Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
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 |