About 3,000 public housing tenants aged 50 or above are invited to join a glaucoma screening test scheme by the University of Hong Kong and Orbis.

They must be tenants living in Southern District, Kwun Tong and Tai Po.

"Glaucoma is a chronic, degenerative disease of the optic nerve which leads to progressive visual field loss and ultimately blindness," said the team organizing the scheme. "Risk factors include increased age, elevated intraocular pressure and family history."

The team recommended people aged 50 or above to take an annual eye test.

Invitation letters for the project will be sent to randomly selected addresses of public rental housing units.

Eligible residents can make appointments online with proof of address and the letter they received, with a quota of two per household.

The team said their project will include free eye examinations such as visual acuity tests, refraction, tonometry, optical coherence tomography imaging and medical consultations with ophthalmologists. It offers referral services for follow-up treatment in public or private eye clinics.

HKU's Department of Ophthalmology said glaucoma - an eye condition that could cause irreversible blindness - affects central vision in the early stages, and that more aggressive treatment is necessary for patients with central vision damage than other glaucoma patients.

The team said this screening project uses Rota - a patented technology developed by a research team at HKUMed - which increases the diagnostic sensitivity by up to 30 percent for detection of early glaucoma compared with the current standard using the OCT retinal nerve fiber layer thickness analysis.

It can detect early glaucoma with central vision damage and other types of glaucoma.

Christopher Leung Kai-shun, chairman and clinical professor at HKU's Department of Ophthalmology, School of Clinical Medicine, said: "Glaucoma screening is not routinely performed in the community because false positive and false negative diagnosis of glaucoma is common and we lack a reliable screening tool.

"Rota allows for a noninvasive, contactless approach to visualize the optic nerve fibers on the retina, facilitating early and effective detection of glaucoma."

The team also hopes the completion of the project could show the prevalence and risk factors of glaucoma in Hong Kong. The university expects Rota to be used on both regional and international levels.

lorraine.chiang@singtaonewscorp.com

Invitation letters will be sent to randomly selected public housing addresses, according to the team behind the test scheme. SING TAO

3,000 housing tenants in line for free glaucoma tests