Effects of intraocular irrigation with melphalan on rabbit retinas during vitrectomy.
OBJECTIVE
To investigate the toxic effects of perfusion of intravitreal melphalan during vitrectomy on the rabbit retina.


METHODS
We performed electoretinography (ERG) in 18 eyes of 18 healthy albino rabbits before and after intraocular melphalan perfusion at concentrations of 5-, 10-, and 20-microg/ml during pars plana vitrectomy. Fellow eyes that underwent vitrectomy without melphalan served as controls. The histopathologic retinal changes were observed in both eyes of two rabbits from each group.


RESULTS
In the 5-microg/ml perfusion group, the ERGs and histology showed no substantial changes compared with control fellow eyes during 28 days postoperatively. In the 10- and 20-microg/ml groups, the mean a-wave amplitude decreased to 52% and 31% respectively of the fellow eye; the mean b-wave amplitude decreased to 52% and 19% respectively. However, the peak implicit time of the a- and b-waves did not significantly differ in the 10- and 20-microg/ml groups during 28 days postoperatively. Histologic sections showed necrosis of the inner nuclear layer and thinning of the outer nuclear layer in the 10-microg/ml group. Loss of the outer nuclear layer and the photoreceptor layer and necrosis of the inner nuclear layer were observed in the 20-microg/ml group.


CONCLUSIONS
The intravitreal 5-microg/ml melphalan perfusion during vitrectomy appears to be nontoxic to the retina. This therapeutic modality might be a potential treatment for retinoblastoma with vitreous seeding.
Shimoda
Yukitoshi
Y
Department of Ophthalmology, Gunma University School of Medicine, 3-39-15 Showa-machi, Maebashi, Gunma 371-8511, Japan. y-simo@pg7.so-net.ne.jp
Hamano
Rika
R
Ishihara
Katuhiko
K
Shimoda
Noriko
N
Hagimura
Norikazu
N
Akiyama
Hideo
H
Kishi
Shoji
S
Kaneko
Akihiro
A
D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage / Q000633:toxicity*; D004596:Electroretinography / Q000187:drug effects; D007263:Infusions, Parenteral; D008558:Melphalan / Q000008:administration & dosage / Q000633:toxicity*; D009887:Ophthalmoscopy; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000473:pathology; D012164:Retinal Diseases / Q000139:chemically induced / Q000473:pathology; D014821:Vitrectomy
D018906:Antineoplastic Agents, Alkylating; D008558:Melphalan