The aim of the study was to evaluate changes in size of Schlemm’s canal (SC) and trabecular meshwork(TM) in response to accommodation stimuli and cycloplegia states in myopia children.
In total, 34 children were enroled in this study. A −6.0 D accommodation stimulus was achieved by looking at an optotype through a mirror. Cycloplegia state was induced with 1% tropicamide. Two states were confirmed by measuring the central lens thickness (CLT), anterior chamber depth and pupil diameter. The size of SC and TM was measured using swept-source optical coherence tomography. The association between changes in SC size and CLT was analysed.
Compared with that in the relaxation state, SC size increased significantly under −6.0 D accommodation stimuli. SC area (SCA) increased from 6371 ± 2517 μm2 to 7824 ± 2727 μm2, SC length (SCL) from 249 ± 10 μm to 295 ± 12 μm and SC width (SCW) from 27 ± 9 μm to 31 ± 8 μm. Under the cycloplegia state, SCA decreased to 5009 ± 2028 μm2; SCL to 212 ± 14 μm, and SCW to 22 ± 5 μm. Changes in SCA (r = 0.35, P = 0.0007), SCL (r = 0.251, P = 0.0172) and SCW (r = 0.253, P = 0.016) were significantly correlated with changes in CLT. TM size was not significantly altered compared to that in the relaxation state. TM length (TML) increased from 562 ± 45 μm to 587 ± 47 μm after exposure to −6.0 D accommodation stimulus.
SC size enlarged in response to −6.0 D accommodation stimuli and shrunk under cycloplegia. TM length increased under the accommodation stimulus state.
Subscribe to Journal
Get full journal access for 1 year
only $34.25 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Overby DR, Bertrand J, Schicht M, Paulsen F, Stamer WD, Lutjen-Drecoll E. The structure of the trabecular meshwork, its connections to the ciliary muscle, and the effect of pilocarpine on outflow facility in mice. Invest Ophthalmol Vis Sci. 2014;55:3727–36.
Grant WM. Clinical measurements of aqueous outflow. Am J Ophthalmol. 1951;34:1603–5.
Bull H, von Wolff K, Korber N, Tetz M. Three-year canaloplasty outcomes for the treatment of open-angle glaucoma: European study results. Graefe’s Arch Clin Exp Ophthalmol. 2011;249:1537–45.
Jenssen F, Krohn J. Effects of static accommodation versus repeated accommodation on intraocular pressure. J Glaucoma. 2012;21:45–8.
Read SA, Collins MJ, Becker H, Cutting J, Ross D, Savill AK, et al. Changes in intraocular pressure and ocular pulse amplitude with accommodation. Br J Ophthalmol. 2010;94:332–5.
Cassidy L, Delaney Y, Fitzpatrick P, Blake J. Effect of accommodation on intraocular pressure in glaucomatous eyes. Ir J Med Sci. 1998;167:17–8.
Barany E, Christensen RE. Cycloplegia and outflow resistance in normal human and monkey eyes and in primary open-angle glaucoma. Arch Ophthalmol. 1967;77:757–60.
Velasco Cabrera J, Eiroa Mozos P, Garcia Sanchez J, Bermudez Rodriguez F. Changes in intraocular pressure due to cycloplegia. CLAO J. 1998;24:111–4.
Marcus MW, de Vries MM, Junoy Montolio FG, Jansonius NM. Myopia as a risk factor for open-angle glaucoma: a systematic review and meta-analysis. Ophthalmology. 2011;118:1989–94. e1982.
Mitchell P, Hourihan F, Sandbach J, Wang JJ. The relationship between glaucoma and myopia: the Blue Mountains Eye Study. Ophthalmology. 1999;106:2010–5.
Leon AA, Medrano SM, Rosenfield M. A comparison of the reliability of dynamic retinoscopy and subjective measurements of amplitude of accommodation. Ophthalmic Physiol Opt. 2012;32:133–41.
Esteve-Taboada JJ, Ferrer-Blasco T, Aloy MA, Adsuara JE, Cerdá-Durán P, Mimica P, et al. Ocular anatomic changes for different accommodative demands using swept-source optical coherence tomography: a pilot study. Graefe’s Arch Clin Exp Ophthalmol. 2017;255:2399–406.
Chen Z, Song Y, Li M, Chen W, Liu S, Cai Z, et al. Schlemm’s canal and trabecular meshwork morphology in high myopia. Ophthalmic Physiol Opt. 2018;38:266–72.
