Cornea Flashcards
1
Q
What is the refracting power of the cornea?
A
40-44D ~2/3rd refracting power of the eye
2
Q
Ehlers-Danlos Syndrome
- Features? Characteristics?
- 6 Major forms?
- Ocular findings
- Systemic findings?
A
- Systemic collagen disorder
- Features
- Hyperextensible joints
- skeletal abnormalities
- Blue sclera
- Mottled teeth
- Neurosensory deafness
- 6 major forms
-
Type VI (Kyphoscoliosis) - most ocular involvement ***
- AR deficiency in enzyme responsible for collagen stability & strength
-
Ocular findings
- Scleral fragility
- Risk of globe rupture
- KCN
- Retinal detachment
- Glaucoma
-
Systemic findings
- Muscle hypotonia
- Joint laxity
- Kyphoscoliosis & other skeletal changes
- Abnormal skin
-
Type VI (Kyphoscoliosis) - most ocular involvement ***
3
Q
Band Keratopathy
- What does it look like?
- Causes?
- Symptoms?
- Treatment?
A
- Interpalpebral deposition of calcium phosphate salts in bowman’s membrane
- Begins peripherally & moves centrally
- 3 & 9
- Starts grey, becomes chalky white
- Clear intervening zone between peripheral edges & limbus
-
Swiss cheese pattern
- Represent corneal nerves that penetrate Bowman’s layer
- Late stage progresses anteriorly through epithelium
-
Causes
- DES
- Chronic exposure
- Chronic inflammation
- Uveitis
- Pthisis bulbi
- Interstitial keratitis
- Long-standing glaucoma
- Repeated trauma
-
Underlying systemic disease
- Hyperparathyroidism
- Vitamin D toxicity
- Sarcoidosis
- Paget’s disease
- Multiple myeloma
- Metastatic cancer to bone
- Norrie’s disease
-
Symptoms
- Asymptomatic
- Decreased VA
- Pain
- FBS
- Epithelial erosions
-
Treatment
-
Lubrication
- Drops
- Drops Gels
- Ointments
- BCL
- RGP/Scleral lenses for induced astigmatism correction
- Chelation with EDTA & superficial keratectomy (corneal scraping)
- PTK
- Reserved for recurrent or advanced cases
-
Lubrication
4
Q
Disciform endotheliitis
A
- Most common presentation
-
Symptoms
- photophobia
- Mild to moderate discomfort
- Decreased vision possible
- Many cases self-limited
-
Presentation
- Limbal injection
- Round area of stromal edema
- Central paracentral
- Entire thickness of stroma involved
- Overlying microcystic edema to bullae formation
- Iritis
- Elevated IOP
- Responds well to tx
5
Q
Lattice dystrophy
- Characteristics?
- Symptoms?
- Treatment?
A
- AD inheritance
- TGFB1 gene mutation
- Presents 1st decade
- Primary, localized corneal amyloidosis
- Begins with development of refractile lines in anterior stroma which progressives to stromal opacification
-
Symptoms
- Blurred vision
- Corneal erosions
-
Treatment
- Bandage CL
- PK
- Tends to recur in graft
6
Q
Salzmann’s Nodular Degeneration
- Statistics?
- Associations?
- What does it look like?
- Symptoms?
- Complications?
- Treatment?
A
- Female >> males
- 72-88%
- Caucasian
- 6th decade
- Bilateral
- 58-67%
-
Associations
- Idiopathic
- Corneal inflammatory disease
- MGD, ocular rosacea
- Phlyctenular disease
- Vernal keratoconjunctivitis
- Trachoma
- Interstitial keratitis
-
Yellow-white to blue elevated nodular lesions
- Single or multiple
- Usually in annular pattern in mid periphery
- Adjacent to corneal scars or pannus
- Iron lines may be present surrounding lesions
- Vascularization may be adjacent to lesion
-
Symptoms
- Asymptomatic 15%
- FBS
- Possible to develop epi-erosions over lesions →
- Pain
- Lacrimation
- Photophobia
- Decreased VA possible if nodule over visual axis
-
Complications
- Corneal erosion
- Photophobia
- Blepharospasm
- Lacrimation
- Corneal Irregularity
- Hyperopic shift
- Irregular astigmatism
-
Treatment
- Lubrication
- Warm compressess
- Lid hygiene
- Topical steroids
- Superficial keratectomy (Super-K)
- Lamellar or penetrating keratoplasty
- Recurrence possible
7
Q
Senile Furrow Degeneration
- What does it look like?
- Where does it occur & diameter?
- Symptoms?
- Treatment?
A
- Rare, idiopathic
-
Shallowing thining in the avascular zone between acrus senilis & limbus in elderly pt
- Occurs circumferentially
- <0.5mm width
- Shallow
- No visual significance
- No inflammation or vascularization
-
Symptoms
- Asymptomatic
- Not visually significant
-
Treatment
- None
8
Q
Fusarium
A
- Filamentous
- Widely distributed in plants/soil
- Readily colonize on tissue that has been injured by other means
- Thrives in hot, humid environments
- Can grow on improperly cleaned CLs
9
Q
Congenital hereditary stromal dystrophy
- Characteristics?
- Symptoms?
- Treatments?
A
-
AD inheritance
- Cornea clear at birth, clouding begins at 1-2yrs
-
AR inheritance
- opacification appears w/in neonatal period
-
Mutation of DCN gene
- codes for decorin protein
- Non-progressive to slowly progressive
- Thought to be caused by disordered stromal fibrogenesis
- Diffuse haze with flaky lesions in central anterior stroma
- Ground glass corneal apperance
-
Symptoms
- Decreaseed VA
- Dense amblyopia
- Esotropia
- Nystagmus - associated with AR form
-
Treatment
- PK at early age
10
Q
What are the dimensions of the cornea?
A
- 11-12mm H x 9-11 mm V
- 0.5mm centrally
- 0.7mm peripherally
11
Q
Clinical Exams and Diagnostic testing for keratoconus?
A
Clinical Exam
- Assessment of vision: c/o ghosting or smeared images
- Retinoscopy: Scissor reflex retinoscopy
- Refraction: inability to correct vision to 20/20
-
External exam:
- look at lids (including eversion) for signs of atopy
- Munson sign
-
Slit lamp examp
- Thorough corneal evaluation
- Look for surgical scars
- Presence & location of thinning
Diagnostic Testing
-
Keratometry
- Done in normal gaze position - failure to superimpose rings
- Repeat in upgaze (to capture steepest portion of cornea)
- No specific K-value that defines KCN
-
Pachymetry
- Compare thinning to “normal” corneas
- Can achieve with ultrasound or optically pachys
-
Corneal topography
- Placido disk
- Scheimpflug photography (Pentacam)
- Anterior segement OCT
-
Specular microscopy
- show evidence of endothelial cell damage
-
Aberrometry
- Vertical coma is most typical aberration
12
Q
Lab work up for bacterial keratitis?
A
- Indicated in cases where corneal infiltrate is central, large, deep, chronic, or has atypical features suggestive of fungal, amoebic, or mycobacterial keratitis
- Corneal scraping for culturing
- Cytology
- Gram staining
- Susceptibility testing
- Start tx empirically after scraping with broad spectrum & adjust tx once results come in
13
Q
Describe the reactivation infection for Herpes simplex?
