The Uveitis Atlas PDF
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Normal Fundus Sameeksha Tadepalli, Aniruddha Agarwal, Mohit Dogra, and Vishali Gupta Contents Thecolorofnormal fundusmay bedescribed as ranging from orange to vermilion, depending Introduction............................................ 1 onthediffusionspectrumofblood(oxyhemoglo- OpticNerve............................................ 1 bin), the amount of pigment in the choroid, and AreaCentralis(Macula).............................. 2 hexagonalepitheliumoftheretina.Fundusshows PeripheralRetina(Figs.3and4).................... 2 a generalized water-silk reflex corresponding to the light reflecting off the surface of the retina VascularArcades...................................... 3 during examination. A fine-stippled reflex SuggestedReading.................................... 4 (tapetoretinal reflex)duetoreflectionoflight off thepigmentepitheliallayermaybeseennearthe macula. The choroid may be deeply pigmented, Introduction appearing as dark polyhedral areas between the lighterchoroidalvessels,calledtessellatedfundus Normal fundus of an adult comprises of visible (Fig.1). part of the retina. Human retina is a transparent The various structures identified on fundus structureextendingfromtheopticdiscposteriorly examinationincludeopticnerve,macula,periph- totheoraserrataanteriorly. eralretina,oraserrata,andretinalvessels. Optic Nerve S.Tadepalli(*)(cid:129)M.Dogra(cid:129)V.Gupta AdvancedEyeCentre,PostGraduateInstituteofMedical Opticnerveheadisthewell-definedpinkish,pale EducationandResearch,Chandigarh,India e-mail:[email protected];vishalisara@yahoo. circular area about 1.5 mm in diameter co.in;[email protected] corresponding to the area of exit of the nerve A.Agarwal fibers of the optic nerve. It is located nasal and AdvancedEyeCentre,PostGraduateInstituteofMedical superiorlywithrespecttothemacula.Atthecen- EducationandResearch,Chandigarh,India ter of the optic disc is a depression called the DepartmentofOphthalmology,AdvancedEyeCenter, physiological cup. It varies in shape, size, posi- PostGraduateInstituteofMedicalEducationandResearch tion,anddepth.Theusualratioofareaofthecup (PGIMER),Chandigarh,India and the disc being from 0.2 to 0.5. It is also the StanleyM.TruhlsenEyeInstitute,UniversityofNebraska pointofentryoftheretinalvessels(Fig.2). MedicalCenter,Omaha,NE,USA e-mail:[email protected];aniruddha. [email protected] #Springer(India)Pvt.Ltd.2016 1 V.Guptaetal.(eds.),TheUveitisAtlas, DOI10.1007/978-81-322-2506-5_2-1 2 S.Tadepallietal. Fig.2 Discphotographofthelefteyeofapatientwithno Fig.1 Normalfundusphotographobtainedusingacon- knownoculardiseaseshowingthephysiologicalcupand ventional fundus camera showing the posterior pole and healthyneuroretinalrim themid-periphery(approximately55(cid:1)view) Area Centralis (Macula) It is the central area of the retina bound by the opticdiscmediallyandthevasculararcadessupe- riorly, inferiorly, and laterally. It corresponds to central 15(cid:1) field of vision. It measures about 5–5.5 mm across and 3.5–4 mm vertically. It is furthersubdividedas: 1.Foveacentralis. It is the central depressed area which is the most sensitive part of the retina. It measures about 1.85 mm in diameter and corresponds to central5(cid:1) ofthevisualfield.Itcomprisesof: (a) Margin– It is situated atabout 1.5 mm from fovealcenter. Fig. 3 Montage (seven-field) view of a normal fundus (b) Foveola–Itisthedepressedbaseofthefovea obtainedusingaconventionalfunduscamera where the highest concentration of cones is present.Itmeasures0.35mmindiameter. (c) Umbo – It is the central 150–200 μm, Peripheral Retina (Figs.3 and 4) correspondingtothefoveallightreflex. (d) Fovealavascularzone–Itisanareawithdiam- eterrangingfrom250to600μmfromthefoveal 1. Near periphery – It is a 1.5 mm wide belt beyondthemacula. centerwherenobloodvesselsarepresent. 