Slit Lamp 1+2- Week 3/4 Flashcards
List the ocular structures examined by direct:
Mostly surfaces
- lashes
- lids (bulbar, palpebral)
- conjunctiva (bulbar, palpebral)
- cornea
- pupil
- iris
*can I last in painting cat I’s (eyes)
What ocular structures are examined with parallelopiped (ppd)?
All layers of the cornea Also surfaces such as: - tear film - corneal epithelium - corneal endothelium - iris and lens layers
Which technique is best for measuring corneal endothelium: PPD or Spec Reflecc?
Spec Reflecc
What ocular structures are examined by Optic section?
Examines cornea and lens in cross sections
Also looks at:
- lens
- ant. Vitreous
- corneal epithelium + stroma
What slit lamp technique is used with Van Herrick?
A very thin optic section
What ocular structures are examined with small spot? What is it used to look for?
Small bit of a cross section (e.g) small bit of cornea
Look for:
- uveitis
- cells and FLARE
- inflammation
Examine anterior chamber
- detect floating debris + ant. Chamber flare/cells
Meme idea: flare as in a firework. Or rick. Woo.
What ocular structures are examined with indirect illumination?
- faint irregularities
- deeper areas of tissue
- foreign bodies (e.g in cornea)
What ocular structures are examine with retroillumination?
- iris, lens, and cornea (in light reflected from other structures)
- useful for looking at cataract
What ocular structures are examined with specc reflecc?
- tear film quality
- corneal endothelium
- ant. lens surface (looks like an orange peel. So looks yellow-ish)
- corneal epithelium
- lens capsule
What does sclerotic scatter identify?
changes in corneal transmittance (which may occur with corneal oedema, scarring, deposits, degeneration)
What is sclerotic scatter useful for detecting?
- stromal oeddema
- particles/foreign bodies
Why do we use Lissamine Green staining?
To diagnose lid wiper epitheliopathy
Why do we use Sodium Fluoroscein staining?
use when you suspect ocular surface abnormalities
Describe the setup for direct ophthalmoscopy.
width: 3-5mm
angle: 30-60deg (no it’s 0deg because direct)
height: max (so 12mm)
mag: low (6-10x)
Illuminance: moderate
click stop: in
What ocular structures are examined by Diffuse illumination?
general observation of the lids, conjunctiva, cornea and lashes
Describe the setup for Diffuse ophthalmoscopy.
width: max
angle: 60deg
height: max
mag: low (6-10x)
Illuminance: low-medium
click stop: in
Describe the setup for Parallelopiped.
width: 1-2mm (2mm really)
angle: 30-60deg
height: max
mag: moderate (10-16x)
Illuminance: increased from diffuse. moderate
click stop: in
When we start slit lamp examination, what technique should we do first?
Diffuse generally (though this can also be done without slit lamp)
Describe the setup for Optic Section
width: as narrow as possible
angle: 30-60deg
height: max
mag: moderate (10-16x) to high (16-25x)
Illuminance: max
click stop: in
Describe the setup for Small Spot
width: 1mm
angle: 30-60deg
height: 1mm
mag: high (more than 16x)
Illuminance: max
click stop: in
Describe the setup for Indirect Illumination
width: 1mm
angle: 60deg
height: max
mag: moderate (10-16x)
Illuminance: medium
click stop: OUT!!! Oh wow the click stop is OUTTTTTT
Describe the setup for retroillumination
width: 1mm
angle: 60deg
height: max
mag: moderate (10-16x)
Illuminance: medium
click stop: in
Describe the setup for specc reflecc
width: 1 or 2-3mm (just 2 then isn’t it)
angle: 45deg
height: max
mag: 40x
Illuminance: medium
click stop: in
(Angle of Incidence = Angle of observation)
Describe the setup for sclerotic scatter
width: 1mm
angle: 60deg
height: max
Illuminance: medium
filter: no
click stop: in
(according to my notes, magnification doesn’t exist for this technique)
Describe the setup for Van Herrick
just like optic section except angle MUST BE 60deg (also use high mag 16-25x)
What is the most common slit lamp method to assess cornea?
PPD - parallelopiped
Indications for slit lamp use?
- anterior segment imaging (e.g. if an eye condition requires it)
- to facilitate ocular foreign body removal
- also in routine stereoscopic view of fundus
- and is also a must for CL fitting and aftercare
- used in tonometry
- used for gonioscopy
In a slit lamp exam: what lid abnormalities might you see?
- meibomianitis
- blepharitis (eyelid infl.)
- hordeolum (bacterial infection of oil gland in lid)
- ectropian
In slit lamp exam: what eyelash abnormalities may you see?
- trichiasis (introversion/ingrowth of lashes)
- pediculosis (infestation with lice)
- distichiasis (abnormal lash growth)
In slit lamp: what tear abnormality might you see?
Dry eye
Slit lamp: What conjunctiva abnormality might you see?
conjunctivitis
Slit lamp: What cornea abnormality may appear?
infiltrates, pannus, pterygium
Slamp: what pupil abnormalities may appear?
anomalous pupillary responses, irregular pupil
Slamp: iris abnormalities?
iris atrophy, transillumination
Slamp: ant. chamber abnormalities?
narrow angle, cells and flare
Name the typical filters for the slit lamps illumination system
Neural density: decrease brightness of light (more px comfort)
Polarizing: increase visibility of subtle defects
Diffusor: to give even illumination
UV and heat filters: usually built in for safety to prevent phototoxic damage with extended exposure
Red-free: enhance blood vessel contrast
Cobalt-blue: for viewing fluoroscein
What is the purpose of red-free filter?
- enhance contrast when looking at blood vessels, haemorrhages, microaneurysms, SVP (esp. for CVD)
- cornea or iris neovascularisation
- RNFL
- layer of pigmentation
What is the purpose of cobalt-blue filter?
for viewing fluoroscein
- look at damage to corneal or conjunctival epithelial cells
- TBUT (tear break up time)
- seidel test
- also useful for viewing Keyser Fleischer ring in keratoconus
What is the rule of thumb for the slit-lamp magnification system?
Always start with low mag and then increase when you see something interesting
(also refine focus when you change mag)
Can diffuse illumination discern depth?
No