A
- Reactivation infection
- Latency in sensory ganglia - ocular infection latency occurs in trigeminal gnaglia
- Viral replication leads to cytopathic effects in cells, or immune response to virion
- Clinical disease varies based on reaction to virus
- Reactivation can occur at any time
- Blepharoconjunctivitis
- Keratitis - epithelial, stromal or endothelial disease
- Uveitis
- Retinitis
- Any ocular structure possible
- Latency in sensory ganglia - ocular infection latency occurs in trigeminal gnaglia
- More likely to cause severe visual consequences from scarring & inflammation
- Essential to make a prompt diagnosis & initiate tx to preserve ocular function
- Careful evaluation of each ocular structure is critical
14
Q
Blunt Force Trauma
A
- Injury from impact of noncutting instrument
-
Contusive: direct impact
- Bruising or fractures
- Concussive: rapid acceleration, deceleration, or oscillation of tissues causing energy transfer to surrounding tissues
- Damage often not localized to only the cornea
- Diffuse endotheliopathy
- Endothelial rings
- Stromal injury & fracture
15
Q
LASEK
A
- Laser epithelial keratomileusis
- Hybrid of PRK & LASIK
-
Procedure
- Epithelium softened with alcohol & rolled back
- Laser ablation of stromal tissue
- Epithelium rolled back into place
-
Benefits
- Reduced post-op haze
- Increase healing time
- Reduce post-op pain
16
Q
Reis-Bucklers Corneal Dystrophy (CBD I)
- Characteristics
- Mutation of which gene?
- Presentation?
- Symptoms?
- Treatments?
A
- AD
- Presents in 1st decade of life
- Born with normal corneas
-
TGFB1 gene mutation
- Subepithelial reticular changes
- Deposits of hyaline-like material that disrupts & may replace bowmans
- Subepithelial reticular changes
- Progress until middle age
-
Presentation
- Fine, reticular superficial opacities
- Become honeycomb-shaped
- Diffuse superfical haze
- Increased central corneal thickness
- Irregular astigmatism
- Decreased corneal sensation
- Prominent corneal nerves visible
-
Symptoms
- Episodic corneal erosions
-
Vision loss
- Irregular astigmatism & opacification
- Occurs early in life
-
Treatments
- Bandage CLs
- Lamellar keratoplasty
- Penetrating keratoplasty
17
Q
Filamentary keratopathy
- Characteristics
- Clinical signs
- Causes
- Symptoms
- Treatment
A
- Women>Men
- Incidence increases with age
- Filaments attach to corneal epithelium
-
Filaments adherent to corneal epithelium
- Loose area of epithelium acts as a focus for deposition of mucus & cellular debris
- Filaments small, gelatinous strands
- Differ in size, composition & distribution
- 0.5-10mm
- Differ in size, composition & distribution
- Location of filament helps assist in diagnosis of underlying cause
- Abnormally high mucous to aqueous
- Aqueous deficiency
- Increased mucin production
Clinical Signs
- Strands of degeneration epithelial cells & mucs that move with blinking, attached at one end to the cornea
- Small epithelial defect may be present at the base of filaments
- Chronic filaments → plaques
- Filaments stain well with rose bengal, less with NaFL
Causes
- Aqueous deficiency DES
- Excessive CL wear
- Corneal epithelial instability
- SLK
- Bullous keratopathy
- Neurotrophic keratitis
- Prolonged or frequent eye closure
- Ocular surgeries
Symptoms
- Discomfort with mild to severe FBS
- Redness
- Occasional photophobia
- Epiphora (overlow of tears)
- Blepharospasm
Treatment
- Treat underlying cause
- D/C all unnecessary medications
- Manual removal of filaments
- Mucolytic agent - acetylcysteine
- Tropical NSAIDs
- Hypertonic saline
- Bandage CL
- Punctal occlusion
18
Q
Spheroidal Degeneration
- What other names is it also known as?
- Statistics? (Men/Women, Bilateral/Uni)
- Etiology?
- What does it look like? Diameter range?
- What are the 3 types?
- Complications?
- Treatment?
A
-
AKA
- Labrador keratopathy
- Bietti nodular hyaline bandshape keratopathy
- Climatic droplet keratopathy
- Proteinaceous corneal degeneration
- Elastotic degeneration
- Fisherman’s keratopathy
- Eskimo’s corneal degeneration
-
Bilateral
- Unilateral, asymmetric cases possible
- Men > Women
- Asymptomatic until crosses visual axis
-
Etiology
- UV exposure
- Microtrauma
- Disease entities associated with neovascularization
-
Clear, to yellow-gold spherules seen in subepithelium, within bowman’s, or in superficial corneal stroma
- Proteinaceous material
- 0.1-0.4mm in diameter
- Continued exposure → coalescence & enlargement of spherules extending deeper corneal stroma & centrally across corneal surface creating a band
- Darken with age: Light yellow → brownish-yellow
- Proteinaceous material
-
3 Types
-
Primary corneal involvement
- Age-related
- Starts nasally → temporally (3&9 o’clock) near limbus
-
Corneal involvements secondary to underlying process
- Previous corneal disease/trauma
- May be diffuse or begin centrally
-
Conjunctival involvement
- May occur with type 1 or 2
- Begins 3 & 9 o’clock on conj
- Lesions smaller & less numerous
- May be present with pinguecula
-
Primary corneal involvement
-
Complications
- Decreases vision
- Epithelial disruptions
- Ulceration of tissue
- Hypoesthetic or anesthetic
- Often become infected
- Cicatricial changes to cornea or conjunctiva
-
Treatment
-
None-asymptomatic
- Observation
- UV protection
- Surgical
- Penetrating keratoplasty (PK)
- Phototherapeutic keratectomy (PTK)
- Excision of conjunctival lesions
-
None-asymptomatic
19
Q
Bacterial Keratitis Presentation?
A
- Depends on causative organism, duration of infection, pre-existing conditions, immune status of pt, & previous drug use (antibiotics, steroids, etc)
- Pain
- Photophobia
- +/- decreased vision
- depends on location of ulcer & severity
- Marked conjunctival injection
- anterior chamber reaction
- +/- Hypopyon
- Pupillary constriction & ciliary flush
- Lacrimation
- Discharge
- Generally mucopurulent
- Tissue loss
- Ragged,irregular epithelial ulceraction with underlying necrotic stroma infiltrations & surrounding epithelial edema
20
Q
DMEK
A
- Descemet’s Membrane Endothelial Keratoplasty
- Transplant of endothelium
- Donor tissue includes Descemet’s membrane & endothelium, doesn ot include stromal tissue
- Benefits
- Improved acuity after surgery
- Improved healing time
21
Q
Note the difference between Terrien’s vs. Senile Furrow Degeneration
A
22
Q
List types of corneal surgeries
- Refractive Surgeries
- Transplants
- Other
A
Refractive surgeries
- LASIK
- PRK
- LASEK
- RK/AK
- Phakic IOLs
- ICL
- Verisyse
Transplants
- PK/PKP
- DALK
- DSEAK
- DMEK
Other
- PTK
- Super-K
23
Q
Corneal Foreign Body
- What is it?
- Presentation
- Symptoms
- Examination
- Treatment
A
- One of the most common ocular traumas
- Often occur at work
- Most often pts not wearing eye protection
-
Symptoms
- Pain
- Photophobia
- Tearing
- Inability to open eye
- Redness
-
Presentation
- Generally obvious FB
- Multiple FBs are common
- Rust ring
- Conjunctival injection
-
Examination
- History: pt specific about injury
- VA: may/may not be reduced depending on location
- SLE: anesthetic, seidel sign, everts lids
- DFE: check for intraocular FB
-
Treatment
-
Superficial
- Removal at slit lamp
- Treat as abrasion
-
Deep/Penetrating
- DO NOT REMOVE
- Protect eye with fox shield
- Send to cornea specialist for surgery
-
Superficial
24
Q
Stromal corneal Abrasions
A
- Uncommon
- Injury extends into stromal tissue = WILL SCAR
- Without flap: treat like epithelial abrasion
-
With flap:
- Smooth: BCL until surface reepithelializes, then
- Rough: sutures
- More likely to need specialty CL fitting or surgical repair
25
Q
Posterior Polymorphous Dystrophy
- Characteristics
- What are the 3 patterns?
- Associations?
