Hello, I’m Dr Croley and welcome to Case of the Day. Today we’re gonna discuss a case involving what’s called Acute Angle Closure Glaucoma, or Narrow Angle Glaucoma. And so first we go over a few basics. Basically there’s two types of Glaucoma; Open Angle Glaucoma and Narrow Angle or Angle Closure Glaucoma, and what is the difference? Probably 95% or so of glaucoma is of the Open Angle variety and then what does that mean?
So, if we look here at the eye, behind your pupil, sits this little gland that produces fluid in your eye. This fluid then goes forward between your iris and your lens, goes to the pupil, fills up the front of your eye, and then goes to this Trabecular Meshwork. This is sort of like cheesecloth that the the fluid filters through into Schlemm’s Canal and then from that canal it drains into a vein into your blood system. So there’s a constant production of fluid in your eye, goes through the pupil, out to this Trabecular Meshwork and into the blood. The angle has to do with the angle between your cornea and your iris. So in Open Angle, this angle is wide open, the fluid has no trouble getting into the meshwork and that is Open Angle Glaucoma.
In Narrow Angle Glaucoma, it’s all about structure and shape of your eye. So someone who has a small eye, which is someone who’s farsighted has a small eye, someone who’s nearsighted has a large eye. So in a small eye, this iris comes more up close to the cornea and across and that angle is very narrow. Now the fluid has to try to get down to the meshwork and has to travel end of this angle and if it’s closed off and as the iris went up against this meshwork, it would suddenly stop the fluid going out of your eye and the pressure would suddenly go out the roof to 60 or 70.
In Open Angle Glaucoma, this pressure would slowly rise and it would not usually lead to that level. It might be 25 or 30 or whatever the number would be and over time, that increased pressure damages the nerve in the back. So this nerve gets damaged over time from Open Angle Glaucoma. When the pressure goes to 60 or 70, it can get so high that the blood flow no longer flows into your eye and it’s almost like having a stroke to your eye because the blood cannot get in because the pressure is so high.
When people get Angle Closure Glaucoma, the pupil dilates, your eye gets red, your vision blurs because the cornea becomes cloudy and you get sick at your stomach and nauseated. In fact people can start vomiting and can have severe pain in their eye. And many, many, many years ago, people would go into emergency rooms with Angle Closure Glaucoma and the people in the ER would be so concerned that they had a brain Aneurysm because of the severity of the pain and the dilated pupil, that they had their brains operated on for Aneurysms. Before we had all the technology that will enable us see if there’s an Aneurysm first.
So, then what do we do about someone who has Narrow Angles or Angle Glaucoma? So if you actually have the attack and the pressure’s 70, and in an emergency basis, we have to come in and laser a little opening in your iris. So instead of the fluid now having to travel up to the pupil and over, some of the fluid goes directly from behind the iris through the little opening in your eyes directly in the meshwork. So that’s like a safety valve. And so if someone’s angle is getting narrow and we look in their eye to the point we might be scared or afraid that their angle would close out, then we would prophylactically go in and laser an opening first before the attack would ever happen.
So it’s important when you get an eye exam that the doctor looks at this angle especially if you’re farsighted to make sure that it’s open far enough because if it’s getting narrow, you want to, ahead of time, do a Laser Iridotomy. An opening in your eye is a preventive thing.
So a lady came in today, post-op, after we’ve performed a Laser Iridotomy, she was doing fine, the opening was great. And she was referred by her retinal doctor because she had problems in her retina and they’re afraid to dilate her eye because her angle was narrow because when you do that, this iris is pulled back, which means it could block the meshwork and cause an acute attack of Angle Closure Glaucoma from the dilation. And that’s the reason why you see on TV about warnings about different medications about if you have Glaucoma. Some medications dilate the pupil a little bit and could cause an Angle Closure attack.
So that’s all the basics about Acute Angle Closure Glaucoma or Narrow Angle Glaucoma and so if you have any questions about that or anything else, you can always contact us through the website. If not, may God bless you with healthy eyes and great vision.