Applying structure-function to solve clinical cases

Transcription

1 Applying structure-function to solve clinical cases Professor Michael Kalloniatis Centre for Eye Health, and, School of Optometry and Vision Science

2 Acknowledgements Some material prepared by Nayuta Yoshioka Paula Katalinic Michael Yapp Images and other clinical data collected by staff at CFEH

3 Overview of lecture Aims of lecture Outline various structure-function modes Anatomy (OCT) Fundus autofluorescence (FAF) Clinical electrophysiology (ERG) Visual function measures: VA, contrast sensitivity, dark adaptation and colour vision Definition and application of Köllner s rule Applying colour vision results to clinical cases Clinical cases to illustrate various functional and anatomical results that help in the differential diagnosis

4 Retinal structure Histological image Optical Coherence Tomography (OCT)

5 Fundus Autofluorescence (FAF) Based upon autofluorescent properties of lipofuscin granules in RPE cells Lipid-containing residues of lysosomal digestion Lipofuscin accumulates with age and in diseased cells Normal = isofluorescence Hyper/Hypo = RPE dysfunction

6 Optomap- FAF Paravenous pigmented chorioretinal atrophy

7 Useful review on electrophysiology

8 Voltage Hyperpolarisation Depolarisation Full field ERG Waveform ON Bipolar Cell & Müller cell Depolarisation ON bipolar cells (Müller cells) Photoreceptors Time Rod &/or Cone Hyperpolarisation

9 Electrophysiology Results: Disease Normal Flicker: Cone Light adapt: Cone Only Dark adapt: Rod Only

10 Visual Acuity and Contrast Sensitivity Visual acuity is the gold standard for visual performance despite only measuring foveal function at high contrast Contrast Sensitivity measurement (MARS chart) extends the assessment to various contrast levels

11 Visual Field (SAP and Amsler grid) Central and peripheral contrast sensitivity Dark adaptometry

12 Colour vision A range of colour vision tests are available to test for congenital and acquired colour vision defects

13 Classification of retinal dystrophies

14 Basic Division of Retinopathies Inherited Retinitis pigmentosa CSNB (eg Oguchi's disease) Achromatopsia Leber s congenital amaurosis (EOSRD Early Onset Severe Retinal Dystrophy) Juvenile macular degeneration Stargardt s disease/fundus flavimaculatus Retinoschisis (X-linked) Acquired Diabetic/hypertensive retinopathy Vascular occlusive disease Achromatopsia Paraneoplastic syndromes (MAR, CAR) Age related macular degeneration (AMD) Central Serous Retinopathy Retinal detachment Retinoschisis (myopic)

15 What do patients with vision loss/anomalies actually see?

16 Normal AMD Diabetic Retinopathy Retinitis Pigmentosa

17 Ophthalmology 2013

18 Vienot et al Nature 1995 Normal perception Protanope perception Tritanope perception Deuteranope perception

19 Acquired colour vision deficiencies

20 Acquired colour vision loss No large scale systematic study using colour vision tests designed for congenital colour vision deficiencies Interpretation of congenital colour vision test results is required when applied to acquired Typically require visual acuity loss when using standard sorting tests

21 Clinical examination Congenital colour vision Ishihara, F2 (tritan plate), D15, Lanthony s D15, 100-hue Test under 270 lux using daylight lamps Suspect acquired colour vision (test individual eyes) Pseudoisochromatic plates Ishihara and F2 to rule out congenital unknown efficacy in acquired but poor visual acuity will result in a FAIL Farnsworth panel D15 Identifies R/G and B/Y acquired defects and scotopic (monochromats or advanced disease) Lanthony s panel D15 [desaturated] (use second test results) Identifies R/G and B/Y acquired defects Farnsworth 100 hue Identifies R/G, B/Y and scotopic

22 Abnormal colour vision (congenital) X-linked (recessive) Dominant? Achromatopsia Congenital monochromacy or Advanced disease

23 Depicting the color confusion on the CIE diagram Confusion lines for protan, deutan and tritan dichromatic observers (from Pitt and Wright) Protan Deutan Tritan

24 Farnsworth Panel D-15

25 Congenital vs Acquired Colour Vision Results Typical monochromat VA 6/50 Fail all Ishihara and F2 plates D15 Juvenile optic atrophy VA 6/40 Fail all Ishihara and F2 plates Kalloniatis & Johnston OVS 1990 Achromatopsia (scotopic axis) ON disease (dominant)? B/Y (tritan) or achromatopsia?

26 Acquired Colour Vision Results Retinitis Pigmentosa VA 6/18 Primary optic atrophy VA 6/75 D15 Kalloniatis & Johnston OVS 1990 Retinal disease B/Y (tritan) ON disease R/G (acquired) or, could be congenital R/G?

