NCLE Basic Exam Study Guide 2024 with complete solution Diffused Illumination
0 view 0 purchase
Course
NCLE
Institution
NCLE
NCLE Basic Exam Study Guide 2024 with complete solution
Diffused Illumination
-Uses widest slit, longest aperture
-Light source positioned at an angle of 40º-50º
-Used to view overall areas, to observe the ocular adnexa, cornea, sclera, lids, conjunctiva, lens surface, and CL fitting charac...
ncle basic exam study guide 2024 with complete sol
Written for
NCLE
All documents for this subject (686)
Seller
Follow
LectDan
Reviews received
Content preview
NCLE Basic Exam Study Guide 2024 with complete
solution
Diffused Illumination
-Uses widest slit, longest aperture
-Light source positioned at an angle of 40º-50º
-Used to view overall areas, to observe the ocular adnexa, cornea, sclera, lids,
conjunctiva, lens surface, and CL fitting characteristics
Direct Illumination
-Most important/useful illumination
-Light source positioned at an angle of 40º-50º to oculars
-Light beam and oculars are focused in coincidence on area being evaluated
-The difference in the illumination is not the angle used, but where the beam is directed
or focused and the width
-Varying width and aperture creates different illuminations
Optic(al) Section
-Type of direct illumination that uses a narrow beam to create a cross-section of the
cornea
-Used to illuminate and observe individual layers of the cornea and tear film
-Used to evaluate corneal thickness, thinning, distortions, or depth of a foreign body
-Shows corneal-lens relationship
Parallelepiped
-Type of direct illumination
-Uses a 0.5-3.0 mm beam and a 40º-50º angle to create a 3-D cube
-Used to assess width, depth, and height of an object within the cornea
-Useful in observing scars, infiltrates, staining, and the corneal-lens relationship
Indirect Illumination
-Light source is moved out-of-click, the beam is 2-3 mm wide and is positioned next to
the area being studied
-Illuminated area is translucent or opaque, allowing for observation adjacent to
illumination
-Used to observe foreign bodies, corneal nerves, and opacities
-Oscillation of light accentuates details
Retroillumination
-Light source is out-of-click, moved to the side of the area being observed
-Using a 1-3 mm beam, the light is reflected off the iris and used to back-light the area
studied
-Useful in examining corneal scars, debris, microcysts, scratches on the lens, sub-
epithelial changes, corneal vascularization, diffuse edema, and surface deposits
Sclerotic Scatter
-Uses a focused parellelepiped placed out-of-click directed at the limbus
-Oculars are not used
-The light is dispersed at the limbus, reflected through the cornea, creating a
circumcorneal halo
, -Used to observe edema, stromal folds, lens deposits, bubbles under the lens, lens
defects, and scratches
Corneal Topography - Axial Map
-Most widely understood map of the cornea for many CL fitters
-Overall shape of the cornea
-Colors relate to steepness/flatness
-Sagittal reading measures the curvature of the cornea in diopters and is called the axial
power map
-Calculates curvature rather than power
Corneal Topography - Tangential Map
-More sensitive map of the cornea
-Calculates corneal curvature based on the tangent to normal
-Found to be more beneficial in identifying corneal pathology
-Not used as frequently to fit CLs
Corneal Topography - Refractive Power Map
-Show spherical aberrations
-More useful when assessing visual performance of post refractive patients
Corneal Topography - Elevation Map
-Shows the difference in the elevation of the cornea
-Measured in microns
Corneal Topography - Irregularity Map
-Similar to elevation maps
-Uses best fit toric surface as a reference
-Eliminates any toricity from the eye and displays the elevation differences
Corneal Topography - Photokeratoscopic Views
Uses the placido rings which are reflected onto the eye to subjectively determine the
location and regularity of the rings
Corneal Topography - Numerical Views
-Arranges individual keratometric findings to depict curvature readings of the eye
-Extremely useful when fitting specialty contacts
-Corneal topographic software calculates the "average keratometric" value
Corneal Topography - Keratometry Views
-Represent the keratometric readings along with the axes of the eye's presumed
astigmatism
-Dioptric values define the findings from the center of the cornea to the periphery
-This view helps the practitioner to quickly determine if corneal astigmatism is
symmetrical
Corneal Topography - Profile Views
-Graphically represent the individual axes of the cornea to help depict the 3-D nature of
the cornea
Radiuscope
-AKA optic spherometer
-Used to verify base curves, including both spherical and toric curves
-Also used to detect warped CLs
-Tolerance for BC is +/-0.025 mm
Lensometer
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LectDan. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.49. You're not tied to anything after your purchase.
