Sattler's layer explained

Sattler's layer
Latin:	lamina vasculosa

Sattler's layer, named after Hubert Sattler, an Austrian ophthalmologist, is one of five (or six) layers of medium-diameter blood vessels of the choroid, and a layer of the eye. It is situated between the Bruch's membrane, choriocapillaris below, and the Haller's layer and suprachoroidea above, respectively.^[1] The origin seems to be related to a continuous differentiation throughout the growth of the tissue and even further differentiation during adulthood.^{[2] [3]}

Measurement methods and clinical impact

After excision the choroid collapses partially, histologic preparations also alter the local pressure and fluid content of different sections in the tissue, thus requiring preparations with rubber solution or others that can conserve the vascular status of living tissue. Novel diagnostic methods, especially optical coherence tomography have widened the understanding of the real-time, in vivo status of the different layers.^[4]

Several papers have shown the relationship between the thickness of the choroidal, Sattler's and Haller's layer between healthy individuals and in people with age-related macular degeneration (AMD).^[5] The studies showed significant reduction of layer thickness in relation to the progression of AMD, which may be important in the understanding of choriopathy in the pathophysiology of AMD. However, also strong variations even throughout the diurnal cycle,^[6] as well as the influence of optical stimuli during eye-growth,^[7] indicate that the complex function of this tissue is not entirely understood and might be one of the reasons for the frequently found separation in vascular size between Haller's and Sattler's layer.

Notes and References

1. The Multifunctional Choroid . Progress in Retinal and Eye Research . 2010 . L. Nickla . Debora . Wallman . Josh . 29 . 2 . 144–168 . 10.1016/j.preteyeres.2009.12.002 . 2913695 . 20044062.
2. Book: Heimann, K.. International Symposium on Fluorescein Angiography Ghent 28 March—1 April 1976. 9. 1976-01-01. Springer Netherlands. 9789061931492. Laey. J. J. De. Documenta Ophthalmologica Proceedings Series. 181–186. en. 10.1007/978-94-010-1573-8_31. The Development of the Choroidal Vascular System.
3. Howard. Harvey. 1917-01-01. A Case Showing Multiple Congenital Abnormalities of the Eye; the Origin of the Vitreous Indicated by One of Them. Transactions of the American Ophthalmological Society. 15. 244–301. 0065-9533. 1318126. 16692420.
4. Považay. Boris. Bizheva. K.. Hermann. B.. Unterhuber. A.. Sattmann. H.. Fercher. A.. Drexler. W.. Schubert. C.. Ahnelt. P.. 2003-08-25. Enhanced visualization of choroidal vessels using ultrahigh resolution ophthalmic OCT at 1050 nm. Optics Express. 11. 17. 1980–1986. 1094-4087. 19466083. 10.1364/oe.11.001980. 2003OExpr..11.1980P. free.
5. Choroid, Haller's, and Sattler's layer thickness in intermediate age-related macular degeneration with and without fellow neovascular eyes. . Investigative Ophthalmology & Visual Science . 22 July 2014 . Esmaeelpour . M. . Ansari-Shahrezaei . S. . Glittenberg . C. . Nemetz . S. . Kraus . M.F. . 55 . 8 . 25052997 . 4132555 . 10.1167/iovs.14-14646 . 5074–80.
6. Brown. Jamin S.. Flitcroft. D. Ian. Ying. Gui-shuang. Francis. Ellie L.. Schmid. Gregor F.. Quinn. Graham E.. Stone. Richard A.. 2009-01-01. In Vivo Human Choroidal Thickness Measurements: Evidence for Diurnal Fluctuations. Investigative Ophthalmology & Visual Science. 50. 1. 5–12. 10.1167/iovs.08-1779. 1552-5783. 4112498. 18719079.
7. Lam. Carly Siu Yin. Tang. Wing Chun. Tse. Dennis Yan-Yin. Tang. Ying Yung. To. Chi Ho. 2014-01-01. Defocus Incorporated Soft Contact (DISC) lens slows myopia progression in Hong Kong Chinese schoolchildren: a 2-year randomised clinical trial. British Journal of Ophthalmology. en. 98. 1. 40–45. 10.1136/bjophthalmol-2013-303914. 1468-2079. 3888618. 24169657.