RETINAL CAPILLARY MACROANEURYSMS.

PURPOSE: To investigate eyes with solitary large aneurysms arising from retinal capillaries. METHODS: Consecutive patients with aneurysms greater than 200 µm in diameter were evaluated with a comprehensive ophthalmologic examination including optical coherence tomography, optical coherence tomography angiography, and fluorescein angiography. The aneurysms were solitary in the sense, and there was only one aneurysm larger than the threshold diameter and a few or no other aneurysms. RESULTS: There were 5 patients, 3 male patients, who had aneurysms that reached a maximal mean size of 273.4 µm. One patient had stable diabetic retinopathy and had a documented growth of a capillary aneurysm to 331 µm over an 8-year 7-month period until the aneurysm was associated with widespread edema. The remaining 4 patients did not have diabetes or any discernable retinal vascular disease. Anti-vascular endothelial growth factor treatment was associated with a partial response in one patient and no apparent response in the others. Laser photocoagulation of the aneurysms resulted in resolution of the edema and involution of the lesions. CONCLUSION: Large aneurysms arising from retinal capillaries occur and have a candidate name of retinal capillary macroaneurysms. Histologic evaluation of retinal capillary aneurysms shows the presence of matrix metalloproteinase-9, which may function to decrease the wall strength in the face of increasing wall tension from aneurysmal expansion, as predicted by LaPlace's law. Thus, retinal capillary macroaneurysms may have multiple forces driving their formation.

[Role of VEGF in diseases of the retina]. / Papel del factor de crecimiento del endotelio vascular en las enfermedades de la retina.

Angiogenesis is the process through which new blood vessels are formed, based on preexisting vessels, and is the paradigm of diseases such as cancer and exudative ageassociated macular degeneration (ARMD). Several proangiogenic factors have been identified, such as vascular endothelial growth factor (VEGF), especially VEGF-A, which activates endothelial cells and promotes cell proliferation, migration, and an increase in vascular permeability. VEGF is also involved in the etiopathogenesis of other retinal diseases, such as diabetic macular edema and macular edema secondary to retinal vein occlusion. Likewise, there is increasing evidence that placental growth factor (PIGF) acts recepsynergetically with VEGF in promoting these diseases. Currently, the main treatment for these diseases are the anti-VEGF drugs, aflibercept, ranibizumab and bevacizumab. These agents differ in their molecular structure and mechanism of action.

Intravitreal bevacizumab (Avastin) in the treatment of macular edema secondary to retinal vein occlusion.

OBJECTIVE: To evaluate efficacy and safety of intravitreal injections of bevacizumab in the treatment of macular edema secondary to retinal vein occlusion (RVO). METHODS: Prospective study, noncomparative, interventional case series. Twelve consecutive patients (12 eyes) with macular edema associated with nonischemic retinal vein occlusion were treated with intravitreal bevacizumab (1.25 mg). All subjects underwent standardized ophthalmic evaluation at baseline and at weeks 1, 4, 12, and 24, consisting of visual acuity (VA) measurement using ETDRS charts, and imaging with ocular coherence tomography evaluating changes in foveal thickness (FT) and macular volume (MV). RESULTS: The median age was 66 years (+/- 4.16), and the median duration of symptoms was 4 months (+/- 1.81). There were six cases of inferior branch vein occlusion and six cases of superior branch retinal vein occlusion. Mean VA improved from 1.32 +/- 0.24 (logMAR values) at baseline to 0.8 +/- 0.15 (p = 0.0003) at the 6-month follow-up. The macular edema responded promptly, and a trend to restoration of normal macular anatomy was observed at by the seventh day. Mean FT improved from 615.50 +/- 116.29 microns to 420 +/- 72.53 microns (p = 0.001), and the mean MV improved from 19.81 +/- 2.31mm3 to 9.23 +/- 1.38 (p = 0.0001) at the 6-month follow-up.