Axial Elongation During Short-Term Accommodation in Myopic and Nonmyopic Children

Abstract

Purpose Axial length increases during accommodation in adults and children; however, refractive error group differences are conflicting and have not been explored in pediatric populations. This study aimed to evaluate differences in accommodation-induced axial elongation between myopic and nonmyopic children. Methods A range of ocular biometric measurements were captured during brief accommodation tasks (0, 3, 6, and 9 D) using a Badal optometer mounted to a noncontact optical biometer (Zeiss IOLMaster 700). Reliable measurements were captured for 15 myopic and 15 age- and sex-matched nonmyopic children. The average central corneal thickness (CCT), anterior chamber depth (ACD), crystalline lens thickness (LT), anterior segment length (ASL), vitreous chamber depth (VCD), and axial length (AL) were determined for each accommodation stimulus. Raw measurements of AL and VCD were corrected for the estimated error associated with LT increases during accommodation. Results All biometric parameters, except CCT, changed significantly during accommodation (all P < 0.001). Myopic children exhibited significantly greater accommodation-induced axial elongation than nonmyopic children ( P = 0.002) at the 3, 6, and 9 D accommodation stimuli, with a mean difference of 7, 10, and 16 µm, respectively (all pairwise comparisons, P ≤ 0.03). The changes in all other biometric parameters were not different between the refractive error groups ( P ≥ 0.23). Conclusions Accommodation-induced axial elongation was greater in myopic than nonmyopic children. This finding could support a potential mechanism linking near work, axial elongation, and myopia development in children or may reflect greater susceptibility to accommodation-induced axial elongation in children with established myopia.

The association between time spent on screens and reading with myopia, premyopia and ocular biometric and anthropometric measures in 6‐ to 7‐year‐old schoolchildren in Ireland

“…Children use short working distances, 41,42 particularly when using screen devices 43 . An accommodative demand over 6D is associated with axial elongation, 44 and 6‐ to 8‐year‐old children appear to be more susceptible to environmental changes than older children 15 . Prior research revealed faster axial elongation between 8 and 11 years of age and slowing between the ages of 13–16 years 45 .…”

Axial Length Shortening and Choroid Thickening in Myopic Adults Treated with Repeated Low-Level Red Light

“…Changes in other ocular components could also contribute to the short-term axial length change. Hughes reported that anterior chamber depth (ACD), crystalline lens thickness (LT), anterior segment length (ASL), and vitreous chamber depth (VCD) altered significantly during accommodation, resulting in an increment in axial length [10]. Moreover, such changes were more prominent in the myopic group and existed in adults and children [10][11][12].…”

“…Hughes reported that anterior chamber depth (ACD), crystalline lens thickness (LT), anterior segment length (ASL), and vitreous chamber depth (VCD) altered significantly during accommodation, resulting in an increment in axial length [10]. Moreover, such changes were more prominent in the myopic group and existed in adults and children [10][11][12]. Whether short-term RLRL treatment can cause changes in anterior segment parameters in myopic adults is currently unknown.…”

Empfehlungen bei progredienter Myopie im Kindes- und Jugendalter. Stellungnahme von DOG, BVA und der Bielschowsky Gesellschaft für Schielforschung und Neuroophthalmologie

“…Obwohl zuverlässige Daten zu Bildschirmzeit oder verwendeten Abständen für große Kohorten fehlen, sollte neben Abständen auch an regelmäßige Pausenzeiten erinnert werden. Möglicherweise handelt es sich bei der akkommodationsassoziierten Progression um einen Mechanismus, der insbesondere bei einer bereits bestehenden Myopie zum Tragen kommt [ 21 ]. Lesezeiten von über 30 min bei weniger als 30 cm Leseabstand sollten durch 10 min Blick in die Ferne unterbrochen werden.…”