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120 Cards in this Set

  • Front
  • Back
A hydrogel lens needs to be on the eye for _______ before evaluating.
1 hour
Major factor in reducing VA in lenses.
surface deposits-usually mucoproteinaceous film
Lipid and "jelly Bump" deposits may reduce VA and affect comfort.
T or F
True
Jelly bump deposits can easily be removed from a lens with MP cleaner.
T or F
False
Tears the lens
How do you determine if lenses are incorrect RX or lenses are switched.
overrefraction
Best option for an astigmatic cornea.
RGP
In a toric lens ________ will experience greater rotation than ___________.
oblique
WTR, ATR
Near tasks may be compromised by toric lens rotation with convergence due to __________ of the globe.
encyclo-rotation
Toric lenses are usually fit more steeper thatn sphere lenses.
T or F
True!
Don't want movement as much.
Absence of improvement in VA with overrefraction may indicate__________________.
lens with poor optics.
An inverted lens with cause epithelial damage.
T or F
False.
Remove and reinsert properly.
Corneal edema causes myopic creep. %______edema needed before able to observe.
7-8%
______lens common with photophobia.
RGP
Sensation of discomfort from excessive light not associated with pain.
Dazzle
Photophobia usually associated with CLs.
T or F
False
ocular problem
Initial adaptation to CL and severe epithelial abrasions can cause photophobia.
T or F
True
An alternative to solution sensitive patients.
Non-preserved system clear care peroxide system
If you note a dirty lens, what is your next step?
Evert lids to see papillary response.
Excessive lens movement can be caused by (3)
1. deposited lens
2. inverted lens
3. flat lens
If corneal edema is noted and is a complication of lens then switch to a ___________.
higher H20 lens- silicone hydrogel
Common symptom of corneal edema is halo around lights. 2 causes of corneal edema.
1. glaucoma
2. CL too tight
Corneal edema due to hydrogel lenses usually are not apparent until severe.
T or F
True
Striae and epithelial edema may be visible with ___% corneal thickening.
4% to 6%
Mild fold of Descemet's membrane apparent with _______% edema and major folds with ______%.
7%
15%
White lines appearing within the pupil margin, 1-6mm long rarely bifurcate.
striae
Seen as "sparkly" when viewed with white light.
epithelial edema
Microcysts are rarely seen in silicone hydrogel.
T or F
True
In corneal edema, ________ are found midperipheral cornea in 3-6 weeks of wear.
microcysts
Due to "tight lens syndrome", corneal edema always occurs.
T of F
False
may or may not
_______if the lens is important parameter that determines corneal edema, not __________relationship in hydrogels.
thickness
lens-to-cornea
Minimal movement may result in conjunc. drag. 2 solutions.
1. flatten base curve
2. decrease diameter
Corneal vascularization occurs more commonly in __________.
EW
Causes of discomfort after lens removal.
1. abrasion
2. infection
3. ulcer
Causes of discomfort after lens insertion.
1. torn lens
2. solution sensitivity
3. prism ballast
List causes of dryness.
1. poor tear quality/quantity
2. pregnancy
3. incomplete blink
4. medications
5. environment
6. computer use
In lens bearing pattern, SPK is found:
in circular pattern with clear center
In edge tear, SPK pattern:
mirror tear area
In dessiccation/incomplete blink, SPK pattern:
inferior area
In solution sensitivity, SPK pattern:
ALL OVER
In lens removal (pinch), SPK pattern:
inferior side
CLs available without handling tint.
Focus N&D
UV absorption give CLs a slight tint.
T or F
False!
UV absorption CLs may help to reduce glare.
T or F
True
CLs that meets Class I UV protection.
Oasis
Therapeutic lenses for R/G deficiency
1. X-Chrom
2. ChromaGen
3. ColorMax
Therapeutic lenses for Achromatopsia deficiency
red-tinted lenses.
Therapeutic lenses for R/G and Achromatopsia deficiency is bilateral.
T or F
False!
1st lens to improve color vision
X Chrom PMMA 1971
List opaque designs:
1. clear pupil w/iris color
2. blk pupil w/clear iris
3. blk pupil w/iris color
4. pupil concentric w/iris
5. decentered pupil and/or iris
Cooper Frequency 55 Clear aspheric BC________ and Expressions BC_______.
8.4 and 8.7
8.7
Acuvue 2 colors
opaque BC_____
enhancer BC_____
8.3
8.3, 8.7
Cooper Expressions is made from ______________.
methafilcon A 55% H2O
Peripheral visual blur/haziness concern with _________.
opaque tints
Opaque tints can help disorders:
1. albinism
2. microphthalmos
3. scars,dense arcus
4. failed grafts
Chromatic aberration of the eye is _____D and with light filtration (vision performance-Maxsight) aberration can be ________D.
2.3D
1.1D
Special performance CLs such as Maxsight improves driving ability.
T or F
FALSE!!!
Enhancing vision with MAxsight can increase contrast sensitivity and stereopsis.
T or F
True
Maxsight is made of ___________, BC_________, RX________.
polymacon 38%
8.7
+4 to -9
Refers to the measurement of the 'contact' or 'wetting' angle to lens surgace with water,saline, or tears.
wettability, in vitro
How retentive the lens surface is of the tear film.
wettability, in vivo
All hydrophillic materials have the suffix____________.
filcon
All hyrdophobic materials have the suffix __________.
focon
HEMA a monomer CL material makes up most ___________ lenses.
hydrogel (water-loving)
Silicone CL material is hydrophobic.
