SINGAPORE - Her wedding was one of the happiest days of her life.

But Ms Nurul Jannah Mohd Nasri’s nuptials ended with her in hospital and having to miss a week-long honeymoon in South Korea.

A week before her special day in March, the 25-year-old pre-school teacher experienced what she thought was a regular migraine behind her left eye.

She started to get worried when her vision went blurry, with what seemed like a grey pixelated line in the middle.

But she ignored it, and it went away after some time.

After celebrating her wedding with family and friends, Ms Jannah noticed the vision in her left eye was getting worse and her head would not stop pounding.

When she went back to the hotel with her husband, marketing executive Zamani Razali, 27, to get some rest, she told him that she did not feel well.

“I was starting to get worried that I would be unable to fly the next day for my honeymoon if I was still unwell. My husband urged me to visit the doctor to get medication,” she said.

Her parents drove her to the emergency department at the National University Hospital (NUH), where she was checked by eye specialists.

They told Ms Jannah she was experiencing inflammation of the optic nerve that could cause blurred vision, and she had to be hospitalised immediately as her symptoms could worsen.

She said: “I felt bad for my husband, especially because we really wanted to go for the honeymoon. We saved and planned a lot for it. I apologised to him many times, but he assured me that my health comes first.”

Ms Jannah underwent multiple procedures, including CT and MRI scans and lumbar puncture and blood tests, to confirm what was causing the inflammation.

A neurologist told her she might have myelin oligodendrocyte glycoprotein antibody-associated disease, or MOG antibody disease.

MOG antibody disease is a recently recognised autoimmune inflammatory disorder that targets the central nervous system.

During an attack, the inflammation targets primarily the optic nerve, spinal cord and/or brain, said Dr Amy Quek, a senior consultant in NUH’s division of neurology.

Depending on which area is targeted, patients with the disease can experience different symptoms.

Those with optic neuritis, like Ms Jannah, may experience vision blurring or loss, while inflammation of the spinal cord can result in limb weakness, numbness and disturbances in urinary or bowel function.

Dr Quek said brain involvement can result in symptoms like confusion, headaches, vomiting, speech problems, weakness and seizures.

The occurrence rate of the disease is unknown as it is a relatively uncommon and newly recognised neurological disorder, she told The Straits Times.

Ms Jannah said: “After getting diagnosed, I realised it might also be the reason I felt tired and sleepy almost every day despite having sufficient rest.

“My students caught me falling asleep in class a few times, and I would get tired more easily when I was out.

“I thought nothing was wrong with my body, just that I felt tired like any other adult out there.”

There is no cure for the disease, but treatments to manage the condition are available.

For now, Ms Jannah takes medication daily to manage her symptoms. She said: “I hope that despite living with this condition, it won’t hinder me from having children, as having my own family is a dream for me.”