Normal physiological and pathophysiological effects of trypan blue on the retinas of albino rabbits.
OBJECTIVE
To determine whether intravitreal injection of trypan blue is toxic to the retina of the albino rabbit.


METHODS
Sixteen albino rabbits were studied for the effects of intravitreal trypan blue (eight with 0.06% solution and eight with 0.15% solution). Saline was injected into the fellow control eye of all rabbits. The electroretinogram and visual evoked potentials were recorded from each rabbit at different time intervals after injection. The rabbits were killed at the termination of the follow-up period, and their retinas were prepared for histologic examination under light microscopy.


RESULTS
In all rabbits, short-term follow-up showed significant reduction of ERG responses in the experimental eye, with the b-wave more affected than the a-wave. Partial to complete recovery was observed during follow-up. After 4 weeks, negligible ERG deficit was observed in the rabbits treated with 0.06% trypan blue, whereas significant ERG deficit was measured in rabbits tested by the 0.15% trypan blue. No differences in flash VEP responses between experimental and control rabbit eyes were found. Light microscopy showed no significant histologic effects in the retinas exposed to the 0.06% solution. Marked disorganization of all retinal layers was observed in areas close to the site of injection in the rabbits injected with the 0.15% solution.


CONCLUSIONS
Trypan blue exerts transient physiological effects on the distal retina of the rabbit, but in concentrations of 0.15% it can induce permanent toxic effects. Therefore, caution should be used when using this dye in vitreoretinal surgery.
Heilweil
Gad
G
Department of Ophthalmology, Tel Aviv Medical Center, Tel Aviv, Israel.
Komarowska
Izabela
I
Zemel
Esther
E
Loewenstein
Anat
A
Perlman
Ido
I
D000818:Animals; D004396:Coloring Agents / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004596:Electroretinography / Q000187:drug effects*; D019773:Epiretinal Membrane / Q000601:surgery; D005074:Evoked Potentials, Visual / Q000187:drug effects*; D005500:Follow-Up Studies; D007267:Injections; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000503:physiopathology*; D013997:Time Factors; D014343:Trypan Blue / Q000633:toxicity*; D014821:Vitrectomy; D014822:Vitreous Body
D004396:Coloring Agents; D014343:Trypan Blue