Direct ophthalmoscope

detailed view of direct ophthalmoscope and clinical findings

1. DIRECT OPHTHALMOSCOPY PAGE 1 BY MEENA.M OPTOMETRY 2 ND YEAR

2. OUTLINE PAGE 2 INTRODUCTION OPHTHALMOSCOPY DIRECT OPHTHALMOSCOPY INDICATIONS FOR USE OPTICS CHARACTERISTICS OF IMAGE INSTRUMENTATION PROCEDURE NORMAL FUNDUS BASIC AND FUNDAMENTALS OF RECORDING OPHTHALMOSCOPIC FINDINGS CLINICAL RECORDING OF OPHTHALMOSCOPIC FINDINGS PATHOGICAL CONDITIONS RECORDING AND INTERPRETING RESULTS MOST COMMON ERRORS ADVANTAGES AND DISADVANTAGES DIFFERENT MODELS OF DIRECT OPHTHALMOSCOPE REFERENCES

3. I NTRODUCTION PAGE 3

4. O PHTHALMOSCOPY PAGE 4 OPHTHALMOSCOPY - “ Seeing the eye “ In Greek ophthalmos – the eye skopeos - to see

5. F UNDOSCOPY TYPES PAGE 5

6. D IRECT OPHTHALMOSCOPY H and held instrument used to examine fundus Used monocularly Examine central 7 to 10 degree of retina PAGE 6

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8. INDICATIONS FOR USE Evaluation of the lens Detection of eye diseases E.g. .glaucoma, diabetic retinopathy, retinal retachment Monitoring progression of disease and symptoms Determine patients fixation pattern To confirm previous clinical findings PAGE 8

9. OPTICS PAGE 9

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11. PAGE 11 Optics of Direct Ophthalmoscope • The instrument consists of a system of lenses which focus light from an electric bulb on to a mirror where a real image of the bulb filament is formed. • The mirror reflects the emitted light in a diverging beam which is used to illuminate the patient's eye. Reflected rays from patients retina refracted by patients crystalline lens become parallel and enters into the observed eye through the mirror hole and the observer views the illuminated eye. • The image of the bulb is formed just below the hole so that its corneal reflection does not lie in the visual axis of the observer

12. CHARACTERISTICS OF IMAGE Erect , virtual 15x magnified 10 degree field of view 50-70% fundus seen PAGE 12

13. PAGE 13 Magnification Field of view

14. INSTRUMENTATION Illumination system and observation system Observation system/ viewing system - peep hole - bank of spherical lenses Illumination system - light source - condensing lenses - reflecting prism - an aperture PAGE 14

15. VIEWING SYSTEM PAGE 15

16. ILLUMINATION SYSTEM PAGE 16

17. Light source Incandescent lamp – this is usually a xenon halogen bright white lamp powered by 2.5vnon rechargeable or 3.5v or Lilon rechargeable battery. Condensing lens There are 2 condensing lens on either side of the aperture dial which focus the light onto the prism. Aperture dial various apertures such as cobalt blue filter , fixation star ,small spot ,large spot ,pinhole ,hemi spot. These have specific functions. Reflecting prism This is mirror angled at 45 degree which is partially reflecting or has a central peephole. It makes the light cone projected upon the patients eye. PAGE 17

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19. PROCEDURE Dilate the pupil Dim the lights Instruct the patient to focus on an object straight ahead on wall Turn on the ophthalmoscope Set the light to correct the aperture To examine patient rt eye use rt hand and rt eye Find the red reflex Move in closer to see optic disc Rotate the diopter lens to focus the optic nerve Scan slightly down, right , left to look at the blood vessels Move out temporally to see macula and fovea Repeat the same technique on another eye PAGE 19

20. NORMAL FUNDUS PAGE 20

21. RETINA CONSISTS OF Optic disc Vessels Macula Peripheral retina PAGE 21

22. OPTIC DISC Pale pink, well defined ,circular area 15mm diameter PAGE 22

23. VESSELS RETINAL SYSTEM - central retinal artery and central retinal veins CAPILLARY SYSTEM - Posterior ciliary arteries and choriocapillaris PAGE 23

24. MACULA LUTEA Yellow spot Comparatively dark area 5.5 mm in diameter Temporal to optic disc Three main areas - fovea - parafovea - perifovea PAGE 24

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26. FOVEA PARAFOVEA -Belt surrounding the foveal margin -0.5mm in width FOVEA -central depressed part - 1.5 mm diameter - 1.55mm thickness Margo fovea – margin Foveola - central floor Umbo – tiny depression PERIFOVEA -Belt surrounding the parafoveal region -1.5mm in width PAGE 26

27. PERIPHERAL RETINA Divided into 4 regions Near periphery Mid periphery Far periphery Extreme periphery PAGE 27

28. BASICS AND FUNDAMENTALS OF RECORDING OPHTHALMOSCOPIC FINDINGS Fundal glow Disc - shape , margin , colour , vessels emerged , cup disc ratio , neural rim. Retina { color – normal } - periphery { lighter than central area } [ 4 quadrants] haemorrhage , exudate ,pigmentary changes, vascularization. - macula{ appears darker than central area ,3mmtemporal to disc, central foveal reflex – healthy / dull } [foveal reflex , hole , oedema , haemorrhage] - vessels [ vascular reflexes , A/V ratio{normal 2:3} Optic disc - shape [ round to oval ,diameter 1:5 -1:7 ] - margin [sharp] { dull ,pigment ring ,conus} - color [red-yellow , temporal part pale] - vessels emerged from disc { neovascularization} PAGE 28

