Ophthalmology: Excellence in Medical EducAation

A great deal of research is done on how to educate medical students. Our government, and the medical schools themselves, have a lot of money invested in the process. The Canadian public depends on that investment having a productive return in the form of competent, quality doctors.

The challenges of medical education are many. Each medical student arrives from a unique background; how can we draw on students’ previous skills and knowledge while bringing them all to the same place of medical competence? Similarly, each medical student is preparing for a different career. The  teaching required to prepare a student for General Practice might be quite different than that needed by a Specialist. How can a single curriculum sufficiently address both? The universe of medical knowledge is simply too vast to be given justice in four years – choosing which information is most important can be a real challenge.

There is currently a paradigm shift occurring in the research of medical education. New studies are showing that the century-old approach of didactic lectures is ineffective. Someone once said that a lecture is: “the process by which the notes of the lecturer become the notes of the student without passing through the mind of either“. There’s some truth to that.

As an alternative to having a lecture, educators are suggesting a team-structured, problem-solving session. Ever since McMaster started the trend, all medical schools have incorporated this approach to some degree in the form of “Problem-Based Learning”. Although the Mac kids seem to love it, the rest of us are a little more hesitant. We prefer our lectures! So do the instructors. Nonetheless, Queen’s and other schools are doing their best to apply the new conclusions in education research, without sacrificing the best aspects of the strong curriculum we have right now!

This past week we studied Ophthalmology. The challenges of conveying a broad overview to Ophthalmology in a single week are a small-scale representation of the challenges in overall medical education. Having now completed the week, I can say appreciatively that the Queen’s Ophthalmology Department delivered the most excellent teaching I’ve encountered. It was incredibly well done. Here’s how they did it:

• Acquisition: Through a series of online videos, and a recommended textbook, students were required to prepare for each session by obtaining the relevant background knowledge independently.
• Application: Each morning we met in teams to discuss clinical cases. We would decide on our approach to each patient, and ask for necessary investigations. As decisions were made, the facilitator would reveal new information that eventually led us to a diagnosis and constructing a management plan.
• Clinical Skills: We finished off the week with a session to learn the necessary skills to examine the eye. The Opthalmology Clinic in Kingston closed their doors to patients for the afternoon, and instead invited us into their department, where in groups of twos and threes we learned from the Ophthalmologists directly the techniques we need to know to examine the eye.

From my perspective, the Ophthalmologists’ approach was highly successful, and  I feel it serves a good model for how medical education should be done in general.

Amblyopia

Cute kid, right ? Take another look. Notice anything not quite right? Although easily missed at a subtle glance, you should see that this boy’s eyes are pointing in different directions. (If you want to confirm, look for the two shiny spots of reflected light from each eye, and observe how they overly different locations). Mal-alignment of the eyes is called strabismus. It’s fairly common, seen in 2-4 children of every 100.

Aside from the aesthetic implications (kids with strabismus are sometimes presumed to be intellectually slow because of their appearance, despite that there is no association between strabismus and cognitive ability), strabismus is a dangerous condition in children. When adults develop strabismus, they report double vision; each eye is looking in a different direction, there are two unique visual inputs to the cortex, and the brain perceives two simultaneous visual representations of the visual field.

In contrast, children whose visual maturation is not yet complete (before age 7-9) are able to suppress the input from one, or both eyes. Chronic suppression over time leads to irreversible loss of visual circuits in the brain. The result is irreversible loss of vision in one eye. This is called Amblyopia. It can be caused by strabismus, as described, or other causes including congenital cataracts, retinoblastoma (an eye tumour), or refractive errors. Amblyopia is the greatest cause of monocular (one eye) blindness in people under 45 yrs old.

Importantly, Amblyopia is painless, and has no symptoms. The only way to detect Amblyopia, is by an objective test of visual acuity. You may notice a strabismus (which can result in Amblyopia) like the picture above, but often the cause of Amblyopia is just as unnoticeable as the result. Can you imagine discovering that your child has become permanently blind in one eye, and worse, that it could have been prevented? The important public-health message about Amblyopia, therefore, is that children should have their vision checked regularly by a health-care professional. This is equally true for the pre-verbal child.

In case you’re curious, treatment for Amblyopia involves reversing the cause when possible (e.g. fixing the strabismus with surgery), and then patching the good eye such that the brain is forced to receive input from the Amblyopic eye. This preserves, and strengthens, the brain circuitry from the affected eye.

(Yes, we’re on Ophthalmology this week! And I love it!!)

Eyes Wide Open

So a couple days ago I sat down to my computer to write a blog post about learning the retina exam. It was only to discover that I couldn’t read the words on the screen… and well, that was the end of that. You see, my pupils were still dilated because in the course of learning the exam, we had been practising on each other. The retina exam becomes vastly easier if you use eyedrops to dilate the pupils, so a few of us had to take a hit for the team.

The screening retina exam is actually way cool ! It’s got to be one of the most exciting moments during a general physical. Using a tool called an ophthalmoscope, you peer through the pupil (like looking through a keyhole) to the retina in the back of the eye. What you’re hoping to see is a nice pink looking retina, a yellow circle called the optic disk at the fundus of the eye, which is where the nerves bundle together to go back into the brain, and arteries coursing peripherally. Here’s what a normal looking retina looks like:

Perhaps the most interesting part of a retinal exam is considering the path of the light. To achieve the above view, light travels from the lamp in the ophthalmoscope, through the lens of the patient’s eye, bounces off their retina, passes through the patient’s lens again, passes through your own lens, and finally hits your own retina. Amazing!

If anybody reading this wants an eye exam, I’m just dying to get some practice ! Do let me know,