27 Köllner s Rule Normal Color Vision Retinal disease Blue-yellow blindness ON disease Progressive red-green (R/G) blindness (B/Y also affected) Combined with R/G leads to (achromatopsia) Total Color loss (achromatopsia)

28 Exceptions to Köllner s rule (B-Y retina and R-G optic nerve) Juvenile Macular Degeneration (get R/G) DIJOA (dominantly inherited juvenile optic atrophy) (get B/Y) Glaucoma (get B/Y) Choked disc (papilloedema, neuritis, toxic amblyopias) Katz (1995) highlights Köllner s law (B/Y predominates in acute phase but both are readily found; B/Y recovers? faster)

29 Acquired CVD: B/Y, R/G or luminance? Greeenstein et al VR 1996 (B/Y) (R/G) Luminance Black bars Glaucoma (N=27)

30 Clinical cases

31 44 year old male cone dystrophy: (VA 6/60 OU)

32 44 year old male cone dystrophy LE RE

33 44 year old male cone dystrophy Color vision testing (6/60 OU) Poor VA will result in Ishihara (plate test) fail Retinal disease B/Y (tritan)

34 54 year old male diagnosed 35 years ago Visual acuity: finger counting at 1 metre (~1/60) ON disease R/G or achromatopsia because of advance disease

35 54 year old male diagnosed 35 years ago Visual acuity: finger counting at 1 metre ON disease R/G in RE and scotopic axis in LE

36 72 yo male with vision reduction 6/12 in OD (gradual over 3 months) Retinal disease expect B/Y (tritan)

37 72 yo male with vision reduction 6/12 in OD (gradual over 3 months) Tritan Protan Deutan Retinal disease B/Y (tritan)

38 Key point #1 Vision loss or alteration does not result in a perceptual absolute scotoma but rather filling in In colour vision deficiencies: there is an altered perception of colour The panel D15 and Lanthony s D15 are useful tests to diagnose the type of acquired colour vision defect, including achromatopsia Köllner s rule is useful in guiding clinical diagnosis

39 15 yo male with strong family history of male associated vision loss -VA 6/38 OD and 6/12 OS; reduced CS OU; -OD no distortions or missing patches; less distinct squares OS

40 15 yo male with strong family history of male associated vision loss

41 15 yo male with strong family history of male associated vision loss Optomap: fundus autofluorescence

42 15 yo male with strong family history of male associated vision loss

43 X-linked retinoschisis

44 Farnsworth Panel D15 Retinal disease B/Y (tritan)

45 Electrophysiology Rod ERG Normal X-linked retinoschisis

46 Electrophysiology Single Cone Flash Normal X-linked retinoschisis

47 Clinical cases Differential diagnosis of retinal splitting

48 Macular appearance - OCT X-linked retinoschisis 6/15

49 Differentials Cystoid Macular Oedema / Dystrophies Vascular Inflammatory Iatrogenic Drugs Dystrophies Tractional Diabetic Vein occlusion Hypertension Telangiectasia Macroaneursym Radiation CNV Toxo CMV Behcets Scleritis Birdshot Multifocal - choroiditis Cataract Sx YAG Cryotherapy Retinopexy Trabeculectomy Scleral buckle PK Propine Prostaglandins Nicotinic acid RP Gyrate Atrophy Dominantly inherited CMO Pattern Vitreo-macular traction Epiretinal membranes

50 Differentials Vitreo-macular traction / epiretinal membranes Vascular Inflammatory Iatrogenic Drugs Dystrophies Tractional Diabetic Vein occlusion Hypertension Telangiectasia Macroaneursym Radiation CNV Toxo CMV Behcets Scleritis Birdshot Multifocal - choroiditis Cataract Sx YAG Cryotherapy Retinopexy Trabeculectomy Scleral buckle PK Propine Prostaglandins Nicotinic acid RP Gyrate Atrophy Dominantly inherited CMO Pattern Vitreo-macular traction Epiretinal membranes

51 A 47 yo female with reduced VA (OS) Aided acuities 6/6-1 OD and 6/38 OS (pinhole 6/12-1). Rx: R: -5.75/-1.75 x 15 & L: /-3.25 x148 Axial length: R: 25.74mm & L: 30.20mm

52 Optomap (central field) OD

53 Spectralis OCT OD

54 Optomap (central field) OS

55 Spectralis OCT Internal limiting membrane (ILM detachment) Vitreous cortex Thickened partially detached posterior hyaloid Myopic Retinoschisis

56 A 48 year old Caucasian female with suspected (epiretinal membrane) ERM in OD: Asymptomatic with 6/6 OU

57 Spectralis Macula Line Scans Epiretinal membrane OD Retinoschisis at OPL (continuous with ONH) OS

58 Are ONH normal? OD OS

59 Spectralis OCT: Optic disc pit retinoschisis

60 Key point #2 Electrophysiology can assist in differentiating inherited versus acquired focal retinoschisis A range of underlying conditions can lead to retinal schisis In retinal schisis Either no colour vision anomaly or B/Y affected more

61 Thank you for your attention