Abstract
Purpose :
Experimental studies show that adrenergic β-blockers are involved with the modulation of vascular endothelial growth factor expression, and inflammatory cytokines in Müller cells in a hyperglycemic environment. In this context, we aimed to investigate the safety and possible effects of a single intravitreous (IV) Propanolol injection on retinal structure and function in patients with proliferative diabetic retinopathy (PDR).
Methods :
Prospective phase-I clincal trial to sutdy the safety of intravitreal propanolol in patients with persistent retinal neovascularization (NV), defined as recurrence of NV showed on fluorescein angiography (FA, SD-OCT Heildelberg), despite pan-retinal-photocoagulation and anti-VEGF treatment. Pre-treatment best-corrected visual acuity (BCVA) should be better than 20/400. Comprehensive ophthalmological examination was performed at baseline and at 1,4, and 12 weeks after one single intravitreal injection of 500μg/0.05ml. These evaluations included fluorescein angiography for new vessels area measument, SD-OCT and full-field electroretinogram (ERG - Diagnosys LLC), according to the recommendations of ISCEV standard.
Results :
So far, 3 patients completed the 4-week study visit. BCVA (logMAR) improved from week 1 to 4 in all 3 cases: 0.9 to 0.6, 0.6 to 0.4 and 0.7 to 0.3 (P = 0.0351 – paired t-Test). Average new vessels area on FA was 10.9 at baseline and 9.05 mm2 4 weeks after treatment (P>0.05). Typical ERG changes associated with PDR (reduced amplitude and prolonged implicit time) were found at baseline for all 3 eyes. No significant changes were observed for ERG a- or b-wave amplitudes or implicit times throughout follow-up. Mean ± SD dark-adapted b-wave amplitude (3.0 cd.s/m2) was 73.0 ± 44.3 µV at baseline; and 83.6 ± 49.3 µV; and 75.7 ± 31.0 µV at 1 and 4 weeks after treatment respectively (P = 0.7865), while light-adapted cone (3.0 cd.s/m2) was 15.2 ± 11.1 µV at baseline; and 24.0 ± 15.0 µV; and 18.5 ± 4.7 µV at 1 and 4 weeks after treatment respectively (P = 0.3322),
Conclusions :
In this small sample, IV Propranolol showed no signs of retinal toxicity, neither on retinal structure nor function, and an improvement on visual acuity was observed after treatment. Further investigation is necessary to confirm these findings and evaluate efficacy of this potential new therapy for PDR.
This is a 2020 ARVO Annual Meeting abstract.