Blinking, Eyelids, Blepharitis

List the 2 main functions of blinking

- protects ocular surface

- promotes even spreading of tears across the eye

List the 3 different types of blinks

- spontaneous

- reflex

- voluntary

Blink rate is under _________ control and is influenced by ___________, _____________. and ___________ factors

under cortical control

influenced by:

- external

- psychological/physiological

- activity-related

Blink rate (increases/decreases) with reading

decreases

The more intense the task, the (smaller/larger) reduction in blink rate there is

larger reduction

Blink rate (increases/decreases) in Parkinson's disease

decreases

Blink rate (increases/decreases) in ADHD

decrease

Blink rate (increases/decreases) with conversation

increases

Blink rate (increases/decreases) in neuro-developmental conditions

increases

Blink rate (increases/decreases) with anxiety and anger

increases

Blink rate (increases/decreases) in Schizophrenia

increases

Which nerve & branches control the upper lid

- ophthalmic division of trigeminal nerve (CNV1)

branches:

- supraorbital nerve

- supratrochlear nerve

- lacrimal nerve

Blink rate (increases/decreases) with excitement

increase

Which nerve & branches control the lower lid

- maxillary division of the trigeminal nerve

branches:

- zygomstic nerve

- infraorbital nerve

We experience a Spontaneous Eyeblink Rate (SEBR) of ___-___/ minutes while resting

12-16 blinks/min

SEBR (increases/decreases) by up to ____% while reading typical text

decreases up to 50%

SEBR (increases/decreases) by up to ____% while on digital devices

decreases up to 75%

SEBR (increases/decreases) in dry eye px

increases

Optical performance of tear film starts to degrade __-__ seconds after a blink

4-5 seconds

Approx. how fast is a spontaneous blink

100ms/sec

List the 4 phases of a spontaneous blink

- downstroke

- turning point

- upstroke

- inter-blink interval

Movement of the upper lid is controlled by what 2 muscles

- orbicularis oculi muscle (OO)

- levator palpebral superior muscle (LPS)

When the eye is (open/closed) there is a balance between the OO and LPS muscle

open

When the downstroke phase of a spontaneous blink is initiated, the (OO/LPS) is inhibited and the (OO/LPS) contracts

LPS inhibited

OO contracts

Both the OO and LPS muscles are inactive at which phase of a spontaneous blink

turning point

To initiate the upstroke phase of a spontaneous blink, the (OO/LPS) resumes in a tonic state and the (OO/LPS) contracts to raise the lids

OO resumes tonic state

LPS contracts

Which muscle is responsible for maintaining the elvation of the upper eyelid between blinks

Muller's muscle

During a spontaneous blink, the lower lid shows a horizontal displacement toward (nasal/temporal) canthus

nasal

What is the hypothesized benefit of the lower lid showing nasal displacement with spontaneous blink

may provide a shearing force to remove debris from the lid margins maintaining MG orifice integrity

(T/F) In a complete blink, the central portion of upper and lower lid touch

FALSE

they do not touch, there is an"overblink"

central upper lid overlaps the lower

(think of it as an overbite)

Describe the term overblink

with spontaneous blink, the central upper lid overlaps the lower resulting in a 0.4mm-0.7mm space posterior to the inner upper lid as it rests over the lower lid lashes

Degree of upper lid overblink (increases/decreases) with age

increases

(skin gets looser)

What role does capillary bridging play in tear mixing

even with over-blink, if tear volume adequate, central lower lid tear meniscus fuses w/upper lid meniscus before "closure" via capillary bridging (water attracting water)

(T/F) If central tear menisci are not brought close enough for bridging, there is guaranteed insufficient tear mixing

FALSE

paracentral capillary bridges may still be able to promote sufficient tear mixing

In normals, upwards of ____% of blinks cover <50% of exposed cornea and ____% of blinks cover <75%

