Undergraduate lecture 4-Dark room tests in ophthalmology

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Dark Room Procedures for undergraduates(MB,BS) in the field of Ophthalmology are explained in simple terms in this presentation. Series of lectures taken at Central Park Medical College Lahore Pakistan.

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Undergraduate lecture 4-Dark room tests in ophthalmology

  1. 1. TheReflection
  2. 2. Dark Room Tests Dr. Zia-Ul-Mazhry FCPS(Pak), FRCS(Edin), FRCS(Glasgow), CIC Ophth- (UK) Assistant Professor Central Park Medical college Lahore Consultant Eye Surgeon & Head of DepartmentWAPDA Teaching Hospital Complex Lahore.
  3. 3. Dark room Tests• Oblique Illumination• Distant Direct Ophthalmoscopy• Direct Ophthalmoscopy• Retinoscopy• Indirect Ophthalmoscopy – Indirect Ophthalmoscope – Slit Lamp Biomicroscopy
  4. 4. Oblique Illumination• Objective – Examination of External and anterior Segment structures• Instruments – Illumination Beam – Magnification Aid/Microscope• Method – Illumination beam at 45 degrees
  5. 5. Slit Lamp• The slit-lamp is a low- power microscope combined with a high- intensity light source that can be focused to shine in a thin beam.
  6. 6. SLE• Observation by optical section• Direct diffuse illumination• Indirect illumination• Retro-illumination• Scattering sclero- corneal illumination• Fundus observation and gonioscopy with the slit lamp
  7. 7. SLE• The slit lamp exam uses an instrument that provides a magnified, three-dimensional (3-D) view of the different parts of the eye. During the exam, your doctor can look at the front parts of the eye, including the clear, outer covering (cornea), the lens, the colored part (iris), and the front section of the gel-like fluid (vitreous gel) that fills the large space in the middle of the eye.• Special lenses can be placed between the slit lamp and the cornea (or directly on the cornea) to view deeper structures of the eye, such as the optic nerve, retina, and the area where fluid drains out of the eye (drainage angle ). A camera may be attached to the slit lamp to
  8. 8. Distant Direct Ophthalmoscopy• Objective – To Examine and classify media opacities against fundal glow• Instrumentation – Direct Ophthalmoscope• Methods – Throw the light with DO at half meter distance – Parallax Method of deviation
  9. 9. Distant Direct Ophthalmoscopy• Parallax Method of deviation – Ask the patient to move his/her eye – Opacities Moving • With – Anterior to nodal point • No movement – At or very near to nodal point • Against Movement – Behind the nodal point
  10. 10. Distant Direct Ophthalmoscopy• Viewing ocular media – Observe red reflex – Look for media opacities • Cataracts • Corneal scars • Large floaters
  11. 11. Direct Ophthalmoscopy• Objective – To examine the retina/fundus• Instrumentations – Direct ophthalmoacope• Methods
  12. 12. Fundoscopy• Fundoscopy is the assessment of the fundus using an ophthalmoscope
  13. 13. Examination Technique• dim the lights.• ask the patient to fixate on a distant target.• approach the patient from the side.• examine the optic nerve and surrounding retina.
  14. 14. Fundoscopy-Video
  15. 15. Direct Ophthalmoscopy: Basic skills• Proper position for central fundus viewing• Right eye to right eye• Left eye to left eye• Don’t rub noses…
  16. 16. Direct Ophthalmoscopy: Basic skills• Proper position for peripheral fundus viewing
  17. 17. Direct Ophthalmoscopy: Exam technique• Be systematic• Start at optic disc & work radially• Observe: – Optic disc: C/D ratio – Vessels: course & caliber, AV ratio, light reflex, crossings/banking – Macula – Peripheral fundus
  18. 18. Direct Ophthalmoscopy: Basic skills• Clinical pearls – FOV incr. when closer to Pt. – Larger pupil increases FOV – Contact lenses – Check lens wheel– watch accommodation
  19. 19. Indirect Ophthalmoscopy• Objective – Fundus Examination• Instrumentation – Indirect Ophthalmoscope – Condensing Lens• Methods
  20. 20. FunduscopyTechniques/instruments• Direct Ophthalmoscopy• Indirect Ophthalmoscopy• Fundus Biomicroscopy• Fundus Contact Lens
  21. 21. Why do we dilate pupils?
  22. 22. Direct Ophthalmoscopy • 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 image
  23. 23. Indirect Ophthalmoscopy• Monocular or binocular• Advantages: – Wide field of view – Binocular instruments provide stereopsis• Disadvantages: – Requires more skill – Decreased magnification (3x) – Requires dilation – Inverted image
