The indirect is one of the harder pieces of ophthalmology equipment to master. There is a steep learning curve, but it will eventually become second nature. It certainly doesn’t feel that way during week 1 though! Here is a list of tips which I wish I would have know when starting out. Knowing these tips won’t make you successful overnight, but they will certainly speed up your learning.
The Indirect Ophthalmoscope
Using the indirect:
- Make sure everything is lined up on your head prior to starting your exam. Your oculars and the light spot should both be centered.
- Don’t go crazy on the brightness (60-80% is generally enough on most models). If too bright, you will often spend more time fighting a patient’s Bell’s reflex (tendency for eyes to roll upwards when trying to shut them).
- If the patient’s pupil is wide and dilated, use the largest spot size. If the pupil is mid dilated, use the medium spot size. If the pupil small, use the small pupil size. The reason for this is that when light hits the iris and reflects back, it creates glare and makes it harder to discern retinal structures.
Positioning the patient
- It’s hard to examine a patient while they are sitting up. Initially, try to lay the patient back at 45-60 degrees to make the distances easier to manage and try to stand directly opposite of where you are looking. E.g. if you are looking at right temporal macula, stand on the patient’s left.
- Have the patient turn their head towards you, whichever side you are standing on.
- When a patient’s nose gets in the way (like when you are standing on patient’s left side examining their right temporal macula) have them turn their head more towards you. They can still move their eye in whatever direction you need them to, but it moves the nose out of the way.
- When describing directions for patients to look, it is sometimes easier to tap on their face than to give a direction (down and right), and makes your exam more efficient.
Performing the exam
- Start with a peripheral view (have the patient look up) as this will help acclimate a patient to the light. If you start the exam by looking at the macula, your patients will be angry.
- To look in the far periphery, tilt your own head 45 degrees to the left or right. At that angle the pupil effectively becomes elliptical and you can fit the indirect’s illumination beam and one ocular into that ellipse.
- Use the diffuser light on the indirect to help illuminate the far periphery when you’re first starting out. It makes the alignment of the lens less critical.
The Peripheral Retina Exam
In my opinion, this is the hardest technical skill in ophthalmology clinic. It is also quite anxiety provoking, as you need to have a good depressed exam to rule out retinal detachments / tears.
- The most important tip is that you do not necessarily need patients to get to the extreme lateral position of gaze (up, down, left, right). Some of our senior retinal docs have the patient looking only slightly off axis, as this lets a lot more light in through the pupil vs. extreme tilt. This can also help you visualize your depressor, as you can depress a point 5mm beyond the limbus, rather than right at the limbus. I had so much trouble seeing my “bump” until someone taught me this. Now, I can 360 visualize my bump on nearly all patients.
- Buy a scleral depressor with a round paddle; they’re relatively cheap. (http://stephensinst.com/wp-content/uploads/2013/10/S4_1236-_both.jpg) It’ll make the exam much more comfortable for the patient, which in turn make your life easier.
Indirect Part 1
Indirect Part 2
Peripheral Retina Exam