Block 15: Lectures 1-3 Flashcards
Which type of herpes simplex virus commonly involves the eye?
Type 1
When does primary infection of HSV typically occur?
childhood
Is treatment more likely to be indicated in primary or secondary infection of HSV?
secondary
Where does the latent herpes simplex virus reside?
sensory ganglion for the dermatome that was infected by primary infection
What are 4 possible causes for reactivation of HSV?
Fever, hormonal change, UV radiation, trauma
For a patient who has had a large number of previous recurrent attacks of HSV, does their chance of future recurrences increase or decrease?
Increase
Which stage of HSV (primary or secondary) does the virus replicate?
Secondary
What portion of the corneal ulcer does Rose Bengal stain in HSV Epithelial Keratitis?
Virus-laden cells at margin of ulcer
What portion of the corneal ulcer does Fluorescein stain in HSV Epithelial Keratitis?
Bed of dendritic ulcer
Is corneal sensation increased or decreased in HSV Epithelial Keratitis?
Decreased
What specific affect may steroids have on an ulcer in HSV Epithelial Keratitis?
Ulcer to enlarge to geographical or amoeboid appearance
Does HSV Epithelial Keratitis occur with “active” or “inactive” viral replication of HSV?
Active
A corneal ulcer caused by HSV Epithelial Keratitis heals w/o treatment, what may result?
Increased scarring and vascularization
What is the most common treatment given for HSV Epithelial Keratitis?
Acyclovir ointment or ganciclovir gel 5x/day (anti-virals)
What are two alternatives for treating HSV Epithelial Keratitis if the patient does not respond to topical anti-virals?
- Debridement of ulcer
2. Oral anti-virals
What type of IOP-lowering medications should be avoided in HSV Epithelial Keratitis?
Prostaglandin derivatives
How long does it typically take for corneal ulcers to heal with anti-viral treatment in HSV Epithelial Keratitis?
99% heal within 2 weeks
What often lingers for weeks after the ulcer heals in HSV Epithelial Keratitis?
Sub epithelial haze
What can eventually threaten vision in HSV Epithelial Keratitis?
Persistent sub epithelial haze in recurrent cases
What type of medication (general) should be avoided in HSV Epithelial Keratitis?
Steroids
What is the most common cause of infectious corneal blindness in developed countries
Herpetic eye disease
What should be performed or considered on any unilateral red eye?
Corneal sensitivity test
What step of secondary infection/reactivation of HSV is Epithelial Keratitis associated with?
Active viral replication
What does the presence of HSV Stromal Keratitis indicate? 2 answers.
- Immune-Mediated response to the reactivation of HSV
2. Active viral replication within stroma
Diffuse or focal infiltration of stroma without a dendritic ulcer is a common sign of what?
HSV Stromal Keratitis
What is a common treatment regimen for HSV Stromal Keratitis?
Topical steroids + oral antiviral
List three potential signs seen in progressed HSV Stromal Keratitis?
- Scarring (opacification)
- Thinning
- Vascularization
A frequent form of recurrent HSV keratitis that is thought to be an immune reaction is known as ________?
Disciform endothelitis
Which form of Keratitis presents with a complaint of “haloes around lights?”
Disciform endothelitis
How can visual loss usually be reversed in Disciform Endothelitis?
Steroid drops
What sign is present before a dendritic ulcer in HSV Epithelial Keratitis?
Swollen and opaque epithelial cells arranged in punctate or stellate pattern
What is commonly used as initial treatment in Disciform Endothelitis?
Steroid drops + antiviral
What is thought to be the cause of Neurotrophic Keratopathy?
Persistent non-healing corneal epithelial defects due to damaged nerves and reduced corneal sensation (hypesthesia or complete anesthesia) in HSV Keratitis.
What would make oval defects in neurotrophic keratopathy worse?
Antiviral drops
Uveitis associated with HSV mandates a thorough funduscopic exam to exclude _______?
Acute retinal necrosis
What are 2 potential cause of an acute elevation in IOP in Iridocyclitis?
- Acute trabeculitis
2. Steroid-induced
How is an acute rise in IOP due to acute trabeculitis in Iridocyclitis treated?