20% cover <50%

45% cover <75%

How does high incomplete blink rate contribute to a higher degree of MG atrophy

lack of complete closure may decrease flow of meibum from MG orifices due to decreased pressure from orbicularis and muscle of Riolan

List 2 common pt complaints that may cause you to think noctural lagophthalmos as a dx

both upon waking:

- FB sensation

- epiphoria

≈___% of symptomatic DE patients have some degree of incomplete closure

≈ 60%

(T/F) Long term inflammation will induce architectural changes to the lid margin

TRUE

Architectural changes in the lid margin is a sign of (acute/chronic) inflammation

chronic

What do telangiectasia on the lid margin signify

new blood vessels developing in response to chronic inflammation

What is Madarosis

loss of lashes and brow hair

What is Milphosis

loss of lashes (only)

What is trichiasis

turning in of the eyelashes

(T/F) Average lid positioning is a at the lower limbus

TRUE

scleral show is not necessarily normal

What is a concretion

degenerating epithelial cells and protein secretion that forms from a small amount of debris getting lodged in the glands of the conj, debris then undergoes calcification

Concretions are present in ___-___% of the population and are generally (sx/asx)

40-50%

asx

Concretions are more common in dry eye px due to:

chronic inflammation

less than ___% of concretions will erode through and cause discomfort or epithelial insult

<10%

(T/F) Eroded concretions stain bright yellow with NaFl

TRUE

List 2 common comorbidities that are seen with floppy lid syndrome

- KCN

- OSA

Give the simple definition of Blepharitis

inflammation of the eyelids

(T/F) There is significant overlap b/w blepharitis and ocular surface disease

TRUE

(T/F) Sequelae of blepharitis-induced lid pathology will exacerbate any coexisting ocular surface disease

TRUE

In its most basic sense, Blepharitis refers to:

an inflammation of the eyelids

Anterior Blepharitis typically refers to:

pathology affecting base of lashes and lid margin anterior to gray line

Posterior Blepharitis typically refers to:

Meibomian Gland Dysfunction

The most common cause of Anterior Blepharitis is:

overgrowth of Staphylococcus

The exact mechanism of Anterior Blepharitis is uncertain, but list the 3 proposed mechanisms

• Direct bacterial infection

• Exotoxin hypersensitivity

• Delayed cell-mediated immune hypersensitivity

Staph bleph more common in (younger/older) patients

younger

Anterior blepharitis leads to what 4 things

- chronic inflammatory response

- lid hyperkeratinization

- decreased MG function

- corneal defects/infiltrates

List 3 causes of Anterior Blepharitis

- overgrowth of staph

- seborrhea

- rosacea

Seborrhea bleph more common in (younger/older) patients

older

The __________ on the lid correspond to the most superficial portion of the orbicularis muscle

gray line

List 6 signs and sx of Staph Blepharitis

- matted, hard scales

- lash loss/misdirection

- lid margin thickening & erythema

- Telangiectatic changes of vessels

- Hx of hordeola/chalazie

- inferior corneal pathology

_________ blepharitis presents with matter, hard scales

staph bleph

_________ blepharitis presents with oly and greasy deposits and scales

seborrheic bleph

(staph/seb) bleph has more inflammation

staph

(staph/seb) bleph has more talengectasic changes

staph

(T/f) Lash changes can be commonly seen in seborrheic bleph

FALSE

lash changes are uncommon except in long-term disease

____% of seborrheic blepharitis presents in px with seborrheic dermatitis and of the face and scalp

95%

Pathologic bacteria can trigger release of __________ and ___________ resulting in an inflammatory cascade

exotoxins and lipopolysaccharides

Staph aureus seen in ≈ ____% normals and ≈ ___% w/ bleph dx

8% normals

50% bleph

Staph epidermidis seen in ≈ ____% normals and ≈ ____% w/ bleph dx

>90% normals

>90% bleph

List the 4 broad tx options for blepharitis

• Lid hygiene

• Antibiotics

• Anti-inflammatories

• Antiseptics

It is important to educate your blepharitis pt on the (acute/chronic) and (curable/incurable) nature of their conditions

chronic

incurable

__________ ___________ lid scrubs are used as bleph tx to debulk the biofilms forms with bacterial colonization

mechanical surfactant lid scrubs

What is the purpose of having surfactant based lid scrubs

they are designed to strip the oils off of the skin of the lids

In the study performed comparing SterLid cleanser vs baby shampoo...

