Chloroquine phosphate was administered to pigmented and albino rats via their drinking water for a period of seven months. The rats were divided into high, medium, and low dose groups. Rats of the low dose groups only survived the seven-month period of chloroquine administration and were found to have degenerative changes in their retinae. The chloroquine-induced changes consisted of membranous cytoplasmic bodies (MCBs) appearing in all the neurons of the retina. The pigment epithelium appeared normal.
Hodgkinson BJ, Kolb H. A Preliminary Study of the Effect of Chloroquine on the Rat Retina. Arch Ophthalmol. 1970;84(4):509-515. doi:10.1001/archopht.1970.00990040511022