The ophthalmic artery resistive index as a predictor of choriocapillaris ischemia in multivariate logistic models

Índice de resistência da artéria oftálmica como preditor de isquemias focais da coriocapilar em modelos logísticos multivariados

ABSTRACT

Objective

Vascular findings in preeclampsia are usually attributed to increased vascular tone. Recently, however, important studies have improved the understanding of the main pathophysiological events in this condition, especially vascular brain remodeling, impaired autoregulation, and damage of the blood-brain barrier, which are well recognized features of cerebral overperfusion.

Methods

In this study, the association between choriocapillaris ischemia with ophthalmic artery blood flow parameters on orbital Doppler ultrasound is reported for the first time using multivariate logistic models. Multivariate logistic models with ophthalmic artery blood flow parameters, as well as major clinical and laboratory predictive variables were established for choriocapillaris ischemia and choriocapillaris ischemia with retinal detachment.

Results

In a series of 165 patients, 46 (28%) presented choriocapillaris ischemia; among them, 20 (12%) presented associated retinal detachment. The ophthalmic artery resistive index was the main predictor for choriocapillaris ischemia and choriocapillaris ischemia with retinal detachment in multivariate logistic models. Ophthalmic artery resistance lower than 0.56 was associated with a significantly high incidence of both outcomes.

Conclusion

This study supports that the branching pattern of choroidal arterioles and the lobular organization of choriocapillaris are the major morphological aspects underlying endothelial damage and lobular ischemia in the context of choroidal overperfusion. Overperfused lobules bordering areas of choriocapillaris ischemia produce a perfusion pressure gradient, with lobular reperfusion, leakage from reperfused choriocapillaris, and retinal detachment. Ophthalmic artery-resistive index lower than 0.56 is proposed as a major predictor of the overperfusion-related choriocapillaris ischemia and choriocapillaris ischemia with retinal detachment in preeclampsia.

Choroid; Retina; Ultrasonography, doppler; Pre-eclampsia; Endothelium; Ischemia