Abstract
Purpose::
The goal of this study was to investigate the presence of chloroquine induced lesions in human retinas obtained pos-mortem from a donor who had received chronic treatment with chloroquine and to establish an experimental model in rats to study the retinopathy caused by this drug.
Methods::
The human retinas were obtained of a donor that had erythematosus systemic lupus (ESL), and was treated with chloroquine during 13 years. A pair of retinas was obtained from a donor with no records of diseases or chronic usage of drugs. In the experimental study, six male rats were treated with 40mg/Kg/day of chloroquine (base) orally for twelve weeks, and four male rats were treated with vehicle orally during the same period. Both human and rat retinas were vertically sectioned using a cryostat and were stained with Sudam III for lipidosis; retinal flat-mounts stained with Nissl method were used for qualitative evaluation. Flat-mounts of rat retinas were used for quantitative analysis of density and size of retinal neurons.
Results::
There was no evidence of disruption of the retinal layers and lipidosis was not observed in either group of rats. The quantitative analysis of cell density and size also did not show any relevant difference between controle and chloroquine-treated rats. On the other hand, large-sized ganglion cells were virtually abesent in human retinas from chloroquine-treated subject in comparison to control retinas. Therefore, the results show that 40mg/Kg/day of chloroquine did not cause any significant qualitative or quantities changes in the rat retinas. Although there were pathological changes in the human retinas from the chloroquine-treated donor, these changes could not be attributed solely to the use of this drug.
Conclusions::
Therefore, other studies are still necessary to investigate the possible relation of chronic chloroquine use with these findings.
Keywords: antibiotics/antifungals/antiparasitics • retina • immunohistochemistry