This introduction to the retina covers all the basics: anatomy, diabetic retinopathy, retinal detachments, and macular degeneration. This is a lot of topics, so I’ve tried to keep things simple and to the point. Here are some screen-captures from this video:
Screen Captures from this Video:
The video begins with a basic review of retinal anatomy. The key point here is that the photoreceptors lay pretty deep in the retina, with the ganglion nerve fiber layer superficial. The underlying choroid provides nourishment for the photoreceptors.
The slit-lamp is the best way to view the posterior pole. This full-motion video segment shows the kind of view you can expect when using a 90-diopter lens.
Indirect ophthalmoscopy is useful for viewing larger areas of the retina. The field of view is much greater and lets you look all the way out in the peripheral retina.
If you can’t view the retina (for example, the patient has a dense cataract) then you can visualize key structures with ultrasound. This full-motion ultrasound demonstrates all the important eye components.
Diabetic retinopathy produces dot-blot hemorrhages. Dot-blot bleeding is discreet because they occur in the deeper, vertically-arrayed layers of the retina. Flame hemorrhages are larger because they occur in the superficial nerve-fiber layer.
With large areas of ischemic retina, diabetics produce VEGF to stimulate angiogenisis.
The new blood vessels can bleed and create traction.
PRP, or panretinal photocoagulation is performed to kill off ischemic retina and decrease VEGF production.
Despite other problems, it’s macular edema that actually causes of majority of diabetic vision loss.
When treating retinal detachments we follow the rubber-band theory. You can relieve traction by cutting the band (vitrectomy) or by shortening the band (buckle).
Pneumatic retinopexy can tamponade superior breaks.
PVDs (posterior vitreous detachments) are common and can be seen at the slit-lamp in this video.
Macular degeneration is a leading cause of blindness in our country, and this video segment describes how it occurs.
Comment by Dr.Gokarna Dhakal — March 7, 2009 @ 10:54 pm
hey, the retina video is not working (and all my friends at www.lf3.cuni.cz my faculty at charles uni 3rd fac i Prague have tried with no luck). So can you please post it again? or email me a copy n i can give it to the rest of my costudenst? please please please!! we all love your videos, it´s really helpfull.
Regards
Håvar Skoland
Editor: The video is working … I can view the video on every computer I have tried. However, this retina video is posted as an embeded windows video file, instead of flash video (the rest of the videos are in flash). If you’re having problems viewing this video, you may be on a mac system or have older hardware without the corect wmv codec support. Most PCs will automatically download the correct codec … but your institution may have blocked this functionality. I’ll eventually upload this video as flash as well, but this will take a long time and I’d rather work on the next lecture.
Comment by Håvar Skoland — April 17, 2009 @ 3:55 am
Thank you very very much, the page help me to do the paper for presentation. My interest topic is retinal detachment, it’s very useful and easy to read and understand.
Dear Editor: Macs are capable of playing the video you have inserted into this page, however, your HTML code is incomplete. In your code, you have “if !IE” - except that next tag should have been “embed” instead of “object” (object is for PC, embed is for Mac). Please feel free to email me and I can give you the exact code you can use to fix this problem. It is a 5-second fix!!! Thank you for all the work you have put into this website!
Comment by Ricardo Lugo, MS-III — August 19, 2009 @ 8:31 pm
thanks so much doctor for the video..it is of great help..
but are there any videos that illustrate how to use the indirect ophthalmoscope using the 20 D lens?
I’ve uploaded the retina video to Vimeo, so it should stream just like all the other videos on the site. Hopefully, you won’t have any more problems.
You may note that the sound is a little low on these earlier lectures. The later lectures are of higher recording quality (upgraded my system). Hopefully, the educational content will make up for everything.
