Flashcards in lens and cats Deck (186):
mittendorf dot is from what embryonic structure
epicapsular star is from what embryonic structure?
tunica vasculosa lentis
Peter's anomaly via what mechanism?
anterior segment dysgenesis/ failure of lens vesicle and surface ectoderm (cornea)at around 33 weeks
Pete's anomaly is associate with what gene defects
PAX6, PITX2, FOXC1
Peter's anomaly is associated with what defects?
-central/paracentral leukoma (corneal opacity)
-Iris sticks to cornea (type 1); iris sticks to lens (type 2)
-anterior cortical cataracts
-anteriorly displaced lens
What is microspherophakia? It's associated with what condition(s)?
whole equator of lens can be seen when fully dilated... leading to high refractive power thus high myopia
-primarily Weill-Marchesani syndrome
- Marfan's syndrome
what is a feared complication of microspherophakia? what can exacerbate this? what can treat this complication?
Acute angle closure glaucoma.
-Exacerbated by miotics
-Treat with cycloplegics-->to pull the lens posteriorly
what is primary aphakia vs secondary aphakia?
Primary aphakia is when lens placode does not form
Secondary aphakia is when the forming lens is absorbed.
What is aniridia? unilat or bilat?
no iris (partial or whole)
almost always bilateral
nonhereditary aniridia... what two conditions do you have to worry about?
what's a common complication of aniridia?
WAGR complex-- wilm's, aniridia, genitourinary, mental Retardation
-early cataract formation
Definition of congenital (aka infantile) cataracts
seen at birth or within 1 year of birth
Most common type of congenital cataract? what are its features? usual pattern of inheritance?
also called zonular.
It has layer of opacification surrounding the nucleus and itself is surrounded by clear cortex.
May have adjacent horseshoe shaped opacity called "riders"
Types of congenital cataracts
lamellar, polar, sutural, cerulean, membranous, coronary, nuclear, capsular, complete
features of anterior polar cataracts. Mode of inheritance. Clinical significance?
-Anterior polar--aka subcapsule and involving cortex.
-usually bilateral, non progressive, no impairment of vision
but could cause anisometropia. sometimes seen with anterior lenticonus, persistent pupillary membranes, microophthalmia
sutural cataracts are also called what?
features of posterior polar cataracts?
Mode of inheritance.
Features of hereditary vs sporadic.
Usually larger and more clinically significant than anterior polar cataracts.
-Associated with capsular fragility
-Autosomal dominant. Inherited is usually bilateral versus sporadic can be unilateral and associated with persistent tunica vasculosa lentil and lenticonus
Mode of inheritance?
opacities along the fetal suture lines.
Usually not of clinical significance
Features of coronary cataracts?
a club shaped cortical opacity usually at the periphery and can't be seen unless dilated.
-autosomal dominant inheritance
Cerulean cataracts are also called what? Features of cerulean cataracts?
Blue dot cataracts.
small bluish opacities on the lens CORTEX.
usually not clinically significant and non progressive
Medical indications for cataract surgery. (4)
-obscured view to back of eye in order to assess for other conditions such as AMD, DR...etc
-phacolytic glaucoma, pharmacomorphic glaucoma (due to intumescent lens --rapid thickened--
Most common indication for cataract surgery?
elective desire to improve vision
What is the key clinical association with congenital nuclear cataracts?
What is a feared complications?
congenital nuclear cataracts tend to be associated with micro-ophthalmic eyes.
Increased risk of aphasic glaucoma (which is the most common long term complication s/p congenital CE)
involves the anterior lens capsule and epithelium. DOES NOT involve the cortex. Protrudes in to the AC?
Generally not clinically significant
What is it called when the entire lens is opacified in a <1 year old?
What is a membranous congenital cataract? Clinical significance?
lens protein resorption from lens (often s/p trauma) allowing anterior and posterior capsules to fuse.
Usually clinically very significant.
Why is CE in congenital rubella infection patients associated with more inflammation?
Rubella virus lives within the lens fibers and live virus can persist 3 years s/p birth. disruption of fibers cause viral release.
