Abstract
Purpose: :
To describe the retinal vascular morphology in eyes that were treated with intravitreal bevacizumab (IB) as monotherapy for retinopathy of prematurity (ROP) stage 3
Methods: :
Prospective, nonrandomized case series. We included six patients (12 eyes) diagnosed with stage 3, thereshold or prethreshold ROP treated with IB. Fundus photographs and FA were obtained before and after IB treatment using a wide-field digital pediatric imaging system.
Results: :
Before treatment, FA showed vascular abnormalities, including capillary nonperfusion throughout the vascularized retina, shunting in the vascularized retina, a demarcation line, and limited vessel development, new vessels leakege, and avascular periphery. After the treatment with the supression of VEGF, FA showed obliteration of abnormal new vessels, followed by involution of the neovascularization, flattening of the demarcation line and subsequent growth of vessels to the capillary-free zones. During the following weeks large areas devoid of microvessels were seen, 6 months post intravitreal injection of bevacizumab, vascular remodelling was seen with uneven spacing of the retinal capillaries and vascular loops in the areas that were previously devoid of vessels. In some patients, the retinal vessels in the far periphery never developed. Subsequently, these patients did not develop pathological neovascularization.
Conclusions: :
Our study shows that even when the vascular pattern is abnormal after intravitreal anti-VEGF therapy, the creation of small vessels, the establishment of directional flow, the association with mural cells (pericytes and smooth muscle cells) and the adjustment of vascular density to meet the nutritional requirements of the retina have been accomplished. Longer follow up is needed of prospective multicenter studies to determine the safety profile for the use of IB in treatment requiring ROP.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00346814
Keywords: retinopathy of prematurity • drug toxicity/drug effects • vascular endothelial growth factor