Steroids and often antivirals
What can cut recurrence rate of HSV epithelial and stromal keratitis in half?
400 mg oral acyclovir bid taken for years prophylactically
When is prophylaxis treatment indicated in HSV keratitis?
Frequent, severe recurrences in monocular patients
What type of secondary infections (general) most often complicate HSV Keratitis?
bacterial
What are 2 risks associated with keratoplasty in HSV Keratitis?
- Rejection of the corneal graft is common
2. Recurrence of herpetic eye disease common
What is Hutchinson Sign and what does it signify?
Shingles involving skin supplied by external nasal nerve - tip, side, and root of nose.
Significance: Correlates strongly with ocular involvement
What nerve is most often affected in Herpes Zoster Ophthalmicus?
Ophthalmic division (V1) of trigeminal nerve (CN5)
A 3-5 day phase of tiredness, fever, malaise and headache followed by a unilateral painful rash is most likely ____?
Herpes Zoster Virus (Shingles)
What virus causes shingles?
Reactivation of varicella-zoster virus
What can protect against the development of shingles?
Re-esposure to VZV via contact with chickenpox or vaccination to reinforce immunity
If clinical observations in a patient with shingles are not clear, how can a diagnosis be determined?
Vesicular fluid sample sent for PCR
What is the best treatment option for most cases of Shingles?
Oral antivirals - 800 mg acyclovir 5x/day for 5-7 days
What is the best window of time to start treatment of shingles?
Within 72 hours
Who should a person infected with Shingles avoid?
Why?
- Pregnant women
- Immunodeficient individuals
Shingles is contagious and can spread chickenpox
A dendritic epithelial ulcer in herpes zoster ophthalmicus signifies what stage of the disease?
Early/Middle - occurs soon after rash
Only about 5% of patients infected with herpes zoster ophthalmicus develop ______ weeks after rash?
Stromal (interstitial) keratitis
What may be a cause of elevated IOP in Herpes Zoster Ophthalmicus?
Anterior uveitis
List 4 possible complications of Herpes Zoster Ophthalmicus?
- Neurotrophic keratitis
- Scleritis
- Lid scarring
- Post-herpetic neuralgia
What is post-herpetic neuralgia?
Pain more than a month after shingles rash heals
Which form of Acanthamoeba Keratitis is highly resilient?
Cystic form
What is a common association with Acanthamoeba Keratitis in USA?
Contact lenses rinsed with tap water
What form of Acanhamoeba Keratitis can cause tissue penetration/destruction?
Cysts that have turned into trophozoites
Perineural infiltrates or “Radial Keratoneuritis” is essentially pathognomonic for ______?
Acanthamoeba Keratitis
Blurry vision and discomfort/pain that is more significant than the clinical signs may represent _______?
Acanthamoeba Keratitis
What stage might corneal melting occur in Acanthamoeba Keratitis?
Any stage
What are early stages of Acanthamoeba Keratitis often mistaken for?
Herpes simplex keratitis
What corneal infection should be considered any time there is limited response to antibiotics?
Acanthamoeba Keratitis
What can be done to facilitate penetration of drops to treat Acanthamoeba Keratitis?
Debridement of epithelium
How often are topical amoebicides administered when treating Acanthamoeba Keratitis?
Initially hourly and then gradually decreased and continued for months
How are Acanthamoeba cases involving either late scarring, perforation, or drug-resistant managed?
Penetrating keratoplasty
How is pain controlled in Acanthamoeba keratitis?
Oral NSAID
In Onchocerciasis, what is necessary within the adult worm for the production of microfilariae?
Wolbachia
What is the role or microfilariea in an individual infected with Onchocerciasis?
Microfilariae produce an intense inflammatory reaction
Snowflake opacities with infiltrates surrounding dead microfilariae might suggest what corneal infection?
Onchocerciasis (river blindness)
What population is most affected by Onchocerciasis?
Africa - especially severe in savanna regions
Which layer of the cornea are initial lesions most commonly found in Onchocerciasis?
Anterior 1/3 of stroma at 3:00 and 9:00
What affect on the pupil could posterior synechiae due to Onchocerciasis have?
