July 2019
Volume 60, Issue 9
Free
ARVO Annual Meeting Abstract  |   July 2019
Anterior scleral changes with accommodation and convergence
Author Affiliations & Notes
  • Hamed Niyazmand
    Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Brisbane, Queensland, Australia
  • Scott A Read
    Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Brisbane, Queensland, Australia
  • Michael J Collins
    Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Brisbane, Queensland, Australia
  • David A. Atchison
    Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Brisbane, Queensland, Australia
  • Footnotes
    Commercial Relationships   Hamed Niyazmand, None; Scott Read, None; Michael Collins, None; David Atchison, None
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science July 2019, Vol.60, 4362. doi:https://doi.org/
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Hamed Niyazmand, Scott A Read, Michael J Collins, David A. Atchison; Anterior scleral changes with accommodation and convergence. Invest. Ophthalmol. Vis. Sci. 2019;60(9):4362. doi: https://doi.org/.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Recent research investigating ocular changes associated with near tasks indicates accommodation may affect the anterior scleral shape. This study aimed to examine the effects of accommodation, convergence and their interaction upon anterior scleral shape.

Methods : The right eyes of 36 young healthy adult subjects (mean age 23.5 ± 3.8 years) had measures of anterior eye shape collected with the Eye Surface Profilometer (ESP) before and during visual tasks under three conditions: 5 D accommodation (0° convergence), 9° convergence (0 D accommodation), and a combination of 5 D accommodation and 9° convergence. Accommodative stimuli were introduced using a Badal optometer via a beam splitter. Three ESP scans were captured and the sagittal height data were averaged along a horizontal cross-section in 0.7 mm width zones in both the peripheral cornea and the anterior sclera (Figure 1).

Results : The anterior scleral surface exhibited a small anterior movement (mean height change of 5 ± 2 µm, p = 0.04) in the zone up to 0.7 mm beyond the nasal limbus during accommodation. Greater movement occurred during convergence in the zone up to 0.7 mm and in the zone 0.7 to 1.4 mm beyond the nasal limbus (mean changes 13 ± 4 and 19 ± 6 µm, respectively, both p < 0.01) (Figure 2), and similar movement (10 ± 4 µm and 15 ± 5, both p < 0.02) occurred in the same nasal scleral zones during the combined convergence and accommodation condition. No significant changes in temporal anterior surface height were observed for any condition.

Conclusions : Accommodation and convergence produce small but significant changes to anterior surface shape in the nasal anterior scleral region. The largest changes occurred during convergence, and this is most likely due to medial rectus contraction.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

 

Figure 1: ESP measurement from a representative subject. Sagittal height data from the horizontal meridian were calculated from a series of 0.7 mm width zones either side of the limbus (denoted by the vertical red dashed lines) on the nasal (N) and temporal sides.

Figure 1: ESP measurement from a representative subject. Sagittal height data from the horizontal meridian were calculated from a series of 0.7 mm width zones either side of the limbus (denoted by the vertical red dashed lines) on the nasal (N) and temporal sides.

 

Figure 2: Changes in anterior eye surface height with different visual tasks in various zones. Dashed vertical lines indicate the location of limbus. Asterisks indicate significant change (p<0.05). Error bars indicate 95% confidence intervals. Positive values represent movement in the anterior direction.

Figure 2: Changes in anterior eye surface height with different visual tasks in various zones. Dashed vertical lines indicate the location of limbus. Asterisks indicate significant change (p<0.05). Error bars indicate 95% confidence intervals. Positive values represent movement in the anterior direction.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×