Effects of subretinal injection of patent blue and trypan blue in rabbits.
OBJECTIVE
To investigate the histologic and clinical effects of subretinal injection of patent blue (PB) and trypan blue (TB) in rabbits.


METHODS
Dutch-belted rabbits (n=8) were vitrectomized followed by subretinal injection of 2.4 mg/ml PB (285 mOsm) and 1.5 mg/ml TB (312 mOsm); balanced salt solution (BSS) (300 mOsm) served as the control. Animals were examined 6, 12, and 24 hr and 14 days after the procedure by fluorescein angiography (FA) and indirect ophthalmoscopy; for retinal toxicity, histologic evaluation studies were performed by light and transmission electron microscopy.


RESULTS
FA examination demonstrated window defects suggestive of retinal pigment epithelium (RPE) atrophy in positions of subretinal TB injection, but this was not observed after subretinal injection of PB or BSS. Histologic evaluation disclosed only minimal abnormalities on the photoreceptor outer segment (POS) after subretinal injection of BSS during all follow-up. Subretinal injection of PB caused POS and photoreceptor inner segment (PIS) abnormalities 12 and 24 hr after surgery as well as outer nuclear layer (ONL) damage 14 days after surgery. Subretinal TB injection resulted in POS and PIS damage at 12 hr follow-up. The ONL damage was observed 24 hr after surgery; additionally, POS, PIS, ONL, and RPE abnormalities were observed 14 days after surgery after TB injection.


CONCLUSIONS
Subretinal injection of TB induced more significant clinical and histologic damage of neurosensory retina/RPE than did PB or BSS. Future human studies are necessary to access the clinical relevance of these in vivo experiments.
Maia
Mauricio
M
Ophthalmology Department, Paulista School of Medicine, Vision Institute, Federal University of Sao Paulo, Brazil.
Penha
Fernando
F
Rodrigues
Eduardo B
EB
Príncipe
André
A
Dib
Eduardo
E
Meyer
Carsten H
CH
Freymuller
Edna
E
Moraes
Nilva
N
Farah
Michel Eid
ME
D000818:Animals; D004396:Coloring Agents / Q000008:administration & dosage* / Q000009:adverse effects; D005451:Fluorescein Angiography; D007267:Injections; D008854:Microscopy, Electron; D020419:Photoreceptor Cells, Vertebrate / Q000187:drug effects / Q000473:pathology; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000473:pathology*; D012394:Rosaniline Dyes / Q000008:administration & dosage* / Q000009:adverse effects; D013997:Time Factors; D014343:Trypan Blue / Q000008:administration & dosage* / Q000009:adverse effects; D014821:Vitrectomy / Q000379:methods*
D004396:Coloring Agents; D012394:Rosaniline Dyes; C008769:sulfan blue; D014343:Trypan Blue