MT 1OC disease Lens Pigmentations and Cataracts

- epicapsular stars
- Vossius rung
- Capsular pigment dusting
- Mittendorf's Dot

examples of lens pigmentations

Epicapsular stars

Remnants of tunica vasculosa lentis -> small light brown or tan dots/ stars deposited on anterior lens capsule. usually unilateral, does not affect vision.

Remnants of tunica vasculosa lentis -> small light brown or tan dots/ stars deposited on anterior lens capsule. usually unilateral, does not affect vision.

describe Epicapsular stars

epicapsular stars

Vossius Ring

Vossius ring

related to some disease processes as well as trauma and uveitis. Is an imprint deposition of melanocytes from pupillary border of the iris due to contusion

Is an imprint deposition of melanocytes from pupillary border of the iris due to contusion. May mimic other lens pigmentary deposits.

describe Vossius ring

fades with time but some pigment may remain permanently. watch for associated traumatic cataract

A Vossius ring usually __________

Vossius ring

capsular pigment dusting resulting in TIDs

Capsular pigment dusting

_________ may be due to Pigment dispersion syndrome, pseudoexfoliation or trauma

retroillumination of iris showing transillumination defects

common associated finding of capsular pigment dusting

corneal endothelial pigment and pigment dusting in angle.

transillumination defects

associated finding of capsular pigment dusting

mittendorf's dot

_________ is usually unilateral

mittendorf's dot

mittendorf's dot

embryonic remnant of hyaloid membrane attached to posterior lens surfance. usually unilateral, and typically infero-nasal. Appears as small, punctate opacity on back of lens (may look like posterior subcapsular cataract)

describe a mittendorf's dot

1. nuclear
2. cortical
3. subcapsular

3 types of age related catarcts

Nuclear cataract: cortex is white while nucleus is brunescent.

describe this image

nuclear cataract

most common type of age related cataracts

yellowing of nuclear are. reduces blue light (blue blocker) will then turn brown in mature form, red in advanced form and milky white in very advanced form (VA's will be severely reduced)

describe the appearance of nuclear cataract

cortical cataract

easiest to see after dilation as most of it often hidden behind iris. inferior nasal portion of lens often worst area for cortical cataracts to develop due to UV

describe a cortical cataract

aging and UV

most common causes of cortical cataract

spoke like radiations

made of anterior and/or posterior linear opacities.

get reduced VA if spokes cross visual axis

what is the appearance of a cortical cataract?

subcapsular cataract

subcapsular

most devastating type of age related cataracts to VA?

most: nuclear
least: subcapsular

most and least common types of age related cataracts?

focal, usually round like opacity. posterior subcapsular most common.

describe the appearance of subcapsular cataract

rarely in senile form

usually secondary to external or systemic etiology

eg. Glaukomflecken, Wilson's disease, mitotic therapy, amiodarone

can be congenital due to alport syndrome

describe who gets an anterior subcapsular cataract

anterior subcapsular cataract

Glaukomflecken, wilson's disease, mitotic therapy and amiodarone can all cause ____________

congenital anterior subcapsular cataract

alport syndrome can cause __________

usually nuclear sclerosis (NS) appears before PSC formation.

most commonly due to steroids if pre-senile.

describe posterior subcapsular cataract

Myotonic dystrophy
Retinitis pigmentosa
mittendorf's dot

besides steroids what are other causes of PSC before old age?

direct ophthalmoscopy about arms length away, rather than slit lamp

best way to view posterior subcapsular cataract

left: PSC viewed with DO
right: PSC viewed with slit lamp (harder)

left vs right

Lamellar cataract

Always congenital

involve lamella of fetal or nuclear zones.

radial spoke like opacities

describe a lamellar cataract

sutural cataract

lamellar cataract

Always congenital

involve lamella of fetal or nuclear zones.

radial spoke like opacities

sutural cataract

congenital; a type of lamellar cataract

more common

Y shaped opacities within the lens nucleus

patient will have no symptoms (20/20 vision)

congenital; a type of lamellar cataract

more common

Y shaped opacities within the lens nucleus

patient will have no symptoms (20/20 vision)

Sutural cataract

quantification should correlate with VA reduction, however, this doesn't always happen clinically.

