Charlie and George are growing at an insane rate. Here’s a photo taken about four weeks ago. And another taken ten days ago:
And they’ve grown a lot since then. When Charlie first came home from his operation he was 3.5 lbs. I’m guessing he’s close to 5 now, but George is far bigger and heavier, more like a young cat. Charlie, though smaller, still gets his preferred perch—the highest level on the condo; George mostly likes to hang out on the third, shaded and sheltered by the second where, when he’s bored, he can grab at Charlie’s tail and chew.
Charlie is still a kitten, still fearless, and still visually impaired–still a nightmare combination for kitty wranglers of a jumpy disposition. But you’ll note I no longer say blind. Neuro-plasticity is an amazing thing, and Charlie’s brain has been frantically rewiring. He can definitely see some things. Equally definitely, he can’t see others. And, most confusingly, that seems to be variable. At first I though the variability might be related to non-visual compensation: being able to sense the movement of air when the feather passes closely enough, or fast enough; or perhaps he can hear it; or smell it. But through experimentation—which both he and George thoroughly enjoy; they’re getting hours of focused play a day—I’ve determined that this is not the case. I think sometimes his brain just sort of fritzes.
On top of that, some part of his visual field is missing. I’ve been researching acquired brain injury and visual impairment and suspect he has some kind of hemi- or quadrantanopia (or -anopsia). There are all kinds of variants. Perhaps the left visual field of both eyes is missing, or maybe part of the right visual field that is, homonymous hemianopia. Or the centre, or the outside (heteronymous hemianopia). I’ve been trying to work out ways to test that.
The games/tests I’ve been using are tracking/chasing games. Sometimes a cursor against a white screen, or a red laser dot on a pale carpet (neither of which he can feel or smell or hear); sometimes Feather (bunch of feather at the end of a line), and sometimes dropping a variety of things from a height.
The first time I tried the laser pointer on the carpet, he lost the red dot about 70% of the time and took a lot of patient tempting to reacquire it. This video was taken about ten days ago:
You can see the difference between Charlie, who doesn’t seem sure he’s really seeing the dot at first, and George, who’s all Kill! But Charlie is improving rapidly. And this morning he did not lose it once at normal twist-and-turn speed, but did lose it when I flicked it away suddenly. And it no longer takes him long to reacquire it. George, on the other hand, can follow it almost anywhere, at any speed, and he reacquires almost instantly.
In terms of the cursor, well, see for yourself: he seems to track left more easily than he tracks right. What does this mean? I’m not sure.
He might be missing some of his right visual field. But that’s not the only problem. Chasing Feather gives a more interesting, 3-dimensional view of what he can and can’t do (though of course complicated by compensatory sound/touch etc.). Here’s a video taken about a week ago of Charlie chasing Feather.
As you can see, most of the time his coordination is fabulous, and then sometimes it goes to pieces. And he can’t seem to see things right in front of him. So I thought: binasal hemianopia, that is, the middle is missing.
There again, one test he fails consistently is seeing/tracking an object falling from a height, whether it’s his white miniature soccer ball, one of my juggling bags, or a piece of white cottonwool. So it could be that he simply can’t process at speed, or perhaps that an upper part of his visual field is missing—maybe heteronymous quadrantanopia. Apparently, while occasionally those with this damage can recover, it’s not massively likely:
The prospects of recovering vision in the affected field are bleak. Occasionally, patients will spontaneously recover vision in the affected field within the first three months after the brain injury; however, vision loss remaining after this period of spontaneous recovery is traditionally thought to be permanent
It’s now been about five weeks since Charlie’s brain injury. So there is a faint possibility of recovery but unlikely. The goal now is adaptation. I have mixed feelings about this. On the one hand, I’d feel much happier about the possibility of letting Charlie outside occasionally if his vision were wholly intact. Right now, I don’t think he’d see a barred owl swooping in to snatch him away. On the other hand, he has a wonderful time indoors and sees everything he needs for a full life, and indoor-only cats do tend to live longer. So we’ll just see how well he adapts with constant training-as-playtime. I suspect he’ll be happy either way.
