SINGAPORE – Life for Ms Tan Siew Ling, 38, an assistant manager in the innovation division at SG Enable, is not only dark, it is also silent. <\/p>\n
Ms Tan lost her sight when she was 10 and, after fully depending on her hearing after, she also lost that when she was 32. <\/p>\n
\u201cShe was around the age of eight or nine when she complained she could not see very well. Thinking it was short-sightedness, our mother brought her to the optician to get a pair of glasses made. It did not help her at all,\u201d her brother and primary caregiver Tan Yan Cai, 41, told The Straits Times.<\/p>\n
She was then brought to the Singapore National Eye Centre, where she was diagnosed with vision loss due to weak optical nerves. To prepare her for a life of blindness, she went to the Singapore Association Of The Visually Handicapped to learn braille, he said. <\/p>\n
Determined not to let her visual impairment hinder her education, Ms Tan completed her secondary education, passed her A levels and pursued a degree in business administration at the London School of Economics and Political Science.<\/p>\n
\u201cI did so relying on my hearing and from close friends motivating me and cheering me on. I do not want to be a burden to anyone \u2013 not friends, not family. With my education and a well-paying job, I would say I am now financially independent,\u201d she said.<\/p>\n
However, Ms Tan faced further challenges as her hearing began to deteriorate. In 2016, she lost hearing in her left ear, just a year after her mother\u2019s death. And in 2019, hearing in her right ear was gone too. <\/p>\n
Dr Amanda Cheang, who is currently a consultant with the department of otorhinolaryngology at Woodlands Health, said when Ms Tan lost her hearing in her left ear, an MRI scan showed that it was due to a growth on the nerve responsible for hearing. <\/p>\n
With her vision loss as a child and hearing loss in adulthood, doctors suspected she had neurofibromatosis type 2 (NF2), a rare genetic disorder that causes benign tumours to grow on nerves, including those affecting the brain and spinal cord. <\/p>\n
The estimated prevalence of NF2 is one in 50,000 people worldwide.<\/p>\n
\u201cNF2 is caused by mutations in the NF2 gene located on chromosome 22, which encodes a protein called merlin, which functions as a tumour suppressor. When it is inactive or defective, nerve cells can grow uncontrollably and form tumours,\u201d said Dr Cheang, who is also a visiting consultant at Tan Tock Seng Hospital (TTSH).<\/p>\n
Adjunct Associate Professor Yeo Seng Beng, emeritus consultant with the department of otorhinolaryngology at TTSH, said that while the tumours are benign, where they are located and their size can result in debilitating consequences. <\/p>\n
For example, tumours compressing the hearing nerves can result in hearing loss, those on the optic nerves may lead to blindness, and those along the spinal cord can result in pain, weakness, or numbness in the arms and legs.<\/p>\n
Dr Cheang said in most patients, these tumours grow slowly, so management typically involves periodic scans to monitor for any changes in their size. <\/p>\n Ms Tan Siew Ling (third from right) is flanked by her care team: (from left) senior audiologist Jocelynn Khoo, Adjunct Associate Professor Yeo Seng Beng, her brother Tan Yan Cai, Dr Amanda Cheang, and principal speech therapist Francoise Lim.<\/p>\n ST PHOTO: BRIAN TEO<\/p>\n<\/figcaption><\/figure>\n \u201cIn patients with progressive or rapid growth in tumours, particularly tumours affecting the hearing and balance nerves, bevacizumab can be prescribed as a treatment option. It is given intravenously every few weeks over the course of several months, sometimes extending to long-term use,\u201d said Dr Cheang. <\/p>\n Bevacizumab is a laboratory-made protein that mimics the immune system\u2019s natural antibodies, enabling it to find and bind to a specific target, such as an antigen on a cancer cell or a virus.<\/p>\n Dr Cheang cautioned that careful evaluation is essential before starting this treatment, as it may lead to side effects such as kidney issues and elevated blood pressure. <\/p>\n In Ms Tan\u2019s case, she completely lost her vision due to the benign tumours affecting both optic nerves.<\/p>\n \u201cShe then developed bilateral vestibular schwannomas \u2013 tumours affecting the nerves responsible for hearing and balance \u2013 which led to the profound hearing loss. She also has multiple meningiomas \u2013 tumours arising from the lining of the brain \u2013 but fortunately, these have not caused any symptoms,\u201d Dr Cheang said.<\/p>\n Said Ms Tan: \u201cI was angry and frustrated. I spent so much time and put in so much effort to maintain my independence, and then (the hearing loss) happened.\u201d<\/p>\n Nevertheless, she expressed gratitude to her close friends and her brother for \u201crallying in my corner\u201d.<\/p>\n In 2021, Ms Tan underwent right cochlear implant surgery to provide hearing stimulation in her right ear. <\/p>\n Her hearing rehabilitation journey is supported by TTSH staff Jocelynn Khoo, a senior audiologist who programmes her cochlear implant, and Francoise Lim, a principal speech therapist who oversees her post-surgical hearing rehabilitation.<\/p>\n Dr Cheang said: \u201cWhile we were hopeful that she might regain the ability to understand speech through the implant, we were also mindful that the tumour affecting her right hearing and balance nerve could limit her outcomes compared with most patients.<\/p>\n \u201cAfter the surgery, she was able to perceive environmental sounds, such as the beeping of MRT doors and approaching footsteps. But, despite intensive rehabilitation, she was unable to achieve clear speech recognition.\u201d <\/p>\n To facilitate communication, her brother, an IT engineer, discovered a Bluetooth-enabled keyboard that allows words to be translated into braille on a tactile display. Using this device, Ms Tan can \u201cread\u201d what he types and communicate more effectively.<\/p>\n Her groups of friends also take her jogging in the park, creating their own taps and hand signals to keep her safe during their jogs. <\/p>\n \u201cMoving forward, she is being considered for an auditory brainstem implant, a device that sends hearing signals directly to the brainstem, bypassing the tumour affecting her hearing and balance nerve. This will be a more major surgery than the cochlear implant surgery and is still a work in progress,\u201d Dr Cheang said, adding that Ms Tan is now undergoing assessments to evaluate her eligibility for the procedure.<\/p>\n Ms Tan remains uncertain about what lies ahead for her. <\/p>\n She admitted, her eyes welling up with tears, that she does not know how to hope or plan, whether for the immediate or distant future. <\/p>\n \u201cI just take life a day at a time, hoping for the best,\u201d she said.<\/p>\n<\/div>\n<\/picture><\/div>