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Dark room

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Dark room

  1. 1. DARK ROOM APPLIANCES PROF. DR. D. SUNDARARAJAN. M.S.,D.O., Associate Professor in Ophthalmology, Dr Rajvin Samuel Ponraj MBBS (MS) Meenakshi Medical College & Research Institute Kancheepuram
  2. 2. PRISTLEY SMITH RETINOSCOPE
  3. 3. MIRROR RETINOSCOPE
  4. 4. RETINOSCOPE • • • • Flat handle with mirrors with hole on either side Plane mirror on one side Concave mirror on other side Holes at centre to view through patient’s eye by examiner • Hole has +2D lens to exclude accomodation error used to examine at 1mt distance • To determine opacity of media • To determine error of refraction.
  5. 5. TRIAL FRAME
  6. 6. TRIAL FRAME • Adjustable with IPD by screw • 3 compartments in front of eye • Inner : to keep occluder, pin hole, stenopic slit, presbyopic correction • Middle : to place spherical lens • Outer : to keep cylinder as in front, it is graduated to know axis.
  7. 7. PLACIDO’S DISC
  8. 8. PLACIDO’S DISC • Disc with alternate concentric dark and light rings • Central hole with +2D lens • Disc attached to a handle • Examining the reflected image of rings over pt cornea • To diagnose keratoconus, corneal surface anamolies, ulcers.
  9. 9. MADDOX WING
  10. 10. MADDOX WING • Instrument that dissociates retinal images of 2 eyes for near • To diagnose and measure heterophoria or latent squint
  11. 11. MADDOX ROD
  12. 12. MADDOX ROD • • • • • • • 4-5 cylinders of red glass prisms Fused side by side in a round disc frame May give the effect given by Deeply grooved red glasses(mad groove) To detect heterophoria As it dissociates two retinal images As macular function test
  13. 13. RED AND GREEN GLASSES/FILTERS
  14. 14. RED AND GREEN GLASSES/FILTERS • • • • Red placed in front of right eye Green glass in front of left eye Used for diplopia charting To test binocular vision in Worth’s four dot test • For malingering test
  15. 15. CONVEX SPHERICAL LENS
  16. 16. CONVEX SPHERICAL LENS • • • • • Biconvex spherical lens mounted on (metal) frame Centrally thick Images – magnified Moves in opposite direction in all meridians on moving lens. Used in HM, Presbyopia, Aphakia, Compound HM astigmatism, Mixed astigmatism, Retinoscope, Placido’s disc, Slit lamp, Operating microscope, Simple & Comp microscopes, Telescopes
  17. 17. CONCAVE SPHERICAL LENS
  18. 18. CONCAVE SPHERICAL LENS • Biconcave spherical lens in (metal) frame • Centrally thin • Images minified – moves in same direction as lens moves (in all meridians) • Used in Myopia, Compound myopic astigmatism, Mixed astigmatism, Hruby’s lens
  19. 19. CONVEX CYLINDRICAL LENS • Magnified image seen thru it • Image moves in opposite direction of lens movement • Image moves 90* perpendicular to axis • Along axis – no movement • Axis – plane of zero power • Used in astigmatism – sim, comp, mixed
  20. 20. CONCAVE CYLINDERS • Image moves in same direction of lens movement & opposite to axis • Along axis – no movement • Used in astigmatism – sim, comp, mixed
  21. 21. OCCLUDER
  22. 22. OCCLUDER • Black opaque disc • To occlude one eye while testing / correcting other eye
  23. 23. PIN HOLE
  24. 24. PIN HOLE • Black opaque disc with small central 1 mm hole • Used to find out impaired vision due to RR or ocular path involving media • Used in macular function test
  25. 25. STENOPIC SLIT
  26. 26. STENOPIC SLIT • Black opaque disc with vertical / horizontal straight slit at centre • To differentiate causes of haloes • Fincham’s test

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