Abstract
Purpose:
Purpose: To determine whether low intensity red light (3000lux, 625-635nm) focused through dilated pupils of rat eyes given at the same time as raised intraocular pressure (IOP, 140mmHg, 60 min) can attenuate cell damage to both the retina and cornea.
Methods:
Methods: Male Wistar (300g) rats were anaesthetised and placed in a stereotaxic frame. The pupils from both eyes were dilated. The anterior chamber in one eye was cannulated with a 30G needle and the IOP increased to 140 mmHg. Raised IOP (60 min) was either delivered in complete darkness or where 3000 lux of red light was directed above the cornea. The other eye served as a control. At different times after raised IOP (reperfusion, RP), flat mount or sections of fixed (4% paraformaldehyde) corneas and retinas from each eye was processed for the localisation of different antigens. RNA was also extracted from freshly dissected retinas and subjected to qPCR analysis.
Results:
Results: Raise IOP caused damage to the mosaic appearance of corneal endothelial cells (3 days RP), a loss of retinal ganglion cells (RGCs, 15 days RP) and changes in the distribution of antigens located to specific cell-types. An elevation of retinal GFAP, vimentin, HO-1 and mTORC1 mRNAs (3 days RP) and a decrease of Thy-1, Brn3a or NF-L mRNAs (15 days RP) also occurred. These negative effects caused by raised IOP and RP to the cornea and retina were significantly attenuated by red light treatment.
Conclusions:
Conclusions: Corneal endothelial cell damage and death of RGCs occur in some glaucoma patients. Using a rat animal model it is demonstrated that such effects can be attenuated by low intensity red light therapy. This supports the notion for the use of red light therapy in the treatment of glaucoma.