Pear-shaped pupillary dilation
What annual vaccine is given in areas where Onchocerciasis is endemic to kill the microfilariea and reduce spread of the disease?
Ivermectin
What medication can be given to target Wolbachia in Onchocerciasis?
Doxycycline
How is anterior uveitis treated in Onchocerciasis?
Steroids
What causes marginal keratitis?
Hypersensitivity reaction to staphylococcal exotoxins and cell wall proteins that causes a lymphocytic infiltration (not infectious)
How is the region between peripheral corneal infiltrates and conjunctival hyperemia described in Marginal Keratitis?
“Clear zone”
In what way/pattern do infiltrates tend to spread in marginal keratitis?
Multiple coalesce/enlarge and spread circumferentially
How is the discomfort/pain described most often in marginal keratitis?
Mild
In addition to the corneal involvement in Marginal Keratitis, what associated feature must always be treated if present?
Blepharitis
What effect/sign can occasionally be seen after resolution of marginal keratitis?
Residual superficial scarring/pannus (vascularization)
What is the name of a nodular inflammation of the cornea due to hypersensitivity reaction to a foreign antigen?
Phlyctenular Keratitis
Which age group primarily shows the common symptoms in Phlyctenular Keratitis?
6 months to 16 years old
Where is the nodule typically located in Phlyctenular Keratitis?
Limbus
What non-corneal feature is commonly associated with Phlyctenular Keratitis?
Intense local conjunctival hyperemia
What are 2 common systemic associations with Phlyctenular Keratitis in under-developed countries?
- TB
2. Helminthic infestation
What can a nodule in Phlyctenular Keratitis lead to?
Ulceration
After spontaneous healing of the nodule in Phlyctenular Keratitis, what can often be expected?
Scar, superficial vascularization, and thinning
What can be prescribed to speed healing and decrease the inflammatory response in Phlyctenular Keratitis?
Topical steroids with or without topical antibiotic
How can the source of antigens be decreased in Phlyctenular Keratitis?
Treat blepharitis or underlying infection
What defect is suspected as part of the multifactorial cause of Rosacea?
Defects in the body’s immune response to common skin and GI pathogens and abnormal vasoregulatory processes
What feature can distinguish Rosacea from Acne?
Comedones (blackheads or whiteheads) are absent in Rosacea
Where are punctate epithelial erosions often located in Ocular Rosacea?
Inferiorly
What are 2 common signs of Ocular Rosacea affecting eyelids?
- Marginal telangiectasia
- Meibomian gland dysfunction
What is typically used as a first step in treating mild signs of Ocular Rosacea?
Lid hygiene and preservative-free artificial tears
What can be prescribed to improve meibomian gland secretions by decreasing bacterial lipase and also protect cornea from perforation by inhibiting collagenase?
Oral tetracyclines given at lower dose than used to achieve antibiotic effect
If lid hygiene and artificial tears are not sufficient to manage Ocular Rosacea symptoms, what might the next step be?
Anti-inflammatory medications - Oral tetracyclines most common and effective
What is the goal in management/treatment of Rosacea?
Managing symptoms and avoiding flare triggers since there is no cure
What is the name of a focal autoimmune disorder isolated to the eye?
Mooren’s Ulcer
Mooren’s Ulcer can be seen in both elderly and younger individuals, but the form of the disorder varies between the two. Which form may affect both eyes and is more aggressive?
Form that affects younger individuals
What is a distinguishing ocular sign between Mooren’s Ulcer and Peripheral Ulcerative Keratitis with Systemic Autoimmune Disease?
Scleritis is not present in Mooren’s Ulcer, but can be present in PUK
How may Mooren’s Ulcer be initially treated?
Frequent topical steroids (hourly)
Where is the ulceration typically located in Mooren’s Ulcer?
Peripheral stromal and progresses circumferentially, sometimes towards center
In Peripheral Ulcerative Keratitis associated with systemic autoimmune disease present ocular signs/symptoms before or after the systemic autoimmune symptoms have appeared?
PUK can present before or after systemic autoimmune symptoms
A crescent shaped destructive lesion (ulceration) located at the juxtalimbal corneal stroma, usually with neighboring scleritis is most likely ______?