2. Mid-periphery – It is the area of the fundus, 2.Parafovea–Itistheareaofthemaculaupto 3 mm wide, from near periphery up to the equator. 0.5mmbeyondthefovea. 3.Perifovea–Itistheareafromtheedgeofthe 3. Far periphery – It extends beyond mid-peripheryuptotheoraserrata. parafoveaupto1.5mmfromit. NormalFundus 3 Fig.4 Ultrawidefield fundusimagingofanormal funduswithacamera showingapproximately 200(cid:1)view Fig.5 Ultrawidefield fundusimagingofanormal fundusshowingthelong ciliarynerve(whitearrow) Structures observed in the peripheral retina ora serrate. They divide the fundus into superior include: andinferiorhalves(Fig.5). Equator–Itistheareathatdividestheeyeball Short ciliary nerves – They are fine, lightly intotwoequalhalves.Itispresentattheposterior colored branching structures located in the cho- marginofampullae ofvortexveins.Thecircum- roid on either side of both vertical meridian ferential diameter at the equator of the adult eye (around 1, 5, 7, 11 o’clock positions) present at averages69mm. theequator,foratotaloffourpereye. Ampullae of vortex veins – They are four to Ora serrata – Serrated anterior margin of the eight in number, located at the equator in all retina. Here retina is firmly attached to the vitre- four quadrants. There is pigment migration, ousbaseandtheretinalpigmentepithelium. toward and around the vortex ampullae, which might sometimes be the only indicators of their location. Vascular Arcades Long ciliary nerves – yellow-to-orange linear structure with variably pigmented borders is The blood supply to the inner retina comes from observed at approximately 3 and 9 o’clock posi- the central retinal artery that emerges from the tionsstartingattheequatorandpassinguptothe opticdisc.Ithasfourmainbranchesintosupero- 4 S.Tadepallietal. nasal, supero-temporal, infero-nasal, and infero- temporal. The arteries appear bright red in color. (cid:129) Peripheral retina is the area beyond the The temporal branches along with the temporal macula, divided as near, mid, and far tributaries of the ophthalmic veins form the periphery. Structures seen include the boundary of the area centralis. The veins of the equator, short and long ciliary nerves, retina follow the arteries and finally drain out ampullae of vortex veins, and the ora through the central retinal vein which leaves the serrata. retinaattheopticdisc.Veinsappearthickerwith dark reddish hue. The normal ratio of caliber of arteriestoveinsis2:3. KeyPoints (cid:129) Normal fundus is the visible part of the Suggested Reading retina. It is described according to the Bowling B, FRCSEd(Ophth), FRCOphth, FRANZCO. landmarks of optic disc, vascular Kanski’s clinical ophthalmology. 8th ed. Elsevier: arcades,macula,andoraserrata. Canada;2016. (cid:129) Opticdiscis1.5mmdiameterareamark- KhuranaAK,KhuranaI.Anatomyandphysiologyofeye. ing the location of exit of retinal nerve 3rded.CBSpublishers andDistributors: NewDelhi; fibers. 2016). Ryan SJ, MD, Schachat AP, MD, Wilkinson CP, MD, (cid:129) Area centralis is the central part of the Hinton DR, MD, Sadda SR, MD Wiedemann P, retina which includes fovea centralis, MD.Retina.5thed.Elsevier:Canada;2013. parafovea,andperifovea. Yanoff M, Duker JS, . Ophthalmology. 4th ed. Elsevier: Canada;2014. Grades of Vitreous Clarity Brian Madow and John H. Kempen Contents Introduction Introduction............................................ 1 Thevitreoushumorisatransparentgel-likestruc- VitreousHaze.......................................... 2 tureoccupyingthespacebetweentheretina,cili- VitreousClarityGrades................................. 3 ary body, and the lens. The vitreous body forms ReportofCases........................................ 5 veryearlyduringpregnancyandundergoesrapid CaseReport1:SevereVitreousHazeDueto transformationinthree phases.First,theprimary InfectiousUveitis,withDramaticClearingAfter Treatment........................................... 