A
- AD
- Disorder at the level of Descemet’s membrane & endothelium
- Bilateral, asymmetric
- Presents in 2nd-3rd decade
-
3 patterns
-
Vesicle-like lesions - hallmark **
- 0.1-1.0 mm diameter
- Sharply demarcated round area
-
Band lesions
- typically horizontal with parallel scalloped edges that do not taper at the ends
- Mostly found just inferior to visual axis
-
Diffuse opacity
- Small, macular, gray-white lesions
- Large sinuous geography lesions
- 0.5-2.0mm
-
Vesicle-like lesions - hallmark **
-
Associations
-
Corneal edema
- Minimal stromal thickening to bullous keratopathy
- Unclear if keratoconus or similar variant
-
Corneal edema
-
Symptoms
- Stable & asymptomatic
- Secondary glaucoma
- Rarely may be progressive & debilitating
-
Treatment
- None
- PK - PPD can recur
- Treat associated conditions
26
Q
Herpes Zoster Opthalmicus
- Reactivation along what nerve?
- Cutaneous lesions?
- Prodromal?
- Clinical course last how long?
A
- Reactivation along CN V1
-
Cutaneous lesions
- 25% involvement of ophthalmic division of CN V
- Acute, painful vesicular eruptions
-
Prodromal period not uncommon
- Fever, malaise, HA, eye pain or pressure, tearing, ocular redness, decreased vision
- Pain occurs along affected dermatome most commonly
-
Clinical course 2-6 weeks for vesicle to clear
- Corneal involvement may take longer
- Ocular involvement begins within 3 weeks of rash
- Virus presumably reaches eye via ciliary nerves
- **Pt presents to you initially with rash on lids and skin lesions without involvement of the globe = must follow pt weekly for minimum of 3 weeks
- Corneal involvement may take longer
27
Q
Graft vs Host Disease
- What is it?
- What are some tissues that may be affected?
- Occurs in which pts?
- Clinical diagnosis?
- Sx?
- Signs?
- Complications?
- Goals?
- Tx?
A
- Donor cells (graft) mount an immune response against recipient (host)
-
Affected tissues
- Skin
- GI system
- Liver
- Mouth
- Lungs
- Eyes (60-90% with GVHD)
-
Occurs in wide range of pt
- Age
- Histocompatibility
- Prophylaxis
- Host environment
-
Clinical diagnosis
- Thorough hx regarding nature of transplant & systemic presentation of GVHD
- Systemic medications = including immunosuppressants
- Complete ocular exam
-
Symptoms
- FBS
- Itching
- Burning
- Moderate conjunctival redness
- Advanced disease
- Decreased vision
- Pain
- Photophobia
- Exacerbated by wind, blinking or prolonged reading
-
Signs
-
Conjunctival
- Hyperemia
- Chemosis
- Pseudomembranous conjunctivitis
- Mucoid discharge
- Cornea
- Decreased tear lake
- KCS
- Filamentary keratitis
- Corneal erosions
-
Conjunctival
-
Complications
- Corneal scarring
- Neovascularization
- Cicatricial changes of conjunctiva
-
Goals
- Lubrication
- Control evaporation
- Decreased ocular surface inflammation
-
Treatment
-
Treat associated systemic disease
- Coordination of care with transplant team
- Lubrication
- Punctal occlusion
- Humidifiers
- Sleep masks
- Tarsorrhaphy
- Immunosuppression
- Directed at affected organ system
- Restasis, topical steroids
-
Treat associated systemic disease
28
Q
Keratitis
A
- Typically unilateral
- Bilateral disease in about 3%
- Can affect all levels of cornea
- Epithelium
- Infectious epithelial keratitis
- Neurotrophic keratopathy
- Stroma
- Immune stromal (Interstitial) keratitis
- Necrotiizing stromal keratitis
- Endothelium
- Disciform endotheliitis
- Diffuse endotheliitis
- Linear endotheliitis
- Epithelium
29
Q
List the Parasitic that can infect the eye
A
- Acanthomoeba
30
Q
Pathogens that can cause Bacterial Keratitis
A
-
Staphylococcus aureus
- Gram + cocci
- MOST COMMON cause of ulcers & conjunctivitis
- Occurs in normal ocular flora
- Rapidly progressive corneal infiltration & AC reaction with hypopyon
- Ulcers centrally located
-
Streptococcus pneumoniae
- Gram + diplococci
- Acute, purulent, & rapidly progressive
- Severe AC reaction with hypopyon
- Perforation common (7-10 days without tx)
- Ulcer centrally located
-
Pseudomonas areuginosa
- Gram - bacillus
- Ubiquitous organism
- Ability for proteolysis
- MOST COMMON cause of bacterial keratitis in CL wearers
- Central or paracentral ulcers
- Highly destructive
- Adherent greenish mucopurulent discharge
- Dense stromal infiltration & necrosis
- Stromal melting with early descemetocele
- Perforation within 72 hours if untrated
- Intense AC reaction w/ hypopyon
-
Moraxella lacunata
- Gram - coccobacilli
- Paracentral ulcer
- Older, debilitated individuals & homeless pt
- Perforation in days to 1 week without tx
31
Q
Fish-Eye Disease
A
- LCAT deficiency
- Progressive arcus which begins in adolescence
- May result in complete opacification of cornea
- AR inheritance
- ~30 cases described
32
Q
Marginal Staphylococcal Keratitis
- What is it?
- Sx?
- Presentation
- Tx?
A
-
Inflammatory infiltration that may lead to ulceration
- Antibody response to toxins rather than bacteria
- Type III hypersensitivity
- Associated with staphylococcal blepharoconjunctivitis
- Most common disorder of peripheral cornea****
Symptoms
- Mild discomfort to pain
- Conjunctival injection
- Lacrimation
- Photophobia
Presentation
-
Peripheral stromal infiltrates - separated by 1-2mm clear zone
- Develop where lid crosses limbus
- Ulceration & necrosis possible
- May develop vascularization between limbus & infiltrate or area of necrosis
-
Often chronic blepharitis
- Staphylococcal blepharitis most common***
- Angular blepharitis or strep species possible***
Treatment
- Lid hygiene - tx underlying cause
- Weak topical steroid
- Antibiotic
- Oral doxycycline - recurrence or maintenance
33
Q
Fleck Corneal Dystrophy
- Characteristics? Gene mutation?
- Symptoms?
- Treatment
A
- AD inheritance
- PIP5K3 gene mutation
- Bilateral, asymmetric
- Flat, gray-white, discrete flecks throughout stroma
- May be oval, circular, comma, or stellate shaped
- Fine, granular texture
- Limbus to limbus
- Little progression
-
Symptoms
- Generally asymptomatic
- VA unaffected
- Mild photophobia occasionally
- Decreased corneal sensation occasionally
-
Treatment
- None
34
Q
The cornea is composed of mainly..?
A
Collagen fibers
Transparent refracting surface
10% outer coat of eye
35
Q
Corneal Epithelial Abrasions
- Sx
- Presentation
- Examination
- Tx
A
- One of the most common ophthalmic injuries
- Removal of all or part of corneal epithelium
- If Bowman’s layer undisturbed = no scarring
Symptoms
- Pain- generally out of proportion to injury
- UV/CL keratitis delayed onset of pain
- Photophobia
- FBS
- Lacrimation
- Decreased VA if central or significant edema
Presentation
- Variable size/shape epithelial defect
- Loose flap of epithelium possible
- Conjunctival injection
- Lid edema possible
Examination
- History - pts generally specific about injury
- VA - may or may not be reduced
-
SLE - best to use anesthetic & NaFL
- Evert lids!
