Visual apparatus Oculus et structurae pertinentes

1. Visual apparatusOculus et structurae pertinentes Morfology and embryology

2. Odilo Redon

3. Orbita • Shape of 4-sided pyramid falled backside • Bony margins • aditus x apex • 10 openings • m. orbitalis Mülleri – smooth muscle in fissura orbitalis inferior • content: eye ball, muscles, adipose tissue and accessory organs

4. Orbita – bony walls

5. Orbita – bony walls Surrounding structures: • medially: cellulae ethmoidales (behind thin lamina orbitalis o.e.) • caudally: sinus maxillaris • cranially: fossa cerebri anterior • dorsally: sinus cavernosus + fossa pterygopalatina

6. Visual apparatus • Eye ball = Bulbus oculi • Accessory apparatus = Structurae accessoriae/pertinentes oculi • Topography - regio orbitalis • Development of eye apparatus

7. Eye ball • tunica fibrosa (externa) • tunica vasculosa (media) • tunica interna (nervosa) • Vitreous body + lens cristallina

8. Eye ball • polus anterior, posterior • equator x meriadiani • axis bulbi externus, internus • axis opticus (= „linea visus“)

9. Tunica fibrosa (externa) • sclera • cornea

10. Tunica fibrosa (externa)Sclera • Thick tissue (= reticulum trabeculare), colagenous fibers, fibroblasts, basic substance • lamina episcleralis, substantia propria, lamina fusca • lamina cribrosa (entrance of n. II.) • 5/6 of surface, ø 2,2 cm • sinus venosus sclerae (canalis Schlemmi s. Lauthi) • sulcus sclerae – sclerocorneal junction = limbus corneae (angulus sclerocornealis)

11. Tunica fibrosa (externa)Cornea • Totally translucent, w/o vessels • limbus, vertex • 5 layers • epithelium anterius cornae (multi l. cuboid) • lamina limitans anterior (Bowmann membrane) • substantia propria corneae • lamina limitans posterior (Descement membrane) • epithelium posterius corneae („endotelium“) • 11 x 12 mm – fyziological astigmatismus

12. Tunica vasculosa (media) = Uvea • choroid (choroidea) • Ciliary body (corpus ciliare) • iris (iris)

13. Tunica vasculosa (media)Choroidea • lamina suprachoroidea (= lamina fusca sclerae) • spatium perichoroideum • lamina vasculosa (choroideal stroma) • Big vessels, tissue, smooth muscle cells, nerves • lamina choroidocapillaris • capillaries • lamina basalis = Bruch membrane • BM pigment epitelium and capillaries + tissue

14. Tunica vasculosa (media) ciliary body = Corpus ciliare • Shape of annulus, section of triangle • processus + plicae ciliares • orbiculus (outer part), corona (inner part) • smooth musculus ciliaris • fibrae meridionales, radiales, circulares, longitudinales

15. Tunica vasculosa (media) ciliary body = Corpus ciliare • stroma • m. ciliaris: parasympaticus akomodation  look close (look remote maintains plasticity of uvea) • Capillaries and nerves supplying muscle • Epitelial cover – production of humor aquosus • BL – continuation of Bruchs membrane • pigment epitelium – (from pigment epitelium of retina) • Cilliary canal • Non pigmented epithelium (from sensory epithelium of retina) • BL • fibrae zonulares – fixate lens

16. Tunica vasculosa (media)Iris • Shape of annulus, flat • Function of shutter • margo ciliaris (outer), m. pupillaris (inner) • pupilla (= pupil) • anulus iridis major + minor (contain circulus arteriosus iridis major + minor) • m. sphincter pupillae (parasymp.) – miosis (circular) • m. dilatator pupillae (symp.) – mydriasis (fanwise)

17. Tunica vasculosa (media)Iris • plicae iridis, stroma iridis • Anterior pole • Does not have epithelial lining (stratum limitans anterius) • fibroblasts and melanocytes (color) • plica radians = serrated line – remnant of membrana pupillaris Wachendorfi • Posterior pole • Two layers of pigment epithelium • Inner pigment • Outer myoepitelial • m. sphincter pupillae • m. dilatator pupillae

18. Lens crystallina = Lens • polus anterior, posterior • axis, equator, radii (sutures in Y shape and reversed Y) • capsula lentis • substantia lentis – cortex, nucleus • zonula ciliaris Zinni • fibrae zonulares • spatia zonularia Gray cataracta - prosthesis