5 vitreous develops at month one of gestation, CaseReport2:SevereBilateralVitreousHazeDue representing the vascular structure necessary to toNoninfectiousPosteriorUveitiswithSignificant support the development of the lens. During the ClearinginBothEyesAfterTreatment second month of gestation, the vitreous, denoted withCorticosteroids................................ 6 as secondary vitreous, loses its vascularity and SuggestedReading.................................... 7 becomesmuchmoretransparent.Thetertiaryvit- reous arises in the third month of gestation and surrounds the secondary vitreous. Maximum vit- reousclarityispresentatterm(Fig.1). The most important function of the vitreous fromthesensorystandpointistoallowtransmis- sion of visible light to the retina. The clarity requiredtotransmitlightappropriatelyisaccom- plishednotonlybecauseofitshighwatercontent (approximately 98 %) but also because nerves andbloodvesselsareabsentwithinthestructure of the vitreous. Vitreous clarity and light trans- mission capabilities also are functions of the B.Madow(*) index of refraction of the vitreous body – UniversityofSouthFlorida,Tampa,FL,USA e-mail:[email protected] reportedtobeequalto1.336.Thisvalueisvery similar to the refractive index of the aqueous J.H.Kempen UniversityofPennsylvania,Philadelphia,PA,USA humor.Vitreousclarityalsodependsonthespe- cific structural composition and high level of DiscoveryEyeInstitute,AddisAbaba,Ethiopia organizationofthecollagenfiberswithdiameter DepartmentofOphthalmology,CenterforPreventive of10–25nm. OphthalmologyandBiostatistics,Philadelphia,PA,USA e-mail:[email protected] #SpringerIndia2016 1 V.Guptaetal.(eds.),TheUveitisAtlas, DOI10.1007/978-81-322-2506-5_3-1 2 B.MadowandJ.H.Kempen Fig.1 Drawingofthe vitreousclarity development Fig.2 Drawingofthe vitreoushazeformationin intermediate(a)and posterioruveitis(b) In order to maintain the opticaltransparency, Vitreous Haze the vitreous body has a barrier function and buffering properties, both of which prevent Vitreous haze from uveitis is produced by pene- cells and proteins from penetrating its structure tration of inflammatory cells and protein exuda- due to the content of hyaluronic acid. Conden- sation of the peripheral collagen fibers creates tion into the vitreous from adjacent structures suchastheciliarybody,choroid,andretina.The strongtransparentboundarymembraneorcortex result is a variable degree of obscuration of the and aids in the barrier function. As a result, the fundus details which impacts visual acuity more vitreous content of macromolecular solutes, profoundlythandoesanteriorchamberinflamma- which are known to decrease light scattering, is tion(Fig.2). very low. These properties allow the vitreous The vitreous haze of uveitis presumably is body to transmit a very high proportion of visi- causedbyinflammationitself.Inanexperimental blelight,reportedly90%. GradesofVitreousClarity 3 model of uveitis, it was found that the degree of constant during the eye examination, it is more the vitreous inflammation was dependent on the practicaltodeterminethedegreeofobscuration, concentration of the protein induced by the startingwiththesmallestperifovealvesselsuntil inflammationinthevitreousbutinverselyrelated theopticnerveheadisnotvisibleanymore.The totheconcentrationofthehyaluronicacid.Vitre- extent of obscuration is transformed into grada- ous opacification from other causes, such as vit- tions of vitreous haze. The levels need to be reous hemorrhage, also can occur. Cryotherapy characterized precisely and described application during retinal detachment surgery accurately in order to be useful for clinical also has been described to increase vitreous grading. haze, perhaps because of protein