- DFE - any risk of penetrating injury
Treatment
- Antibiotic
- Cycloplegia
- Patching/BCL
36
Q
List the immunologic disorder of the cornea
A
- Rheumatoid arthritis
- Phlyctenular keratoconjunctivitis
- Marginal staphylococcal keratitis
- Mooren’s Ulcer
37
Q
Keratoglobus
A
- Rare
- Bilateral
- Globular cornea which leads to high myopia & astigmatism
- Congenital & acquired variants
- Often present at birth
- Associated conditions
- Leber’s congenital amaurosis
- Ehlers-Danlos syndrome type VI
- Cornea clear, normal size to slightly large
- Stroma diffusely thinned 1/3 - 1/5 normal thickness
- More pronounced in mid-peripheral cornea
-
Corneal Structure
- Fragmented or absent bowmans layer
- Diffusely thinned stroma
- Thinned Descemet’s membrane
- Normal endothelium
- Thinned sclera
-
Breaks in Descemet’s membrane possible
- leads to opaque, edematous cornea
- Takes weeks to months to heal
-
Characteristics findings in KCN not present
- No striae
- No iron lines
- No subepithelial
- Keratometry readings 60-70D
- Acute hydrops rare
- Perforation may ocur after minimal trauma
-
Treatment
- Spectacle correction
- Keratoplast - difficult, should be delayed when possible
- CLs considered - esp scleral, but must consider increased risk for rupture
38
Q
Herpes zoster (Shingles)
- What is it?
- Prodrome?
- Presentation?
A
-
Reactivation of virus following a dermatome
- Must have prior exposure to virus to develop shingles - either wild-type or vaccine
- Replicates in nerve cells & sends virions down the axon to the skin
- Presentation is the result of immune response to virions (not the virions themselves)
-
Prodrome (early signs/sx)
- Fever, malaise, HA, pain in the dermatome
- Affective disorder possible - anorexia, lassitude (lack of energy) , mood changes, antisocial behavior, severe depression, insomnia
-
Presents as acute, painful, vesicular eruptions
- Rash progression: erythematous → macules → papules → vesicle → pustules → crusting
- Generally occurs in cluster
- Lesion formation occurs ~3-7 days
- Resolution in 2-6 weeks
39
Q
PTK
A
- Phototherapeutic keratotomy
-
Ablative photodecomposition of epithelium to eliminate surface irregularities
- Laser ablation to depth of anterior stroma
-
Indications
- Corneal dystrophies or degenerations
- Scars
- Band keratopathy
- Infectious
- Therapeutic & visual improvements
40
Q
Fuch’s Endothelial Dystrophy
- Characteristics?
- Where does it usually begin in the eye?
- Sx?
- Tx?
A
- AD
- Late onset - 5th decade
- Slowly progressive
- Women > men
- Earlier presentation
- More severe
-
Guttata - refractile excrecences on the posterior cornea
- Abnormal functioning endothelial cells
- Begins centrally & spreads peripherally
-
Leads to corneal edema
- Worse in am, improves throughout the day
-
Symptoms
- None in early disease
- Blurred vision - worse upon waking
- Improves throughout the day
- Bullae formation -> pain, photophobia
-
Treatment
- None early disease
- hypertonic solutions
- Muro128 gtt or ung (dehydrates cornea)
- Hair-dryer aimed at eyes - pts find this uncomfortable
- Reduction of IOP - only at higher IOP levels
- Bandage CL, if pt has bullae formation
- DSAEK/DMEK (corneal surgery/endothelial transplant)
41
Q
Diffuse Endothelitis
A
- Rare, more severe presentation
- Symptoms
- Pain
- Photophobia
- Injection
- Decreased vision
- Clinical course similar to disciform
- Responds well to tx
42
Q
Varicella Zoster Virus
A
- Primary infections occurs in childhood is chickenpox
- Reactivation infection occur as shingles
- Generally in older or immunocompromised patients
- In otherwise healthy young adults, be suspicious for generalized immunosuppressive diseases
- Virus remains latent in sensory ganglions
- Reactivation follows a dermatome
43
Q
List the Descemet’s & Endothelial Dystrophies
A
- Posterior polymorphous dystrophy
- Fuch’s endothelial dystrophy
- Congenital hereditary endothelial dystrophy
44
Q
Meesmann’s Dystrophy
- Characterisics? What is another name?
- Symptoms?
- Treatment?
A
- AKA: Juvenile hereditary epithelial dystrophy
- AD inheritance
- Intraepithelial microcysts/vesicles
- Most prominent interpalpebral zone
- Central & mid-peripheral
- Slowly progressive
- Bilateral, symmetric
- First 1-2 years of life
-
Symptoms
- Mild to nonexistent
- Vision good initially
- Worsens as cyst increase in size & number which leads to irregularity of corneal surface
- Glare sensitivity
- FBS
- Erosions or PEK not common
-
Treatment
- Bandage CL
- Lubrication
- Superficial corneal debridement
- PTK (photo therapeutic keratectomy)
45
Q
Arcus Senilis
- What other names are they known as?
- What is it?
- Statistics? (men/women/age)
- What can arcus senilis indicate?
- What location does it begin to grow in the eye?
- Symptoms?
- Treatment?
A
- AKA:
- Corneal arcus
- Gerontoxon
-
Degenerative change involving depostion of lipid in the peripheral cornea
- Grey/white arc that as it progresses becomes a ring around cornea
- Near limbus with clear intervening zone
-
Normal older adults
- Men > Women
- Extremely common
- 60% in 50-60yo pts
- Nearly 100% affected by age 80
-
May indicate disruption in lipid metabolism
- Young pts should warrant a visit to PCP for lipid panel testing
-
Begins inferiorly then superiorly
- Spreads circumferentially
- Bilateral
- Symmetric
-
Symptoms
- None, Cosmesis
-
Treatment
- None, Refer to PCP for lipid panel testing in young pt
46
Q
Granular Dystrophy Type I
- Presentation?
- Symptoms?
- Treatment?
A
- AD inheritance
- TGFB1 gene mutation
- Leads to deposition of hyaline-like material in stroma
- Presents 1st-2nd decade
- Bilateral
- Grayish white opacities form in CENTRAL anterior stroma with clear intervening space
- Drop-shaped, crumb-shaped, ring-shaped
-
Symptoms
- Glare
- Decreased vision late (_>_40)
-
Treatment
- None until late
- Lamellar or penetrating keratoplasty if vision reduced
47
Q
List the stromal dystrophies
- Autosomal Dominant Inheritance
- Autosomal Recessive Inheritance
- Unknown Inheritance pattern
A
-
Autosomal dominant inheritance
- Granular dystrophy
- Avellino dystrophy
- Lattice dystrophy
- Schneider’s crystalline dystrophy
- Fleck corneal dystrophy
- Posterior amorphous corneal dystrophy
-
Autosomal recessive inheritance
-
Congenital hereditary stromal dystrophy
- Has both AR & AD inheritance patterns
- Macular dystrophy
-
Congenital hereditary stromal dystrophy
-
Unknown inheritance pattern
- Central cloud dystrophy of Francois
- Pre-Descemet’s corneal dystrophy
48
Q
Stromal keratitis
A
- Accounts for 20-48% of recurrent disease
- Primary involvement
- Necrotizing stromal keratitis
- Direct viral invasion of stroma
- Immune stromal keratitis
- Immune reaction in stroma
- Necrotizing stromal keratitis
- Secondary involvement
- Sequelae of epithelial, neurotrophic or endothelial infection
49
Q
What are the characteristics for corneal degeneration?
