BDNF reduces the retinal toxicity of verteporfin photodynamic therapy.
OBJECTIVE
Verteporfin photodynamic therapy (PDT) is the most effective treatment for age-related macular degeneration, using laser activation of a photosensitizing dye to achieve closure of choroidal neovascularization. Although PDT preferentially affects pathologic vessels, it can also cause collateral damage to the overlying retina. In the current study, it was found that the neuroprotective agent brain-derived neurotrophic factor (BDNF) reduces this retinal damage.


METHODS
Normal adult rats received intravitreal BDNF in one eye and PBS or no injection in the other eye 2 days before PDT.


RESULTS
Control eyes exhibited choroidal hypofluorescence, moderate to severe photoreceptor loss, and depression of local retinal function measured using multifocal ERG in the laser-treated area. BDNF-injected eyes had more surviving photoreceptors and improved multifocal ERG responses 1 week after PDT. BDNF did not diminish the effect of PDT on the choroidal circulation as assessed by fluorescein angiography, and there was no evidence of retinal toxicity due to BDNF treatment.


CONCLUSIONS
These results suggest that adjunctive neuroprotective therapy may reduce collateral damage to photoreceptors and improve visual outcome after PDT.
Paskowitz
Daniel M
DM
Department of Ophthalmology, University of California, San Francisco, 94143-0730, USA.
Nune
George
G
Yasumura
Douglas
D
Yang
Haidong
H
Bhisitkul
Robert B
RB
Sharma
Shivani
S
Matthes
Michael T
MT
Zarbin
Marco A
MA
Lavail
Matthew M
MM
Duncan
Jacque L
JL
D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology*; D002829:Choroid / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D004596:Electroretinography / Q000187:drug effects; D005451:Fluorescein Angiography; D005453:Fluorescence; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010778:Photochemotherapy; D020419:Photoreceptor Cells, Vertebrate / Q000187:drug effects / Q000473:pathology; D017319:Photosensitizing Agents / Q000633:toxicity*; D011166:Porphyrins / Q000633:toxicity*; D051381:Rats; D011914:Rats, Inbred BN; D012160:Retina / Q000187:drug effects* / Q000473:pathology; D000077362:Verteporfin
D019208:Brain-Derived Neurotrophic Factor; D018696:Neuroprotective Agents; D017319:Photosensitizing Agents; D011166:Porphyrins; D000077362:Verteporfin