Medicine From The Trenches

Experiences from undergradute, graduate school, medical school, residency and beyond.

How to use the ophthalmoscope

Starting this week, I will be teaching my students how to use an ophthalmoscope  and how to perform an optic fundus examination as part of mastery of the physical exam. Many of my colleagues never mastered the use of this instrument and tend to dismiss fundal exams as not necessary in today’s world of modern medicine. As I begin to teach this skill, I am reminded of how my professors in medical school, placed importance on having this skill in my toolbox of weapons against disease. At my medical school, we saw plenty of people who were morbidly obese, hypertensive and diabetic. Being able to examine their retinas was a cheap and simple task that might make a difference in helping them to better health by  control of their weight, blood pressure and blood sugars. In short, a fundal exam is a tool that can make a difference in the prevention of the complications of chronic diseases that afflict many people today.

As a vascular surgeon, I am happy to have ophthalmoscopic skills because an exam of the vessels in the retina can give me valuable information in terms of the condition of a patient’s peripheral arteries. The retina is often the first indication of lack of blood sugar control in Type II and Type I diabetics and after a couple of decades with Type II diabetes, just about all patients will show some retinal changes. Without careful blood sugar control, these changes can go on to blindness which is a huge complication of diabetes. In my trauma patients, retinal examination can give a clue to increased intra-cranial pressure right in the trauma bay if one knows how to look for the early signs of papilledema.

I first have my students learn how the ophthalmoscope works. This is an instrument that must be held properly and used properly for best results. The ophthalmoscope is not an instrument that one can simply pick up and use right away. The student needs to learn how to turn the diopter wheel, how to adjust the light for the best results and how to choose the proper aperture for viewing. Many people attempt to look through the instrument with their corrective glasses in place (the diopter wheel corrects for both you and the patient) or will start with the biggest and brightest light (believing that this will result in better visualization). If one starts with a smaller light spot and dimmer light, one get more time to look around before the patient becomes uncomfortable. Additionally, the brighter the light, the more reflection off the cornea  which is quite distracting to a new user.

Many people forget to darken the room and forget to ask the patient to focus on a spot over the examiner’s shoulder. both of these techniques need to be utilized in order to see anything. In the dim light, one should place their other hand on the patient’s eyebrow to help the patient keep their eye open. I utilize this technique because when my head touches my other hand, I have moved into the proper position/distance, which is very close to the patient. Many new examiners are quite uncomfortable with the closeness that this exam requires but just as one needs to be pretty close to a door “peep” hole in order to see out, one needs to be close to the patient in order to see into the eye through the very small pupil. (Breath mints are handy so that you don’t have to worry about being too close).

The new “Panoptic” ophthalmoscope head allows for a longer distance from the patient but one needs to learn how to hold and use the “Panoptic” score in much the same manner as learning to use the conventional scope. The Panoptic scope gives a wider view of the retina which is helpful too. The Panoptic ophthalmoscopic exam is easier to learn but Panoptic heads are quite expensive and not readily available in most clinics. If you have a Panoptic ophthalmoscope, then you need to guard it carefully because these expensive instruments have a way of “disappearing” from their owners on a regular basis. It’s also very easy to learn how to use a Panoptic scope if you have mastered the conventional ophthalmoscope.

One of the biggest mistakes that teachers ( and medical students) will make when learning to use the ophthalmoscope is believing that you are going to see the pictures in your physical diagnosis textbook. You are first going to see only the “red reflex” which you will learn to follow in as your learn to visualize a retinal vessel (see these when you learn to focus by turning the diopter wheel). Once you see a vessel, you can follow it into the optic disk. Once you see the optic disk, you can move your eye and body so that you can examine the entire retina.

