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 have reported.

The Chengdu Research Base of Giant Panda Breeding in 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, 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 contacted by the Global Times on Thursday.

In humans, a disease called Vogt-Koyanagi-Harada (VKH) causes similar symptoms, turning hair, eyebrows and eyelashes into white and grey.

However, Dr Luo Qingli, an ophthalmologist at Chengdu Huaxia Eye Hospital, dismissed VKH as the cause of the pandas' ailment, reported the Science and Technology Daily.

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 pandas at the base have suffered from an eye disease.

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

"There were reports about the disease several months ago, but why haven't the pandas been healed?" said a user on China's Sina Weibo social media platform who goes by the name Tusansui.