At this point, though, my main suspicion is that I’m not training Charlie and George, they are training me: hours and hours of play time a day, plus treatsies for playing, and endless comfy lap time afterwards. Oh, well. I’m getting a lot of reading done.
In a few days I’ll do another post, this time about all the non-vision-related adventures of Charlie Kitling and Master George. There are many. Meanwhile, catch up on previous kitten reports here.
11 thoughts on “Kitten Report #05: Visual rehab [photo and video]”
Is the difficulty in his perception of depth of field? If one eye is very weak, he may not have strong binocular vision, which seem to be what you are describing with both tracking and falling objects.
Or do I mean “stereoscopic” vision? The right eye might have less vision that the left, which explains why he responds more quickly to objects on his left.
The answer to both questions is: I don’t know. But I don’t think it’s an eye problem, so I don’t think it affects just one side. It’s a brain problem so, in my opinion (but am happy to be corrected!), more likely to affect both left and right.
Vision is always in the brain, as I understand it. The eye is perceptive, but vision does not actually happen in the eye, but in the brain’s interpretation of that perception. And since you see a difference in right and left tracking and in depth perception, I thought perhaps this was in a difference in how the brain was processing left and right “vision” with weaker information on the one side. He is your cat, of course, but another difference may be the “what the hell” response to games in general. Cats are not predictably responsive to games, in my experience. There is the cattish tendency to play us, while we think we are playing them. It is one of the things I love them for.
Of course, I certainly don’t know. You are making such a fascinating study, I could not resist commenting. I was just reading an article about octopi and how they and other species process light an other perception. Thank you. (I feel like my mother just now, who always called back to ensure she had not been rude or offensive in our phone conversation.)
Neither rude nor offensive! I love talking about this stuff
I think I may love your kitties almost as much as you and Kelley do. If such is possible, of course. I suppose I casre about Charlie and George vicariously. I just want to offer you a comment on the two little ones. I would strongly suggest you keep them in the house and o not let them go outside. Outside cats do not live nearly as long as inside ones do. This reflects my own experience. There are numerous predators you need to worry about, among them coyotes (I have family who lived in West Seattle, where they made sure not to let their cat out at night because the coyotes were making pets disappear), owls you mention, other cats that will fight them… and the biggest predator of all, humans with automobiles. All throughout my childhood (back when we chiseled symbols on stone tablets) we had numerous cats which we let outside. None ot them lived longer than two or three years. And we lived in a new neighborhood without as much traffic as nowadays. Hope you don’t think I’m being rude or intrusive when I say this.
Inlteresting that your bio mentions you fronted a band. My wife and I have just returned from a wonderful Celtic festival held each year in Bethlehem, PA. As you probably know, there are tons and tons of fiddle players at such events. I just saw one with a group called The Town Pants, a terrific player named Johanna So. This lady blew all the other fiddlers there right off the map. I’ve enclosed a link to their web page bio of Johanna, just in case you are interested. There are links on the site to The Town Pants’ music, which I hope you enjoy. I can’t talk enough about this great band. You haven’t lived until you’ve heard the old Elvis Presley tune “Can’t Help Falling In Love” played as a reel. Anyway, see what you think (if you like; I’m not ordering you to enjoy the music I enjoy).
More next time.
We live on the edge of a ravine that runs into Carkeek Park which is on the Sound. We have coyotes and eagles, raccoons and owls, hawks and–once–a fisher. Our last cat was an indoor/outdoor cat; he lived until he was 17.
Here in Salem, we have the risk of coyotes and cougars just a little bit outside of town, as well as cars and hostile dogs, so we’ve reprogrammed our two cats to live indoors. Better for birds and small wild critters and better for them. Hopefully, we will have them with us a long time.
Best of luck to Charlie! He clearly loves life.
Unless you are talking outside as taking him outside on a leash, don’t. Cats roam and unfortunately they have no idea of property lines. I love cats, have 3 of my own, but I do not want your cats, or dogs, on my property. Or killing wildlife. Just as there is a push to neuter there should also be a push to not allow cats to roam.
Pam are you a neighbour? If so, you no doubt have problems with raccoons and coyotes and rabbits. If you have sufficient fencing to keep them out, then I suspect it would the job for cats, too.
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