seepage from Thefirstattemptatgradingvitreoushazewas theinflammationinducedbycryotherapy. describedbyKimuraetal.,in1959.Theauthors The rate of clearing of the vitreous haze has offer a descriptive five-step scale with levels been studied and was found to be similar in from 0 to ++++. Level (0) represents a clear vitrectomized and non-vitrectomized eyes, view without opacities, level (+) opacities with suggesting that factors external to the vitreous clear view, level (++) fundus details somewhat are of principal importance. Based on clinical obscured, level (+++) opacities with marked observations, severe vitreous haze tends to clear blurringofthefundus,and++++noviewofthe much slower than the aqueous cells often taking fundus. This scale’s gradations are imprecise severalweeksforsignificantchangewithcortico- because not all the factors contributing to vitre- steroid treatment. Complete clearance may take ous haze are described; hence, the scale was of muchlonger. limitedvalueforclinicaluse.Animprovedscale forvitreoushazegradingwasdescribedin1985 by Nussenblatt et al. This “NEI” scale not only VitreousClarityGrades uses a better description of the vitreous opacificationlevelsbutalsooffersphotographic Current clinical concepts for measurement or standardsforeachlevel(Fig.3). quantitation of the vitreous haze or opacification TheNEIscalehassixordinalgradesofvitre- resemblethemethodsusedbytheenvironmental ousopacificationrangingfrom(0)to(4+).Level sciences. The method of turbidimetry has been (0)representsclearfundusviewandlevel(4+)is used widely to determine the level of cloudiness fullobscurationofthefundusdetails.Thosetwo as an inverse measure of clarity of the water in extremegradesaresimilartothoseintheKimura lakes, reservoirs, and channels. It is designed to scale. The levels adjacent to these extremes are quantitate the intensity of the transmitted light “trace” (with slight blurring of the optic disk through a sample of water. A simple device, margin)and(3+)(wheretheopticdiskisvisible known since 1864 as a Secchi disk, has been buttheretinalvesselsarenotvisible).Forgrade used for quantitation. The disk has black and (2+),someretinalvesselsarevisible.Level(1+) white sectors on its surface; it is submerged in offers better visibility of the optic disk and the the tested water until the visibility of the surface vesselsthanlevel(2+).Allstepsarerepresented sectorsislost.Thedistancefromthesurfaceofthe by three standard color film-based photos to water is recorded and isexpressed as a measure- account for variations within the levels, except mentofwatertransparency. forlevel(4+),whichisrepresentedbyonestan- Similarly, when vitreous cavity opacification dard photograph. An expert panel subsequently is measured clinically, the currently accepted suggestedchangingthenameofthegrade“trace” methods rely on the determination of the level to“0.5+.” ofvisibilityofthenaturalfunduslandmarkssuch CurrentlytheNEIscaleisacceptedbytheUS as the optic nerve head and the retinal blood FoodandDrugAdministration(FDA)asasurro- vessels.Sincethedistancefromthelightsource gatemeasureofthediseaseactivityinintermedi- to the focused retina remains approximately ate,posterior,andpanuveitissuitableforuseasa 4 B.MadowandJ.H.Kempen Fig.3 VitreoushazescalepublishedbyNussenblattRB,PalestineAG,ChanCC,RobergeF(Reprintedwithpermission) primary outcome in therapeutic trials. Excellent In this scale, high-quality 30(cid:1) standard color agreement within 1 grade has been reported for fundus images were precisely generated to repre- vitreous haze grading in clinical settings. Limi- sentthehazelevels.Eachimagewasproducedby tationsofthescaleincludeitsordinalratherthan using Bangerter foils17 with designated grade of quantitativebasis(stepsarenotestablishedtobe artificialvisualdegradationinfrontofthecamera, equal distances