Test 2 Flashcards
1
Q
how does the conjunctival epithelium heal?
A
migration of cells and mitotic proliferation
2
Q
how long does it take to re-epithelialize conjunctival wounds?
A
wounds as large as 1 cm can be healed within 48-72 hours
3
Q
what layers of the cornea do we look for through the slit lamp?
A
tear film (movement and appearance), epithelium, bowman’s layer, stroma, descemet membrane, endothelium.
4
Q
what does the stroma of the cornea contain?
A
contains wbc, macrophages, lymphocytes, and PMN. this cannot regenerate after damage
5
Q
What does the descemet membrane of the cornea contain?
A
It terminates at the limbus (schalbe’s line). This does have regenerative properties.
6
Q
What does the endothelium of the cornea do?
A
maintains the dehydration of the cornea by pumping out the excess fluid from the stroma.
7
Q
what is deturgescence?
A
a state of relative dehydration to keep the cornea transparent.
8
Q
how long does it take for the entire corneal epithelium to turn over?
A
7-10 days. The superficial squamous cells heal by sliding off surrounding cells ( few hours). The cuboidal wing and basal cells heal within hours to days, and basal cells secrete basement membrane every 8- 12 weeks.
9
Q
what does the corneal epithelial stem cells do?
A
they are located at the superior and inferior limbus at the palisades of vogt. They migrate into basement membrane and eventually to the superficial area and are shed off. They also act as a barrier to prevent conjunctiva from growing into the cornea.
10
Q
What happens when there is a disfunction of the stem cells in cornea?
A
cornea becomes vascularized or conjunctiva starts growing into it.
11
Q
what are organic FB?
A
from animal or plant origin. Eg: nuts, seeds, bones, branches, food or wood
12
Q
what are inorganic non-metallic FB ?
A
objects not derived from living material. Eg: sand, plastic, stones, glass, soil.
13
Q
CHx questions for circumstances surrounding the injury
A
CC = pain (most important), lacrimation, redness Onset – time/place, FLORIDA oIf more time has passed, could have traveled/embedded deep
Circumstances (extremely important) – what they were doing when it began can tell you type of FB and how far it has penetrated
actions taken in attempt to remove or relieve pain
14
Q
what procedures must be done before removing foreign body?
A
Always take VA BEFORE and after removing FB oSc, cc, ph
Put anesthesia drop before if very painful, esp if in cornea
Check pupils and EOMs before and after
Look for circumlimbal flush (redness only at the limbus) –characteristic of uveitis
oCheck AC for cells/flares If chamber is shallow, AH could be leaking out Seidel test – put fluorescein and look for outflow
Evert lids, look for perforation oIf FB is in palpebral conj, may be difficult to see – stain with fluorescein to see its track of movement
Superior palpebral conj = most common FB location oMay have to double evert (UL and LL simultaneously) to find FB lodged in fornix – use a retractor or paper clip (video)
15
Q
What can we do if there is a suspected Intraocular FB? (IOFB)
A
If you suspect IOFB (intraocular), dilate oXray, B-scan, UBM (ultrasound biomicroscopy), CT to see depth of FB NOT MRI, especially if metal FB.
Laser in vivo confocal microscopy (IVCO) HRT3
16
Q
How are the instruments disinfected?
A
clean instruments from debris, then use cidex, or Opti Cide 3 (glutaraldehide 3%) or autoclave instruments.
17
Q
cotton tip applicator
A
this must be used with saline if FB is superficial
Caution: this can disrupt the epithelium or cause FB to break apart. (irrigation)
18
Q
Gulf Spuds
A
used to remove larger FBs they are safer than needles and are used to scoop out the FB.
19
Q
needles
A
for smaller and more delicate fbs. used to remove symptomatic concretions and conjunctival cysts. do not come in perpendicular, come in from an angle.
CAUTION: can penetrate deeper layers so be careful. most commonly use 25 g
20
Q
Alger brush
A
used for rust ring removal. is a hand held drilling burr. use in sweeping or circular manner and stops if too much pressure is applied. can also be used to create a smoother area in case of large, loose epithelium.
21
Q
where is the most common place for FB location
A
superior palpebral conj.
22
Q
when should lids be everted to look for FB?
A
when the symptoms suggest FB but cannot be seen.
23
Q
when should lids be double everted?
A
to localize objects in the sulcus, or fornix
24
Q
what symptoms should we look for in the anterior segment?
