While many people were enjoying a recent long weekend, I was getting my retina reattached. A few days before, I’d experienced swirls in my eye, like a threatening sky in Harry Potter, then the alarming curtain effect.
The swirls and specks were tiny drops of blood. My retina, the light-sensitive layer that sits on the back of the eye, had torn in a couple of places and blood had leaked into my vision. The specialists at Auckland’s Greenlane Clinical Centre swiftly diagnosed the problem as retinal tears, and the back of my eye was lasered to seal them. They start on low power and work their way up; the last few zaps have a dull ache. Fixed. Or so I thought. When shadows appeared a few days later, I rushed back. My retina had definitely detached, the duty ophthalmologist said, and I would need surgery immediately, so as not to risk sight-threatening damage to my macula, the part of the retina that does most of the seeing. Some detachments are due to trauma, but mostly it’s just a disagreeable part of ageing.
After a day of lying with my head to one side, I had my retina reattached. It’s similar preparation to, say, cataract surgery: dilating drops, numbing drops, an eye “block” injection, a prop (speculum) to keep your eye open. The surgeon fixes the retina back in place by first sucking out most of the vitreous gel at the back of the eye. A combination of laser, cryo (freezing) and diathermy (heat) is then used to seal the retina back to the eye wall. But first, a bubble of gas is injected to “splint” the retina – that is, hold it in place.
The surgery takes almost an hour. Afterwards, you can’t do any brisk exercise for a few months, and because the bubble might expand, you can’t fly or climb mountains. Pity, that. And you have a goldfish bowl in your eye that washes around as you walk. It’s not enjoyable, but you get used to it, and it’s better than going blind.
Standard post-op care involves steroidal and antimicrobial eyedrops. You might also need other drops if the pressure increases too much – or a short course of Diamox, which is also given to glaucoma sufferers and people with altitude sickness; it’s thoroughly unpleasant and gave me horrible jitters, but it does the job. Retinas detach in many spots, and the “positioning” instructions you’ll be given will differ depending on where the tear is. Some people are told to lie face down as much as possible; I had to have my head elevated to at least 30 degrees for a few days, then raised on a couple of pillows when sleeping (reattachment scars take about a week to reach maximum adhesion).
The gas bubble – which appears at the bottom of the eye, as a result of the inversion of your vision – slowly dissipates over two or three months; progress is monitored with regular check-ups. Mine disappeared eight weeks to the day after it was injected. Normally, the removed gel is replaced by aqueous fluid, the “glorified saline solution” that fills the front of the eye, according to Hamilton consultant ophthalmologist Steve Guest.
Retina operations can give rise to cataracts, but cataract operations can also bring on retina detachments, I discovered. Your natural eye lens is quite thick, says Guest, who didn’t operate on me. The plastic replacement lens is thinner, which means the fluid at the back of the eye comes forward a bit. That forward movement is thought to encourage the jelly to condense and separate from the retina.
The bottom line is that eyes don’t like to be messed with. Surgery creates inflammation, and in rare cases retina reattachment can implicate the other eye, too. Apart from both being associated with getting older, there is no major link between cataracts and age-related macular degeneration (AMD), nor with retinal detachment, says Guest. An increase in intraocular pressure is “reasonably common”, he adds, happening in about a third of patients. It usually settles down after a few days.
Before vitrectomies – where most of the vitreous humour (a gelatinous mass between lens and retina) is removed – scleral buckling, in which the eyeball is “squeezed” in to meet the retina, was more common. Before buckling, there were few options, says Guest. You might lie for a month with your head down, hoping the retina settled, then try laser treatment or diathermy. “But most people went blind.” Buckling is still done, he says, often after trauma or in young people, whose vitreous gel is stickier, and when more things can go wrong.
Most patients won’t notice it, but they will have reduced peripheral vision, says Guest. The areas lasered will be damaged. As with vision in general, the other eye and our brain cleverly cover the gaps. But Guest has had patients who’ve lost so much peripheral vision they can no longer drive. Visual acuity can also change. Taking out the gel can change the position of the lens and so the focus of the eye a little.
It’s not uncommon to have a feeling of grittiness and aches around the eye. Some people still see flashes and a fairy-light effect around the edges well after the gas bubble has gone. This can be the result of residual gel behind the lens tugging on the retina in a few places, or scar tissue activating. Detachment recurrence rates are 5-10%, Guest says, and generally occur within three months of surgery.
For those who’ve had one detachment, the risk for the other eye is generally higher. Guest’s advice for those who’ve had retinal surgery is to do their best to avoid being poked in the eye, and all contact sports. Some people have “weak” retinas, he says, but their optometrist should pick this up. Happily, the public-health system usually deals swiftly with urgent need. “When the centre of the vision is still spared, as yours was, we like to get on to it pretty quickly.”
Age & vision
Risk factors for age-related macular degeneration include smoking and too much exposure to UV light and, possibly, screens.
This article was first published in the June 29, 2019 issue of the New Zealand Listener.