What kind of cataracts are associated with congenital rubella infection?
Dense nuclear cataracts
Complete cataract (cortex sometimes liquified)
Congenital Rubella syndrome:
-Corneal clouding (transient or permanent)
-cataracts (nuclear or complete)
-diffuse pigmentary retinopathy
(of note: usually glaucoma and cataracts are not simultaneously in the same eye)
what is ectopia lentis
displacement of lens--can be congenital, developmental, or acquired.
what is the difference between lens subluxation vs dislocation (luxation)
Subluxation implies displaced but still in the pupillary space.
Dislocation implies complete displacement from the pupillary space indicating disruption of zonules.
Symptoms of lens subluxation?
decreased VA, monocular diplopia, high astigmatism, iridodonesis.
what is the most common cause of lens dislocation?
What are non traumatic causes of dislocation?
--less common causes: weill-marchensani, ehlers dans, hyperlysinemia, sulfite oxidase deficiency, simple ectopic lentil as inherited.
-mode of inheritance? genetic aberrance?
- ocular manifestation?
-Complications to be on the look out for due to ocular findings?
-autosomal dominant, mutation of fibrillar gene on Chr 15.
-ectopia lentis (usually supratemprally) bilateral symmetric with elongated zones. axial myopia
- increase risk of RD due to myopia; and angle closure glaucoma and amblyopia, poor accommodation due to lens subluxation/dislocation.
-MVP, aortic root dilatation
-long limbs, arachnodactyly
CE in Marfan's syndrome is associated with what complications? (2)
vitreous loss, RD
-Mode of inheritance?
-what is the disease?
- Systemic manifestations?
- Ocular manifestations?
-elevated homocysteine and methionine.
-seizures, osteoporosis, cognitive impairment, tall, light colored hair, VTEs
-bilat symmetric lens dislocations (30% at birth; 80+% are affected by 15) usually infranasal (zonules are high in cysteine)
How to treat homocystinuria?
low methionine diet,
supplement cysteine diet and vitamin B6
Clinical features of hyperlysinemia?
ectopia lentis, muscular hypotony, cognitive impairment
What is the gene identified to be associated with cortical cataracts?
EPHA2--age related cortical cataracts
What is the number one risk factor for developing cataracts (age related non syndromic)
What are the features of ectopia lentis et papillae?
other ocular associations?
asymmetric eccentric dislocation of lens in the opposite direction of abnormal pupil (which is eccentric and irregular)... hard to dilate.
-Associated with enlarged corneal diameter, atrophic pupils with transillumination defects, cataract, RD, axial myopia,
persistent fetal vasculature (PFV) is also known as what?
PHPV (persistent hyperplastic primary vitreous)
three types of age related cats
nuclear, cortical, and sub capsular
what does intumescence mean?
swollen and enlarged cataract--watch out for angle closure
What are Wedl Cells?
The abnormally swollen/enlarged cells in PSC when epithelial lens cells migrate from equator in to the visual axis.
what are the ocular side effects of corticosteroids?
elevated IOP, PSCs
Does slow release intraocular steroids (subconj and intravitreal) lower risk of IOP elevation and PSCs?
ocular manifestations of amiodarone? (2)
verticillata, optic neuropathy
what class of drug is chlorpromazine and thioridazine? what kind of visual side effect does it cause?
these are phenothiazines (psychotropic meds).
can cause pigment deposition to anterior lens... usually not visually significant.
What is a ocular complication of anticholinesterase medications? what are examples of this class of med?
It causes cataracts (starting with vacuoles then cortical and nuclear opacification)
-pilocarpine and thiophate iodide (for echo)
cataract incidence with statin is increased with concurrent use of what medication?
what ocular side effect does Tamoxifen has?
crystalline maculopathy (NOT cats)
what is a vossius ring? what does it signify?
imprint of pigment in the shape of the pupil to the anterior lens. Indicates prior blunt trauma
What is a rosette cataract?
Rose like cataract s/p blunt trauma involving visual axis and posterior capsule. Mild ones can resolve.
