Title
THE LIGHT-ADAPTED FULL-FIELD ERG LUMINANCE-RESPONSE SERIES IN PROLIFERATIVE DIABETIC RETINOPATHY TREATED WITH INTRAVITREAL RANIBIZUMAB AND MULTISPOT LASER PANRETINAL PHOTOCOAGULATION
Introduction
We aim to investigate the effects of intravitreal Ranibizumab (IVR), combined or not with conventional (ETDRS) or Multispot Laser Panretinal (PASCAL) photocoagulation (PRP) on light-adapted full-field ERG luminance-response series in eyes with proliferative diabetic retinopathy (PDR).
Methods
Laser-naive PDR patients that required PRP were randomly and prospectively assigned to receive IVR or IVR combined to PASCAL or EDTRS. PRP was performed at baseline in 1 (PASCAL) or 2 (ETDRS) sessions. Best-corrected visual acuity (BCVA), fluorescein angiography: to measure the leakage area (FLA), and OCT were performed at baseline and every 4 weeks after treatment. Full-field light-adapted electroretinography (Diagnosys LLC) was recorded using a 30 cd/m2 background and a sequence of six flashes stimuli from 0.1 to 30 cd.s/m2. B-wave amplitude data were fit with a sum of a logistic-growth and a Gaussian function (photopic hill equation). Reported parameters: VMax: sum of maximal amplitude from the two components, and μ: flash strength at the peak of the Gaussian component, in cd.s/m2.
Results
IVR=13, PASCAL=15, and ETDRS=15 eyes finished 48-weeks follow-up. There was a significant BCVA improvement of 0.1 to 0.3 logMAR in all groups (P<0.05). Overall, significant a- and b-wave amplitudes reductions were observed for dark- and light-adapted ERG for ETDRS and PASCAL, but only minor dark-adapted b-wave reduction was found for IVR, up to 48 weeks. Parameter VMax reduced significantly (P<0.05) after treatment (week 12, 24 and 48 respectively) on groups ETDRS (33%, 40% and 42%) and PASCAL (34%, 30% and 33%), while a significant reduction was observed only on week 48 for IVR (13%, 13%, 22%). Parameter μ increased significantly only on groups ETDRS and PASCAL.
Discussion
These parameters of cone-driven function show retinal damage on PDR eyes treated with PRP, and highlighted that IVR alone seems to avoid, at least partially, these changes.
Keywords
Diabetic Retinopathy; Electroretinography; Anti-VEGF; Retinal Photocoagulation
Area
CLINICAL CASE
Authors
Andre Messias, Katharina Messias, Rafael Barroso, Rodrigo Jorge