Analysis of Potential Ischemic Effect of Intravitreal Bevacizumab on Unaffected Retina in Treatment-Naïve Macular Edema Due to Branch Retinal Vein Occlusion: A Prospective, Interventional Case-Series.
BACKGROUND
To study potential ischemic effects of intravitreal Bevacizumab (IVB) on unaffected retina in treatment-naive eyes with macular edema secondary to branch retinal vein occlusion (BRVO) and contralateral eyes secondary to systemic absorption.


RESULTS
Prospective, interventional series included 27 treatment-naive eyes with BRVO and macular edema.


METHODS
Eyes with diabetic retinopathy, glaucoma, vasculitides, papilledema or systemic neurologic condition. Subjects underwent complete ophthalmological examination including fluoroscein angiography (FA), optical coherence tomography (OCT) and multifocal electroretinogram (mf-ERG). All subjects received single 1.25 mg/0.05ml IVB injection. Two observers measured all parameters; inter-observer agreements were expressed as kappa values. Paired t-test was used to compare values at baseline and follow-up. The statistical analysis was done using SPSS for Windows, Version 14.0. (Chicago, SPSS Inc.) Presenting mean CFT (central foveal thickness) was 499.5(+/-229.7) μm, mean BCVA (best corrected visual acuity) was 0.64(+/-0.41) logMAR. At last follow-up, mean CFT was 267.9(+/-159.3) μm (P<0.001), 95% CI [127.18, 422.32]; mean BCVA was 0.28(+/-0.24) logMAR. Respectively, mean N1 and P1 amplitudes of mfERG in 'unaffected quadrant' at presentation were -6.10(+/-4.00) nV/deg2 and 17.17(+/-11.54)nV/deg2; and -5.33(+/-1.30)nV/deg2 and 15.29(+/-4.69)nV/deg2 at final follow-up (P = 0.631 and 0.197, respectively), (95% CIs [-0.93, 1.42] and [-4.22, 1.08] respectively). In fundus quadrant of fellow eyes corresponding to unaffected quadrant in treated eyes, mean N1 and P1 amplitudes at presentation were -5.39(+/-1.56)nV/deg2 and 15.89(+/-3.89)nV/deg2; and -5.39(+/-1.90)nV/deg2 and 15.9(+/-5.52)nV/deg2 (P = 0.380 and 0.208), (95% CIs [-0.57, 1.28] and [-4.1, 1.1]) at last follow-up, respectively.


CONCLUSIONS
This study analysed the effects with a single injection of bevacizumab. However, whether ischemic adverse effects will emerge with repeated IVB injections as a consequence of cumulative dosing needs further investigation. The setting of our study being a tertiary care centre, the numbers of fresh BRVO cases without prior intervention were limited. Thus, the limitations of our study include a small sample size with a small follow-up period. No major ocular/systemic adverse event was observed in the study period.


CONCLUSIONS
No evidence of progressive ischaemia attributable to single bevacizumab treatment was observed in this study. However, a larger prospective study involving subjects with cumulative dosing of bevacizumab and a longer follow-up could provide a better understanding of the potential ischaemic effects of bevacizumab or other anti-VEGF agents.
Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Chennai, TamilNadu, India.
Pukhraj
P
Rishi
Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Chennai, TamilNadu, India.
Neha
N
Raka
Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Chennai, TamilNadu, India.
Ekta
E
Rishi
D000328:Adult; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D000068258:Bevacizumab / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D008269:Macular Edema / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012160:Retina / Q000187:drug effects* / Q000473:pathology; D012170:Retinal Vein Occlusion / Q000150:complications* / Q000503:physiopathology; D012171:Retinal Vessels / Q000473:pathology / Q000503:physiopathology; D041623:Tomography, Optical Coherence; D014792:Visual Acuity; D014822:Vitreous Body
D020533:Angiogenesis Inhibitors; D000068258:Bevacizumab