Managing patients with traumatic brain injury can be difficult.
We have all been moving through the day only to notice our next patient has a history of concussion or some other traumatic brain injury (TBI).
You might feel panicked or perhaps you think nothing of it.
Either way, you have two options:
- treat them like everyone else
- consider the possible effects this TBI may have had on their vision
For a quick review:
- 10-20% of people will have visual symptoms that persist for months past the concussion or injury (Post-Concussion Vision Disorder)
- Many of these patients will complain of blurred vision, double vision, and/or loss of place while reading
- Often they will feel overwhelmed/get dizzy in busy visual environments and may overall just feel visually ‘off’
The Concussion Project is a great resource for both you and your patients to learn more about concussion and vision!
Here I will share with you 4 quick tests to help identify those patients that might need more than just help seeing 20/20.
1. Case History
I think I mention this in all of my articles, but it is truly the most important part of your exam. Ask your patients these questions and you’ll be surprised at how many are having issues:
- Do you ever experience intermittent blurred vision at distance or near?
- Is there a lag of clarity when you switch from distance to near and vice versa?
- Do you find yourself losing your place while you read?
- Do you have to re-read things to understand what you’ve read?
- Do you find yourself avoiding reading because it just is uncomfortable?
- How long can you read for?
- Are you getting headaches when you do something visually related such as looking at your phone, reading or on the computer?
- Do you feel visually unstable? Like your world just seems ‘off.’
Additionally, you can give your patients a symptoms survey to fill out. I use the COVD Quality of Life survey as it is a really useful tool in flagging binocular vision disorders.
2. Cover Test/ Near Point of Convergence
These two tests take a total of maybe 2 minutes to perform if you check both distance and near visual posture! Make sure to start with unilateral cover test and move to alternating.
Tip: Look for small eso deviations or vertical deviations in the distance. A small amount of compensatory prism for these patients can make a world of difference!
Test NPC. On. Every. Patient. (PLEASE!)
It is a quick test that gives you a lot of useful information on how the patient is performing visually at near.
- Do this slow, making sure the patient understands the directions
- Look for any deviation/loss of fixation… sometimes patients are unaware of diplopia.
- Consider testing with both an accommodative target and a non-accommodative target (penlight).
- Repeat NPC at the end of the exam when they are visually fatigued to see if it has degraded at all.
3. Oculomotor Testing
To test fixation, saccades and pursuits all you need is two pens and an occluder.
Fixation: Have them cover one eye and focus on your pen for 10 seconds; observe if there is any loss of fixation.
Saccades: Set up two pens of different color by about 12 inches; call out to the patient to look at one then the other making sure to change the pace. Look for any under or over-shooting or motor overflow (tongue movement, head or body movement)
Pursuits: For this you need just one pen and have your patient fix and follow. I like to make the classic “H” pattern to see if there are any restrictions and then I end with two large circles. Note if there are any losses of fixation or motor overflow.
If you notice an issue in any of these areas, you want to ask your patient about what it is like for them to read, work on the computer and complete their work.
It is likely that the patient will tell you they are having trouble focusing at near for a prolonged period of time, find themselves losing their place and have noticed a decrease in their reading comprehension.
4. Vergence Testing
A hallmark sign of a TBI patient who is suffering from visual instability is decreased vergence ability and flexibility in the distance.
Additionally, it is not uncommon to find convergence insufficiency, convergence excess or just overall fusional instability in this population.
Perform the traditional Von Graefe ranges at both distance and near to see how your patient is functioning.
Combined these tests add maybe an additional 5-7 minutes to your exams, but can make a huge difference to those patients that are suffering from post-concussion visual disorder.
These are not the only things to consider with a TBI patient, but will help identify those that need further testing and treatment.
Once you have identified the cause of your patients’ symptoms, you can discuss possible solutions:
1) Change in prescription
- Small Rx’s can make a big difference.
- consider separate DV/NV specs vs. PALs