Author: Simone Donati (Italy)
Co-authors: Massimo Venturini, Cristian Metrangolo, Chiara Recaldini, Liviana Fontanel, Edoardo Marelli, Claudio Azzolini
Purpose
Primary Oucome: to evaluate changes in retrobulbar blood flow by using colour Doppler ultrasonography (CDUS) in naïve patients affected by retinal vein occlusion (RVO). Secondary outcome: to study the behaviour of retrobulbar vascular flow after intravitreal injection of antiVEGF (IV antiVEGF) to treat macular edema (ME) as complication of RVO and to correlate functional and morphological retinal data to flow parameters.
Setting/Venue
Ophthalmology and Radiology Unit, Department of Medicine and Surgery, University of Insubria – ASST Sette laghi Varese, Italy
Methods
Prospective, cross-sectional interventional study to evaluate changes in retrobulbar vascular flow in patients affected by RVO and treated with IV antiVEGF for ME. Naïve patients diagnosed for ME secondary to central and branch RVO examined in our Medical Retina Service, Ophthalmology Unit, ASST Sette-Laghi in Varese, Italy were enrolled. Each patient underwent a complete ophthalmological examination completed by instrumental evaluation at baseline (fluorescein angiography, OCT-angiography and SD OCT for central retinal thickness-CRT) and after treatment at week 1, at month 1 and 4 (OCT-angiography and SD-OCT). Treatment was performed by a loading phase of IV antiVEGF every month for three months and then a PRN regimen. CDUS was performed to study vascular flow of retrobulbar vessel by means of Epiq, Philips, 12-3 MHz linear probe. In particular, central retinal artery (CRA) and vein (CRV), ophthalmic artery (OA), superior ophthalmic vein (SOV) and posterior ciliary artery (PSA) have been evaluated. The same operator M.V. measured for arteries Peak Systolic Velocity (PSV), End Diastolic Velocity (EDV), Resistance Index (RI); for veins: Maximum (MV) and minimum Velocity (mV). Clinical and instrumental evaluations were performed in both eyes. All data were collected in a dedicated database for quantitative and inferential statistical analysis.
Results
In this preliminary study, we enrolled 14 patients affected by RVO, four CRVO and ten BRVO. Mean age was 67,43±23,31yrs. Eight patients completed the loading phase with three IV antiVEGF. Mean baseline VA in the affected eye was 0,283±0,135Snellen and mean CRT 647,86±231,54micron; 0,283±0,043Snellen and 251,56±71,35micron (p<0.01) at month 1 and 0,62±0,231 and 219,15±87,34 (p<0.01) at month 4, respectively. CDUS parameters revealed interesting results comparing baseline till month 1. CRA showed a progressive increase of mean PSV values from 11,26 to 13,86cm/s; EDV and RI remained almost stable. OA showed a decrease in mean PSV (from 51,72 to 39,92cm/s) as well as mean EDV (from 14,74 to 7,86cm/s); mean RI remained stable. PCA showed an increase in mean PSV (from 11,10 to 16,75cm/s) as well as mean EDV (from 3,35 to 4,63cm/s); mean RI was almost unchanged. CRV showed a stability of MV and mV from 6,09 to 5,62cm/s and from 4,06 to 3,96cm/s respectively. SOV showed a stability of mean MV from 7,47 to 7,37cm/s; mean mV was unchanged. All measurements were performed with a standardized methodology, by the same experienced operator M.V. No adverse events have been reported, due to diagnostic or treatment procedures
Conlusions
The study confirmed, as known from literature, the efficacy of IV antiVEGF as the gold standard therapy to treat ME as a complication of RVO, and to improve visual acuity, in particular in naïve patients. However, the behaviour of retrobulbar vessels flow after occlusive venous pathology is nowadays limited, particularly before and after antiVEGF treatment. The possibility to apply this diagnostic method supported by an expert operator could give to ophthalmologists interesting and useful information that could be correlated to the retinal pathology and visual acuity impairement. The results reported in this preliminary study showed that after treatment, arterial and venous flow changes in the studied vessels specially, in central retinal and ophthalmic arteries. Again, venous flow did not show an increase in velocity probably due to the inner vascular obstruction, Actually, the role of antiVEGF drugs on retrobulbar vascular dynamics to improve retinal clinical features in RVO are not well known. In our study, we provided useful data to increase the basis of the knowledge of this mechanism, and to better understand the clinical significance of these changes in retrobulbar vascular flow.
Financial Disclosure
no financial relations
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