BLOG: Masters of the retinoscope
In our quest to provide primary eye care and primary health care, it is critical that we remember our unique role in the health care system.
This blog series is dedicated to expanding the optometric encounter to include other aspects of comprehensive health care, but today I want to spend some time on the core reason for that optometry encounter. People seek our care because they want to improve their vision.
Optometry is a vital health care profession because we are uniquely trained in physics and optics and the application of these sciences to the human visual system. I was not a pre-med major in college, but rather natural sciences and mathematics. My optometrist wife majored in physics and engineering. Our family practice in Philadelphia is hospital-based, and we spend most of our clinic time managing macular degeneration, keratoconus, postcorneal transplants, failed refractive surgery and traumatic brain injury. Our treatments are not surgery, pills or drops, but rather lenses, prisms, magnification, filters and vision therapy.
Our most valuable diagnostic instrument is the retinoscope. It not only finds the best starting point for refractive testing, it tells us the quality of the optics of the eye and the ocular media. In the hands of one who is a master of the retinoscope, critical refractive data can be obtained in cases where all of the automated devices may have provided nonsense numbers or flat-out “error” messages.
Likewise, a manual keratometer allows the optometrist to look at a ring of light reflected right down the visual axis. The quality and shape of that reflected image provides vital refractive information even when the number scale cannot be used.
The trial frame and the handheld Jackson cross cylinder lens are also key tools to improve vision where the phoropter is impractical or unusable. Head movement and eccentric viewing are important for most low vision patients and required to execute an accurate refraction.
The actual manifest refraction, even in a healthy patient, is not a rote cookbook procedure that can performed well by a technician or a computer. It is a communication art that depends on the patient understanding the questions that are being asked and the optometrist providing the correct visual targets and manipulating the lenses in a meaningful way. For example, showing a target below the best acuity level and always flipping lenses with a 0.25-D power difference is a waste of everyone’s time.
Sadly, these basic optometric skills are not being taught in most modern optometry programs. Students are barely exposed to the art of refraction before being rushed over to autoretinoscopes, autorefractors, autokeratometers, corneal topographers and autophoropters. Although these tools provide an adequate number to fill in the electronic chart for the refraction box, the final glasses are just that, adequate ... not optimal. Perhaps 80% of patients may be satisfied by adequate vision. The other 20%, however, will still be looking for a good optometrist.
The act of prescribing optimal glasses is yet another dying art form. Although correctly obtaining the exact refraction is critical, the best glasses are not necessarily the same as the best refractive numbers. The final glasses prescription depends on the vision and comfort of the previous correction, the visual tasks that the patient preforms in his or her everyday life and the overall health status of the patient.
Health care reform is driving optometry to expand the scope of practice to include primary health care. As important as this expansion may be to the health of a nation, it is of no value without the core reason for the optometric encounter: optimal vision correction.