  24. 24. IndirectOphthalmoscopy
  25. 25. Fundus Biomicroscopy • Field of View & Mag: – FOV <indirect but >direct – varies w/lens & slit lamp mag • Inverted image • Stereopsis • Dilated pupil • Requires skill
  26. 26. Fundus Biomicroscopy
  27. 27. Fundus Contact Lens • Requires physical contact w/eye • Viewed w/Biomicroscope • Advanced dx & surgery • Field of view & Mag vary w/lens design
  28. 28. Direct Ophthalmoscopy: Basic skills • Optics: – Illumination system – Magnifier • Hyperopes • myopes – Observation system • Lens wheel • Apertures
  29. 29. Normal Fundus
  30. 30. Viewing the Optic Nerve Head• Observe: – Size – Shape – Color – Margins – Cup to disc ratio (C/D) horiz & Vert
  31. 31. Blood Vessel Evaluation• Observe: – Vessel diameter – Shape/tortuosity – Color – Crossings – Light reflex – Artery/Vein (A/V) ratio: after 2nd bifurcation
  32. 32. Hypertensive Retinopathy• Scheie classification: I: Thinning of retinal arterioles relative to veins II: Obvious arteriolar narrowing w/focal areas of attenuation III: Stage II + cotton wool spots, exudates & hemes IV: Stage III + swollen optic disk (similar to papilledema)
  33. 33. Vessel “Crossings”• Normal crossing Direction change “banking’” or “nipping”
  34. 34. Arteriolosclerosis• Increased light reflex (1/2)• “Copper wire” arterioles• “Silver wiring” arterioles – whitish appearance w/continuing sclerosis• Increased A/V crossings
  35. 35. Macula• Lies about 2DD (disc diameters) temporal to the optic disc• Should be avascular• May appear darker red than surrounding retina• Should see bright foveal reflex on younger pts
  36. 36. The Indirect Ophthalmoscope George T. Timberlake, Ph.D. Department of Ophthalmology University of Kansas Medical Center Gullstrand Indirect Ophthalmoscope ca. 1910
  37. 37. Allvar Gullstrand 1862 - 1930 Professor of Physical & Physiological Optics, University of Uppsala First “reflex free” ophthamoscope Nobel Prize 1911 for work on optics of eyeSwedish Ophthalmologist GTT 04
  38. 38. Gullstrand Principle for Reflex-free OphthalmoscopyLight entrance and exit separated in pupil plane Light entering eye Light leaving eye Pupil GTT 04
  39. 39. Retinoscopy• Objective – To determine refractve status of the eye• Instrumentation – Retinoscope – Trial Lens set – Trial frame
  40. 40. Retinoscopy• Methods – Ask the patient to fixate on a distant target – Half to 1 meter distance – Project the streak on pupil – Move the streak and observe the movement of red reflex
  41. 41. Retinoscopy• Moves with – Emetropia – Hyperopia – Myopia of less than 1 diopter• No Movement – Myopia of exactly 1 diaopter• Moves against – Myopia of more than 1 diopter
  42. 42. Retinoscopy• Insert +1 D Lens in front of the eye while working at 1 meter – No movement • Emetropia – With movement • Hyperopia – Against movement • Myopia of < 1 D
  43. 43. RETINOSCOPEWelch Allyn Neitz
  44. 44. RETINOSCOPESight holePolarizingfilter External intergrated Streak rotator And focusing sleeve
  45. 45. RETINOSCOPESight hole External focusing SleeveStreak rotator rheostat
  46. 46. RETINOSCOPEBASIC CONCEPT1) EMMETROPIA • Light emerge Parallel2) HYPEROPIA • Light emerge Diverge3) MYOPIA • Light emerge Converge
  47. 47. RETINOSCOPEEMMETROPIA Parallel
  48. 48. RETINOSCOPEHYPEROPIA Diverge
  49. 49. RETINOSCOPEMYOPIA converge
  50. 50. RETINOSCOPETHE STREAK LIGHT REFLEXCONCEPT 1) Break Phenomenon 2) Thickness Phenomenon 3) Skew Phenomenon 4) Movement Phenomenon
  51. 51. RETINOSCOPE• BREAK PHENOMENONIris pupil Streak light light reflex No Break Break
  52. 52. RETINOSCOPE• THICKNESS PHENOMENON Same thickness Different thickness
  53. 53. RETINOSCOPE• SKEW PHENOMENON light reflex movement streak movement No skewness Skew
  54. 54. RETINOSCOPE• MOVEMENT PHENOMENON With movement Against movement
  55. 55. RETINOSCOPE• NEUTRALITY - pupil fills - no movement
  56. 56. RETINOSCOPE• With movements – Hyperope – Neutralize with Plus lenses (convex lenses)• Against movements – Myope – Neutralize with Negative lenses (concave lenses)
  57. 57. RETINOSCOPE• Working Distance Lenses – Purpose : Light emerge from Pt eye conjugate with examiner’s retina • +1.50 D - @ 66.7cm • +2.00 D - @ 50.0cm
  58. 58. Retinoscopy Video
  59. 59. TheReflection
  60. 60. • Thank you

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