Visual field problem

 Dated: Sunday 26th January 2025

Yesterday evening I was watching TV in a low-lit room when suddenly the lower left half of my visual field vanished from my right eye. It had been replaced by what appeared to be a grey rectangle stretching from the lower left boundary of my visual field about two thirds of the way across.

There was a quite clear right-angled edge to the rectangle, just to the right of the lower-centre of my visual field. This sudden transition to partial visual occlusion was painless but I had a 'funny feeling' in my head as it happened.

After ten minutes or so the occluding rectangle vanished, although for a few subsequent minutes there was a flickering at the bottom-centre of my right visual field, as if I were seeing things there through rippling waves. But this too soon passed and my vision returned to normal. This is not the first time this has happened although episodes are spaced months apart (to-date).

I also quite often (weekly to monthly - for a number of years) have those jagged scintillating patterns which grow in size for maybe fifteen minutes before vanishing. Also accompanied by a 'funny feeling' in my head. I have put these down to a migraine aura - scotoma which I first started experiencing in 2016.

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ChatGPT is quite worried about all this ("What you’re describing strongly suggests a transient ischemic attack (TIA) involving the visual cortex or the blood supply to the retina of the right eye. TIAs are temporary episodes of reduced blood flow to a part of the brain or retina, often called “mini-strokes.”") but I'm inclined to add it to my list of concerns when I see the cardiologist in May 2025. But I will also take this note (not the ChatGPT part) around to the GP surgery tomorrow morning.

Diary: a brief history of scotoma

I visited the optician yesterday, an annual check-up as my father had Low-Tension Glaucoma.

What a scotoma can look like

Being organised, I prepared a detailed record of those weird scotoma events I've been experiencing this last year,. I suppose I secretly believed, despite Internet/Google reassurance, that something else might be implicated.

The optician read the note below with care.

Vision scotoma record of occurrences

1. 5th November 2016.
After weights exercise, visual illusion to the right of central visual field (both eyes separately). A flickering jagged arc. This is consistent with a scotoma. Same phenomenon with either eye closed. After half an hour it began to move out and enlarge while retreating further into peripheral vision. After an hour it disappeared.
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2. 19th January 2017.
This phenomenon reappeared 19th January 2017, again (some time) after exercise, at 6.10 pm. Visible duration 20 minutes. Started at the centre of the visual field, a flashing-lightning V-shape with vertex at 8 o’clock. Gradually got larger until it vanished past the boundary of the visual field.
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3. March 8th 2017
Same symptoms as before: jagged V-shape fading in five to ten minutes.
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4. March 26th 2017
Five hours after exercise, proximately after ice cream (!)
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5. Saturday July 29th 2017, 8.40 pm
While reading on the Kindle app felt a bit weird in the head and noticed an opaque, light grey cloud in the centre of the right visual field. I could see text clearly above and below (more above). The shape was like a large horizontal island from a great height; wider than tall with rough edges. The effect lasted about five minutes then vanished. I abandoned reading and went for a shower.
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6. Tuesday 22nd August 2017 8 pm
Visual field cloud (right eye) - repetition of July - exactly the same symptoms. Grey/brown rectangular/angular/jagged-edged opaque patch screening the visual field in the right eye. Centre of the visual field, could see above and below it. Around 8 pm while watching Game of Thrones. Felt like scotoma but lasted only a couple of minutes. Had done fairly intensive exercise the day before.

He then proceeded to confirm that it was indeed scotoma, entirely consistent with my advancing age and generally low blood pressure, and that a darkened room was the best way to recover.

During the rest of the examination, as a bonus, I got treated as an intelligent patient - almost a peer, I felt.