Methylprednisolone fails to preserve retinal ganglion cells and visual function after ocular ischemia in rats.
OBJECTIVE
Methylprednisolone (MP) is commonly used to treat traumatic optic neuropathy and optic neuritis, but its benefit in terms of neuronal survival remains controversial. The aim of this study was to investigate the effects of MP on retinal ganglion cell (RGC) survival and visual function after ischemia in rats.


METHODS
Ocular ischemia was induced by elevated intraocular pressure. Rats were treated with NaCl, 1 mg/kg/d, or 30 mg/kg/d intraperitoneal MP over 3 days. RGCs were labeled retrogradely 4 days after ischemia and were quantified 6 days later. Post-ischemic retinal function was assessed by scotopic and photopic electroretinography (ERG). Optic nerve function was investigated on days 4 and 10 after ischemia by visual evoked potentials (VEPs).


RESULTS
Compared with nonischemic eyes, ischemia reduced RGCs with NaCl to 47% +/- 3% (mean +/- SEM) and to 46% +/- 3% and 43% +/- 6% with 1 mg/kg/d and 30 mg/kg/d MP. ERG did not differ significantly for any parameter among the three groups. Four days after ischemia, the VEPs of rats receiving any dose of MP were significantly higher than the control. VEPs in both steroid groups fell to control levels 10 days after ischemia.


CONCLUSIONS
Treatment with MP did not improve RGC survival or retinal function. The VEP showed a short-term benefit because of steroids.
Dimitriu
Cornelia
C
University Eye Hospital Freiburg, Freiburg, Germany.
Bach
Michael
M
Lagrèze
Wolf A
WA
Jehle
Thomas
T
D000818:Animals; D002452:Cell Count; D002470:Cell Survival / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004596:Electroretinography; D005074:Evoked Potentials, Visual; D005938:Glucocorticoids / Q000627:therapeutic use*; D007511:Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use*; D009900:Optic Nerve / Q000187:drug effects / Q000503:physiopathology; D051381:Rats; D011914:Rats, Inbred BN; D012164:Retinal Diseases / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D017211:Treatment Failure
D005938:Glucocorticoids; D008775:Methylprednisolone