Specialist eye movement assessments performed by orthoptists may help clinicians diagnose Progressive Supranuclear Palsy (PSP) earlier and more accurately, according to new UK research funded in part by the PSP Association (PSPA).
Published in the British and Irish Orthoptic Journal, the study investigates how oculomotor testing and eye-tracking technology can be used to identify subtle visual signs associated with the rare neurodegenerative condition, which is frequently misdiagnosed in its early stages.
PSP is a progressive neurological disorder that affects balance, movement, speech, swallowing, cognition, and eye movements. Around 60 percent of patients are initially diagnosed with other conditions such as Parkinson’s disease, stroke or depression, often delaying access to specialist support and therapies.
The research team, led by Dominic Burdon, Advanced Orthoptist at University Hospitals Plymouth NHS Trust, UK, investigated whether orthoptic assessments could help distinguish PSP from other atypical Parkinsonian disorders. The researchers reviewed 26 patients referred for specialist oculomotor and eye-tracking assessment after presenting with atypical neurological symptoms. Orthoptic findings were then compared with final diagnoses made by neurology and neurosurgery specialists.
The study found that orthoptic assessments aligned with final neurological diagnoses in more than 80 percent of cases (21 out of 26 patients). Among patients initially flagged by orthoptists as having suspected PSP, nearly three quarters later received a confirmed PSP diagnosis from neurology teams. Meanwhile, assessments identifying “suspected non-PSP” cases matched final diagnoses in all patients reviewed.
Eye-tracking technology proved particularly useful for detecting subtle early abnormalities, including slow vertical saccades – a feature considered highly specific to PSP. The assessments also evaluated reduced blink rate, impaired convergence, and eyelid opening difficulties, all of which can emerge before more obvious neurological signs develop.
Burdon said the findings demonstrate that orthoptic eye movement testing can provide “valuable diagnostic clarity at a stage when symptoms may still be ambiguous” for PSP. Co-authors Stephen Mullin and Christopher Harris added that earlier diagnosis allows patients to access supportive therapies – including physiotherapy, speech and language therapy, and nutritional support – while they are still most likely to benefit.
The CEO of PSPA, James Cusack, noted that these delays in diagnosis can have a major impact on patients and families, both emotionally and practically. “The findings… reinforce the importance of specialist eye movement assessment in improving the diagnostic pathway for people with PSP,” Cusack added. “We are proud to help fund this work that brings us closer to earlier recognition and better care for those living with this devastating condition.”
Source: PSPA.
