The Application of Optical Coherence Tomography Angiography in Systemic Hypertension: A Meta-Analysis

Abstract

Objective: Multiple studies have compared various optical coherence tomography angiography (OCTA) parameters in participants with systemic hypertension vs. controls and have presented discordant findings. We conducted a meta-analysis to pool together data from different studies to generate an overall effect size and find out whether OCTA parameter(s) significantly differed in participants with systemic hypertension as compared to controls.Methods: We conducted a literature search through a search of electronic databases to identify studies before 19 June 2021, which compared OCTA parameters in non-diabetic participants with systemic hypertension vs. controls. If the OCTA parameter had a minimum number of 3 studies that analyzed it, the mean difference between participants with systemic hypertension and controls were analyzed using a random-effects model.Results: We identified 11 eligible studies. At the macula, 9 studies analyzed vessel density at the superficial capillary plexus (SVD), 7 analyzed vessel density at the deep capillary plexus (DVD), and 6 analyzed the area of the superficial foveal avascular zone (FAZ). Participants with systemic hypertension had significantly lower SVD (standardized mean difference [SMD], −0.50 [−0.70, −0.30], P < 0.00001, I2 = 63%), lower DVD (SMD, −0.38 [−0.64, −0.13], P = 0.004, I2 = 67%) and larger superficial FAZ (SMD, 0.32 [0.04, 0.61], P = 0.020, I2 = 77%).Conclusion: The eyes of people with systemic hypertension have robustly lower superficial and deep vascular densities at the macula when compared to control eyes. Our results suggest that OCTA can provide information about pre-clinical microvascular changes from systemic hypertension.

Methods for the assessment of microcirculation in patients with hypertension

“…Meta-analysis of 11 studies comparing selected OCTA parameters in the group of HT patients showed that eyes of HT individuals have lower superficial and deep vascular densities at the macula in comparison with healthy patients. The authors also indicated that OCTA was a useful tool in microcirculation assessment in HT patients [48]. The changes observed in eye microcirculation are consistent then with those observed in skin microcirculation of HT patients -in both cases it results in capillary rarefaction.…”

The New Era of Retinal Imaging in Hypertensive Patients

“…The OCTA is also highly attractive for use in large cohort studies and for consecutive follow-up visits as it does not require the administration of intravenous dye 42 . A recent meta-analysis by our group reviewed the studies on quantitative OCTA parameters in hypertensive patients and concluded that certain OCTA parameters could provide objective information about preclinical microvascular changes from systemic hypertension 43 …”

“…42 A recent meta-analysis by our group reviewed the studies on quantitative OCTA parameters in hypertensive patients and concluded that certain OCTA parameters could provide objective information about preclinical microvascular changes from systemic hypertension. 43…”

Association of Neuroretinal Thinning and Microvascular Changes with Hypertension in an Older Population in Southern Italy

“…However, first of all, we should consider some technical limits of OCT-A whereby a slow blood flow above a minimum threshold detected by the machine may be wrongly reflected as a vascular rarefaction or even an area of non-perfusion on OCT-A images [37], and some optical parameters, such as the axial length of the eye, and in particular myopic condition, that could induce noise in the image, making the vascular network appear artificially denser because of the larger area being scanned under smaller magnification [38]. Furthermore, the results of 11 studies on macular vessels rarefaction reported in a recent meta-analysis [39] should be analyzed considering the Asiatic ethnicity of most of the study populations (9 out of 11 studies considered Asiatic populations) [8,10,11,34,[40][41][42][43][44], and the inclusion of patients with hypertensive retinopathy in the study groups [10,44].…”