Abstract
Purpose :
This study aims to investigate the influence of blue LED light on the visual cortex layer-5 pyramidal neurons(L5PN) and the protective efficacy of 2commercially available blue blocking lenses(BBL) namely Crizal Prevencia(CP) and Duravision Blue(DB).
Methods :
This study was approved by animal ethics committee of The Manipal Academy of Higher education, Kasturba Medical College (IAEC/02/2017). 24 male Wistar rats divided into 4 groups: 1light exposure (LE),2BBL group (CP and DB) and 1control group (NC). In LE group, rats were exposed to blue LED (400-490nm), in CP and DB group, BBL was fitted on top of LED, in NC group, rats were in normal lab illumination. In all groups, rats were exposed for 28 days,12:12 hours of light:dark cycles and a uniform (450-500 lux) light intensity. Rats were sacrificed at the end of 28 days; brain was embedded in Golgi-cox stain. Brain tissues of 150 microns sections were obtained using sledge microtome. Golgi stained L5PN were identified using the 20X objective of a wide-field microscope and images were capture using a Moticam 580-5.0 mp. Totally 30 photomicrographs were obtained from each neuron and they were separated by 5μm in the z-plane. All photomicrographs were projected to a calibrated Sholl’s grid. Dendrites were manually traced in a masked fashion. For apical and basal dendrites, the number of branching and intersections with 20μm concentric circles up to 140 μm from the soma were quantified using Sholl analysis
Results :
The L5PN of NC had significantly more intersections compared to LE, CPandDB. LE group had significant (p<0.001) loss of dendritic branches (13.72±3.2) compared to NC (21.3±0.3).Similarly, the CP (10.69±1.93) and DB (15.58±3.88) group had significantly less (p<0.05) dendritic branches compared to NC group (21.3±0.3) (Figure:1). Although, not statistically significant the number of dendritic branches and intersections were higher in CPandDB compared to LE group
Conclusions :
Exposure to blue LED damages the L5PN of visual cortex. BBL may offer moderate protection from blue LED.
This is a 2021 ARVO Annual Meeting abstract.