from one another) and that the when the retina of a normal subject was scale offers limited resolution of the vitreous photographed. The foils were chosen based on haze grades, especially when low to moderate theirexpectedcorrespondencetothevisualacuity levels of opacification are present as is typical level.Thevisualacuityintervalbetweentwocon- withuveitis.Becausemostcasesfallinthecate- secutivefoilswasselectedtorepresentadifference goryof0.5+or1+haze,thescaledoesnotoffer ofapproximately0.3logMARunits.Thescalewas enough discrimination in order to meet reliably validatedonthesetofphotographsfromtheMul- the requirement for two-step change as an indi- ticenter Uveitis Steroid Treatment (MUST) Trial, catoroftreatmenteffectivenessinclinicaltrials, showing veryhighintra-and interobserver agree- unlessenrollmentislimitedtothesmallsubsetof mentinthereadingcentersetting. caseswith 2+orhighervitreous haze.Thislim- In clinical setting, however, a modest exact itation creates logistical problems in enrolling agreement was reported and excellent agreement sufficient patients and raises generalizability withinonestepforbothscales. concerns even when this obstacle can be The recommendations for clinical grading overcome. usingbothofthesescalesincludedarkroomenvi- In order to avoid these limitations, another ronment,well-dilatedpupil,andconductingindi- vitreous haze scale was designed and described rect ophthalmoscopy using a setting of mid- to in 2010 by Davis and associates. The new high level of the light source brightness with a “Miami” scale is more photographic and less +20.0 or +28.0 diopter aspheric lens. The view descriptive and offers more levels of vitreous fromtheophthalmoscopeiscomparedtoaprinted haze discrimination at the lower end of copy of the scale on non-glossy paper, which is opacification;ithasninelevels(Fig.4). placedincloseproximitytothepatient. GradesofVitreousClarity 5 Fig.4 PhotographicvitreoushazescalebyJ.Davis,B.Madow,J.Cornett,R.Stratton,D.Hess,V.Porciatti,W.Feuer (Reprintedwithpermission) Report of Cases CaseReport1:SevereVitreousHaze DuetoInfectiousUveitis,withDramatic ClearingAfterTreatment A-52-year-oldpreviouslyhealthyimmunocompe- tent man presented with decreased vision (countingfingersat2ft)inhisrighteyeandante- rior chamber reaction characterized by the pres- ence of (1+ grade) white cells. The patient had vitreous haze with severity grading of (3+ grade) bytheNEIscaleand(7+grade)withMiamiscale (Fig.5).Thevitreoushad(3+grade)cells.Large, deep,whiteconfluentretinalplaqueswereseenin Fig. 5 Fundus photograph of the right eye showing theinferiorretinalperiphery.Thepatientwasdiag- vitreous haze with barely visible optic nerve and retinal nosed with acute retinal necrosis and started on vessels 6 B.MadowandJ.H.Kempen Fig.8 Fundusphotographoftherighteyeshowinghazy vitreous with no visible retinal vasculature and barely Fig.6 Controlfundusreflexphotographoftherighteye visibleopticnervebeforetreatment showingthattherearenosignificantcornealorlensopac- itiestoaccountfortheretinalblurringandthatthevitreous hazeissolelycausedbysevereinflammation Fig.9 Fundusphotographoftherighteyeshowingdra- maticvitreoushazeclearingaftertreatment CaseReport2:SevereBilateralVitreous Fig.7 Fundusphotographoftherighteyeshowingclear HazeDuetoNoninfectiousPosterior retinal vasculature and optic disk after vitreous haze has UveitiswithSignificantClearing clearedcompletely inBothEyesAfterTreatment withCorticosteroids valacyclovirandoralsteroids(Fig.6).Onemonth ParticipantintheMUSTclinicaltrialwithsignif- later his vision recovered to 20/20, and vitreous icantbilateralvitreoushazegradedas(8+grade) hazehascompletelyclearedtogetherwithresolu- onMiamiscaleand(3+grade)ontheNEIscalein tionoftheperipheralretinitis(Fig.7). therighteye(Figs.8and9).
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