A
hyperemia, ischemia, chemosis, staining with fluorescein, epithelial compromise, corneal edema. IOP, punctate keratitis
25
what is a white quiet eye?
an eye that has chemically induced ischemia and cauterization can mask severe occult injury
26
removal of FB
determine: # of FB, location and degree of embeddedness.
27
when to give anesthesia
avoid it unless there is too much pain or fb is really deep
28
conjunctival FB removal technique
SL at 10-16 X diffused illumination at medium intensity.
29
how to use a spud to remove FB from conjunctiva
align spud close to eye from outside and then use slit lamp to loosen edges of FB. once periphery is loosened use flicking motion to lift off then irrigate. use spatula or forceps to remove residual particle matter.
30
what should be done if after thorough exam a FB cannot be found?
irrigate superior and inferior cul de sacs followed by swabbing with a moistened cotton tip the palpebral conj.
31
meds to use after FB removal
DO NOT GIVE topical anesthetic. Polytrim q6h, polysporin q 6h to q 12h. cyclopegics and pressure patches are rarely needed
32
cyclopegics after fb removal
elax accommodation (reduce pain) and inflammatory response Let pt know they will see blurry at near, photophobia
33
Follow ups after FB removal
conj usually heals within 12-24 hrs. if FB sensation persists RTC, then F/u 5-7 days
34
contraindications or complications of FB removal
2ry infections are possible. FB at the bulbar conj. may be a sign of perforating injury(Hx of hammering metal on metal or using high speed machinery as a grinding wheel). and perforating can be masked by SCH. SPK might happen after irrigation due to disruption of the cornea.
35
seidel test
helps in diagnosis radiological studies of the eye and orbit. refer if signs of perforation of globe are present.
36
loop of nylon
used for loosely embedded FB material. It is good for poor fixating patients
37
where does the patient fixate during FB removal?
at a target away from the instrument.
38
which hand do you use to remove OS fb?
right
39
what motion do you use for each instrument?
spud or needle: strokes
| loop: flicking motion
40
what can happen when an fb has been embedded for a while?
anterior uveitis, must be treated
41
what does increased intraocular inflammation after fb removal suggest?
that there is a retained fb
42
what facial nerves control the MG, Moll and Zeiss glands in the eyelids?
CN VII and V= facial and trigeminal
| these glands produce lipid layer of tear film
43
what causes tear reflex?
emotional center of the frontal cortex, irritation of the trigeminal nerve endings, retinal stimulation by bright light
44
lacrimal gland
aqueous component of tear film
45
kraus glands and wolfring glands
aqueous and mucous components
46
what percent of tears are drained vs. evaporated?
90% drained 10% evaporated
47
what variables are considered during evaporation of tears
palpebral aperture, blink rate, humidity and ambient temperature
48
goblet cells
mucous component of tears
49
causes for hyper secretion
usually secondary to inflammation or surface disease, usually tx is medical
50
what is punctum stenosis?
closed punctum
51
what is conjunctivochalasis?
extra conjunctiva, can lead to dry eyes
52
centurion syndrome
a gap between the globe and the lower lid, leads to drainage problems
53
dacryocystitis
inflammation of the lacrimal SAC. happens most often in children and post menopausal women. usually 2ry to NLD obstruction. in infants, chronic infection accompanies the NLD.
54
what are the signs of dacryocystitis
erythematous, tender, tense swelling over the nasal aspect of the lower lid and around peri-orbital area. a mucoid or purulent discharge can be expressed from punctum when pressure is applied over the lacrimal sac. may have chronic mucopurulent conj. itis
55
acquired stenosis of canaliculi
usually viral origin
56
canaliculitis
rare disorder only 2% pts.
57
obstruction of canaliculi causes
steven johnson, pemphigoid, systemic chemotherapy w fluoruracil and topical idoxuridine (for HSK)
58
dacryocystography
is used to visualize the passage of tears and extent of blockage. inject radiopaque material in the sac with canula. x ray 5-30 min after
59
lacrimal scintillography
radioactive tracer into the conjunctival sac, its passage is traced using an anger gamma camera. non invasive
60
regurgitation test
under the SLE apply pressure to the lacrimal sac. observe if mucoid or mucopurulent discharge come out of puncta.
61
fluorescein disappearance test
apply fluorescein on lower cul de sac and observe after 2 min if there is any dye.
