Why Instrument-Based Screening for Amblyopia?
To be sure, newer screening devices for early detection of amblyopia will provide reasonably good results compared to screening with a long lane in your office and the child covering their own eye. So, it may be a no-brainer to invest in one. However, there are several important factors to consider that—if done carefully—will help you make the right decision, noted Daniel J. Karr, MD, FAOO, FAAP, professor of ophthalmology and pediatrics and the director of the Elks Children’s Eye Clinic and Strabismus Services in Portland, OR.
Start off by determining the target group to be screened. Is the device for a pediatrician’s office, a preschool head start program, or for community screening use? Next, ask who will perform the screening: volunteers, office staff, or researchers? Of course, budget always plays a role. And that can mean more than just the purchase or lease price of the device. Look carefully for potential hidden or extra costs, including costs per test/click or cost per interpretation. Also think about the level of interpretation needed for the device you are considering, since that can result in added expense. Beyond this, consider the level of reimbursement you may or may not receive. Then be sure to have additional eye exam slots available for those who fail screenings.
Why Instrument-Based Screening …
With the availability of the affordable American Association for Pediatric Ophthalmology and Strabismus Screening Kit, why consider instrument-based screening? Photo-screening, explained Dr. Karr, is proven and medically necessary 1) as a mass screening instrument for children 1 to 3 years of age; and 2) in children ≥4 years of age who are developmentally delayed and are unable or unwilling to cooperate with routine visual acuity screening.
… and Which One Should You Use?
If you’re ready to make the plunge, here are your major options:
- Diopsys Enfant Pediatric VEP Vision Testing System: It produces a visual stimulus of an equal number of horizontal black and white bars. You assess visual acuity by changing the width of the bars. The test is performed rapidly and separately for each eye. If a significant between-eye difference is detected, the patient fails the test.
- Retinomax autorefractor with keratometry: “We use this one in our office, and find it very effective on very small children, since you don’t have to get them up to a machine. You actually bring the machine to them.”
- iScreen: Works with a sophisticated set of rapidly-timed flashes at different angles, “which gives you a modified red reflex that can be evaluated by an ethernet connection. A trained technician looks at the device and then gives you a pass-fail pretty quickly.”
- Spot: This device follows American Academy of Pediatric screening guidelines for early detection of amblyopic risk factors. “You get a printout with immediate pass/fail available to the family and the patient. It’s pretty easy to use and the manufacturer claims a 97% capture rate for getting good results in a screening situation.”
- Plusoptix: Similar to the Spot, except “that you end up with a photograph of the child rather than a printout of the result. You can see the pupillary light reflex. It is reminiscent of the MTI photo-screener.” You get “both a strabismus assessment a refraction assessment. It also measures pupil diameter and pupil distance.”
- GoCheck Kids: This provides the same information that you get from Spot and Plusoptix, but it leverages the camera and flash of a smartphone to capture the red reflex. Relies on software and algorithms to identify those at risk. It also provides acuity assessments. Currently it is the only FDA-approved device designed to be used on a smartphone.
- REBIScan Pediatric Vision Scanner: “Looks for the presence or absence of certain bifoveal responses to [determine] if you really have or do not have [a patient with] amblyopia.”
Karr D. Vision screening devices for early detection of amblyopia risk factors. Talk presented at: AAO 2018 annual meeting; October, 26-30, 2018; Chicago.