19. Lens crystallina (lens) • transparent biconvex w/o vessels • capsula – similar to basal lamina • Lens epithelium – single layer cuboid • Only on anterior side of lens • Lens matter • cortical – contains elongated cells (fibers) with organels and nucleus • nuclear – cellular fibers w/o organles and nucleus • Cells contain specific proteins (filensin, crystallins)

20. Acommodation • Focusing on close distance • Contraction of m. ciliaris • fibrae zonulares relaxing • Lens forms ball • Together with contraction of m. sphincter pupillae (= miosis) • Focusing on remote distance • Tonus of vessels maintains fibrae zonulares extended • Lens is flattened • Contraction of m. dilatator pupillae (= mydriasis)

21. Vitreous body = Corpus vitreum • membrana, stroma, humor vitreus • Composed of 99% water • Hyaluronic acid, kolagen fibers • cells – hyalocytes – only during development ! • Does not regenerate ! – in case of injury it flows out – exchanged by chamber fluid • canalis hyaloideus Cloqueti – remnant of fetal arteria hylaloidea • fossa hyaloidea • Maintains inner eyeball pressure, pushes retina

22. Chamber fluid= Humor aquosus • Produced by ciliary body • Reabsorbed in angulus iridocornealis • 0,2-0,3 ml translucent, watery fluid • Daily produced cca 3 ml • composition: 0,7-1,2 % NaCl, traces of urea and glucose (0,1%), no proteins • Serves as lymph • Intraocular pressure 14-17 mmHg  Intraocular pressure  pressure on retina  glaucoma (= glaukom)

23. Eyeball chambers = Camerae bulbi • Vitreal chamber (camera postrema s. vitrea) • Between ciliary body, lens and retina • Contains vitreous body • spatium retrozonulare • posterior chamber (camera posterior) • Between iris, lens and ciliary body • Contains and produces humor aquosus • Anterior chamber (camera anterior) • Between cornea and iris • angulus iridocornealis • Contains and reabsorps humor aquosus

24. Iridocorneal angle= angulus iridocornealis • At the sclerocorneal junction • Trabecular frame of the back side = spatia anguli i.c. = Fontana spaces • Not connected with Schlemm canal • Resorption of humor aquosus • Maintenance of intraocular pressure • !!! No parasympaticolytics in glaucoma !!!

25. OCTOpticalcoherent tomographmeasurement of light reflection

26. Tunica interna (nervosa)= Retina • pars caeca • pars iridica • pars ciliaris • ora serrata • pars optica – 11 layers • pigment part • Sensory part

27. Tunica interna (nervosa)Retina– pigment part • stratum pigmentosum • Single layer cuboid epithelium • cells (pigmentocytus) connected by tight junction • Apical part contains melanin granules • Surrounds external segments of sensory cells • interfotoreceptor matrix Cell nutrition, fotopigment rejuvenation, degradation of membranous discs

28. Tunica interna (nervosa) Retina – sensory part • Light recepting neurons • Rods and cones • Conduction neurons • Bipolar and ganglionic cells • Association neurons • Horizontal and amacrine cells • Supportive cells (glia) • Müllers cells

29. Tunica interna (nervosa)Retina – sensory part • discus n. optici (= blind spot) • No light perceiving elements  excavatio disci • macula lutea (= yellow spot) – higher layers to the side • Sharpest vision • fovea centralis (100.000 cones)  foveola (2500 cones)

30. Tunica sensoria (interna)Rods = Neuron bacilliferum • rod = bacillum retinae • synaptic disc (discus membranaceus) • axon • nucleus • Inner segment • GA, ER, MIT; synthesis of ATP and rhodopsin • Outer segment (segmentum externum) • Membranous discs with fotopigment • migrate externally till separation black-white vision

31. Tunica sensoria (interna)Cones = Neuron coniferum • rod = conus retinae • synaptic pod (pes terminalis) • fotopigment is iodopsin • External segment • Membranous discs with fotopigment • Communicate with around • Color vision – three types of rods – according to wave length • „blue“ – 420 nm – type S • „green“ – 535 nm – type M • „red“ – 565 nm – type L

32. Tunica sensoria (interna)conduction neurons • Bipolar cells (Neuron bipolare) • Staminate bipolare cells (n.b. bacillotopicum) • Cony bipolar cells (n.b. conotopicum) • Dwarfy cells (n.b.c. nanum) x diffuse cells (n.b.c. diffusum) • contact with ganglionic cells • Ganglionic cells (N. ganglionare multipolare) • Diffuse type (n.g.m. umbelliforme) – connects more bipolar cells • Dwarfy type (n.g.m. nanum) – connects to dwarfy bipolar cell • Their axons form nervus opticus