What surgical procedure is associated with nuclear cataracts? What are other procedures associated with cats?
trans pars plana vitrectomy
intravitreous injections, trabeculectomy, penetrating keratoplasty
Which population is more susceptible to lens damage and delayed cats from ionizing radiation?
young patients as they have more actively replicating lens cells.
siderosis bulbi is caused by what?
iron containing FB
Siderosis bulbi features? long term implications?
yellow colored iron depositions in the iris, trabecular meshwork, lens epithelium/cortical fibers... can lead to cortical cataracts and retinal dysfunction long term.
What is a sunflower cataract?
Chalcosis: aka copper deposition to various basement membranes via intraocular FB.
What is chalcosis
intraocular FB, deposition of copper to descent's, anterior lens capsule. Copper intraocular FB can also cause severe inflammatory reaction and necrosis
characteristics of electrical injury induced cataracts?
likely when pt's head is involved in the electrical current.
First anterior vacuoles are seen in the lens. then linear opacities in anterior sub capsule cortex.
what's more likely to involve intraocular abnormalities? acid injuries or alkali injuries?
what are likely injuries from alkali chemical injuries?
injuries to cornea, conj, iris, and lens leading to cats.
what are two causes of verticillate?
What is a snowflake cataract? what population is it associated with?
-Associated with diabetics--generally type I, young, and uncontrolled.
-It's a axial rapidly developing sub capsular and cortical cataract that has the appearance of a snow flake.
what are the three lens abnormalities associated with an "oil droplet" appearance"? which two are similar?
nuclear sclerosis and galactosemia --similar
posterior lenticonus is different as it casts an oil droplet appearance on the red reflex.
What are the three enzyme deficiencies responsible for galactosemia?
galactose-1-phosphate uritidyl transferase (Gal-1-PUT) is classic galactosemia
galactokinase, and UDP-galactose 4 epimerase
how do you confirm classic galactosemia?
presence of galactose in the urine
What are the systemic and ocular signs and symptoms of galactosemia?
malnutrition, hepatomegaly, jaundice, cataract development (NSC and cortical from deep out)
What is the treatment for galactosemia?
elimination of milk from diet
what do hypocalcemia (tetanic) cataracts look like? laterality? can be caused by what?
punctate iridescent opacities in the cortical layers separated by zones of clear lens. bilateral usually
-can be associated with parathyroid/thyroid surgery
high copper related ocular abnormalities? (Wilson's disease)
Kaiser Fleischer ring (descemet's) and sun flower cataracts (usually not visually significant.
where is kaiser fleischer ring located
descemet's membrane of the cornea.
polychromatic iridescent crystals of the lens are associated with what disorder? what are these crystals?what other ocular abnormalities do these patients have?
myotonic dystrophy; cholesterol crystals; ptosis, facial musculature weakness, progressive cataracts
myotonic dystrophy. systemic signs and ocular signs
-impaired relaxation of muscles, cardiac conduction Abel, cognitive disability, frontal balding
-polychromatic iridescent crystal cataracts, ptosis, facial weakness
what life style modifications can be used to prevent cataracts?
stop smoking, drinking, and wear sunglasses
women who take vitamin A are at increased risk for what?
smokers who take what supplement are at risk of lung cancer, mortality from lung cancer, and CVD?
episodes of dehydration due to diarrhea may cause what ocular abnormality?
what kind of cataracts are associated with Fuch's heterochromic uveitis? why is this type of uveitis associated with favorable prognosis?
cortical; it usually doesn't involve posterior synechiae and usually steroids aren't needed.
Fuch's heterchronic uveitis can cause cataracts. What kind of intraoperative complication is associated with this condition?
what kind of cataracts are associated with uveitis in general? why?
PSCs because of steroid use; anterior capsular due to posterior synechiae
what changes to the lens are associated with hyperbaric oxygen therapy?
transient myopic shift; cataracts have been documented but not common.
what environmental risk factor is associated with pseudo exfoliation syndrome?
lifetime UV exposure
What is pseudo exfoliation syndrome? where do the stuff deposits?
systemic deposition of fibrillogranular matrix material to various organs... cornea, iris/ciliary/trabucular meshwork, lens/zonules, anterior hyaloid face
Clinical consequences of pseudoexfoliation syndrome?
