1. noncontact
2. high quality steroscopic views,
3. well illuminated
4. ability to view: vitreous, optic nerve & macular, retina, choroid

1. high plus powered condensing lens:

double aspheric = fewer optical aberrations, more uniform illumination, optically coated, hand held, focuses diverging light into aerial image.

2. slit lamp,

Real Image,

Magnified Image,

Inverted Image,

Reversed, Image.

• HIGHEST magnification,
• good for detailed disc and macular viewing.
• good for seeing the optic nerve in a lot of detail.

excellent general diagnostic lens,

medium magnification.

the in between lens

small pupil capabilities, good for undilated patients,

not as much magnification but has a LARGER field of view so it is easier to get a sense of where you are

Specialized Lens:

digital lenses;

 may reduce glare and reflections,

good for slit lamp photography

Wide field of view

Less magnification
Inverted image

Smaller field of view,

higher magnification,

upright image

-58.6 diopter plano/ concave lens:

• Mounted on slit lamp (swings down in Zeiss, other brands: insert it into sliding track)
• Extednd range of slit lamp posteriorly to retinal plane.
• Noncontact examination of optic disc, macula, posterior pole & vitreous.

Hruby Lens

Virtual Image

Erect Image,

Steroscopic view

What do you use to see the posterior pole:

 optic disc & macula,

retina,

vitreous

1. binocular indirect ophthalmoscopy,

2. biomicroscopic indirect opthalmoscopy with 78D/90D/ Hruby lens.

which has the highest magnification?

A) 60D

B)78D

C) 90D

D) Hruby Lens

which has the LARGEST field of view?

A) 60D

B)78D

C) 90D

D) Hruby Lens

which provides the most detailed view of macula &optic disc ?

A) 60D

B)78D

C) 90D

D) Hruby Lens (-58.6D)

Which has a wide field of view?

a) plus lens

b) minus lens

Which has HIGHER magnification?

a) plus lens

b) minus lens

multiple optical interfaces induce reflections and aberrations.

smaller field of view

Which has an inverted image?

a) plus lens {60D/78D/90D}

b) minus lens {hruby lens -58.6D}

Which has an inverted image?

a) plus lens {60D/78D/90D}

b) minus lens {hruby lens -58.6D}

which has the smaller field of view

a) plus lens {60D/78D/90D}

b) minus lens {hruby lens

-58.6D}

1. variable magnification (use different mag lens, turn on mag on SLE)
2. adjusts illumination on slit lamp: (can change beam size/orentation to evalutate of contour of retinal lesions, easily used on photosensitive pt to turn light down, adjust beam height and width.
3. can change filters on slitlamp: red free filter allows you to better visualize hemorrhages and NFL (nerve fiber layer)

1. successful lens alignment

(visual axis centration and minor readjustments)

2. pupil dialation

1. dilate pupils, sit pt, adjust slit lamp beam to 2-3mm width, 10x mag,
2. instruct pt to fixate straight ahead (at examiner's ear) with opposite eye
3. align microscope and illumination arm of slit lamp so light beam entering pupil is perpendicular to corneal apex.
4. move slit lamp forward and focus on cornea through the oculars
5. hold condensing lens with thumb and index finger
6. look outside oculars to see that light is drected into pupils, center the lens .rest remaining fingers of hand on forehead strap, may have to hold upper lid as needed,
7. view red reflex beam in oculars, pull back slit lamp till retinal image comes into focus.

• check pt fixation
• make lens is held parallel to pt's face (no tilt)
• realign light and lens from outside slit lamp oculars.
• Additional hints: make minor adjustments in lens centration, and lens tilt to improve image.
• keep joystick in upright postion to allow for fine focus,

clean lens

• move light toward area to be seen,
• move lens slightly in same direction as light, which is toward extended are of image to be viewed.

1. vertical & horizontal ratio,
2. depth of cup (deep or shallow),

3) pink if normal, +pallor for optic atrophy.

