Color Doppler imaging of the retrobulbar circulation and plasmatic biomarkers of vascular risk in age-related macular degeneration: A pilot study

Abstract

Purpose:To evaluate preliminarily and compare the level of plasmatic biomarkers of vascular risk in patients with and without exudative age-related macular degeneration (ARMD) and to relate it to vascular resistance alterations in the ophthalmic artery (OA), central retinal artery (CRA), posterior temporal ciliary artery (PTCA), and posterior nasal ciliary artery (PNCA).Methods:Color Doppler imaging of the OA, CRA, PTCA, and PNCA was performed in 30 eyes of 30 cataract patients (control group) as well as in 30 eyes of 30 patients with naive exudative ARMD (study group), measuring the peak systolic velocity, end-diastolic velocity (EDV), and Pourcelot resistive index (RI). Likewise, in both groups, a blood test was performed to determine the plasmatic levels of homocysteine, C-reactive protein (CRP), B12 vitamin, and folic acid.Results:A positive and significant correlation was found between the level of CRP and RI of the OA in the ARMD group (r = 0.498, P = 0.005), with an increased RI in all arteries compared to controls, although differences only reached statistical significance for the PTCA (P = 0.035). Likewise, a significantly lower EDV for the CRA was found in ARMD eyes compared to controls (P = 0.041). In the study group, significantly higher plasmatic levels of homocysteine (P = 0.042) and CRP (P = 0.046) were found. In contrast, no significant differences were found between groups in the levels of folic acid (P = 0.265) and B12 vitamin (P = 0.520).Conclusion:The decrease of the choroidal perfusion related to hyperhomocysteinemia, and increase in the CRP plasmatic levels may play an etiological role on the exudative ARMD. This should be investigated in future studies with larger samples of patients.

Increased Systemic C-Reactive Protein Is Associated With Choroidal Thinning in Intermediate Age-Related Macular Degeneration

“…Prior studies have shown that CRP increases vascular resistance in the ophthalmic artery in patients with treatment-naïve exudative AMD. 8 Increased levels of monomeric CRP (mCRP), the proinflammatory breakdown product of pentameric CRP, has also been found in the choroidal vessels of donor eyes of patients with AMD. 9 Higher levels of mCRP have also been found in donor eyes of patients with the homozygous Y402H single-nucleotide polymorphism in the gene encoding complement factor H, which has been shown to increase risk for AMD.…”

Case series of retinal vein occlusions showing early recovery using oral l-methylfolate

“…Elevation of homocysteine is inversely correlated with retinal vessel diameter and choroidal perfusion and positively correlated with retinal occlusive disease. 66 – 69 Elevation of homocysteine also causes apoptosis and atrophy of retinal neuronal tissue, particularly the photoreceptors and ganglion cells forming the optic nerve. 70 , 71 Homocysteine is converted to methionine by l -methylfolate and B12, key ingredients of Ocufolin ® ( Table 1 ).…”

Implication of Hyperhomocysteinemia in Blood Retinal Barrier (BRB) Dysfunction

“…Several clinical studies suggested its involvement to both neuronal and vascular diseases of the retina such as; central retinal venous [ 31 , 32 ], retinal artery occlusion [ 33 , 34 ], glaucoma [ 35 ], and corneal pathologies and cataracts [ 36 , 37 , 38 ]. Furthermore, elevated Hcy has been suggested as a risk factor and a biomarker for the most common retinal diseases resulting in loss of vision worldwide such as DR [ 39 , 40 , 41 , 42 , 43 , 44 ] and AMD [ 45 , 46 , 47 , 48 ].…”