cataract density grading

0-4 scale. with 4 being the worst

describe the LOCS grading intervals for cataracts

a nuclear sclerotic lens will absorb blue light. using a 45 degree optic section and max illumination with cobalt filter, estimate the depth of beam penetration in %

what is the blue light test for cataract density grading?

more sensitive than snellen test, especially for PSCs

pelli- robson chart most clinically applicable technique

describe contrast testing for cataract density grading

immature (mild)
moderate
mature
hypermature

cataracts can be be classified upon maturity

lens retroillumination may appear clear

describe an immature (mild) cataract

may be 'presurgical' or 'surgical'

some opacification seen on retroillumination

describe a moderate cataract

cortex is totally opaque; surgery needed. posterior pole views are difficult

describe a mature cataract

water leaks out of lens, surgery needed

lens is slightly smaller with wrinkled capsule

describe a hypermature cataract

hypermature cataract

total liquidifaction of cortex, can lead to phacolytic glaucoma.

describe a hypermature cataract

most common: senile
second most common: congenital

most common age of onset for a cataract? second most common?

congenital, infantile, juvenile, adult, senile

age of onset of cataracts

use direct scope for advanced cataracts, hand help slit lamp for milder cataracts, anesthesia may be required. look for any associated ocular findings, note morphology as may give hint to etiology

how to view congenital/ infantile cataracts

OS cataract

1. inspect presence or absence of central fixation, nystagmus, strabismus (bruckner, hirshberg)

2. general observation of facial symmetry

3. assess parents conditions

4. visual acuity testing using preferential looking (normal at birth 20/400 but should be 20/40 by 1 year old)

describe management for congenital/ infantile cataracts

1. bilateral advanced cataracts

2. unilateral cataract

-> key is to prevent deprivational amblyopia

surgical indications for congenital/ infantile cataracts

1. spectacles if aphakic (+15 to +20 needed)

2. CLs if aphakic

3. laser keratoplasty (KP)

4. intraocular lens (IOL)

correction options for a child with congenital/ infantile cataracts

20/40 Visual acuity is typical referral criteria for surgery. IOL power calculated using Ks and axial length nomogram -> posterior chamber IOL most common (anterior chamber less common)

describe management for juvenile, adult and senile cataracts

extracapsular cataract extraction and phacoemulsification

current procedure for removal for juvenile, adult and senile cataracts

PCIOL (posterior chamber IOL)

ACIOL (anterior chamber IOL) -> need chunk of iris taken out so aqueous can escape, more likely to get uveitis

accommodative amplitude after cataract extraction is zero!!! Not as critical with older patients but VERY critical for younger patients. may need asymmetrical add power in glasses if unilateral.

what do you need to remember to talk to your patients about if they want cataract removal

1. potential acuity meter

2. super pinhole

3. laser interferometry

ALL best if pupil is dilated

types of potential acuity testing

Potential Acuity Meter (PAM)

projects around cataract and helps determine actual retinal visual acuity potential. -> similar to super pinhole in that regard.

describe the potential acuity meter (PAM)

super pinhole

assesses the potential acuity through the cataract

The pinhole occluder also helps reduce glare, if VAs are not better with this method something else might be causing reduced vision

describe the super pinhole

bright overhead light shone on nearpoint card, patient views nearpoint card through mutliple pinhole

describe modified super pinhole

laser interferometry

what potential acuity testing is best if the patient has VERY DENSE cataracts

laser light waves pass through opacities to superimpose on retina, patient says which direction bars of light are. Can therefor determine potential retinal acuity, may be more effective than PAM or super pinhole with DENSER cataracts

describe the laser interferometry

Laser Interferometry

BAT (glare/brightness acuity test)

__________ is NOT a potential acuity test!!!!

BAT (not a potential acuity test)

converts visual acuity test or contrast sensitivity test to a test for disability glare (distinguished from discomfort glare)

-> check acuities without light and then on the three light setting. if patients VAs are worse with BAT then they would benefit from cataract surgery. If VA's improve glare not causing the VA issue

describe BAT

glare- recovery time measured

tests of macular photostress than cataract testing

- keratometry (Ks, Topography), necessary to determine astigmatic amount

- A scan: determine IOL power

_________ required prior to cataract surgery

to determine IOL power

what is the A scan for prior to cataract surgery?

Optical Biometry

current standard for IOL calculation

cataract surgery referral criteria