62
probing
probe with a dilator through puncta. hard stop normal, soft stop not normal
63
jones dye test 1
instil fluorescein to lower cul-de-sac after 5 min, ask pt. to blow the other nostril. inspect tissue for fluorescein. if negative wait another 5 min and repeat, if still negative, place sterile cotton tip 1 cm into nose for 10 secs. and examine
64
jones 1 interpretation
if no fluorescein on cotton tip, massage lacrimal sac and ask pt. to blow nose again. if + jones 1 with narrowing or partial obstruction of NLD. if NO fluorescein go to jones 2
65
jones test 2
irrigate inferior canaliculus with saline solution. ask pt. to lean forward and blow nose. if pt. tastes saline or fluorescein in tissue then +, if not negative. both means functionally blocked system but patent
66
dilation and irrigation contraindications
do not perform on pts. with dacryocystitis .review symptoms and signs if fluid regurgitates from superior punctum then there is blockage in common canaliculus. block superior with dilator and irrigate for 15 secs. this can dislodge blockage.
67
what medication can decrease aqueous production?
anticholinergics, antianxiety and antihistamines
68
problems with the tear film can arise from
```
• Incomplete blinking or twitching may cause problems for CL
wearers and subclinical dry eye.
• Nocturnal lagophthalmos
• Tear osmolarity with decreased tear volume during sleep
• overnight CL
• Bell’s palsy
• Ectropion
• Inflammatory or trauma eyelid
• Trichiasis
• Blepharitis
• MGD
• Alacrima
• Lacrimal Hypersecretion
• Paradoxic Lacrimation ( Crocodile Tears)
• Bloody Tears
• Lacrimal gland tumors
• Dacryoadenitis
```
69
dacryoadenitis
inflammation of the lacrimal GLAND
70
normal tear film
3 protein factors: albumin, globulin and lysozyme. IgA is most prominent, igG most prominent in allergies, IgM in acute infections. Na, K and Cl electrolytes are in higher concentration in tears than in blood.
71
lipid layer of tears
By Meibomian galnds ( MG) and x Moll and Zeiss
glands.
– reduce evaporation
– Polar phase has phospholipids adjacent to the aqueousmucin
and a non-polar phase with waxes, cholesterol
esters and triglycerides
– Polar lipids bound to aqueous layer lopicalins, which are
proteins that bind to hydrophobic molecules, contributing
to tear viscosity
– Blinking : to release lipids from glands. Forceful blink,
then more lipids
72
Aqueous layer of tears
By lacrimal glands and accessory glands Wolfring and Krauss
– Is 98 to 99 % water combined with electrolytes, glucose,
urea, soluble proteins and mucins
– Provides atmospheric oxygen to the corneal epithelium
– Wash away debris
– Allow passage of leucocytes after an injury
– Provide a smooth optical surface
– Its production rate decreases with age
–Contains Ig, mostly IgA, epidermal growth
factor (which increases the production
with injury), inhibitor of proteolytic activity
–Has protective substances: Lactoferrin,
nonlysozyme antibacterial factor,
interferon, Ig and lymphocytes.
• Lactoferrin has some antibacterial activity
• Lysozyme facilitates Ig A bateriolysis
• Pro-inflammatory interleukin cytokines accumulate
@ night when there is a reduction in tear production
73
Mucin layer of tears
Secreted by conjunctival goblet cells, crypts of
Henle and glands of Manz
Provide lubrication and permit the conversion of
the corneal epithelium from a hydrophobic surface
to a hydrophilic surface
When disrupted or contaminated, it triggers tear
break up
Deficiency of mucin layer is a feature of aqueous
deficiency and evaporative state.
Secreted by goblet cells. Mucin anchors to the corneal
epithelium microvilli and absorbed onto epithelium,
providing a hydrophilic corneal surface and inhibiting
bacterial adhesion to the ocular surface
Rose Bengal staining indicates that the transmembrane
and gel mucus layers are absent and the cell surface is
exposed.
Goblet cell loss is associated with cicatrizing
conjunctivitis, vitamin A deficiency, chemical burns
and toxicity from medication
74
what is tear volume?
normal 6-7uL
75
what is the tear osmolarity?
Tear Osmolarity normal value: around 304mOsm/L
– Values over 316mOsm/L indicate dry eye.
