Changes in the retina and choroid in patients with internal carotid artery stenosis: a systematic review and meta-analysis

Background

Internal carotid artery stenosis (ICAS) is a prevalent vascular condition associated with ischemic cerebrovascular disease. The ophthalmic artery is the first branch of the internal carotid artery stenosis (ICA). Given the crucial role of the ICA in ocular perfusion, we aimed to assess the thickness and vessel density of the retina and choroid in individuals with ICAS.

Methods

The PubMed and Embase databases were searched from inception to 10 January 2023 for studies evaluating retinal and choroidal changes between ICAS patients and healthy controls using optical coherence tomography (OCT) or optical coherence tomography angiography (OCTA). Data of interest were extracted and analyzed using Stata software version 16.

Results

Thirteen studies involving 419 ICAS eyes and 398 healthy eyes were included. The pooled results demonstrated that the average thickness of peripapillary retinal nerve fiber layer (pRNFL) (WMD = -0.26, 95% CI: -0.45 to -0.08, P = 0.005), ganglion cell complex (GCC) (WMD = -0.36, 95% CI: -0.65 to -0.06, P = 0.017), and choroid (WMD = -1.06, 95% CI: -1.59 to -0.52, P = 0.000), were significantly thinner in patients with ICAS than in healthy controls. The overall vessel density of the radial peripapillary capillaries (RPC) in whole-image scans was lower in ICAS patients than in healthy control subjects (WMD = -0.94, 95% CI: -1.49 to -0.39, P = 0.001). No differences were detected in the vessel density of the superficial capillary plexus (SCP) (WMD = -0.84, 95% CI: -1.15 to -0.53, P = 0.092), the deep capillary plexus (DCP) (WMD = -0.27, 95% CI: -0.56 to 0.03, P = 0.074), or the choriocapillaris (CC) (WMD = -0.39, 95% CI: -1.12 to 0.35, P = 0.300).

Conclusion

This systematic review and meta-analysis demonstrated that ICAS can reduce the vessel density of the RPC and the thickness of the retina and choroid. The retinal and choroidal microvasculature is a potential biomarker of the initial signal of ICAS.

Systematic review registration

https://inplasy.com/, identifier NPLASY202410038.

Choroidal thickness in patients with cardiovascular disease: A review

The choroid is a vascular network that supplies the bulk of the retina's oxygen and nutrient supply. Prior studies have associated changes in the thickness of the choroid with the presence of various cardiovascular diseases. This is the first review that summarizes current knowledge on the relationship between choroidal thickness and cardiovascular diseases while highlighting important findings. Acute hypertension increases choroidal thickness. Chronic hypertension and heart failure may decrease choroidal thickness, but controversy exists. Both coronary artery disease and carotid artery stenosis result in decreased choroidal thickness and blood flow. Carotid endarterectomy may reverse these changes. Choroidal thickening in early stages of carotid stenosis may arise from mechanisms compensating for ischemia. Hyperlipidemia is linked to choroidal thickening, while caffeine intake is linked to choroidal thinning. The effects of smoking and exercise are mixed. Changes in choroidal thickness have been linked to cardiovascular disease. Clarity regarding these changes could lead to the use of choroidal thickness changes as a noninvasive screening or prognostic test for pathological cardiovascular changes. Future studies should also investigate the effect of cardiovascular disease treatments on the choroid.