Lens Flashcards by laura Capelle

what are some causes of cataracts?

BMI, diabetes, hypertension, sunlight/irradiation, smoking (3x increase in NSC), age/education and myopia

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what are the 6 congenital or infantile cataracts?

anterior polar, coralliform, lamellar, cerulean, sutural and mittendorf’s dot

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what does it mean when a congenital cataract is unilateral vs. bilateral?

unilateral = trauma or intrauterine infection (syphilis, rubella, measles) bilateral = inherited and associated with other diseases (60%) (hypoglycemia, trisomy, infectious disease and prematurity)

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what is an anterior polar cataract?

congenital - caused by imperfect seperation, epithelial damage or incomplete vascular re-absorption as lens develops

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what is a coralliform cataract?

congenital - autosomal dominant: round/oblong opacities that appear coral-like and have a variable affect on vision

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what is a lamellar cataract?

congenital - common, bilateral and symmetrical: round, gray opacities that surround the nucleus (inherited or metabolic/inflammatory cause)

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what is a cerulean cataract?

congenital - bilateral, non-progressive, small bluish dots scattered through lens (no affect on vision)

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what is a sutural cataract?

congenital - dominantly inherited bluish dots or a dense, chalky band around the Y-sutures (if posterior it can affect vision)

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what is Mittendorf’s dot?

embryological remnant of hyaloid artery on posterior surface of lens (inferior nasal)

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what are the 3 types of age-related cataracts?

nuclear sclerotic, cortical, and posterior subcapsular

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what are nuclear sclerotic cataracts caused by?

an alteration in lens metabolism which increases the concentration of insoluble proteins (amino acid residue = color change)

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what are some symptoms of a nuclear sclerotic cataract?

as nucleus becomes more dense - changes refractive index and patient can have a myopic shift, can also have glare (halos/glare at night)

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what causes a cortical cataract?

an imbalance of electrolytes that leads to an over-hydration of the lens = liquification of lens fibers

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what are some signs and symptoms of cortical cataracts?

vacuoles, clefts, wedges (spoke pattern in periphery) or lamellar separations, swelling/edema, decreased night vision

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what causes posterior subcapsular cataracts?

a loss of lens fiber nuclei and replacement by aberrantly migrating epithelial cells (cells cluster and breakdown adjacent cells) - seen in uveitis, RP and trauma

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what are the symptoms of posterior subcapsular cataracts?

more day symptoms (more glare)

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what are the 2 types of advanced cataracts?

mature/intumescent and hypermature/morgagnian

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what are mature/intumescent cataracts?

dense and white (20/200), complete opacification and lens starts to swell

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what are hypermature/morgagnian cataracts?

complete liquification of cortex, lens my sink/float, and need immediate surgery

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what are the causes of anterior/posterior subcapsular secondary cataracts?

trauma, electric shock, glass blower, uveitis, RP, RD, degenerative myopia, diabetes, galactosemia, wilson’s disease, atopic dermatitis, steroids, miotics, chloroquine and amiodarone

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what are the causes for nuclear secondary cataracts?

rubella, degenerative myopia, anterior segment ischemia

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what are the causes for cortical secondary cataracts?

UV exposure, ciliary body tumors, Fabry’s, and dystrophia myotonica

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what are 3 lens-induced ocular diseases that are indications for cataract surgery?

phacolytic glaucoma, lens-particle glaucoma, and phacoanaphylaxis

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what are 3 indications for cataract surgery?

improvement of daily life, lens-induced ocular diseases, and prevention of sight threatening conditions (diabetic patients)

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what are some contraindications for cataract surgery?

no improvement to daily living, bad systemic health/mental status, significant ocular health concerns (NVG, chronic uveitis, blind eye, decreased endothelial cell count)

what are 2 ways to check potential acuity prior to cataract surgery?

interferometry (laser/white light) and potential acuity meter (PAM) \*dilated for both

how do you test glare prior to cataract surgery?

brightness acuity meter (BAT) \*not dilated

which existing condition can a patient have before cataract surgery that can lead to endophthalmitis?

blepharitis

what are two additional pre-surgery tests used for advanced cataracts?

macular/retinal function (entopic images) with maddox rod and B-scans

why should you perform an endothelial cell count test before cataract surgery?

performed on patients with significant corneal edema or corneal guttata = poor candidate if less than 800 cells/mm^2

what would a 0.3mm error in an A-scan result in for cataract surgery?

