RETINAL ROTATION

“I keep tripping and falling over my children, so now they know not to run right in front of me,” a young mother of three told me in the retinal genetics clinic. “I just don’t see them until it’s too late.” That’s it, I thought! Finally, I’ve found a clear indication that someone had real visual field loss. Only someone with a serious constriction of their visual field would ever fall over their own children.

Before I developed my retinal observation skills enough to make sense of my funduscopic examination, I relied heavily on my history-taking to come to a useful differential diagnosis. I hadn’t yet learned to evaluate abnormalities in so many locations and in so many layers. So, I tried to get as far as possible just speaking with the patients: Age at onset? Family members with the same problems? Consanguinity? Night blindness?

I realised that asking about night blindness was too vague for most patients, and very few people notice a constriction of their visual field until very late in the disease. So instead I began to ask, “Do you frequently fall over your young children because you don’t see them?” A comprehensive history, however, can only get you so far. At a certain point, you have to look at what’s going on in the retina. And that’s when it gets really difficult!

Some abnormalities are obvious, but some signs are so subtle. And the overlap between various hereditary retinal diseases is enormous. The genetics specialist in our hospital, Dr van den Born, receives all the “I have no idea what this is” referrals. She is completely familiar with an entire group of diseases that most ophthalmologists read about during their residencies but probably haven’t seen since.

But the medical retina rotation isn’t limited to exotic retinal dystrophies and ERGs. Working in the fluorescein angiography clinic is an adventure full of unusual and unsettling juxtapositions. The fantastic feeling of making a correct diagnosis, like an unusual chorioretinitis, is often immediately followed by the shame of an unsuccessful venous cannulation for fluorescein injection. One moment you feel like an advanced subspecialist, and the next moment like a struggling first-year medical student.

It’s a humbling experience. The FA clinic keeps you sharp, because the pathologies themselves are so varied. Vascular, inflammatory, neoplastic, degenerative and traumatic come one after the other. Yes, they’re all (chorio) retinal, but no, they have nothing else in common.

Wednesday afternoons in the macular degeneration clinic offer a few hours of intellectual relaxation. For most of the patients seen here, the diagnosis has usually already been established and the treatment initiated. We simply have to decide, based on visual acuity and OCT scans, how to proceed with treatment.

This isn’t to say it’s easy, but really, the options are pretty limited. More injections, fewer injections, no injections. More difficult is managing patients’ expectations, particularly those in whom the macula of their best eye is progressively worsening. You can feel these patients’ worlds shrinking as they sit before you. Driving a car has long been abandoned. The bicycle has been sold. Visits to the museum have stopped. But until recently they could at least identify their family and friends. No longer. They now pass old friends on the street without recognising them. They can no longer distinguish the faces of their grandchildren. The computer skills that they worked so hard to develop have become irrelevant, as they can no longer read what is written on the screen nor enjoy the photographs that they have been sent. It seems as though every macular degeneration sufferer has always loved to read or knit. No longer. Joining them on their emotional journey can be quite intense.

The diabetic & vascular (“Diva”) retinopathy is a different story. “I know you absolutely want to initiate treatment of this early diabetic macular edema,” said my supervisor about a new patient. “But I’d suggest you wait a few months until her vision decreases. Her visual acuity will decrease during the next few months, even with early treatment. But if we treat now, she’s likely to blame the vision loss on your treatment. That will lead to distrust, poor treatment compliance, and worse outcomes.”

The diabetic patient is for us a difficult one to decipher. We ophthalmologists, as compulsive, detail-obsessed individuals for whom vision is so crucial, cannot comprehend the seemingly careless attitude that some at-risk patients have. But then a quick reminder of these patients’ daily schedules – dietary sacrifices, fingertip pricks, insulin injections and the constant threat of hypoglycaemic misery, not to mention the sword of Damocles perpetually hanging over their heads and hearts – allows us to understand their occasional deviation from all their doctors’ recommendations. It remains difficult to accept the fact that some patients will continue to miss important laser appointments and won’t return for treatment until they develop a vitreous haemorrhage or worse.

Of course, when it comes to sheer complexity, uveitis is king. Just when the diagnosis seems clear, when the treatment plan appears logical, when you think you’ve got the inflammation more or less under control, it takes a surprising turn. Recurrences, complications, referrals, masquerade syndromes. It seems uveitis can always stay one step ahead.

In this case, we take refuge in the intravitreal injection clinic. Twenty-five consecutive injections, simple as can be. Left eye or right? Do you have your antibiotic drops? Great, see you next month!