a patient is at risk to develop ASI.

Methods

• Researchers conducted this prospective case series study in an academic center.
• They prospectively recruited the adults undergoing strabismus surgery on at least 1 vertical muscle.
• The study was conducted from June to November 2017, and the analysis began in January 2018.
• Interventions included the indocyanine green angiography and OCT-A of the iris preoperatively and 1 day postoperatively.
• All images were evaluated by a masked examiner and determined whether any filling defects were present qualitatively (lack of perfusion) and quantitatively (for OCT-A using internal software to calculate vessel density).

Results

• They included 10 eyes of 9 individuals (mean [SD] age, 63 [11] years).
• As per data 2 individuals (22.2%) identified as Hispanic, and 7 (77.8%) identified as white.
• Findings suggested that there were 6 women (66.7%).
• Results demonstrated that the mean preoperative vessel density (percentage of the area occupied by vessels) averaged for all quadrants decreased from 57% preoperatively to 55% postoperatively (mean difference, 2%; 95% CI, 0.4%-4.2%;P=.05).
• The mean vessel density decreased from 56% to 53% (mean difference, 2.6%; 95% CI, 0.17%-4.8%;P=.02), while comparing quadrants adjacent to operated muscles.
• Moreover, vascular filling defects were detected by OCT-A in the quadrant adjacent to the operated muscle on the patients in whom they were present (n=1, inferior rectus recession).