"Not knowing how long more I'm going to have my vision, it could be next year or a few years' time. What I have is a progressive disease that ultimately leads to blindness."
Chong, who has a 20-year-old son Matthew Wong and 10-year-old daughter Chloe, said her biggest anguish was the thought she will not be able to see them get married or start a family.
"Family means everything to me and it's painful to think that I cannot see their future partners or my grandchildren ... but what can I do, I have no control," Chong said.
Chong, originally from Malaysia, was just 28 when signs first appeared that there was some problems with her sight.
"I started seeing black spots and sometimes, I see words on signboards that didn't appear complete," she said.
"I lost my peripheral vision and didn't realise it. I had lots of accidents, but usually it's people banging into me."
She was a high flying executive - having been the marketing director of Boston Consulting Group and senior marketing manager for Telecoms before it was renamed Spark.
But the fading eyesight forced her to stop driving in 2002 after she hit a pedestrian and stop working in 2009. She now depends mainly on her photographer husband Vincent Wong to take her around.
"It's affected my confidence badly especially since I was such an active person," Chong said.
"I don't want anybody to pity me, but it is scary to think that one day I could be living in darkness."
Chong said she currently has less than 10 degrees of visual field and is legally blind.
Dr Patel said RP sufferers made up about 5 per cent of referrals to the New Zealand Blind Foundation.
"Usually patients start noticing symptoms before 30 years of age and typically starts by affecting night vision and side vision resulting in 'tunnel vision'," Patel said.
"But sometimes central vision can also be affected due to swelling of the macula – the central part of the retina."
Patients have poor vision, he said, but most do not go completely blind.
"Karen does have very advanced disease but it has been stable over last few years," Patel said.
"Our aim is to maintain her current level of vision long term by addressing the macula swelling and the secondary glaucoma."
Patel said glaucoma was a common feature of RP because of the use of steroid eye drops to reduce swelling over the macula.
"Unfortunately, there is no cure, but we can treat some of the clinical features – like swelling at the macula that sometimes occurs as in Karen's case," Patel added.
Chong said she was keeping positive and planned to make the most of her time left with sight.
"I'm losing my vision but I'm not losing my brain, I can still do a lot and I can contribute a lot to society and the community," she said.
Chong, a Catholic, is an active volunteer at her daughter's school and in church.
Daughter Chloe, a Year 6 student at St Dominic's School, said she was worried for her mother.
"Even when I'm in school I worry about my mother falling down or hurting herself, I don't want her to go blind," she said.
RP, an eye disease with no cure:
• RP is a genetic condition whereby vision loss is caused by the breakdown and loss of cells in the retina.
• People with RP first notice difficulty seeing at night, next they will find their peripheral vision beginning to disappear.
• To understand individual condition, genetic testing is recommended.
• People experiencing unexpected change in vision or odd visual effects should contact an optometrist or ophthalmologist immediately.
(Source: Blind Foundation / Retina NZ)