33. Tunica sensoria (interna)Association neurons Have only axonal extensions – both direction • Horizontal cells (N. horizontale) • Connection with rods and cones • Amacrine cells (N. amacrinum) • Connection with bipolar and ganglionic cells Modification and synchro of signal

34. Tunica sensoria (interna)supporting cells • Müllers cells (Gliocytus radialis) • macroglia • processus radiales • Have their own BL = membrana limitans interna • zonulae adherentes with rods and cones • = membrana limitans externa

35. Tunica sensoria (interna)Vrstvy zrakové části sítnice • celkem 11 vrstev !!!  neděste se  !!!

36. Tunica sensoria (interna)layers of visual part of retina • stratum pigmentosum (1.) • stratum nervosum (2.-10.) • stratum segmentorum externorum et internorum(2.) • stratum limitans externum (3.) • stratum nucleare externum (4.) • stratum plexiforme externum (5.) • stratum nucleare internum (6.) • stratum plexiforme internum (7.) • stratum ganglionicum (8.) • stratum neurofibrarum (9.) • stratum limitans internum (10.)

37. Tunica sensoria (interna)Specific places of retina • ora serrata – termination of sensory epithelium • pars optica – 10 layers • discus n. optici /formerly papilla/ (= blind spot) – place of nerve separation • No light detecting elements • excavatio disci • macula lutea (= yellow spot) – higher layers bent to the side, sharpest vision • fovea centralis (100.000 cones) – only cones • Higher layers bent side • Sharpest vision  foveola (2500 cones)

38. OCTOptical coherent tomographmeasurement of light reflextion

39. OCT

40. OCT Retinal dystopia

41. Arterial supply of eye a. carotis interna a. ophthalmica  • aa. ciliares posteriores breves  choroid • aa. ciliares posteriores longae (24)  corpus ciliare + iris • aa. musculares  aa. ciliares ant., aa. episclerales, aa. conjuctivales lat. • a. centralis retinae retina • a. lacrimalis  aa. palpebrales lat. • aa. palpebrales med.  aa. conjuctivales med.

43. Vasa sanguinea retinae– eye backside (fundus oculi) a. centralis retinae arterioles • a. temporalis sup.+ inf. • a. nasalis sup.+ inf. • a. macularis sup.+ inf. (+ media) Veins corresponding to arteries, often crossing

44. Arteria cilioretinalis • appearance: 10-33 % • Branch from a. ciliaris posterior brevis • Enters via discus n.II independently on a. centralis retinae • Acessory arterial supply of macula lutea from choroid circuit • Only source of blood for retina during closure of a. centralis retinae • 90 % temporally - 10 % nasally • closure of a. cilioretinalis → central scotoma • Closure of a. centralis retinae → spared central vision of macula lutea

45. A. cilioretinalis

46. Venous supply of eye – 3 directions • vv. episclerales • vv. ciliares ant.  vv. sclerales  sinus venosus sclerae Schlemmi s. Lauthi • vv. vorticosae (4 in quadrants of eye ball) • v. centralis retinae • v. ophthalmica sup.  sinus cavernosus • v. ophthalmica inf.  plexus pterygoideus • v. angularis  v. facialis  v. jugularis int. ! Danger of inflammation spreading !

47. Nervous supply of eye • n. opticus – sensory • pars intraocularis, canalis, intracranialis • vagina interna, externa • n. ophthalmicus nn. ciliares longi – sensory • n. lacrimalis, n. frontalis, n. nasociliaris – for surrounding • nn. ciliares breves  ganglion ciliare - autonomous (sympaticus does not connect, parasympaticus yes) • n.III., n. IV., n.VI – motoric

49. Nervus opticus • Exvagination of diencephalon (thalamus opticus) • Axons separated by endoneurium • On the surface are analogs of cerebral coverings • Inside nervus running a. et v. centralis retinea

50. OPTICAL PATHProjection → Ascending → Sensory path 4 - neuronal, partially crossed • neuron: rods and cones of retina • neuron: bipolar cells of retina • neuron: ganglionic cells of retina  n. II  chiasma opticum  corpus geniculatum laterale • neuron: cells of corpus geniculatum laterale  tractus geniculocorticalis (= radiatio optica Gratioleti)  lobus occipitalis, area 17 (around fissura calcarina)