– Hyperosmolarity of the tears is a key mechanism for the
disease and may be a major pathway for epithelial
damage
76
dry eye disease
– International Dry Eye Workshop (DEWS) "…a
multifactorial disease of the tears and ocular surface
that results in symptoms of discomfort, visual
disturbance, and tear film instability with potential
damage to the ocular surface. It is accompanied by
increased osmolarity of the tear film and
inflammation of the ocular surface.“
– The definition and classification of dry eye disease: Report of the Definition and Classification Subcommittee
of the International Dry Eye Workshop (2007). Ocul Surf. 2007 Apr;5(2):75-92
• Prevalence
– estimated prevalence ranging from approximately 5%
to more than 35%, according to various studies
77
signs of DES or DED
```
– bulbar conjunctival hyperemia
– redundant bulbar conjunctiva
– decreased tear meniscus
– irregular corneal surface
– increased tear film debris
– fine, granular, confluent or coarse epithelial
keratopathy
```
78
objective tear film evaluation
• Ophthalmic Dyes
– Fluorescein (NaFl), Rose Bengal, Lissamine green
staining patterns
• Tear film stability (Tear Break Up Time TBUT)
• Tear meniscus
• Noninvasive Break up time (NIBUT)
– Tearscope (Keeler) ( also c Keratometer)
• Shirmer Test I and II
• Red phenol Thread
• Dry eye questionnaire
• MMP-9 levels; Osmolarity tests
79
ophthalmic dyes tests for quality assessment
• Fluorescein
• Fluorescein staining penetrates areas of the
corneal epithelium and conjunctival epithelium
where intercellular junctions are disrupted.
• Factors that affect fluorescence
– Concentration
– Solution pH
– Presence of other substances
– Intensity and wavelength of the absorbed light
80
the rose bengal test
identifies areas of devitalized
tissue (conj or cornea):
– Instill a drop of Rose Bengal dye into the inferior
fornix
– Ask patient to blink and wait 3-5 minutes before
evaluation
– Score the staining using a slit-lamp:
• interpalpebral corneal and bulbar conjunctival staining
is typically seen with aqueous tear deficiency
- Selectively stains devitalized
epithelium cells of cornea and
conjunctiva
- Lasts for hours
- Can cause toxicity and cell death
under certain circumstances.
81
lissamine green
```
– Colorant in the food
industry
• Stains desiccated and dying
cells on the ocular surface.
• No burning or stinging
sensation like with rose Bengal.
• Needs good technique to see
stain
• Supervital stain that combines the
diagnostic advantages of fluorescein and
rose bengal.
• Stains healthy epithelial cells when they
are not protected by a mucin layer in a
manner similar to rose bengal. It also
stains dead or degenerated cells like
fluorescein.
Set proper illumination levels.
• Too intense or bright will diminish the
contrast and underestimate the degree of
staining.
– (consider red filter Wratten 25)
• View will be washed out with normal
illumination.
• Start with a low illumination and increase
the level until the lissamine green staining is
most visible may be the best method.
```
82
schirmer test
tear quantity test
– Prepare a filter paper (5mm x 35mm with folded end) folding the end.
– Gently dry the eye.
– Apply Schirmer hooked end onto the LL margin at the lateral canthus
NOT touching the cornea ( ask pt to look up and nasal to insert)
– Tell patient to keep their eye open and blink normally ( give a straight
ahead target)
– After 5 min, Measure the amount of wetting on the filter:
• 13-15mm wetting rules out a dry eye
• 6-10mm is borderline
• less than 6mm indicates dry eye. Higher or wetting all strip before 5 min is by
reflex ( unreliable )
– The filter paper strips can cause reflex tearing and may require the use
of anesthetic agents. (Schirmer II)
Schirmer is a Whatman no.41 filter paper 5mm wide x 30 mm long ( or
50)
Fold the “head” that is 5mm long
If too much irritation, instill anesthesia- now you are measuring the
basal reflex only ( reflex by irritation gone)
83
Phenol Red test
```
• A cotton thread impregnated
with phenol red dye
• Phenol red is pH sensitive and
changes from yellow to red
when wetted by tears.
• 70mm long thread and its end
is placed in the lower
conjunctival fornix.
• After 15 seconds, the length of
the color change on the thread -
indicating the length of the
thread wetted by the tears (in
mm).
• Normal tear quantity: 9mm to
20mm.
• Dry eye :less than 9mm.
```
84
tear prism height test
Observe the height of upper and lower tear meniscus ( tear
prism) with the SL
• Measure the tear meniscus of the LL , but avoid excessive or
prolonged use of the illumination (prevent artificial drying of
the tear prism).