A
-
Definition: Deterioration & decrease in function
- May be unilateral or bilateral
- Often asymmetric
- Often considered aging changes
- Often eccentric or peripheral & correspond with vascularity
- Progression variable
- Local & systemic disease associations often
50
Q
List the Bowman’s Layer Dystrophy
A
- Reis-Buckler corneal dystrophy (CBD I)
- Thiel-Behnke Honeycomb dystrophy
51
Q
Describe the vascularization and nutrition of the cornea
A
- Avascular
- Vascular arcade in the limbal region provides nutrition to the cornea
- Anterior ciliary artery anastomoses with facial branch of external carotid artery
- Glucose obtained by diffusion from aqueous humor
- Oxygen obtained by diffusion from tears
52
Q
Tamoxifen
A
- Blocks action of estrogen
- Used in tx of breast cancer
- Ocular side effects
- Decreased VA
- Corneal microdeposits
- Retinopathy
53
Q
Necrotizing stormal keratitis
A
- Rare
- Direct viral invasion of stroma
- Presentation
- Necrosis
- Dense stromal infiltration with overlying epithelial defect
- Thinning & perforation possible after short period of time
54
Q
Super K
A
- Superficial keratectomy
- Removal of epithelium with alcohol & manual scraping
- USed to improve epithelium
- Corneal dystrophies & degenerations
- Recurrent corneal erosions
55
Q
PixL
A
- Photorefractive intrastromal corneal cross-linking
- Non-surgical tx for low myopia
- ~0.75D myopia correction potential
- 2 studies have shown good results after 12 months
- Not approved in US & not currently in clinical trials
56
Q
Phakic IOLs
A
- FDA approved for moderate to high myopia correction
- Not currently approved for hyperopic or astigmatic correction
- Reversible
- Increased risk for cataract development
- Possible corneal decompensation
-
ICL (Implantable collamer Lens)
- Visian
- Lens placed between lens & iris
- -3D to -20D
- Cannot see with naked eye
- Verisyse
- Lens to anterior chamber
- -5 to -20
57
Q
Fluoroquinolones
A
- 2nd gen
- Ciprofloxacin 0.3%
- Ofloxacin 0.3%
- 3rd gen
- Levofloxacin 0.5%
- Levofloxacin 1.5%
- 4th gen
- Moxifloxacin 0.5%
- Besifloxacin 0.6% = no systemic equivalent
- 2nd & 3rd generation
- Single agent therapy
- Available in commercial prep
- Bactericidal activity
- Broad antimicrobial spectrum
- Low incidence of resistance
- 4th gen
- Improved gram + coverage with maintenance of gram - coverage
- Excellent potency against atypical mycobacteria
- Effective against MRSA & fluoroquinolone resistant pseudomonas
- Better penetration
- Less likely to develop resistance
58
Q
Meesman’s vs EBMD
- Inheritance pattern
- Age of onset
- Presentation
- Symptoms?
- Treatment?
A
59
Q
Macular Dystrophy
- Characteristics? Gene mutation?
- Most prevalent where?
- Treatment?
A
- AR inheritance
- Mutation in CHST6 gene
- Intra & extracellular deposits within the stroma
- Least common stromal dystrophy
- Most severe
- Most prevelent in Iceland & Saudia Arabia
- Characterized by attacks of irritation & photophobia
-
Anterior stroma becomes hazy 1st decade, progressing to opacified lesions
- Haze extends to peripheral cornea
- Involves entire thickness by 2nd decade
- Vision loss by 20s to 30s
- Treatment
- Variable, depends on severity of tx
- Tinted CL to reduce photophobia
- Tx of recurrent erosions
- PK - reccurence possible in graft
60
Q
Hepres simplex
Primary infection & Presentation?
A
- ~6% of pt manifest disease, therefore 94% of pt do not
- Neonatal infection
- HSV II
- Acquired during vaginal delivery
- Post-neonatal infection
- HSV I
- Acquired from exposure to infectious secretions
- Incubation period
- 1-28 days
-
Presentation
- Nonspecific URI - often not recognized as HSV
- Variable ocular presentation
- Periocular skin vesicles
- Follicular conjunctivitis
- Keratitis
- Preauricular adenopathy
- Blepharoconjunctivitis - unilateral vesicular lesions on lid or adnexa, follicular conjunctivitis & PAN
61
Q
Kayser-Fleischer Ring
- What is it?
- Where is it usually seen in the eye?
- What occurs with this?
- Treatment?
A
- Copper deposition in Descemet’s layer at corneo-scleral junction
- Begins at Schwalbe’s line & extends into cornea <5mm
- Deposit and extend into trabecular meshwork
- Golden to green-brown band in peripheral cornea
- Gonioscopy necessary in early disease cases
- Bilateral
- Begins superiorly, then inferiorly & moves circumferentially
-
Wilson’s hepatolenticular degeneration
- AR
- 1st & 4th decades
- Inborn error copper metabolism
- ATB7B gene
- Sx typically present in teens to 20s
- Leads to retained copper in the body causing liver & brain damage
- Cirrhosis, renal disease, neurologic dysfunction
- 95% WD with neurologic signs have KF ring
- 65% WD with hepatic signs have KF ring
- Fatal if left untreated
- Dissappears with treatment
-
Treatment
- Copper chelation to fade ring
- Low copper diet
- Systemic treatment of Wilson’s disease
- Copper chelators
- Zinc therapy
- Surgical treatment
- Liver transplant in severe cases
63
Q
Coat’s White Ring
- What does it look like? Diameter? What layer is it located in?
- What causes this?
A
- White rings in cornea <1mm diameter at the level of Bowmans layer
- May be oval or incomplete
- Discrete white dots with areas of coalescence
- Granular
- Usually inferior position
- Iron or calcium deposit
- Often associated with previous trauma - espc metalic FB
- Asymptomatic, incidental finding
64
Q
Iron Lines
- What does it look like?
- What are the types of iron lines? Characteristics of each?
A
-
Faint yellow to dark brown discoloration in the epithelium
- Easier to see with cobalt filter
- Etiology unclear
-
Types
- Hudson-Stahili line
- Fleischer ring
- Stocker’s line
- Ferry’s line
69
Q
Comparison of Corneal Transplant surgery
A
72
Q
Neurotrophic Keratitis
- Characteristics?
- Causes
- Stages?
- Complications
- Signs
- Diagnosis
- Treatment
A
- Loss of trigeminal innervation to the cornea resulting in anesthesia (partial or complete)
- Degeneration of corneal epithelium
-
Causes
- Acquired CN V damage
- Systemic disease
- Ocular disease
- Congenital
- Toxicity from long term medication use
Stages
-
Stage 1
- Mild, nonspecific sn/sx
- Rose bengal staining of inferior palpebral conjunctiva
- Increased viscosity of tears with decreased TBUT & subsequent dry patches on the cornea
- Stain with NaFL
- Vascularization & scarring occur if progression not halted
-
Stage 2
- Non-healing corneal epithelial defect with surrounding loosening of epithelial tissue
- Folds in Descemet’s develop as stromal edema increases
- Punched-out lesion develops
-
Stage 3
- Stroma melting which leads to perforation
- No pain due to decreased corneal sensation
Complications
- Intracellular edema
- Exfoliation of epithelial cells
- Impairment of epithelial healing
- Loss of goblet cells
- Persistent ulceration
Signs
- Interpalpebral punctate keratopathy
- Epithelial opacification
- Persistent epithelial defect with rolled edges
- Enlargement of defect with stromal edema & infiltration
- Stromal corneal melting
- Perforation uncommon, generally a result of secondary infection
Treatment
- D/C toxic medication
- Topical lubrication
- PFAT drops or ointment
- Punctal occlusion
- Protect ocular surface
- Lid taping at night
- Prophylactic antibiotic
- BOTOX injection to induce ptosis
- Tarsorrhaphy
- Therapeutic CL
- Amniotic membrane
- Corneal transplant in late disease
75
Q
Lipid Degeneration
- What is it?
- What is the difference between primary & secondary lipid degeneration?
- What are the secondary disease associations?
- Complications?
- Treatments?
A
- Dense, yellow-white opacity that may fan out with feathery edges from blood vessels
- Deposit consist of cholesterol, fats & phospholipids
- Multicolored crystals may be seen at the edge of opacity
-
Primary
- Rare, spontaneous development
- Not associated with vascularization
- No previous trauma
- Serum lipids in normal range
- Lipid deposition central or peripheral
- Lesion consists of cholesterol, triglycerides, & phospholipids
- Theorized that may be due to increased vascular permeability of limbal vessels
- Women > Men
-
Secondary
- More common
- Develops rapidly in an area with long-standing vascularization
- Grey to yellow-white lesion
-
Variable appearance to lesions
- Sea-fan shaped with feathery edges (post-inflammatory)
- Dense discoid (active inflammation)
- Regression possible with normalization of lipids or decrease of inflammation
-
Secondary Disease Associations
- Trauma
- Ulceration
- Hydrops
- Interstitial keratitis
- HZO
-
Complication
- Cosmesis
- Decreased vision
- May be rapid onset
-
Treatment
- Argon laser to feeder vessels
- Needle point cautery to feeder vessels
- PK - may recur in graft
76
Q
Congenital Hereditary Endothelial Dystrophy (CHED)
- Characteristics?