a 1D error in refractive component

what is intracapsular cataract surgery (ICCE)?

entire lens is removed (mainly 3rd world countries) - more prone to complications (vitreous prolapse, CME, RD)

what is extracapsular cataract surgery (ECCE)?

the posterior capsule is left in place - has two types: planned ECCE and phacoemulsification

what happens during planned ECCE?

limbal incision is made at sclera, nucleus is expressed out, PCIOL is implanted in capsular bag

what happens during phacoemulsification?

involves ultrasound which vibrates at a high frequency and fragments the lens material - corneal incision (smaller incision, foldable IOL, quicker recovery)

what is a complication of phacoemulsificaiton?

may cause endothelial cell damage

which procedure is more common: planned ECCE and phacoemulsification?

phacoemulsification

what is an iris clip/iris fixated IOL?

it is clipped onto the iris or sutured into place \*\*do not dilate these patients

what is the most common type of IOL?

posterior chamber IOL

what are some complications of an anterior chamber IOL?

uveitis/glaucoma/hyphema = UGH syndrome and can cause corneal damage to endothelium

what are the 3 types of multifocal IOL's?

apodized diffractive IOL, ReZoom multifocal and crystalens

which multifocal IOL is designed to mimic the eye's natural ability to focus on all distances?

Crystalens

what are some contraindications of multifocal IOLs?

extreme perfectionists, anyone whose job requires excellent night vision, and high amounts of astigmatism

what is performed at a 1 day post-op appointment?

history/cc, clean wound site, VA's, SLE, GAT, and DO

what drops are a 1 day post-op patient using?

(shield), steroid/antibiotic combo q2-4h, NSAID?, analgesic prn, and restricted physical acivity

what treatment changes are made at 1 week post-op visit?

discontinue the shield and discontinue antibiotic drops - begin tapering steroid, still on NSAID

what are the treatment changes at the 2-4 week post-op visit?

tapering steroid and still on NSAID (perform DFE if \<20/100)

what happens at the 6-8 week post-op appointment?

final refraction, possible DFE, discontinue all drops

what are 2 early post-op conjunctiva complications?

injection and sub-conjunctival hemorrhage

what are some early post-op corneal complications?

edema (common), descemet's layer folds or descemet's detachment (rare)

what are some early IOP post-op complications?

transient rise in IOP, pupillary block glaucoma, hypotony/flat AC

what are 2 early post-op complications in the anterior chamber?

hyphema and endophthalmitis (2-3 days post-op)

what is the common organism that causes endophthalmitis and what are the sources?

staph. epidermidis and aureus normal flora, instruments, contaminated IOLs/solutions

what are the signs and symptoms of endophthalmitis?

pain, redness, reduced VA inflammation, hypopyon, corneal edema, AC reaction and viritis

what is the treatment for endophthalmitis?

IV/topical antibiotics (may need to be cultured)

what is an early post-op complication of the iris?

iris atrophy or prolapse (may cause peaked pupil/distorted)

what is a late complication of the cornea from cataract surgery?

bullous keratopathy - see striae, stromal folds, microcysts and bullae

what is the treatment for bullous keratopathy?

hypertonics and PKP

what late complication can occur if the steroids are not properly tapered?

rebound iritis and inflammation

when does posterior capsular opacification occur following cataract surgery? What is the treatment?

occurs in 50% of ECCE patients - 6 months to 5 years after treatment = neodymium - YAG laser

what is the late complication windshield wiper syndrome?

due to zonular weakness (PXF, trauma) and capsular bag isn't stable

which type of cataract surgery is CME more common in?

more common in ICCE than ECCE - can occur up to 1 year post-op (cause is unclear)

how do you diagnose CME and what is the treatment?

diagnose = fluorescein angiogram or OCT treatment = oral and topical NSAIDs or steroids

when is a retinal detachment following cataract surgery most likely going to occur?

in first 3 years after surgery - more often in ICCE due to loss or compromise to capsular bag - shift in anterior vitreous

Seidel's Sign

Nuclear Sclerotic

Cortical

Posterior subcapsular

What are 3 types of cataracts in this photo?

NSC, PSC, cortical

Congenital - Anterior Polar

Congenital - Coralliform

Congenital - lamellar

Congenital - Cerulean

Congential - sutural

Congenital - Mittendorf's dot