4) contour:  excarvated, notched

5) Margins of optic disc: distinct/indistint. the margins of the DISC not the cup!!

nasal and temporal arcades A/V rato-- normal A/V ratio = 0.7

Arteriolar narrowing = 0.5 (or less)

A/V crossing changes

record "cl" if normal

"+" if present

"-" if absent

color/pigmentary changes of macula,

record cl -if normal

 + FLR if present

-FLR if not present

cl; if normal

+PVD; if posterior vitreous detachment seen ( ring appearance)

1. Adjust slit lamp beam height to vertical limits of ON and record (mm).
2. multiply that height by magnification factor. (also consider color of cup, depth of cup-- stereoscopic view, vessel contour).

average:

1.88 mm vertical

 1.77 mm horizontal

can vary:1.2mm to 2.5mm

who has larger disc area? a) african americans

b) caucasians

1. pupil margin
2. iris contour & angle of approach
3. iris insertion
4. ciliary body
5. scleral spur
6. trabecular meshwork --> schlemm's canal
7. Schwalbe's line

iris cysts, iris atrophy

rubeosis (new blood vessels growing on the iris),

exfoliative material

• visualize the anterior chamber angle
•  detailed view of anatomy of ant. chamber angle,
•  screen for narrow angles before pupil dilation

1. Glaucoma suspects &/ ocular hypertensives,
2. diagnose and treat glaucoma (open-angle vs narrow-angle glaucoma)
3. Assess angle pigmentation
4. find if pt at risk of angle closure with dilation in cases of narrow van Herick angles.
5. diagnose angle recession, damage or pigment liberation in cases of ocular trauma
6. evaluate for angle neovascularization, tumors, foreign bodies.
7. rule out contributing cause of elevated IOP, such as pigment dispersion syndrome and pseudoexfoliation,
8. peripheral anterior synechiae
9. ocular inflammation
10. laser trabeculoplasty (improve drainage by hole in trabecular meshwork)
11. laser iridotomy (make hole for stuff to drain out)

• corneal disease

• recent trauma: wait 1 mo post trauma
• recent hyphema: wait initially to prevent rebleed, then do it eventually.

• normally you can't see that anterior chamber angle directly, because the opaque scleral tissue blocks.

• Concave contact Gonio lens used and the angle recess can be viewed through obliquely inclined mirror.

slit lamp biomicroscope,

gonioscopy lens (coned shap with reflecting mirrors),

gonioscopic solution (viscous mainly used w/ 3-way mirror lens,)

topical anesthetic solution, tissue.

1. gonioge/ Goniosol (2.5% methylcellulose)
2. Celluvisc (1.0 % carboxymethyl cellulose)

1) Cleaning to remove debris and deposits (water, detergents Dawn dish soap.

2) Disinfection: inactivate of virtually all pathogenic microorganisms, thermal or chemical means. (recommend use  2% glutaraldehyde, hydrogen peroxide OR 1:10 bleach  and rinse

3) Sterilization: eliminate all viable microorganisms.

do NOT soak in alcohol, acetone or other solvents.

do NOT autoclave

• 10-16 mag,

• medium beam width 3-4mm,

• microscope arm and illumincation arm aligned straight ahead

• NO the mirror is opposite angle being viewed; what you seein mirror is mirror age flipped over an imaginary axis (either horizontal axis or vertical axis) 
• mirror superiorly placed, the image viewed in mirror is the inferior angle.

1. iris,
2. ciliary body: darker than iris,
3. scleral spur: scleral tissie is bright white
4. Trabecular meshwork: grayish-pinkish, 2 layers: the layer closer to iris filters more aqueous and becomes more pigmented
5. Schwalbe's line: where trabecular meshwork ends, tough to see

 angle width: 35-45

closure risk = impossible

angle width = 20-35

closure risk = improbable

angle width = 10

closure risk = possible

angle width = 10

closure risk = probable

width = 0

closure risk = closed already!

record most posterior structure,

iris approach: flat, concave, convex

Grade pigment in TM 0 [none] to 4 [heavily pigmented]

what does a convex iris surface relate to?

myopia,

pigment disperstion

Shaffer's system of chamber grading is based on what measurement?

[image]

it is based on: the more posterior the iris inserts, the wider the angle between the iris and the angle wall

[image]a = wide open, b = moderately narrow,

c = extremely narrow,

d= partially to totally closed.

1. Flat iris surface,
2. normal chamber depth,
3. narrow van Herick angle.

Its where peripheral iris drops off steeply just before insertion (this configuration happens with normal central anterior chamber depth.,