T or F
True
USANC stands for:
United States Adopted Names Council
Silicon (SI) or Fluorine (FL)?Increases flexibility and gas permeability through the material's bond to oxygen but has the disadv. of poor wettability.
Silicone (SI)
Silicon (SI) or Fluorine (FL)? Adds a smaller degree of gas permeability and improves wettability and deposit resistance in silicone containing lenses.
Fluorine (FL)
Dk=_________
oxygen permeability
Dk/t=________
oxygen transmissability
Min Dk/t value needed in an overnight wear lens in order to limit the corneal swell to ______%.
87
4%
Low water content lenses limited by_________.
Dk
Thin high water content lenses produce corneal __________.
dehydration
Limbal injection is asymptomatic in _______ wearers but put in ______ and injection will disappear.
hydrogel
silicone
Current research target goal of Dk/t value________.
125
Hyper oxygen transmissibility offered by __________.
silicone hydrogels
Promotes oxygen transfer to the cornea (Dk/t) and reduces/eliminates corneal swelling in overnight wear.
Hydrophobic.
silicone
Allows fro fluid and ion transfer-lens on eye movement. Minimal dehydration.
Hydrophillic.
hydrogel
Lower water content then_____oxygen content
HIGHER
As water content increase the Dk value in hydrogel _________.
increases
As water content increase the Dk value in silicone_________.
decreases
High silicone content = _________Dk/t value.
High
Low to high silicone content in CL.
1. J &J Acuvue advance
2. B&L purevision
3. CIBA O2 Optix
4. J&J Oasys
5. CIBA Night & Day
Comparing swelling between no lens eye and silicone hydrogels worn overnight.
Close to no difference
Acuvue Advance (Vistakon) has a Dk/t value of 60 and is approved for ____________.
DW ONLY!!!
Acuvue 2 (Vistakon) has a Dk/t value of 33 and is approved for ______________.
6 nights EW???huhhh.
1st best seller worldwide ________ and 2nd best ____________.
AV2
oasys
1st generation silicone hydrogels are _________ which causes problems with ________.
hydrophobic
wettability
__________require a surface treatment.
silicone hydrogels
Surface treatment for PureVision
Balafilcon A
Surface treatment for Focus N & D
Lotrafilcon A
Surface treatment for O2Optix
Lotrafilcon B
Silicon surface converted to a hydrophillic surface through ionized gas.
T or F
True
Surface process for B&L Purevision.
Performa
Surface process for N&D and O2Optix CIBA.
Full surface coating
Surface process for Acuvue Advance and Oasys (J&J)
Hydraclear
Hydraclear Plus
2nd generation silicone hydrogels.
1. Acuvue Adv. Galyfilcon A
2. Acuvue Oasys senofilcon
Molecules that attract water throughout a CL is called_________.
Humectant
Silicone lenses tend to repeal _________ but attract _________.Ex.
protein
lipids
lotrafilcon- CIBA N&D
Hydrogel lenses tend to attract _______________. Ex.
protein and lipids
Etafilcon- AV2
Dk/t of ___ to avoid stromal anoxia. Lens that has value above this.
125
Ciba Focus N&D 175!
CW 29 days
Fitting pts with silicone hydrogels offers a safe and reliable alternative to LASIK surgery.
T or F
True
Mucin and tear proteins that roll with eye movement are called __________. Look like "cleats". Treatment not necessary but may refit with steeper CL.
Mucin Balls
Silicone hydrogels offer minimal corneal changes, less limbal injection, no myopic shift, and no build up of bacteria.
T of F
True
2 types of peripheral corneal furrow staining:
1. LEH-Limbal Epith. Hypertrophy w/furrow staining
2. Peripheral corneal corrugation (furrow staining)
Lipid, protein, and jelly bumps are notes deposits on _______.
hydrogels
Jelly bumps seen more on ___________versus _______________.
hydrogels
silicone
Excellent indicator of chronic hypoxia.
Microcysts- common in EW hydrogel
___________displayed with reversed illumination and _________displayed with unreversed illumination.
microcysts
microcystic edema
accumulation of very small fluid filled cysts within the epithelium found in the central cornea and secondary to CL wear.
microcystic edema
Inflammation of superior tarsal conjunctiva involving hyperemia and papillae greater 1mm; itch; mucous; more common hydrogel
CL induced papillary conjunctivitis
Hydrogel induced GPC zones
whole upper lid
Silicone induced GPC zone
3 due to mechanical irritation
Syndrome of conjunctival injection, IK, corneal staining.
CLARE- CL induced red eye
CLARE causes:
1. hypoxia
2. trapped debris
3. preservative adverse rxn
4. low grade infection
Singel, peripheral or mid-perip. white-gray lesion in anterior stroma. 0.1 -1.2mm diam, circular. bull's eye appearance and may fade.
CLPU-CL inducaed peripheral ulcer sterile
Superior arcuate epithelial lesion (SEAL) more prone in _____________ since it is a ___________module.
silicone hydrogel
stiffer
Raised rough edges next to the superior limbus with white heaped epithelium. Stains with NaFL.
SEAL-Superior Arcuate Epitheial Lesion
Invasion & infection of corneal tissue by micro-organisms such as bacteria, fungi, amoeba, or viruses.
MK-Microbial Keratitis
Incidence of MK in EW low Dk_______; DW low DK_______; CW high DK_________.
1/500
1/2500
1/20000
Symptoms of MK
1. mod to severe pain
2. redness
3. blur
4. photophobia