lens Maeda Flashcards
What is the leading cause of visual impairment worldwide?
A) cataracts
B) injury
C) glaucoma
D) angle closure
A) cataracts (50% of the 160 million cases)
cataracts creates:
A) a myopic shift
B) a hyperopic shift
C) no change in vision
D) better distance vision
A) a myopic shift
What is the greatest risk factor for cataracts?
A) smoking
B) alcohol
C) sun exposure
D) age
D) age (while smoking, drinking alcohol and sun exposure do contribute as risk factors, if you live long enough you are almost guaranteed to get cataracts)
The lens capsule is:
A) several cell layers thick
B) an acellular envelope composed of lamellae
C) a single layer thick envelope composed of fibrils
D) also known as the lens cortex
B) an acellular envelope composed of lamellae
The lens epithelium is:
A) several cell layers thick
B) a single cell layer envelope composed of lamellae
C) a single cell layer that forms the fiber mass of the lens
D) also known as the lens cortex
C) a single cell layer that forms the fiber mass of the lens
What is the embryologic remnant of the hyaloid artery on the posterior surface of the lens
Mittendorf’s dot
Sutural cataracts are bluish dots or a chalky band around the Y sutures in the lens. The lens has both an anterior and posterior Y suture. Which, if affected, is more likely to affect vision?
A) posterior Y suture cataract
B) anterior Y suture cataract
C) either would effect vision the same
D) neither would affect vision because they do not lie in the visual axis
A) posterior Y suture cataract
what are the 3 types of age-related cataracts? (pick 3)
A) nuclear sclerotic
B) cortical
C) posterior subcapsular
D) congenital
A) nuclear sclerotic
B) cortical
C) posterior subcapsular
Which type of cataract gives you “second sight”?
nuclear sclerotic (2nd sight is a myopic shift where pt sees better before things get worse)
You are examining your patients lens in the slit lamp. Their lens is mildly yellow and their VA is 20/20. What kind of cataracts is this?
none. if vision is 20/20, they do not have a cataracts.
A nuclear cataract is caused by which of the following?
A) An imbalance of electrolytes that leads to an overhydration of the lens and liquification of lens fibers
B) loss of lens fiber nuclei and replacement by aberrantly migrating epithelial cells
C) congenital factors; A patient would most likely be born with this type of cataract
D) alteration of the lens metabolism which increases the concentration of insoluble proteins.
D) alteration of the lens metabolism which increases the concentration of insoluble proteins.
A cortical cataract is caused by which of the following?
A) An imbalance of electrolytes that leads to an overhydration of the lens and liquification of lens fibers
B) loss of lens fiber nuclei and replacement by aberrantly migrating epithelial cells
C) congenital factors; A patient would most likely be born with this type of cataract
D) alteration of the lens metabolism which increases the concentration of insoluble proteins.
A) An imbalance of electrolytes that leads to an overhydration of the lens and liquification of lens fibers
A posterior subcapsular cataract is caused by which of the following?
A) An imbalance of electrolytes that leads to an overhydration of the lens and liquification of lens fibers
B) loss of lens fiber nuclei and replacement by aberrantly migrating epithelial cells
C) congenital factors; A patient would most likely be born with this type of cataract
D) alteration of the lens metabolism which increases the concentration of insoluble proteins.
B) loss of lens fiber nuclei and replacement by aberrantly migrating epithelial cells
A baby is born with a unilateral congenital cataract. This was most likely caused from:
A) trauma or intrauterine infection like syphilis, rubella, or measles
B) a metabolic disorder like hypoglycemia, a genetic disorder like downs syndrome, an infectious disease like cytomegalovirus, or prematurity
A) trauma or intrauterine infection like syphilis, rubella, or measles
A baby is born with a bilateral congenital cataract. This was most likely caused from:
A) trauma or intrauterine infection like syphilis, rubella, or measles
B) a metabolic disorder like hypoglycemia, a genetic disorder like downs syndrome, an infectious disease like cytomegalovirus, or prematurity
B) a metabolic disorder like hypoglycemia, a genetic disorder like downs syndrome, an infectious disease like cytomegalovirus, or prematurity
What is the difference between an intumescent and morgagnian cataract?
Intumescent = (mature) complete opacification, lens starts to swell, urgent, pt needs to be seen within 1 week for cataract surgery.
Morgagnian = (hypermature) complete liquifaction of lens cortex, lens may sink or float, emergent, pt needs to be seen in 24-48 hours before lens leaks out.
Which type of secondary cataracts can develop from medications such as steroids, miotics, chloroquine, and amiodorone?
A) Anterior/posterior subcapsular
B) Nuclear
C) Cortical
A) Anterior/posterior subcapsular
Which type of secondary cataracts can develop from disorders such as diabetes, galactosemia, wilson’s disease, and atopic dermatitus?
A) Anterior/posterior subcapsular
B) Nuclear
C) Cortical
A) Anterior/posterior subcapsular
Which type of secondary cataracts can develop from anterior segment ischemia and/or rubella and/or deg. myopia?
A) Anterior/posterior subcapsular
B) Nuclear
C) Cortical
B) Nuclear
Which type of secondary cataracts can develop from dystrophia myotonica (muscular dystrophy) and/or excessive UV exposure and/or ciliary body tumors?
A) Anterior/posterior subcapsular
B) Nuclear
C) Cortical
C) Cortical
Which type of secondary cataracts can develop from ocular diseases such as uveitis, RP, RD, and deg. myopia (post) and/or electric shock/trauma?
A) Anterior/posterior subcapsular
B) Nuclear
C) Cortical
A) Anterior/posterior subcapsular
A poor candidate for cataract lens surgery would have less than ___ cells/mm2 endothelial cell count.
A) 600
B) 700
C) 800
D) 900
C) 800
what is the main difference between intracapsular extraction and extracapsular extraction?
intra=entire lens removed, extra=posterior capsule is left in place
(T or F) it is okay to dilate a pt with an iris clip
False, the clip might float away into the posterior seg
(T or F) the most common type of IOL is the posterior chamber IOL
true
(T or F) the Apodized diffractive IOL (ReStor) has 12 concentric rings of decreasing power while the ReZoom multifocal IOL has 5 refocusing zones
true
(T or F) cataract surgery always presents a subconjunctival hemorrhage post-op
true
