BEIJING - Some giant pandas at China's main panda research base are suffering from a disease that turns their distinctive eye patches from black to white, Chinese media reported.

The Chengdu Research Base of Giant Panda Breeding in the south-western Sichuan province has consulted two Chengdu-based medical experts on the disease, but a report issued by the experts gave no conclusive diagnosis, Global Times reported on Thursday (May 3), citing the Science and Technology Daily.

According to the report, the base confirmed that some giant pandas recently contracted partial depilation around the eyes.

The breeding base declined to provide further information when reached by the Global Times on Thursday.

In humans, a disease called Vogt-Koyanagi-Harada Disease (VKH) causes similar symptoms, with hair, eyebrows and eyelashes turning white and grey. But Luo Qingli, a ophthalmologist at Chengdu Huaxia Eye Hospital, was quoted by the Science and Technology Daily as dismissing VKH as the cause of the the pandas' ailment .

Netizens have been quick to express their concern and question the Chengdu base's treatment of the pandas.

This is at least the second time this year that the giant pandas at the Chengdu base have suffered from an eye disease.

Ten giant pandas at the base caught mite infections around the eyes which also turned their black patches partially white, the Chengdu Economic Daily reported in January 2018.

A Sina Weibo user "tusansui" questioned the base's treatment of giant pandas, saying "there were reports about the disease several months ago, but why haven't the pandas been healed?"

Another user, "anyihhh", accused the base of not admitting that the pandas are affected by mites.