29. [Cup/disc] ratio PAGE 29

30. ISNT rule PAGE 30

31. CLINICAL RECORDING OF OPHTHALMOSCOPIC FINDINGS IN NORMAL CASES Shape – round Margin – sharp colour – pink C/D ratio – 0.3:1 A/V ratio – 2:3 Macula – healthy and bright foveal reflex PAGE 31

32. RETINAL VEIN OCCLUSION Disc – Virtually obscured by edema and hemorrhages Retina - Extensive blot retinal haemorrhages in all quadrants to periphery Vessels- Dilated tortuous veins; vessels partially obscured by haemorrhages PAGE 32

33. HYPERTENSIVE RETINOPATHY Disc: Outline clear Retina: Exudates and flame hemorrhages Vessels: Attenuated arterial reflex PAGE 33

34. ADVANCED MALIGNANT HYPERTENSIVE RETINOPATHY Disc: Elevated, edematous disc; blurred disc margins Retina: Prominent flame hemorrhages surrounding vessels near disc border Vessels: Attenuated retinal arterioles PAGE 34

35. INFERIOR BRANCH RETINAL ARTERY OCCLUSION DUE TO EMBOLUS Disc: Prominent embolus at retinal artery bifurcation Retina: Inferior retina shows pale, milky edema; superior retina is normal Vessels: Inferior arteriole tree greatly attenuated and irregular; superior vessel is normal PAGE 35

36. NON PROLIFERATIVE DIABETIC RETINOPATHY Disc: Normal Retina: Numerous scattered exudates and hemorrhages Vessels: Mild dilation of retinal veins PAGE 36

37. PROLIFERATIVE DIABETIC RETINOPATHY Disc: Net of new vessels growing on disc surface Retina: Numerous hemorrhages, new vessels at superior disc margin Vessels: Dilated retinal veins PAGE 37

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39. MACULAR DRUSEN Disc: Normal Retina: Extensive white drusen of the retina Vessels: Normal PAGE 39

40. END STAGE OF DIABETIC RETINOPATHY Disc: Partially obscured by fibrovascular proliferation Retina: Obscured by proliferating tissue; small area of retina with hemorrhage seen through “window” of fibrovascular membrane Vessels: Abnormal new vessels in fibrous tissue Vitreous: Prominent fibrovascular tissue PAGE 40

41. INACTIVE CHORIORETINITIS Disc: Normal Retina: Well-circumscribed lesion with areas of hyperpigmentation and atrophy of retina, white sclera showing through Vessels: Normal PAGE 41

42. ADVANCED HAEMORRHAGIC MACULAR DEGENERATION Disc: Normal Retina: Large macular scar with drusen; prominent macular hemorrhage Vessels: Normal PAGE 42

43. ADVANCED RETINITIS PIGMENTOSA Disc: Normal Retina: Scattered retinal pigmentation in classic bone spicule pattern Vessels: Greatly attenuated PAGE 43

44. RETINAL DETACHMENT Disc: Normal Retina: Gray elevation in temporal area with folds in detached section Vessels: Tortuous and elevated over detached retina PAGE 44

45. OPTIC NEURITIS Disc: Elevated with blurred margins Retina: Mild peripapillary edema Vessels: Mild dilation of vessels on disc PAGE 45

46. BEGNIN CHOROIDAL NEVUS Disc: Normal Retina: Slate gray, flat lesion under retina; several drusen overlying nevus Vessels: Normal PAGE 46

47. OPTIC ATROPHY Disc: Margins sharp and clear; pale white color Retina: Normal Vessels: Arteries attenuated; veins normal PAGE 47

48. PAPILLEDEMA Disc: Elevated, edematous disc; blurred disc margins; vessels engorged Retina: Flame retinal hemorrhage close to disc Vessels: Engorged tortuous veins PAGE 48

49. GLAUCOMATOUS CUPPING OF DISC Disc: Large cup, disc vessels displaced peripherally; pale white color; pigment ring surrounding disc Retina: Normal Vessels: Normal PAGE 49

50. PAGE 50 RECORDING AND INTERPRETING RESULTS

51. PAGE 51 Recording Lens: If there are no opacities record clear', Record cortical and subcapsular cataracts by drawing them . The un dilated pupil can be recorded as dashed line. Nuclear cataracts just present as a nondescript opacity that makes the view of the fundus hazy and these should be diagnosed and graded using slit-lamp biomicroscopy . Vitreous : Record any findings or abnormalities noted in the posterior vitreous such as posterior vitreous detachment, floaters or cells. If no abnormalities are detected, record 'clear' . Interpretation the cup-to-disc ratio is generally judged to be smaller when using a direct ophthalmoscope (monocular image) compared to when examined stereoscopically with fundus biomicroscopy

52. MOST COMMMON ERRORS 1. Not getting close enough to the patient when performing the technique, particularly when attempting to view the macula. 2 Using the cup pallor instead of the deflection of the blood vessels as the determinant of the edge of the cupping. 3 Assuming that any optic disc cupping or possible macular edema has been evaluated adequately with the direct ophthalmoscope non-stereoscopic view. 4. Not having the patient view in different directions of gaze to obtain a better view of the non-central retina. 5. Not using a systematic method of viewing for assessing the posterior pole and as far peripherally as is possible. 6 Assuming that the periphery has been evaluated adequately with a direct ophthalmoscope. PAGE 52

53. ADVANTAGES AND DISADVANTAGES ADVANTAGES Portable Easy to use Upright image Magnification 15x Can use w/o dilation DISADVANTAGES Small field of view Lack of stereopsis Media opacities can degrade images PAGE 53

54. DIFFERENT MODELS OF DIRECT OPHTHALMOSCOPE PAGE 54

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56. REFERENCES http://www.medisave.co.uk http://morancore.Utah.edu/basic Clinical procedures in primary eye care Borish’s clinical refraction. PAGE 56

57. PAGE 57 THANK YOU