-iris atrophy, poor dilation of pupils
-open angle glaucoma
atopic dermatitis is associated with what?
anterior sub capsular cats
what is phacoantigenic uveitis?
lens antigen s/p trauma or incomplete CE... creating inflammation. Can also affect the other eye.
what is phacolytic glaucoma?
mature/hypermature cataracts--lens material leak out and are engulfed by macrophages.... then this debris plug up the trabecular meshwork.
How can you differentiate phacolytic glaucoma with phacoantigenic glaucoma
phacoantigenic has KPs.
How to treat phacolytic glaucoma?
lower pressure, treat inflammation with steroids, surgery to remove cat
cataract related glaucoma before extraction? what two types should you thinking of?
cataract related glaucoma s/p extraction? what two types should you think of?
phacoantigenic, retained lens material glaucoma.
what is glaucomflecken?
It's anterior lens opacification s/p episode of marked IOP elevation; epithelial necrosis and cortical degeneration
what eye lid conditions can predispose to endophthalmitis?
acne rosacea, severe blepharitis
congenital posterior polar opacity is associated with what intraoperative complication for CE?
what are the potential complications of retrobulbar anesthesia?
retrobulbar hemorrhage, toxicity to extra ocular muscles, optic nerve damage, globe rupture, IV injection resulting in arrhythmias and seizures
what is peribulbar anesthesia? how does it compare with retrobulbar?
It's introduced external to muscle cone and underneath the tenon capsule. It's LESS good for both akinesia and anesthesia as compared to retrobulbar
what are the disadvantages of topical anesthesia being used for cataract surgery?
lack of akinesia--should be used for cooperative patients who won't look away from the light.
Types of anesthesia that can be used for cats surg
-topical/intracameral with sedation
-facial nerve block
what are disadvantages of multifocal IOLs?
-Reduced contrast sensitivity
-less good best corrected VA
causes of post op corneal edema after CE?
-mechanical trauma intraop
IOL related inflammation
Brown McLean syndrome
corneal endothelial disease
floppy iris syndrome predispose patients to what intraoperatively?
risk factors intraoperative iridialysis (6)
poor wound construction
shallow anterior chamber
multiple entries and exits of instruments through wound
surgical manipulation of iris
floppy iris syndrome
what type of cataracts are seen in retinitis pigmentosa
what percent of lens glucose pass through the TCA cycle
patients with hx of herpetic corneal disease should avoid what topical eye medication?
steroids as they can reactivate the disease
carbonic anhydrase inhibitors. What 2 things should you check before giving.
creatinine, sulfa allergy
if there's an area of damaged/missing zonules during a cataract surgery. what plan of action can you consider?
Capsule tension ring (CTR) to support the capsule while phaco is done
hyperbaric oxygen is associated with what kind of cats?
what kind of IOL is associated with increased risk of anterior capsular phimosis?
what are risk factors for anterior capsular phimosis s/p CE/IOL?
anything with zonular instability..
cataract surgery can lower IOL by how much?
histologically what are PSCs?
posterior migration of epithelial cells
whats the time frame for endophthalmitis post cat surgery
time frame of developing toxic ant set syndrome?
hours post CE
what is the most common serious intraoperative complication of phaco CE
posterior capsule rupture
what are the top complications after CE?
corneal edema, PCO development, CME, retained lens fragments.
what are treatment options for corneal edema post op?
hyperosmolar agents (muro), corticosteroids, aqueous suppressants.
what is the general time frame for corneal edema to resolve post CE?
