dark room
TRANSCRIPT
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
PRISTLEY SMITH RETINOSCOPE
MIRROR RETINOSCOPE
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.
TRIAL FRAME
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.
PLACIDO’S DISC
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.
MADDOX WING
MADDOX WING
• Instrument that dissociates retinal images of 2 eyes for near
• To diagnose and measure heterophoria or latent squint
MADDOX ROD
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
RED AND GREEN GLASSES/FILTERS
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
CONVEX SPHERICAL LENS
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
CONCAVE SPHERICAL LENS
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
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
CONCAVE CYLINDERS
• Image moves in same direction of lens
movement & opposite to axis
• Along axis – no movement
• Used in astigmatism – sim, comp, mixed
OCCLUDER
OCCLUDER
• Black opaque disc
• To occlude one eye while testing / correcting other eye
PIN HOLE
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
STENOPIC SLIT
STENOPIC SLIT
• Black opaque disc with vertical / horizontal straight slit at centre
• To differentiate causes of haloes
• Fincham’s test