It’s the drops. Also, one of the electrodes has fallen out of his eye.

“You can go and get a coffee if you like,” the ophthalmologist tells me. 

She is pleasant to Dan, if a little distant. This makes me happy. Distance means focus. It’s better for the science.

“I’ll stay, I say.”

Sitting in the dark is a useful metaphor, anyway.

Dan is a tall, solid, blond lead guitarist whose image screams confidence. I have pictures of him when he was small. On the trampoline, because I told him to pose there. Sailor-style T-shirt. Smile like a country.  Glasses like a 1970s serial killer.

Big sisters smother their little brothers with care. I tell Dan I’m coming down to write about him. Really, I’m here for the diagnosis.

I remember my own. Not the same disease, but incurable, scary, and genetic. Afterwards I walked around these dark grey footpaths above Spring Street, where it’s all politics and cancer.

I just don’t want him to be alone.

After a morning of tests, Dan hasn’t yet been diagnosed. We think he has macular dystrophy. A genetic kind, called Stargardt disease. There are six of us kids – five boys and me – and two of us have it for sure. Statistically, we’re unluckier than most.

By day Dan cares for physically and mentally disabled people. But he’s also a brilliant artist and the guitarist in a metal band, DIEFM.

These days, when he draws, he has to push his face into the paper. He can’t see the frets on his guitar. He doesn’t recognise people he knows when he sees them in the street.

After hours of tests, a new doctor comes in.

“You have Stargardt disease,” he says. He talks low and fast, like he and Daniel are seasoned actors, rushing through their lines before going onstage.  

“So … what are the cures?” Daniel asks.

“It’s never going to get worse,” says the doctor. Which sounds good, until you realise that he means it literally couldn’t get any worse. It’s done. Run its course.

“There is currently no cure,” he says.

Stargardt disease is a rare genetic eye disorder that causes frontal but not peripheral vision loss. Kind of like the opposite of tunnel vision. People get it young.

German ophthalmologist Karl Stargardt described it in 1909 and then, in 1997, geneticists found ABCA4 - it is the disruption of this protein which leads to the disease.

The macula is part of the retina, the light-sensing tissue at the back of the eye; dystrophy means “wasting away”.  The macula gives us sharp vision. People with Stargardt usually rely a lot on their peripheral vision.

Recessive genetic diseases are a game in divisions of four. Mum and Dad both had two sets of ABCA4; one functioning normally, one not. If one gene doesn’t work, the body generally uses the other. But Dan inherited two faulty genes. 

In the normal population, one in 72 people, like Mum and Dad, are unaffected “carriers”, with one bad gene each.

Our chances of getting Stargardt were reduced to one in four. There are six of us so, statistically speaking, only one of us might have had it.

Daniel was the fourth roll of the dice. Adam was the sixth.

“It hasn't been confirmed that I’ve got it yet, but everything is exactly like Dan describes,” says Adam.

He is 10 years younger than me, four years younger than Dan. He works with at-risk and incarcerated youth, and he’s studying Outdoor Education at TAFE.

“At TAFE I constantly struggle. Today there was a lot of natural light, but I'd need a really deep amount of light on it, so that I could read it,” he says. “In sea kayaking, to measure how far you are away from something, you put a compass at arm's length. I flat out can't see it.

“It took ages for any doctor to take it seriously and send me to the [Royal Victorian] Eye and Ear [Hospital]. They just wanted to give me more powerful contacts, which did nothing,” he says. “And any of the treatment research is probably a fair way off.”

Professor Alex Hewitt is a scientist at the University of Tasmania and a clinician at the Royal Victorian Eye and Ear Hospital, specialising in genetic eye diseases.

“This is a bloody exciting time on the research front for many of these conditions,” he says. “I’m confident that, in my working career, there will be treatments for these diseases.”

​He is so optimistic that I almost believe he could generate a cure through enthusiasm alone. He outlines a ladder of therapies:

And then there are external therapies; replacing rather than fixing. “There is some amazing bionic eye research happening in Victoria,” says Hewitt, although his enthusiasm pulls him in another direction.

“I think we’re at the time to approach the national health minister to invest some Medical Research Future Fund (MRFF) money into this sort of work,” he says.

“In Australia, the genetic testing isn't paid for by Medicare, unless it's going to change what we do.”

There are no genetic therapies ready for Stargardt, so Medicare doesn’t pay to confirm a faulty ABCA4.  

“It’s disappointing, because it means that for many diseases, we're not ready for gene therapy trials, because the genetic testing hasn't confirmed which genes have changed in which people,” Hewitt says.

“So we don't have an amazing catalogue of patients with a genetic diagnosis. But we do have probably the best DNA bank and register for inherited eye diseases in the world.”

He is referring to the Australian Inherited Retinal Disease Register and DNA Bank, of which Dan and Adam will soon be members.

One of the problems with these trials is that the first stage – is it safe? – is generally only undertaken by those with nothing left to lose. Dan has a lot to lose.

Sometimes we discuss moving to Britain, where we hear stem cell therapy is more advanced, for both our conditions. I’d go with him. It’s what big sisters do.

And genetically, neither of us was ever destined to be patient.