Related Experiment Video
Updated: Aug 20, 2026
Using an Automated Hirschberg Test App to Evaluate Ocular Alignment
Published on: March 24, 2020
Pediatric Vision Screener 2: pilot study in adults
Deborah S Nassif1, Nadya V Piskun, Boris I Gramatikov
1Harvard Medical School, Children's Hospital Boston, Department of Ophthalmology, 300 Longwood Avenue, Boston, Massachusetts 02115, USA.
Insights
A new Pediatric Vision Screener (PVS) shows high accuracy in detecting strabismus, a key risk factor for amblyopia (lazy eye). Early detection is crucial for treating this common childhood vision impairment.
Area of Science:
- Ophthalmology
- Pediatric Vision Science
- Medical Devices
Background:
- Amblyopia, or lazy eye, is a visual impairment often caused by untreated strabismus or defocus.
- Early detection and treatment of amblyopia in children under 5 are critical, yet over half are missed.
- Current detection methods may not be sufficient for widespread pediatric screening.
Purpose of the Study:
- To evaluate the performance of a newly developed Pediatric Vision Screener (PVS) in identifying amblyopia risk factors.
- To assess the sensitivity and specificity of the PVS in detecting strabismus in an adult population.
- To determine the PVS's effectiveness in measuring ocular alignment (binocularity) and focus.
Main Methods:
- The study tested 40 adults (20 controls, 20 patients with strabismus) aged 22-79.
- The Pediatric Vision Screener (PVS) generated binocularity and focus scores for each participant.
- Patient strabismus was characterized by type (constant/variable) and magnitude (in Diopters).
Main Results:
- The PVS demonstrated high sensitivity and specificity in detecting strabismus among adult participants.
- 11 out of 12 patients with strabismus had binocularity scores below 50%, indicating misalignment.
- Controls consistently scored above 50% for binocularity; focus scores were sensitive but not specific for good focus.
Conclusions:
- The Pediatric Vision Screener (PVS) shows significant promise for accurately detecting strabismus in adults.
- Further research is needed to confirm the PVS's efficacy in preschool-aged children, the primary target group for amblyopia screening.
- The PVS could become a valuable tool for early identification of amblyopia risk factors, potentially reducing long-term vision loss.
Abstract:
Amblyopia is a form of visual impairment caused by ocular misalignment (strabismus) or defocus in an otherwise healthy eye. If detected early, the condition can be fully treated, yet over half of all children with amblyopia under age 5 escape detection. We developed a Pediatric Vision Screener (PVS) to detect amblyopia risk factors. This instrument produces a binocularity score to indicate alignment and a focus score to indicate focus. The purpose of this study is to assess the performance of the PVS by testing adults who were fully cooperative for testing. The study group includes 40 subjects (20 controls, 20 patients) aged 22 to 79 years. 12 patients had constant strabismus (8 to 50Delta), and eight had variable strabismus (12 to 55Delta). All controls had binocularity scores >50%. Binocularity was <50% in 11/12 patients. The patient with binocularity >50% had a well-controlled intermittent exotropia and was not at risk for amblyopia. Focus scores were highly sensitive for good focus but not specific. The PVS shows high sensitivity and specificity for detection of strabismus in adults. Future studies will determine whether this performance can be achieved in preschool children, who are at greatest risk for vision loss.