4-6 weeks if it's just normal post op swelling
what is Brown McLean syndrome
peripheral corneal swelling s/p CE that usually only starts inferiorly and progresses circumferentially. May have inferior pigment and central gutattae.
what are risk factors for corneal melting after CE?
dry eyes/sjogrens, rheumatic conditions
post op s/p CE use of ketorolac has been associated with what complication?
corneal melting. treatment options?
topical lubrication, punctal plugs, lateral tarrsorhaphy
what is the cause of toxic anterior segment syndrome? what are sx/signs on presentation
it's inflammatory reaction caused by introduction of toxic substance to the AC.
pain, decreased vision, redness, hypopyon. Limited to the AC and usually pain is less than endophthalmitis. can occur hours post op vs endophtahlmitis usually occurs 3-10 days.
"positive vitreous pressure" pushing forward to decrease AC depth is associated with what type of patients?
patients with thick necks or have COPD/pulm diseases.
what is Fluid Misdirection Syndrome?
It's where the BSS seeps to the posterior segment/vitreous and causes volume exapansion leading to flat AC.
how to manage fluid misdirection syndrome? (3)
give gentle pressure to iris/lens, IV mannitol infusion, pars plana take out of the fluid/vitreous
CE post op hypotony with shallow AC differential?
differential for post op (CE) IOP increase?
-retained viscoelastic (OVD) if 4-6 hrs post op
-retained lens material
-acute angle closure due to pupillary block/ciliary block, pigment dispersion, epithelial ingrowth, neovascularization, hyphen/blood, ghost cell glaucoma
Floppy iris syndrome --what are the triad?
1. billowing iris
2. progressive miosis
3. iris prolapse
floppy iris syndrome is associated with what class of meds?
alpha 1 antagonists (tamsulosin, ) and nonselective alpha agonists --terazosin, doxazosin, alfuzosin, silodosin, CHLORPROMAZINE, LABETALOL
complications associated with floppy iris?
-posterior capsule rupture
what is Lens-Iris Diaphram Retropulsion syndrome? (LIDRS) who is at risk/cause? what are complications? how to manage it?
-intraop deepening of the AC due to regression of lens and pupil leading to reverse pupillary block.
-High infusion pressure causes this, and high myopes s/p vitrectomy are at highest risk
-This causes stress on the zonules
-gentle pressure to separate the pupil from the lens.
which individuals are more prone to post surgical inflammation? 7
-iris manipulated during surgery
-long term use of miotics
what organisms can cause post op chronic uveitis?
p acnes and staph epi
signs of retained lens material?
increased IOP (if blocking angle)
How to manage retained lens material?
start with antiinflammation: Steroids and NSAIDS, and IOP lowering.
Consider surgery but not always needed.
is retained cortex or nucleus s/p CE more tolerated?
If there's retained lens material in the vitreous.. when is the best time to do vitrectomy?
within 1-2 weeks. less complications as compared to delayed surgery.
complications associated with vitreous loss?
RD, CME, and endophthalmitis (vitreous acts as a wick and pulls in stuff)
what can you stain the vitreous with for better visualization?
preserved or washed triamcinolone
what is the most common cause of intracapsular IOL dislocation?
pseudoexfoliation syndrome leading to zonular degradation.
whats the most common extracapsular cause of IOL dislocation?
inadequately sized IOL.
what is UGH syndrome?
uveitis-glaucoma-hyphema syndrome. Basically iris/ciliary body chaffing on IOL that is either decentered or single piece in the sulcus...
what kind of IOL is associated with UGH syndrome?
1 piece uniplana acrylic IOLs
What is an advantage of suturing IOL to pupil rather than sclera?
less chance of suture breakage. (which occurs 3-9 years after surgery usually)
complications associated with ACIOL?
iris tuck, UGH syndrome, corneal edema, pseudophakic bullous keratopathy, pseudophacodonesis.
what are factors associated with pupillary capture?
anterior displacement of PCIOL optic. associated with nonagulated IOLs inciliary sulcus. or upside down placement of an angulated IOL
what are two things you can do to decrease chance of pupillary capture?
placing posteriorly angulated PCIOL
creating anterior capsulrrhexis smaller than lens optic
what is capsular block syndrome? and what are complications if untreated.
forward displacement of IOL/nucleus due to fluid accumulation in the posterior bag (such as during hydrodissection or due to OVD). This can cause shallowing of AC leading to posterior synechiae and glaucoma
how do you treat capsular block syndrome?
