Добавил:
kiopkiopkiop18@yandex.ru t.me/Prokururor I Вовсе не секретарь, но почту проверяю Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Ординатура / Офтальмология / Английские материалы / Retinal Degenerative Diseases Laboratory and Therapeutic Investigations_Anderson_2008.pdf
Скачиваний:
0
Добавлен:
28.03.2026
Размер:
10.55 Mб
Скачать

Chapter 42

Near-Infrared Light Protect the Photoreceptor from Light-Induced Damage in Rats

Chao Qu, Wei Cao, Yingchuan Fan, and Ying Lin

Abstract

Background: A project originally developed for NASA plant growth experiments in space demonstrating the Light-Emitting Diode (LED) could promote the wound healing. Further study showed that the LED’s could protect cells by stimulating the basic energy processes in the mitochondria of each cell.

Objective: The purpose of this study was to assess the effects of 670 nm LED to protect the photoreceptor from the light-induced damage in a rodent model.

Methods: SD rats were randomly assigned to one of eight groups: untreated control group, the LED-treated control group, three light-induced damage groups, and three LED-protected groups. The rats were exposed to constant light for 3 h of different illuminations of 900, 1,800 and 2,700 lux, respectively. The LED treatment (50 mW) were done for 30 min, 3 h before the light damage and 0, 24 and 48 h after the light damage. Using the electroretinogram as a sensitive indicator of retinal function, and the histopathologic change was showed as a proof of the protective effect of LED treatment.

Results: The 900 lux illumination for 3 h did not cause damage to the retina of rats, however, the 1,800 lux illumination for 3 h caused significant damage to ONL of an approximate half retina, which caused the swing of ERG b wave to be 431 μV. With the LED protection: the damage of ONL was near 1/6 of retina, which was significantly reduced than the ones without LED protection (P < 0.01); and the swing of ERG b wave was recorded to be 1,011 μV, which was

Y. Fan (B)

Department of Ophthalmology, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, Sichuan 610072, China

e-mail: lucyjeffersonqu@hotmail.com

This work was supported by National Natural Science Funds No: 30771220; by Provincial Funds No: 303005002082 & 303005002127037

R.E. Anderson et al. (eds.), Retinal Degenerative Diseases, Advances in Experimental

365

Medicine and Biology 664, DOI 10.1007/978-1-4419-1399-9_42,C Springer Science+Business Media, LLC 2010

366

C. Qu et al.

increased significantly than the ones without LED protection (P < 0.01). The illumination of 2,700 lux for 3 h caused severe damage to the rats’ retinas and the LED could not protect them significantly in both of morphology and function (P > 0.05, P > 0.05).

Conclusions: 670 nm LED treatment has an evident protective effect on retinal cells against light-induced damage, which may be an innovative and non-invasive therapeutic approach to prevent or to delay age-related macular degeneration.

42.1 Introduction

Light-emitting diodes (LED) arrays, which consist of light in the far-red to nearinfrared region (NIR) of the spectrum (630–1,000 nm), were developed for National Aeronautics and Space Administration manned space flight experiments (Whelan et al. 2001). Thenceforth Whelan and others designed a serial of animal experiments and clinical trails, the results of which indicted the LED could prevent the development of oral mucositis in pediatric bone marrow transplant patients (Whelan et al. 2002), accelerate wound healing in genetically diabetic mice (Whelan et al. 2003), reduce TCDD-induced mortality in the developing chick embryo (Yeager et al. 2006, 2005), improve recovery from ischemic injury in the heart (Sommer et al. 2003), and attenuate degeneration in the injured optic nerve (Eells et al. 2004, 2003). The mechanism of LED therapy, commonly referred to as ‘Photobiomodulation’, has been shown to stimulate signaling pathways resulting in improved mitochondrial energy metabolism, antioxidant production, and cell survival (Desmet et al. 2006). Whelan proposed that NIR-LED photobiomodulation represents an innovative and non-invasive therapeutic approach for the treatment of tissue injury and disease processes in which mitochondrial dysfunction is postulated to play a role including age-related macular degeneration (Eells et al. 2004).

The light-induced retinal damage (LIRD) profile in the SD rat manifests similarities to advanced human atrophic AMD, so which was chosen as the optimal animal model to research the mechanism of AMD (Marc et al. 2008). Recent observations demonstrating the importance of mitochondrial function and the high metabolic demands of rods make it likely that loss of calcium homeostasis, free radical damage, and any other processes leading to mitochondrial failure may also be of significance in light induced damage (Barron et al. 2001; Missiaen et al. 2000; Carmody et al. 1999).

The present studies extended the LED investigations to an in vivo system to determine whether 670-nm LED treatment would attenuate the retinal degeneration in an animal model of light-damage, implications for age related macular degeneration.