Abstract
Purpose :
The most representative model of human ROP is the rat oxygen-induced ischemic retinopathy (OIR) model. As a result of the addition of BS (Beat Strength) to the analysis items covered by the Laser Speckle Flowgraphy (LSFG) -Micro system, it is now possible to analyze blood flow waveforms even in small animals. BS/MBR, obtained by dividing BS by the ocular blood flow value (Mean blur rate (MBR), is believed to be positively correlated with peripheral vascular resistance (Annual Meeting of the Japanese Ophthalmological Society, 2017). In this study, we reviewed the results of past animal studies reporting on the relationship between MBR and disease state and investigated the relationship between ocular blood flow waveform and oxygen-induced retinopathy (OIR).
Methods :
BS values in 16 previously reported cases involving 50/10 OIR model rats and 17 cases involving reared in room air rats (RmA) were analyzed and reevaluated. Blood flow was measured using the LSFG-Micro system with subjects placed under anesthesia with age in days (P) at 14 (P14) and 18 (P18). BS/MBR values were compared between the 2 OIR and RmA groups.
Results :
BS reproducibility was favorable, with a variability coefficient of 10% or less and an interclass coefficient above 0.85. The BS/MBR at P14 (OIR vs. RmA: 0.64 ± 0.16 vs. 0.41 ± 0.17; p = 0.0004) and P18 (OIR vs. RmA: 0.4 ± 0.12 vs. 0.28 ± 0.12; p = 0.0089) were recorded.
Conclusions :
Although BS/MBR decreased in both the OIR and RmA groups by P18, both BS and MBR values were significantly higher in the OIR group. Subjects in the OIR group also exhibited high MBR values (Greafes Arch Clin Exp Ophthalmol, 2017) and increased blood flow despite high peripheral vascular resistance. Blood flow waveform analysis was possible even in small animals such as rats, and BS values may be considered to be useful in examining vascular resistance.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.