Trabecular meshwork

<h2 id="structure">Structure</h2>
<p>The meshwork is divided up into three parts, with characteristically different ultrastructures:
</p>
<ol><li><i>Inner uveal meshwork</i> - Closest to the anterior chamber angle, contains thin cord-like <a href="/facts/Trabecula/3dfcqlwH">trabeculae</a>, orientated predominantly in a radial fashion, enclosing trabeculae spaces larger than the corneoscleral meshwork.</li>
<li><i>Corneoscleral meshwork</i> - Contains a large amount of <a href="/facts/Elastin/9S2w5thw">elastin</a>, arranged as a series of thin, flat, perforated sheets arranged in a laminar pattern; considered the <a href="/facts/Ciliary_muscle/dxkVzBek">ciliary muscle</a> <a href="/facts/Tendon/M0Kdf7Fy">tendon</a>.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a></li>
<li><i>Juxtacanalicular tissue</i> (also known as the <i>cribriform meshwork</i>) - Lies immediately adjacent to Schlemm's canal, composed of connective tissue <a href="/facts/Ground_substance/nvpvRF9e">ground substance</a> full of <a href="/facts/Glycoaminoglycans/fo22ktAQ">glycoaminoglycans</a> and <a href="/facts/Glycoproteins/bKPzzW7m">glycoproteins</a>. This thin strip of tissue is covered by a monolayer of endothelial cells.</li></ol>
<p>The trabecular meshwork is assisted to a small degree in the drainage of aqueous humour by a second outflow pathway, the uveo-scleral pathway (5-10% of outflow occurs this way). The uveo-scleral pathway is increased with the use of <a href="/facts/Glaucoma/MWqWVNz3">glaucoma</a> drugs such as prostaglandins (e.g., <a href="/facts/Xalatan/46zyKkbX">Xalatan</a>, <a href="/facts/Travatan/pP8MEVRm">Travatan</a>).
</p><p>The trabecular meshwork had previously been thought to arise from a point (apex) corresponding to the termination of the DM
(<a href="/facts/Schwalbe%2527s_line/tHPvsHM9">Schwalbe's line</a>) however it is now considered to extend into the cornea, forming the <a href="/facts/Dua%2527s_layer/Tp0LRDSh">Dua's layer</a>.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a>
</p>
<h2 id="clinical-significance">Clinical significance</h2>
<h3>Glaucoma</h3>
<p>It is thought that most cases of glaucoma (although not all) are caused or enabled by an increase in <a href="/facts/Intraocular_pressure/VVnweTza">intraocular pressure</a>. Pressure increases either when too much aqueous humor fluid is produced or by decreased aqueous humor outflow. The trabecular meshwork is responsible for most of the outflow of aqueous humor. When outflow is blocked, interventions such as <a href="/facts/Trabeculectomy/LFJL9CWD">trabeculectomy</a>, <a href="/facts/Trabeculoplasty/lRmUaTyp">trabeculoplasty</a>, or aqueous shunt may be required to restore it.
</p>
<h2 id="see-also">See also</h2>
<p class="note">This article uses <a href="/facts/Anatomical_terminology/n3IASQlr">anatomical terminology</a>.</p>
<ul><li><a href="/facts/Ocular_hypertension/PgzT17Tw">Ocular hypertension</a></li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="https://www.bu.edu/phpbin/medlib/histology/p/08005loa.htm">Histology image: 08005loa</a> – Histology Learning System at Boston University</li>
<li><a href="http://www.glaucoma-association.com/media/images/medical/diagrams/labelled/english/Conventional_Outflow_Diag_L.jpg">Diagram at glaucoma-association.com</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Karpinich NO, Caron KM (September 2014). "Schlemm's canal: more than meets the eye, lymphatics in disguise". The Journal of Clinical Investigation. 124 (9): 3701–3. doi:10.1172/JCI77507. PMC 4151199. PMID 25061871. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4151199" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4151199</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Sampaolesi R, Sampaolesi JR, Zárate J (2009). "Ocular Embryology with Special Reference to Chamber Angle Development". The Glaucomas. Berlin Heidelberg: Springer-Verlag. pp. 61–9. doi:10.1007/978-3-540-69146-4_8. ISBN 978-3-540-69144-0. <a href="978-3-540-69144-0" target="_blank">978-3-540-69144-0</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Dua HS, Faraj LA, Branch MJ, Yeung AM, Elalfy MS, Said DG, et al. (May 2014). "The collagen matrix of the human trabecular meshwork is an extension of the novel pre-Descemet's layer (Dua's layer)". The British Journal of Ophthalmology. 98 (5): 691–7. doi:10.1136/bjophthalmol-2013-304593. PMID 24532799. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
</ol>

Trabecular meshwork open-in-new

Trabecular meshwork