Intravitreal bevacizumab for persistent macular edema with proliferative diabetic retinopathy

Abstract

To evaluate the effectiveness of an intravitreal bevacizumab injection on retinal neovascularization and diabetic macular edema (DME) refractory to laser photocoagulation therapy. Thirty-four eyes of 22 patients with proliferative diabetic retinopathy and DME refractory to laser photocoagulation therapy received an intravitreal injection of 1.25 mg/0.05 ml of bevazicumab. Changes in mean best-corrected visual acuity (BCVA), central macular thickness (CMT), regression of neovascularization over time, and correlation between BCVA and CMT were evaluated. Follow-up visits were at weeks 1, 2 and 4 and months 3 and 6. Mean BCVA was significantly better than baseline only at week 2 (P = 0.036). Mean CMT decreased significantly from baseline at weeks 1, 2, and 4 (P = 0.001). At months 3 and 6, mean CMT increased, albeit insignificantly (P = 0.804 and P = 1.0). The decrease in fluorescein leakage was moderate in all eyes at the end of week 1. At week 2, there was total resolution of fluorescein leakage in 24 (70.5%) eyes and moderate resolution in 10 (29.5%) eyes. At the end of month 3, the fluorescein leakage was fully resolved in 5 (14.7%) eyes, moderately resolved in 24 (70.5%) eyes, and was similar to baseline in 5 (14.7%) eyes. At month 6, the fluorescein leakage was fully resolved in 3 (8.8%) eyes, moderately resolved in 20 (58.8%) eyes, and was similar to baseline in 11 (32.4%) eyes. A moderate but insignificant negative correlation was found between visual acuity and CMT (P > 0.05). Persistence or recurrence of neovascular tissue after panretinal photocoagulation may be attributed to the production of vascular endothelial growth factor by the residual ischemic retina, which also results in persistent or recurrent DME despite macular grid photocoagulation.

On the relationship between visual acuity and central retinal (macular) thickness after interventions for macular oedema in diabetics: a review

“…A second level of scrutiny (generally removing case reports, in which the data were not presented in the way defined as suitable et cetera) reduced this further to a total of 140 cohorts reported in 121 different publications, of which only 88 were found to include a full set of data for the planned analyses comparing CMT to VA. The reasons for exclusion were generally because of an incomplete data set (for example, by just reporting percentage changes or the fraction of eyes with a certain range of changes in VA or CMT), leaving 43, nine, 18 and 17 data sets of information for the different interventions (Table ) with some publications yielding more than one set of data …”

“…Specific statements on the use of time‐domain optical coherence tomography method were provided for 76 per cent of the data sets . CMT: central macular thickness.…”

Intravitreal Bevacizumab for Treatment of Diabetic Macular Oedema

“…46 Several other case series studies have also provided evidence supporting beneficial effect of iVB for persistent DMO with the logic that persistence or recurrence of DMO after Mpc may be attributed to the production of VEGF by the residual ischaemic retina, which may result in persistent or recurrent DMO despite Mpc. [47][48][49] in summary, literature searches conducted in this study disclosed that almost all studies published up to now provided evidence supporting use of iVB for treatment of either naïve or persistent DMO in short and long term up to 2 years. 115 eyes a) three injection of 1.25 mg iVB at 6 weeks intervals B) iVt (2 mg) followed by two injections of iVB at 6 weeks intervals c) sham injection cMt was reduced significantly in both the iVB and iVB/ iVt groups.…”

The effect of intravitreal bevacizumab on ocular blood flow in diabetic retinopathy and branch retinal vein occlusion as measured by laser speckle flowgraphy

“…It can improve vision by temporarily blocking VEGF action and subsequently reducing macular edema. However, in cases of DR- or BRVO-associated macular edema (DME and BRVOME, respectively), the effect of IVB is often insufficient, requiring the treatment to be repeated many times 8–11. It is not known why the effectiveness of the treatment is poor in these cases, as the underlying mechanism of IVB’s ability to reduce macular edema is still not well understood.…”