describe the changes in MG capping

SterLid = unchanged

Shampoo = increased

In the study performed comparing SterLid cleanser vs baby shampoo...

describe the changes tear film MMP-9 levels

SterLid = decreased

Shampoo = unchanged

In the study performed comparing SterLid cleanser vs baby shampoo...

describe the changes in MUC5AC expression

SterLid = unchanged

Shampoo = decreased

What is the benefit of having a lid scrub decrease MMP-9 levels in the tear film

MMP-9 is a pro-inflammatory cytokine involved in ocular surface inflammation and integrity of tight junctions of corneal epithelial cells

What is the benefit of a lid scrub leaving MUC5AC expression unchanged

MUC5AC is a mucin specific to conjunctival goblet cells and its expression is a measure of goblet cell density and function

Ocular surface inflammation and hyperosmotic stress can compromise goblet cell integrity and reduce MUC5AC expression

Baby shampoo is not used as commonly as a lid scrub anymore, why

study findings suggests potential presence of pro- inflammatory mechanism

(d/t decrease in MUC5AC expression and worsening of MG capping)

Lid scrubs usage should be limited to ____ times a day

2 times a day

Why is antibiotic therapy not the best choice of tc for staph bleph

bleph is an inflammatory condition not an infection

so decreasing the staph on the lids does help a bit but not a ton

AzaSite is used off-label for bleph tx, but it is FDA approved for:

bacterial conjunctivitis in children

List 3 pros and 2 cons of Azasite as a bleph tx

pros:

- low level anti-inflammatory properties

- penetrates conjunctival tissue and epithelium of the outer eyelid

- antibiotic effect lasting up to 6 days with a single drop

cons:

- not commonly in formulary of pharmacies

- expensive... $250 for a 2.5ml bottle

After application of topical Azasite, pt are instructed to:

rub residual drop into eyelids

What is the anti-inflammatory mechanism of Doxycycline

decreasing release of pro-inflammatory cytokines and decreasing MMP-9 activity

List the 5 negative aspects of Doxycylines to consider when prescribing as an oral medication

- serious interactions with many other drugs

- contraindicated during pregnancy

- contraindicated in kids <8yo

- long list of adverse effects both mild and severe

- foods/supplements containing calcium reduce absorption

List the 5 serious side effect that can be seen with Doxycyclines

- Stevens-Johnson Syndrome

- Idiopathic Intracranial Hypertension

- Esophagitis

- Anemia

- Pancreatitis

Foods/supplements containing ___________ reduce absorption of Doxycylines

calcium

Doxycylines cannot be taken with _____________ or _________

dairy products

antacids

(T/F) Studies suggest that a Z-pak may be as effective as 1mo doxycycline

TRUE

Z-Paks have a very small increase in risk of:

cardiac arrhythmia and heart death

(T/F) Topical steroids are effective for chronic blepharitis tx

FALSE

effective for flareup/exacerbations but not indicated for chronic treatment

not safe to keep a pt on steroids for a long time

Hypochlorous acid is naturally produced in the human body by ___________ as part of the _______________ system

produced by neutrophils

as part of the cytotoxic myeloperoxidase system

List the 4 in vitro actions of Hypochlorous Acid against bacteria

- causes oxidation of nucleotides

- inactivation of cell enzymes

- disruption of cell membranes

- rapid cell lysis

(T/F) Hypochlorous Acid has minimal cytotoxic effects on normal cells

TRUE