Retinoscopy Flashcards
Static retinoscopy
Objective evaluation of the refractive status of a patient
Performed with accommodation at rest
2 main parts of retinoscope
Illumination system
Observation system
Components of illumination system
Energy source light source Condensing lens Mirror Focusing sleeve
Components of observation system
Front peephole
Aperture hole
Back peephole
Hyperopia
Far point behind retina
Not enough plus power or too short of eye
Myopia
far point in front of retina
Too much plus power or too long of eye
With motion
Hyperopia, need more plus power
Against motion
Myopia, need more minus power
Working distance
66.7cm
.12D for 5cm error
Speed
Slowest furthest from far point
Brightness
Dimmest farthest from far point
Width
Narrowest farthest from far point
Bracketing
Determining neutrality as halfway between the zone where with motion was last detected and the zone where against motion begins
Gross retinoscopy finding
Result of the lens power needed to find neutrality scoping from working distance
Net retinoscopy finding
Gross retinoscopic finding with the working distance mathematically accounted for
Subtracting 1.5D or 6 clicks of phoropter
Regular astigmatism
Principal meridians are 90 degrees apart
Irregular astigmatism
Principal meridians do not exist and are not 90 degrees apart
Symmetric astigmatism
Sum of the minus cylinder axes are 180 degrees
Break
When the streak and reflex are not parallel
Most useful for greater than 1D of astigmatism
Width astigmatism
Narrowest when streak is aligned with one meridian and widest with the other
Skew
Disappears when moving on meridian
Refines meridian in small cylinders
More with
Slowest, dullest, thinnest