Peripheral Ulcerative Keratitis with associated systemic disease.
Which associated systemic disease is most commonly seen in Peripheral Ulcerative Keratitis?
#1 Rheumatoid arthritis #2 Wegener's Granulomatosis
What type of treatment is often needed to control ocular inflammation in Peripheral Ulcerative Keratitis with associated systemic disease?
Systemic immunosuppression from rheumatologist
What other disease may look clinically similar to Terrien’s Marginal Degeneration?
Corneal Arcus (Arcus Senilis)
Non-inflammatory peripheral thinning of cornea due to degeneration that results in a peripheral gutter
Terrier’s Marginal Degeneration
What are 3 features of Terrien’s Marginal Degeneration that can help differentiate it from other corneal thinning disorders?
- Lack of both inflammation and epithelial defect
- Slow progressive course
- Linear deposition of lipid
What type of treatment is most often needed for Terrien’s Marginal Degeneration?
Most often no treatment required
What is it called when there is loss of trigeminal innervation to the cornea with epithelial breakdown and persistent ulceration, resulting in partial or complete anesthesia?
Neurotrophic Keratopathy
Thickened and rolled edges around defects on cornea in Neurotrophic Keratopathy probably resemble what?
Non-healing epithelial defects
Why does progressive stromal melting have minimal discomfort in Neurotrophic Keratopathy?
Due to loss of trigeminal innervation to cornea
What should be discontinued, if possible, when attempting to treat Neurotrophic Keratopathy?
All eye drops, except preservative-free artificial tears
What kind of medication could be prescribed to an individual with Neurotrophic Keratopathy and a high concern for perforation?
Anti-Collagenase medication
What can result from lagophthalmos with drying of cornea, despite normal tear production?
Exposure Keratopathy
Where are punctate epithelial changes most commonly seen in Exposure Keratopathy?
Inferior 1/3 of cornea
If Exposure Keratopathy is not severe and is reversible, what are 3 treatment options?
- Lubricants
- Lid taping
- Bandage contact lens
Bilateral disorder with episodic (on/off) appearance of corneal epithelial opacities causing irritation and blur is known as _______?
Thygeson’s SPK
How frequent are steroids used for when managing Thygeson’s SPK?
Low potency twice a day initially. Then tapered to as few as once every 1-2 weeks.
Weak attachments between basal cells of corneal epithelium and its basement membrane can cause what syndrome?
Recurrent corneal erosion syndrome
When is Recurrent Corneal Erosion Syndrome unilateral vs bilateral?
Unilateral: when associated with prior trauma
bilateral: when associated with corneal dystrophies
Why may epithelial defects not be seen on a slit lamp exam in an individual with Recurrent Corneal Erosion Syndrome?
Quick healing rate of epithelium
What are 2 basement membrane disturbances that may be seen in Recurrent Corneal Erosion Syndrome?
Microcysts and swirls
What treatment regimen has been shown to reduce the frequency of Recurrent Corneal Erosions?
50 mg Doxycycline twice a day + topical corticosteroid (Prednisolone acetate) 2-3 times per day for three weeks
What 3 procedures may be considered for frequent recurrent cases or corneal erosion syndrome?
- Anterior stromal puncture
- Diamond bur polishing
- Phototherapeutic keratectomy
What condition describes strands of mucus and cellular debris attached to the epithelial surface?
Filamentary Keratopathy
What can be given in Filamentary Keratopathy to break up mucus strands on the eye and reduce their formation?
Acetylcysteine drops
What is deficient in Xerophthalmia?
Vitamin A
Nearly 50% of world’s population with Vitamin A deficiency and Xerophthalmia are from where?
South and Southeast Asia
What role does Vitamin A play in the eye?
Maintains the integrity and proliferation of epithelium of conjunctiva and cornea
What photoreceptor protein is vitamin A a precursor to?
Rhodopsin
Which is more sensitive to deficient Vitamin A, rods or cones?
Rods - affecting night time vision first
How is Xerophthalmia treated systemically?
Oral or injected Vitamin A supplementation
How are the ocular components of Xerophthalmia treated?
Intense lubrication
