11 - Lens/Cataract/IOL Flashcards
Cataracts
-nuclear sclerosis
Most common aging
MYOPIC SHIFT in elderly pts - report of “second sight” due to improved ability to read without specs
Cataracts
-cortical
Radial spokes
HYPEROPIC SHIFT
Cataracts
-anterior subcapsular
Directly underneath anterior lens capsule
Cataracts
-posterior subcapsular
Directly in front of posterior lens capsule
AFFECTS NEAR VISION > distance
Commonly results from systemic/topical steroids
-high myopes
-late stages RP
-mild PSCs can cause significant reduction in acuity, typically assoc with worse glare than other cts
Cataracts
-infant
Assoc with GALACTOSEMIA + RUBELLA
Most common type is lamellar/zonular: lens opacity surrounding embryonic nucleus
Cerulean is a type of congenital that rarely affects VA, app as tiny dot-like or flake-like white or bluish-green opacities
Cataracts
-presenile
“Mr. Wilson is MAD about his early cataracts” -Wilson’s dz -myotonic dystrophy: PSC christmas tree -atopic dermatitis -diabetes mellitus And ANY CHANGES IN CALCIUM
Cataracts
-traumatic
aka Rosette
Look for vossius ring
Cataracts
-toxic
ASC:
- chlorpromazine = stellate
- amiodarone = deposits
- miotics = vacuoles
- gold salts = gold deposits
PSC: corticosteroids
Cataracts
-secondary
Common causes:
- chronic anterior uveitis (e.g. Fuchs)
- high myopia (esp PSC, NS)
- RP (PSC)
- gyrate atrophy
Cataracts -testing —PAM —BAT —axial length —B-scan
PAM: incr VA
BAT: glare disability = decr VA
AL: A-scan or IOL master, helps calc appropriate IOL power
- avg 24mm
- 1mm error = 3D error in calc IOL power
B-scan: post seg abnorm
Cataract surgeries
-intracapsular cataract exctraction
ICCE - think “ice age”, not done anymore
Entire lens + capsule removed -> aphakia -> need for 2nd surgery for IOL
Cataract surgeries
-extracapsular cataract extraction
ECCE
Lens removed, capsule remains
-large incision (9-11mm, lens taken out as whole)
Cataract surgeries
-phacoemulsification
Form of ECCE with smaller incision (1-3mm)
- lens is fragmented with ultrasound
- no suture as AH will push against flap to close it
Cataract surgeries
-femtosecond laser
Used for corneal incisions, ant capsulorhexis, lens fragmentation
Cataract surgeries
-post-op complications
—frequency
—corneal edema + folds in Descemet’s
5%
Striate keratopathy
Cataract surgeries
-post-op complications
—acute post-op bacterial endophthalmitis
Rare
With tx 50% go blind
Symptoms in 2-4 days
-signs: significant AC rxn, hypopyon, etc.
70% gram(+) from normal flora
-most common STAPH EPIDERMIDIS (cat+, coag-)
-also Staph aureus
Cataract surgeries
-post-op complications
—delayed post-op bacterial endophthalmitis
—toxic anterior seg syndrome
Delayed:
- symp in 1wk-1mo
- insidious vision loss, pain
- fungal also common
TASS:
- STERILE INFLAMMATORY rxn -> damage to ant seg structures
- due to chemical exposure during sx
Cataract surgeries
-post-op complications
—lens subluxation
Rare - common in PXF, Marfan’s*
-also Ehlers-Danlos*, Weill-Marchesani, homocysteinuria
*ME in t-dome
Due to pupillary capture and poor capsular support
Cataract surgeries
-post-op complications
—posterior capsular opacfication
—cystoid macular edema
PCO: #1 post-op complication
- equatorial epi cells -> post capsule (2-6mo)
- elschnig pearls = kids
CME:
- surgical trauma -> inflammation, release of PGs + disruption of lens-vitreous interface
- ct sx is most common cause of CME; Irvine-Gass
- develops in OPL/Henle’s
- peak 6-10wks, most resolve with tx in 6mo
Cataract surgeries
-post-op complications
—corneal edema: low vs high IOP
Low -> Descemet’s folds
High -> microcystic edema
Cataract surgeries
-post-op complications
—assoc with anterior chamber IOLs
UGH: uveitis, glaucoma, hyphema syndrome
