The effects of iodoacetic acid on the mouse retina.
BACKGROUND
To characterize the effects of intravitreal injections of iodoacetic acid (IAA) in comparison to its systemic application as a measure to induce unilateral photoreceptor degeneration.


METHODS
Seven-week-old C57BL/6 J mice received either intravitreal injections of IAA or systemic treatment (intraperitoneal vs intravenous) and were observed in the following 5 weeks using ERG, OCT, and histology.


RESULTS
Systemic treatment with IAA induced high toxic effects and a high mortality in contrast to the intravitreal injection. Intraperitoneal application had no effect on the retina. Intravenous application of 2 × 30 mg/kg BW IAA (time between injections 3.5 h) resulted in an extinction of the ERG and a thinning of the retina, in particular of the outer nuclear layer (ONL) indicating photoreceptor degeneration. Animals receiving intravitreal injections developed cataracts already at low concentrations (up to 100% at 0.25 mg/kg BW). Higher intravitreal IAA doses led to extinguished ERGs. In histology, a thinning of the entire retina was observed that was most prominent in the inner part of the retina.


CONCLUSIONS
In contrast to intraperitoneal administration, intravenous application of IAA led to a selective photoreceptor degeneration. After intravitreal injection, dense cataracts were already observed at concentrations lower than those needed to induce changes in the ERG. ERG results must be interpreted carefully. A thinning of all retinal layers rather than a specific outer retinal degeneration was observed upon intravitreal injection. IAA is not a useful model to induce outer retinal degeneration in mice.
Department of Ophthalmology, RWTH Aachen University, Pauwelsstr. 30, 52074, Aachen, Germany.
Sarah
S
Rösch
Sandra
S
Johnen
Babac
B
Mazinani
Frank
F
Müller
Christiane
C
Pfarrer
Peter
P
Walter
D000818:Animals; D002386:Cataract / Q000139:chemically induced* / Q000473:pathology; D004596:Electroretinography / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000633:toxicity*; D005260:Female; D007275:Injections, Intravenous; D058449:Intravitreal Injections; D019807:Iodoacetic Acid / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D012160:Retina / Q000187:drug effects* / Q000378:metabolism; D012162:Retinal Degeneration / Q000139:chemically induced* / Q000473:pathology; D041623:Tomography, Optical Coherence
D004791:Enzyme Inhibitors; D019807:Iodoacetic Acid