YAG either peripheral anterior capsule or posterior capsule to release the fluid.
what two types of IOLs (no longer inclinical use) are associated with Pseudophakic Bullous Keratopathy?
iris clip lenses
closed loop flexible ACIOLs.
in the event of unintended refractive error after CE/IOL what are 4 options?
2. IOL exchange
3. piggy back IOL
4. refractive surgery.
how does post op steroids/nsaids affect PCO development?
which kind of IOL material is most resistent to damage per YAG capsulotomy?
what are the complications of YAG capsulotomy?
damage/dislocation of IOL
two major complications of prolonged hyphema
elevated IOP and corneal staining.
what is the hallmark of endophthalmitis?
clinical signs of expulsive suprachoroidal hemorrhage?
sudden loss of red reflex
expulsion of lens, vitreous and bright red blood
what factors are associated with increase chance of endophthalmitis?
posterior capsular rupture
what time frame is considered "acute endophthalmitis"
what are the most common acute endophthalmitis organisms?
staph epi, staph aureus, strep species
what are the most common chronic endophalmitis organisms?
p acnes, staph epi, fungi
How do you treat endophthalmitis with LP in that eye
biopsy/culture AC and vitreous. Start on fortified abx if doesn't delay referral to retina. Retina needs to do PPV
if endophthalmitis with HM or better VA...what should you do.
get cultures of AC or vitreous biopsy. Intravitreal abx (vanc 1g and caftaz 2.25mg. Also add cycloplegia and steroids.
what is Irvine-Glass syndrome?
CME s/p CE
CME is common post CE... what is classified as clinically significant CME?
vision reduction to 20/40 or worse.
when does post op CME usually show up? and when does it usually resolve if uncomplicated?
6-10 weeks post op it shows up and 95% will resolve in 3-12 months
which meds are associated with CME post op?
topical epinephrine and dipevfrin (for aphakic glaucoma)
-prostaglandin analogues cause reversible CME.
pre op risk factors for post op CME?
ERM, vitreomacular traction, DM, DR, previous CRVO, hx CME, retinitis pigments, uveitis.
How do you treat CME?
combo of ketorolac and prednisolone are better than either alone.
If this fails then sub tenon or intravitreal steroid injections, systemic carbonic anhydrase inhibitors, or VEGF inhibitors
prolonged light exposure during CE could result in what?
CME, burn of RPE
What are strategies to minimize retinal light toxicity during CE?
use oblique angles
filtering lights below wave length of 515nm
what would cause a myopic shift in a pt s/p CE (when vision immediately post op was 20/20?)
what would cause a hyperopic shift in pt s/p CE when vision immediately post op was 2020?
what's the best way to asses macular function in patient with dense cataract?
Maddox rod. Mac disfunction may result in "breaks" in the rod lines
when do patients undergoing eye surgery have to stop anticoag
hx of suprachoroidal hemorrhage. consider stopping if doing retro bulbar anesthesia as well.
what's the mainstay treatment for MGD?
doxy, minocycline, tetracycline--saponify inspissated secretions
what should you do prior to capsulerrhexis if intumescent cataract?
pierce the ant capsule and suck out some milky cortex.
what should you be worried about for cat surgery if iris is abnormal
iris coloboma/corectopia are associated with zonular weakness/absence...consider capsule tension ring and/or iris hooks.
what is capsular block s/p CE/IOL? what refractive issue can it cause? how to treat?
anterior shift of PCIOL with distension of posterior bag. Causes myopic shift. do YAG to release fluid
What factor decrease chances of PCO? what increases it?
square haptic IOLs decrease PCO due to more force on the capsule and blocks epithelial migration. larger capsulharrexis causes wrinkles and PCO.
patients who has had refractive surgeries prior to cataract surgery-- likely to have what kind of refractive error after cataract surgery
hyperopic shift. should be observed before considering interventions
atopic dermatitis is associated with what kind of cataract?