Exercise-induced acute changes in systolic blood pressure do not alter choroidal thickness as measured by a portable spectral-domain optical coherence tomography device

Abstract

Purpose: To measure choroidal thickness in patients manifesting an acute change in systemic arterial blood pressure using a portable spectral-domain optical coherence tomography device (iVue).

Methods: Fifteen patients (15 eyes) undergoing cardiac exercise stress testing were scanned using a portable spectral-domain optical coherence tomography system (iVue). Two scan protocols were used: cross line scan for measuring choroidal thickness and the retina map scan to measure retinal thickness. Each patient was scanned before and within 3 minutes after the stress test. Blood pressure was measured at the same time as the acquisition of the scans. Choroidal thickness was measured from the posterior edge of the retinal pigment epithelium to the choroid-sclera junction at 500-μm intervals up to 1,000 μm temporal and nasal to the fovea. Retinal thickness was measured by an automated software. All choroidal thickness measurements were performed by two independent observers.

Results: Fifteen patients (15 eyes) with a mean age of 60.6 (±10.4 years) were scanned. There was a significant increase in systolic but not diastolic pressure after stress testing (P < 0.05). The mean choroidal thickness measurements showed no significant difference before and after exercise stress testing (P > 0.05). In addition, there was no significant difference in retinal thickness before and after stress testing measurements (P > 0.05).

Conclusion: There was no change in choroidal thickness or retinal thickness, despite an acute change in the systemic systolic blood pressure induced by exercise.

Fig. 1

Graph displaying the choroidal thickness at the different location: N2 (1,000 μm nasally), N1 (500 μm nasally), SF (subfoveal), T1 (500 μm temporal), and T2 (1,000 μm temporal). No significant difference was observed before and after stress testing measurements, despite significant change in systolic blood pressure, as outlined in Table 1.

Fig. 2

Graph showing the retinal thickness for the different regions in relation to the fovea: N (nasal), C (center), T (temporal), S (superior), and I (inferior). There is no significant difference in thickness measurements before and after stress testing.

Fig. 3

Graph comparing the choroidal thickness obtained from the Cirrus SD-OCT versus those obtained using the iVue portable SD-OCT system. There was no statistically significant difference in the choroidal thickness measurements obtained by the 2 systems (P = 0.75).