• Compare the tear prism height with the illuminated slit width
by setting the slit horizontally in alignment with the lower lid
margin, altering the slit width until it appears to match the
height of the tear prism.
• Heights of less than 0.2mm indicate reduced tear fluid
quantity.
• A regular tear meniscus is typically observed in a healthy eye
while a meniscus with a scalloped edge is often associated
with a dry eye
85
conjunctival impression cytology
millipore filter paper of cellulose acetate is cut into strips. proparacain is instilled in eye and then the paper is pressed against the nasal, t,i and s conj. pressure is applied for 2-3 secs. paper then put for 10 mins in 70% ethyl alcohol, 37% formaldehyde ad glacial acid and then stained with PAS. this is then evaluated under light microscope for epithelial cell morphology and density .
86
Dry eye tx
```
pt. education
• Tear Substitutes
• Mucolytic Agents
• Punctal occlusion
• Anti-inflammatory agents
• Contact lenses
• Conservation of existing tears
• Other options
• Topic Anti-inflammatory drops if inflammation
• Lipid base Tears
• Fish oil
• Doxycycline for very symptomatics
• Pulse therapy
• Autologous serum
```
87
collagen plugs insertion
in canaliculus, decreases excretion of tears by 60-80%. dissolved in 7-10 days. 2.0 mm in length different size diameters
88
procedure of collagen punctum plug
• Anesthetize the punctum
• Prepare the collagen implant for insertion
• Remove implant from foam package with jeweler’s forceps
• Naked eye vs slit amp
• Return rest to the package
• Position the patient in slit lamp, directing patient’s vision upward
• With one hand, expose the inferior lid margin
• punctum exposed (not total eversion)
• Holding the implant with the jewelers forceps in the other hand, slowly
approach the punctum, lining up the implant with the punctum opening
• Never perpendicular to the eye
• Insert the implant into the punctum as far as possible
• To position the implant all the way into the canaliculus
• release the forceps so the implant rests in the punctum
• close the forceps
• holding the tips closed, gently push the implant into the punctum until it is
flush with the lid margin
• push the implant further down into the canaliculus until it disappears from
sight
• After all the desired implants are placed, reevaluates the punctums to
ensure that the implants are in correct position
• As prophylaxis
• one drop of topical antibiotic can be instilled in-office
• Ex. Gentamicin, Polytrim
• Patient should be reexamined about 10 days after insertion to
ascertain if the implants have been beneficial
• If patient complains of epiphora, then he’s not a candidate for permanent
implants/punctum occlusion
89
pressure patching
• Immobilizes the eyelid to reduce discomfort and promote healing
• Major indicators:
• corneal injuries and corneal epithelium compromise
• Protection
• after ophthalmic surgery like Chalazion or Pterygium Excision
• amblyopia therapy
• F/U 24 hrs
• Need:
• sterile gauze eyepads
• hypoallergenic tape of 1 inch
• alcohol swabs
• Depending on the case also needed proparacaine 0.5%, mydriatic /cycloplegic (ex. Homatropine)
topical ophthalmic antibiotic (ex. Erythromycin)
• Recline chair or patient’s head.
• Instill proparacaine 0.5%, instill mydriatic/cycloplegic drop and
make sure pupil is dilated
• Will decrease discomfort and reduce chances of secondary traumatic
anterior uveitis
• Place small ribbon of AB ointment into the inferior cul-de-sac.
• Wipe skin of cheek and forehead with alcohol swab
• Tape will adhere better
• Ask to keep both eyes closed
• PP: Pressure Patching-
• Fold one patch in half and place over the closed eyelid.
• Place a second and third over it (wo folding) aligned with the nose ridge
and the ear.
• Place a micropore tape
• one end at the midpoint of the forehead
• Ask patient if he/she can see or can open that eye.
• The others diagonally to the cheek and top of mandible ( tape is ~ 6 -7
inches long)
• Close to the nose bridge and overlapping the first tape.
• Curve it so it follows and covers the superior and lateral edges of the
patch. Continue until you cover all the area.
• Keep tape away from nasolabial fold and side of mouth to let patient eat
and talk.
• You can pinch the cheek upward where the tape will be placed and this
increases the pressure of the patch
• Prescribe analgesic if patient is in considerable discomfort
• Reexamine in 24 hours.
• Advise not to wet the PP, therefore showers are not indicated.
• Advise eye will feel worst once the anesthesia wears out
• To remove the PP lift tape from bottom toward forehead.
