eLetters

82 e-Letters

published between 2019 and 2022

  • The educational value of Saccades

    Many thanks for your response to the editorial ‘What are you looking at?’, which highlights some important principles for this extensively studied research area (despite being a relatively new field in healthcare) [1]
    Despite the emergence of new methods to analyse gaze behaviour terminology has not been revised to reflect scientific advances. A recent article by Hessels et al. outlined significant inconsistencies in the definitions of fixations and saccades held by eye movement researchers and highlighted the conceptual confusion surrounding these terms.[2]

    The term saccade is derived from the French for ‘jerk’. The phrase appears to have been coined by Emile Javal, a French ophthalmologist, in the 1800’s.[3] By 1916 it had been accepted into the English literature.[4]

    Saccades are frequently defined in the literature as rapid, ballistic movements of the eyes that abruptly change the point of fixation.5 Definitions have included;

    ‘Rapid eye movements used to voluntarily move gaze from one target of interest to another.’[6]

    ‘Ballistic movements, 20-150ms long, reaching a velocity up to 800°/s. They direct the eye so that external visual objects are projected onto the fovea.’[7]

    ‘Rapid eye movements used in repositioning the fovea to a new location in the visual environment.’[8]

    The term ballistic refers to the fact that the saccade-generating system cannot respond to subsequent changes in the position of a target during th...

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  • Improving newborn and infant screening

    Hall and Sowdon regret that the Newborn Infant Physical Examination (NIPE)/child health surveillance (CHS) programme fails to deliver improved outcomes for developmental dysplasia of the hip (DDH), contrasting with the success of other screening programmes. I would like to make some proposals for improvement.

    Current NIPE standards are focused on timeliness of the screening pathway and explicitly exclude treatment outcomes as ‘outside the screening pathway’1. Yet potential outcome measures are routinely available for three of the four NIPE screening programmes and shown to be measurable for two of these. McAllister et have demonstrated that records of surgical intervention for DDH can be used to show variation in outcomes2. Similarly, the NHS Atlas of Variation has demonstrated that age at orchidopexy can be used for undescended testis (UDT)3. Surgery for congenital cataract could be used in the same way. While I accept that definitions and actual measures might need some discussion to reach a national consensus, measuring these outcomes is possible from routine data.

    McAllister et al conclude that dedicated leadership of the DDH screening programme is associated with improved outcomes. This has also been shown for UDT4. Unfortunately, clinical leadership of the Healthy Child Programme (HCP) has been dismantled in recent years and the RCPCH recorded a community paediatric HCP lead in only 16% of services in 2015.

    Lastly poor outcomes may indicate...

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