- Symptoms?
- Signs?
- Tx?
A
- AR & AD
- Congenital to 1-2 years
- Saudia Arabia & India
- Bilateral, symmetric
-
Noninflammatory corneal clouding
- Extends to limbus without clear zones
- No other anterior segment anomalies
- Dx of exclusion
-
Sx
- Blurred vision
- Photophobia
- Tearing
- Nystagmus - in AR cases
-
Signs
- Level of clouding variable
- Mild haze to dense clouding
- Increased corneal thickness & thickening of Descemet’s
- Level of clouding variable
- Treatment - PK
79
Q
Describe the image
A
80
Q
Crocodile Shagreen
- What does it look like?
- What are the 2 forms?
- Tx?
A
- Bilateral, central, grey-white opacification in anterior or posterior cornea
- Mosaic or cracked ice pattern
- Anterior form = senile change or associated with ocular trauma/inflammatory conditions
- Posterior form = solely senile change generally not visually significant
- Tx = none
81
Q
Thygeson’s Superficial Punctate Keratitis
- Characteristics
- Features
- Symptoms
- Signs
- Treatments
A
- Uncommon, usually bilateral
- Asymmetric
- Idiopathic keratopathy
- Viral & immunologic mechanisms speculated
- Most commonly affects young adults, but can occur at any age
- Female>men - slight
Characteristics
- Coarse punctate epithelial keratitis
- Often occur in central cornea
- Little or no hyperemia of the bulbar or palpebral conjunctiva
- Episodes of exacerbations & remissions
- Episode can last 1-2 months
- Remissions ~6 weeks
Features
- Chronic, bilateral punctate epithelial keratitis
- Long duration with remission & exacerbations
- Healing without scars
- Lack of response to systemic or topical antibiotics sulfonamides or to the removal of the corneal epithelium
- Striking symptomatic response to topical steroids
Symptoms
- Recurrent attacks
- FBS
- Photophobia
- Blurred vision
- Watering
- Minimal decrease VA
Signs
- Oval to round grouped punctate intraepithelial deposits
- Numerous, discrete, granular, white/grey opacities
- Slightly elevated
- May have stellate appearance
- Often in/near visual axis
- No staining during inactive phase
- Staining with NaFL/Rose Bengal during active phase
- Mild epithelial/subepithelial edema or haze
- No infiltration
- White eye
Treatment
- Lubrication in mild cases
- Steroids with gradual tapering
- Restasis
- CLs - if steroids contraindicated or in addition
- PTK
82
Q
Fleischer’s ring (Iron lines)
A
- Forms at base of keratoconus, may progress to full ring
- Ferritin deposits in cytoplasm of corneal epithelial cells & in widened epithelial intercellular space
84
Q
Granular Dystrophy Type 2 (Avellino Dystrophy)
- Inheritance? Mutation?
- Characteristics?
A
- AKA: Avellino Dystrophy
- AD inheritance
- TGFBI gene mutation
-
Combined granular-lattice corneal dystrophy
- Early diseases has granular appearance & develops lattice lines later
- Presents in 2nd decade
-
Characteristics
-
Anterior stromal discrete white-grey granular deposits
- Become larger & coalesce with age
- Mid to posterior stromal lattice lesions
- Move more centrally with age
- Anterior stromal haze
-
Anterior stromal discrete white-grey granular deposits
-
Symptoms
- FBS
- Pain
- Photophobia
-
Treatment
- Lubrication/BCL for epi erosions
- PK
85
Q
Infectious epithelial keratitis/Dendritic keratitis
- Epithelial dendrite?
- Sx?
- Signs?
A
- Reactivation of live virus
-
Epithelial dendrite
- Most common presentation in herpes simplex keratitis
- Linear, branching ulcerated lesion with terminal end bulbs
- Ulcerations = represent areas of epithelial breakdown due to cytopathic effects of herpes simplex virus
- Terminal end bulbs
- Intact, virally-infected epithelium
- Lead edge of the dendrite
- Stain with NaFL & Rose Bengal
-
Symptoms
- Tearing
- Photophobia
- Pain
- Blurred vision
- If cenral lesions present
- Decreased corneal sensation
- Intense ciliary injection
- **Most painful at first manifestation
-
Signs
- Corneal vesicles
- Ulcer develop within 24 hrs
- Dendritic ulcers
- Linear, branching ulcerated lesion with terminal end bulbs
- Most common presentation of HSV keratitis
- Stains w/ NaFL along length of lesion & Rose Bengal at base of lesion
- Ulcerations
- Represent areas of epithelial breakdown due to cytopathic effects of herpes simplex virus
- Terminal end bulbs
- Intact, virally-infected epithelium
- Leading edge of the dendrite
- Dendritic ulcers
-
Geographic ulcers
- Enlarged, non-linear ulcer with scalloped borders
- Associated with longer duration of sx & longer healing time
- Marginal ulcer
- Ulceration near limbus
- Stromal infiltrate directly under ulcer
- Adjacent limbal injection uncommon
87
Q
Reis-Buckler’s Vs. Thiel-Behnke
- Inheritance pattern
- Age of onset
- Presentation
- Symptoms
- Tx
A
88
Q
Hudson-Stahli line (Iron lines)
A
- Formed in inferior 1/3 of cornea in band zone where the lids meet
- Iron deposition in cytoplasm of epithelial cells
- Normal aging process
- 5th-6th
- Association with chronic DES
95
Q
Dellen
A
- Area of localized thinning located adjacent to a paralimbal elevation
-
Cause
- Age-related change
- Local dehydration of the cornea
- Short-lived - usually last 24-48 hrs
-
Treatment
- Lubrication (tears or ointments)
- Pressure patch
97
Q
Ferry’s Line (Iron lines)
A
- Forms in front of filtering bleb
- Iron deposited in cytoplasm of basal epithelial cells
- Only forms in elevated bleb
98
Q
Hassell-Henle Bodies
- What layer is this found in?
- What is it?
- What is identical to?
A
- Descemet’s warts
- Excresence of descemet’s membrane in peripheral cornea
- Localized thickening occurring in peripheral cornea
- Histologically identical to guttata
- DO NOT signify cornea disease
- One of the most common age-related corneal changes
99
Q
Fabry’s Disease
- Characteristics?
- Systemic?
- Ocular effects?
A
- X-linked recessive disorder
- Males = full expression
- Females = carriers, can exhibit disease characteristics
- Multisystemic disorder that ultimately results in irreversible, potentially life-threatening disease of kidney, heart & brain
- Deficiency of a-galactosidase A
- Lysosomal storage disorder
-
Disease characteristics
- Angiokeratomas
- Febrile crises with peripheral extremity pain
- Renal failure
- CVD
- Neurologic changes
- Symptoms generally appear in childhood, but go unrecognized until adulthood
- damage already ocurred
- Corneal changes are earliest & most consistent ocular abnormality
- Affected males & females carriers
-
Systemic
- Progressive &/or unexplained kidney disease
- Premature cardiac disease
- Premature stroke
- Burning pain in hands/feet
- Hypohydrosis/Anhydrosis
- Angiokeratomas
-
Ocular
- Corneal verticillata
- Posterior subcapsular cataracts
- Whitish spoke-like deposits of granular material
- Aneurysmal dilation of venules on bulbar conjunctiva
- Mild to marked tortuosity & angulation of retinal vessels
102
Q
Acanthamoeba
- Characteristics?
- What can it cause?