You won’t master the ophthalmoscope unless you look into every patient’s eyes on every exam. If you don’t stick with attempting to learn (frustration levels are high at first), you will not master this instrument. I can’t tell you how many of my students “give up” before mastery and join the legions of “naysayers” who don’t believe an optical fundal exam is a necessary part of a physical examination. Many of my colleagues will just send their patients to the ophthalmologist for ongoing retinal exams which is a better strategy than not following retinal changes. It’s good to know what your patient’s retinas look like for yourself because you are going to see those patient’s more often than the ophthalmologist will see those patients. It’s a good idea to find changes earlier rather than  later.

A technique that I teach my students for them to practice using the diopter wheel as the move in closer and closer to the patient is to put a small dot on the palm of their hand. Then practice keeping that dot in focus as they move their hand closer and then more distant from the ophthalmoscope. If they can turn the diopter wheel and keep the dot in focus, then try doing the same thing with text in a book as you move in and out keeping a letter in focus. Once the student can see a red reflex (right eye of patient and opthalmoscope in examiners right hand) the examiner can move in closer to the patient and keep the red reflex in focus.

As you learn to use the ophthalmoscope properly, keep practicing with this instrument. At first you will only see a red reflex; then follow that red reflex as you move in (might see a vessel at this point). If you can keep a vessel in view, you can follow it into the optic disk. If you can see and focus on the optic disk, you can keep practicing until you learn to detect things like copper wiring, cotton wool spots, neovascularization , flame hemorrhages and other pathological findings. You will also learn to appreciate the different pigment changes from patient to patient which can be pretty interesting too.

With any new technique or procedure in medicine, one has to learn to practice to make that new procedure/skill second-nature. With ophthalmoscopic examination, the practice takes months of dedicated trial and error until you find what works best for you. The important thing to learn is not to “give up” , throw you hands in the air and then label the skill as “unnecessary” because you can’t perform it. Fundal exams are a worthwhile skill to master in order to give your patient’s the best care possible.

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3 February, 2013 - Posted by | medical school coursework, medical student., physican assistant, success in medical school |

6 Comments »

  1. I can’t see the optic disc or vessels – only the red shift. I’m practicing on fellow students in dim light and not too bright opthalmoscope light.
    I’m being told that dilating drops must be used. Is this so, or should I just keep practicing? Only one fellow student reports temporarily seeing someone’s arteries. I myself saw floaters in someone’s eyes, but nothing more.

    Comment by Leo | 20 July, 2016 | Reply

    • To Leo:
      I have never any dilating agents for eyes. If you are using a conventional ophthalmoscope, you have to move from left to right and up to down in order to see the complete retina once you have the retinal vessels in focus. The key is getting the vessels in focus and following them to the disk. Just as you are looking through a keyhole in a door, you have to move your head in order to see the disk. If you saw floaters (could have come from your eye), then you were still in front of the retina. Practice focusing as you move in close the the patient by placing a small dot of ink on your hand. Then keep this dot in focus as you move in and out from your hand which stays in place. Good luck.

      Comment by drnjbmd | 21 July, 2016 | Reply

  2. i see a straight vessel and thus, even if i tilt , i just see an extreme view of the straight vessel. how do i overcome this?

    Comment by amrit k | 8 September, 2014 | Reply

    • To Amrit K: See other reply

      Comment by drnjbmd | 8 September, 2014 | Reply

  3. hi, do you move the whole fundoscope beam of light to trace the vessel or just tilt the fundoscope through the same beam of light? i always see a straigt vessel and even after tilting y head nasally to the patient.

    Comment by amrit k | 8 September, 2014 | Reply

    • To Amrit K.
      First, turn the beam of light down a bit. If you are using a very strong light beam, the patient’s pupil will be smaller and thus it will be more difficult to see. Second, one you have focused on a vessel, you have to move both your head and the light as you follow the vessel. Again, if your light is very, very bright, you won’t have time to get much studied before the patient is in distress. If you were looking through a keyhole, you would have to move from side to side, up and down to see objects that were not in your direct line of vision. Keep practicing and dim your light (Not too dim) so that you don’t blind the patient.

      Comment by drnjbmd | 8 September, 2014 | Reply


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