Effects of photocoagulation on ocular blood flow in patients with severe non-proliferative diabetic retinopathy

Abstract

PurposeTo investigate ocular blood flow and correlations between ocular blood flow and variables in patients with severe non-proliferative diabetic retinopathy (S-NPDR) following panretinal photocoagulation (PRP).MethodsIn this retrospective, cross-sectional study, the blood flow on the optic nerve head (ONH) and choroid was assessed with laser speckle flowgraphy (LSFG) using the mean blur rate (MBR) in 76 eyes of 76 patients with S-NPDR who underwent PRP, 39 eyes of 39 patients with S-NPDR who did not undergo PRP, and 71 eyes of 71 normal subjects. The correlation between MBR and variables, including visual acuity (VA) and choroidal area determined by binarization method, was analyzed.ResultsThe mean age was 62.9 ± 11.9 years in the S-NPDR with PRP eyes, 55.6 ± 11.4 years in the S-NPDR without PRP eyes, and 60.3 ± 11.1 years in the normal subject eyes. The ONH MBR in vessel and tissue areas and the choroidal MBR were significantly lower in the S-NDR with PRP group than in the other groups (p < 0.001, p < 0.001, and p < 0.001, respectively). The luminal and the stromal areas were significantly smaller in the S-NDR with PRP group than in the other groups (p < 0.001 and p < 0.001, respectively). LogMAR best corrected visual acuity (BCVA) exhibited significant negative correlation with the ONH MBR in vessel (r = −0.386, p < 0.001), tissue (r = −0.348, p < 0.001), and the choroid MBR (r = −0.339, p = 0.002) in the S-NDR with PRP group. Stepwise multiple regression analysis demonstrated that BCVA was a common independent factor associated with the ONH MBR in vessel, tissue, and the choroidal MBR in the S-NDR with PRP group.ConclusionsONH and choroid MBR in addition to choroidal component, including the luminal area, were significantly lower in eyes of patients with S-NPDR after PRP compared with no PRP and normal subjects group. This could suggest that the significantly reduced ocular blood flow in PRP-treated S-NPDR eyes correlated with long-term decreased post-PRP luminal area and visual acuity.

Quantifying vascular density and morphology using different swept-source optical coherence tomography angiographic scan patterns in diabetic retinopathy

“…Another limitation is that this cohort included eyes that had and had not received panretinal photocoagulation (PRP) laser. As previous research using laser speckle flowgraphy identified blood flow decreases after PRP,21 PRP may have confounded our results. However, our cross-sectional design prohibited us from evaluating the pathological microvascular alterations that were specifically related to the presence/absence of DMO or the effects of PRP treatment.…”

Retinal Microvascular Resistance Estimated from Waveform Analysis Is Significantly Higher With a Threshold Value in Central Retinal Vein Occlusion

“…[6][7][8][9][10][11] LSFG is a recently developed technique that has been used for visualizing blood flow distributions in the ocular fundus. This method is convenient for measuring blood flows and can be useful for clinical applications (e.g., diabetic retinopathy, [12][13][14][15][16][17][18] glaucoma, 8,19-25 uveitis [26][27][28]. We have previously reported LSFG findings in eyes with CRVO.…”

Bioactive lipids and pathological retinal angiogenesis

“…Non-proliferative DR is characterized by microaneurysms (the earliest sign, reflecting the pericyte loss and consequent weakness of the micro-vessels walls), micro-haemorrhage, macular oedema (the main cause of visual impairment), vascular tortuosity and beading. On the other hand, proliferative DR is characterized by retinal angiogenesis, vitreous neovascularization, haemorrhage or retinal detachment (Duh et al, 2017;Iwase et al, 2017).…”