A
- One of the most ubiquitous organisms in the environment, rarely causes infection
- Infections serious & vision threatening
- Increased risk: CL use
- 80% cases associated with CL use
- Using tap water to clean CLs or CL case
- Swimming with CLs in, esp in lakes & rivers
- Poor CL hygiene
- Any age of onset
- No sex predilection
- Usually Unilateral
Acanthomoeba keratitis
- Severe, incapaciting pain
- Ring infiltrate
- Decreased VA
- Radial keratoneuritis
- Photophobia
- Limbitis
- Scleritis
- Uveitis
- Eyelid edema
- Dacryoadenitis (inflammation of lacrimal glands)
Radial keratoneuritis
- Inflammatory response of the corneal nerves
- Infiltrate along corneal nerves
- Clinical appearance
- Thickened corneal nerves with ragged borders
- Located in the anterior or mid-stroma
- Distributed in a linear radial pattern
- Occurs early in acanthamoeba corneal infection
107
Q
Central cloudy dystrophy of Francois
- Characterisitics?
- Symptoms?
- Treatment?
A
-
Uknown inheritance
- AD supsected
- Bilateral, symmetric
- Non-progressive
-
Cloud central polygonal or rounded stromal opacities
- Occur in central 1/3 of cornea
- Deep stromal layers
- Develops in 1st decade
- Symptoms - Mostly asymptomatic
- Treatment - None
109
Q
Review of stromal corneal dystrophies
- Inheritance pattern
- Age of onset
- Presentation
- Sx
- Tx
A
110
Q
Linear endothelitis
- Sx?
- Presentation?
- tx?
A
- Sx similar to other forms of endothelitis
- MOST SEVERE presentation & hardest to get them undercontrol
-
Presentation
-
Line of KPs that progress centrally from the limbus
- May be sectoral or circumferential
- Peripheral stromal & epithelial edema
-
Line of KPs that progress centrally from the limbus
- Tx difficult
111
Q
Describe the innervation of the cornea?
A
-
Heavly innervated & sensitive tissue
- Density of nerve endings about 300-400x greater in cornea than in skin
-
Derived from ciliary nerves
- Penetrate cornea in deep peripheral stroma radially and move anteriorly
- Lose myelination shortly after entering cornea
- Penetrate Bowman’s layer
- Terminate in wing cells of corneal epithelium
-
Sensation helps maintain functional integrity of the cornea
- Reflex tearing
- Blinking
-
Innervation
- Enlarged, prominent corneal nerves
112
Q
Pre-Descemet’s Corneal Dystrophy
- Characteristics?
- Sx?
- Tx?
A
-
Unknown Inheritance
- AD, sporadic, age-related theorized
- Bilateral, symmeric
-
Older adults
- _>_30yo
- Focal, fine gray opacities in deep stroma
- Some lesions larger
- Variable shape - snowflake
-
Symptoms
- Asymptomatic - VA not affected
-
Treatment
- None
113
Q
Name the 6 layers of the cornea ? What are the characteristics of each?
A
Epithelium
- Surface layer
- 55um
- Barrier function: block debris, bacteria & foreign substances
- Constantly regnerating & sloughed
Bowman’s Layer
- Basement membrane
- 5um
- Prevents forward corneal swelling
Stroma
- Majority of cornea
- 485um
- Strength elasticity
Dua’s Layer
- newly discovered
- 10-15um
Descemet’s membrane
- basement membrane
- 10um
- endothelial cell health
Endothelium
- innermost layer
- 5um
- Barrier pump maintaining proper hydration of cornea
- single cell layer thickness
114
Q
Schnyder’s Corneal Dystrophy
- Other names?
- Characteristics? Gene mutation?
- Symptoms?
- Treatment?
A
- AKA: Schnyder’s crystalline dystrophy, central stromal crystalline dystrophy
- AD inheritance
-
Rare
- <100 case reported
- Large cohort from central MA
- Presents 1st decade
-
Mutation in UBIAD1 gene
- Leads to improper metabolism of corneal keratocytes and deposition of crystalline cholesterol & phospholipids in the stroma
- Strong association with hypercholesterolemia
-
Ring-shaped accumulation of fine needle shaped polychromatic crystal deposits
- Throughout entire stroma
-
Symptoms
- Vision loss in middle age
- Decreased corneal sensation possible
-
Treatment
- PTK - ablate crystals
- PK - deeper involvement
115
Q
Congenital Anterior Staphyloma
A
- Rare
- Bulging, opaque cornea lined with uveal tissue that protrudes beyond normal plane of lids
- Unilateral or bilateral
- Variable thinning of cornea
- Deep, disorganized anterior chamber
- Lens may be adherent to cornea
-
Cause
- Abnormal migration of neural crest cells into developing cornea
- Abnormal differentiation of mesodermal cells
- Intrauterine keratitis
- Bilateral anterior staphyloma
- B-scan showing iris adherent to cornea
- T2 MRI showing enlarged globes & lens displaced into vitreous cavity
-
Complication
- Blind eye
- High risk of glaucoma
-
Treatment
-
Penetrating keratoplasty
- Graft failure common due to size
- Boston K-pro
- Glaucoma filtering surgery
- Enucleation
-
Penetrating keratoplasty
117
Q
Corneal dystrophy
- Define
- Which layers are affected? Characteristics of each?
A
- corneal opacity or alteration which is most often bilateral & progressive, occurs after birth, & is not inflammatory
- Characterized by layer affected
- Epithelial
- Bowman’s layer
- Stromal
- Descemet’s & Endothelial layer
120
Q
Stocker’s line (Iron lines)
A
- Vertical line that forms at advancing edge of pterygium
- Color yellow to golden brown
- Role in development of pterygia is unknown
122
Q
Limbal Girdle of Vogt
- What does it look like, where does it mostly occur?
- At what age does it start?
- What are the 2 types? Characteristics for each?
A
-
Yellow-white crescent-shaped band in interpalpebral limbus
- Nasal > Temporal
- Inferior possible
-
Incidence increases with age
- < 20 yo = 0
- 40-60 yo = 55%
- _>_80 yo = 100%
-
Types
-
Calcific - lucid interval at limbus
- May contain holes
- Central border sharply defined with no extensions
- Thought to represent early calcific band keratopathy
-
Elastotic - no lucid interval
- True limbal girdle
- Chalky band
- No holes
- Central irregular linear extension
-
Calcific - lucid interval at limbus
123
Q
Posterior amorphous corneal dystrophy
- Characteristics?
- Symptoms?
- Treatments?
A
- AD inheritance
- Gene mutation has not been determined
- Appears in 1st decade
- Slow progression
- Bilateral, symmetric
- Diffuse, gray-white, sheet-like opacities in the posterior stroma
- Central corneal thinning
- Flat topography
-
Symptoms
- Mild vision reduction
- >20/40
-
Treatment
- None
124
Q
Amyloid Degeneration
- What does it look like?
- Characteristics?
- Describe primary vs secondary form?
- What are the systemic associations for amyloid degeneration?
- Treatment?