Chen Z, Sun J, Li M, Liu S, Chen L, Jing S, et al. Effect of age on the morphologies of the human Schlemm’s canal and trabecular meshwork measured with sweptsource optical coherence tomography. Eye. 2018;32:1621–8.
Richdale K, Sinnott LT, Bullimore MA, Wassenaar PA, Schmalbrock P, Kao CY, et al. Quantification of age-related and per diopter accommodative changes of the lens and ciliary muscle in the emmetropic human eye. Invest Ophthalmol Vis Sci. 2013;54:1095–105.
Farouk MM, Naito T, Shinomiya K, Eguchi H, Sayed KM, Nagasawa T, et al. Optical coherence tomography reveals new insights into the accommodation mechanism. J Ophthalmol. 2015;2015:510459.
Esteve-Taboada JJ, Dominguez-Vicent A, Monsalvez-Romin D, Del Aguila-Carrasco AJ, Montes-Mico R. Non-invasive measurements of the dynamic changes in the ciliary muscle, crystalline lens morphology, and anterior chamber during accommodation with a high-resolution OCT. Graefe’s Arch Clin Exp Ophthalmol. 2017;255:1385–94.
Lewis HA, Kao CY, Sinnott LT, Bailey MD. Changes in ciliary muscle thickness during accommodation in children. Optom Vis Sci. 2012;89:727–37.
Lossing LA, Sinnott LT, Kao C-Y, Richdale K, Bailey MD. Measuring changes in ciliary muscle thickness with accommodation in young adults. Optom Vis Sci. 2012;89:719–26.
Stachs O, Martin H, Kirchhoff A, Stave J, Terwee T, Guthoff R. Monitoring accommodative ciliary muscle function using three-dimensional ultrasound. Graefe’s Arch Clin Exp Ophthalmol. 2002;240:906–12.
Sheppard AL, Davies LN. In vivo analysis of ciliary muscle morphologic changes with accommodation and axial ametropia. Invest Opthalmol Vis Sci. 2010;51:6882.
YD LCassidy, Fitzpatrick P, Blake. J. Effect of accommodation on intraocur pressure in Glaucomatous Eyes. Ir J Med Sci. 1998;167:17–9.
Rohen J. Über den Ansatz der Ciliarmuskulatur im Bereich des Kammerwinkels. Ophthalmologica. 1956;131:51–60.
Kupfer C. Relationship of ciliary body meridional muscle and corneoscleral trabecular meshwork. Arch Ophthalmol. 1962;68:818–22.
Grierson I, Lee WR, Abraham S. Effects of pilocarpine on the morphology of the human outflow apparatus. Br J Ophthalmol. 1978;62:302–13.
Rohen JW, Futa R, Lutjen-Drecoll E. The fine structure of the cribriform meshwork in normal and glaucomatous eyes as seen in tangential sections. Invest Ophthalmol Vis Sci. 1981;21:574–85.
Hann CR, Fautsch MP. The elastin fiber system between and adjacent to collector channels in the human juxtacanalicular tissue. Invest Ophthalmol Vis Sci. 2011;52:45–50.
Lepple-Wienhues A, Stahl F, Wiederholt M. Differential smooth muscle-like contractile properties of trabecular meshwork and ciliary muscle. Exp Eye Res. 1991;53:33–8.
de Kater AW, Shahsafaei A, Epstein DL. Localization of smooth muscle and nonmuscle actin isoforms in the human aqueous outflow pathway. Invest Ophthalmol Vis Sci. 1992;33:424–9.
Wiederholt M, Bielka S, Schweig F, Lutjen-Drecoll E, Lepple-Wienhues A. Regulation of outflow rate and resistance in the perfused anterior segment of the bovine eye. Exp Eye Res. 1995;61:223–34.
Kaufman PL, Barany EH. Loss of acute pilocarpine effect on outflow facility following surgical disinsertion and retrodisplacement of the ciliary muscle from the scleral spur in the cynomolgus monkey. Invest Ophthalmol. 1976;15:793–807.
This work was supported by Natural Science Foundation of China (81770921 to H.Z. and 81470632 to J.W.).
This work was supported by the Natural Science Foundation of China (81770921 to H.Z. and 81470632 to J.W.)
Conflict of interest
The authors declare that they have no conflict of interest.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Xiang, Y., Chen, L., Zhao, Y. et al. Measuring changes in Schlemm’s canal and trabecular meshwork in different accommodation states in myopia children: an observational study. Eye (2019) doi:10.1038/s41433-019-0548-2