A
-
Group of proteins with starch-like staining characteristics
- Stains w/ congo red
- Exhibits birefringence in polarized light
- Exhibits dichromism in green light
-
Local or systemic
- Systemic rarely has ocular manifestations
-
Primary or Secondary
-
Primary
-
Pleomorphic amyloid degeneration
- Pleomorphic punctate of filamentous opacities in the central cornea
- Refractile, polygonal grey-white opacities in central cornea
- _>_50 yo age related change
- No visual effect
- Not associated with systemic disease
- Pleomorphic punctate of filamentous opacities in the central cornea
-
Conjunctival amyloidosis
- Yellow or pinkish mass located in eyelids or conjunctival fornix
- Rarely occurs on bulbar conj
- Warrants a referral to r/o life-threatening disease
- Yellow or pinkish mass located in eyelids or conjunctival fornix
-
Pleomorphic amyloid degeneration
-
Secondary
- Occur in association with trauma or prolonged inflammatory conditions
- Most common cause of corneal amyloidosis involvement
- Associations
- Trauma
- ROP
- Trachoma
- Phlyctenular disease
-
Primary
-
Amyloid Degeneration: Systemic Associations
-
Primary
- Cardiomyopathy
- GI disease
- Peripheral neuropathies
- Facial nerve palsies
-
Secondary
- Tuberculosis
- Osteomyelitis
- Rheumatoid arthritis
- Syphilis
- Leprosy
-
Primary
-
Treatment
- Depends on presentation, patients sx & visual significance
- Conjunctival
- Conservative therapy
- Liquid nitrogen cryotherapy
- Monitor/treat IOP
- Vitreal
- Pars plana vitrectomy (PPV)
126
Q
Posterior Keratoconus
A
- Rare, development condition
- More commonly unilateral
- Usually present at birth
- Non-progressive
- Thinning due to increased curvature of posterior cornea
- Guttata occasionally seen within lesion
- Pigment occasionally present at edge of lesion
- Mild to moderate corneal astigmatism
- Decrease vision
- Corneal scarring
- Associated ocular disease
- Amblyopia
-
Forms
-
Generalized
- Increased posterior curvature with shorter radius
- Normal anterior curvature
- Central cornea may be thinned
- Cornea clear
- Focal
- More common
- One or more localized, crater-like lesions in central or peripheral posterior cornea
- Corneal clouding common
- Thinning variable
- Associated with ocular or systemic anomalities
-
Generalized
-
Complications
- corneal clouding possible
- Rarely affects VA
- Myopic astigmastims most frequent
-
Treatment
- None
- Spectacle correction
- Penetrating keratoplasty (PK)
127
Q
Mooren’s Ulcer
- What is it?
- Presentation?
- Types?
A
- Painful, progressive, idiopathic chronic ulcerative keratitis
- Begins peripherally & moves circumferentially & central
- No associated systemic disease or scleritis
- Men > Women
- 40-70yo, but any age possible
- More common unilateral
Presentation
- Grey-white crescent shaped infiltrate & ulceration in peripheral cornea
- Progressive circumferential & central stromal thinning
- Vascularization involving bed of ulcer up to the lead age
- Thinning, vascularization & scarring
Types
-
Unilateral Mooren’s Ulceration
- Painful, progressive ulceration in ELDERLY pts
- Associated w/ non-perfusion of superfical plexus of the anterior segment
-
Bilateral, aggressive Mooren’s ulceration
- YOUNG pts
- Ulceration that progresses circumferentially, then centrally
- Vascular leakage & neovascularization extending to the base of the ulcer
-
Bilateral, indolent Mooren’s ulceration
- Middle-AGED pts
- Bilateral, progressive peripheral guttering
- Little inflammatory response
- No vascular changes or neovascularization
Symptoms
- Pain - often out of proportion to inflammation
- Photophobia
- Injection
- Lacrimation
- Blurred vision - due to 2^iritis, central corneal involvement or irreg. astigmatism
Complications
- Severe irregular astigmatism
- Perforation from minor trauma
- More common in peripheral ulceration, compared to total ulceration
- Infection
- Cataract
- Glaucoma
Treatment
- Tropical steroids - hourly
- Prophylactic antibiotic Restasis - takes weeks to become effective
- Restasis - takes weeks to become effective
- Supportive therapy
- Conjunctival resection
- Systemic immunosuppression
- Doxycycline
- Lamellar/penetrating keratoplasty
129
Q
Review of endothelial corneal dystrophies
A
133
Q
Corneal Verticillata
A
- AKA: corneal whorls
- Whorl-like pattern of powdery, white, yellow or brown corneal epithelial depositis
- Form in a vortex pattern in inferocentral cornea & swirls outward sparing the limbus
- Cause
- Amiodarone
- Chloroquine
- Tamoxifen
- Fabry’s disease
134
Q
Fungal keratitis
- Symptoms?
- Signs?
A
- Varies by organism
Similar sx to bacterial uclers
- Pain
- Initially FBS x several days that worsens to increasing pain
- Photophobia
- Decreased VA
- Redness
- Lid swelling
- Discharge
- Pt report of “white spot” on eye
Sign
- Feathery, poory defined borders of infiltrate***
- Unifocal or multifocal infiltrate
- Rough looking surface texture
- Ulcer may be elevated & exhibit branching lines
- White PMN ring often present
- Possible neovascularization
- Superficial epithelium may heal while organism continues to invade deeper into tissue
- Hypopyon
- Keratitis 1-3 weeks after trauma
- **Definitive diagnosis of bacterial vs fungal keratitis cannot be made by clinical appearance alone
Management
- Culture!
- Sabouraud’s agar without cyclohexamide
- Thioglycolate broth
- PCR
- Confocal microscopy
- Therapy usually not begun until microbial evidence
- Usually lasts 6 weeks
- Daily mechanical debridement because antifungals have poor corneal penetration
-
Filamentous fungi
- Natamycin
- only commercially available antifungal
- Q1hr around the clock
- Yeast
- Q30 mins x 1st 24 hrs
- Q1hr x 2nd 24 hrs
- Slow taper according to clinical response
- Oral antifungals
- Usually maintained x 12 weeks
- NO STEROIDS
- Subconjunctival injection for severe keratitis or keratoscleritis
- Considered hospitalization
- Natamycin
135
Q
Corneal Surgery Post/op meds & Protocol?
A
-
Post-op meds
- Topical antibiotics - generally given for 1 wk
- Topical steroids - tapered
- Topical NSAID possible
- depends on surgeon & procedure varaible duration
- PFATs
- Used frequently to improve ocular surface comfort & healing
- Other
- Eyeshield at bedtime
- Avoidance of water in eye
137
Q
Neurotrophic Keratopathy
A
- Results from impaired corneal innervation & decreased tear production
-
Presentation
- Corneal irregularity
- Lack of normal corneal luster
- Oval shaped epithelial defect with smooth borders
- Leads to stormal ulceration
-
Complications
- Corneal neovascularization
- Necrosis
- Perforation
- Secondary Infection
138
Q
Keratoconus
- Characteristics?
- Signs?
- Sx?
A
-
Progressive thinning and protrusion of cornea leading to conical shape
- Cone apex usually just below visual axis
- Bilateral, often asymmetric
-
Onset around puberty
- Progression x 10-20 yrs until gradually stabilizes
- Rate of progression variable
- Generally stabilizes by 40s
- No gender predilation
- Affects all races - some to higher degree
- Inheritance unknown
- Incidence ~1:2000
-
Symptoms
- Progressive visual blurring
- Snellen acuity initially preserved
- Contrast sensitivity descreases earlier
- Distortion
- Photophobia
- Glare
- Monocular diplopia
- Ocular irritation
- Progressive visual blurring
-
Keratoconus Signs
- High, irregular astigmatism
- Scissor reflex with retinoscopy
- Munson’s sign (V-shaped indentation observed in the lower lid)
- Fleischer ring (Iron deposition)
- Corneal thinning
- 1/2 to 1/5 normal thickness
- Prominent corneal nerves
- Vogt Striae in posterior stroma
- Corneal scars at apex - ruptures in Bowmans layer
- Corneal hydrops (caused by acute disruption of descemet’s membrane in setting of corneal ectasia, abnormal accumulation of fluid ina . body tissue or cavity)
139
Q
Immune stroma (interstitial) keratitis
A
- Occurs in ~20% of chronic recurrent HSV
- Inflammation due to retained viral antigen in stromal tissue
- Presentation
- Stromal inflammation
- Intact epithelium
- Stromal infiltration
- Immune ring
- Stromal neovascularization
- Stromal inflammation
142
Q
Terrien’s Marginal Degeneration
- What is it?
- Statistics?
- What does it look like?
- What are the 2 types?
- Presentation?
- Symptoms?
- Treatment?
A
- Peripheral inflammatory condition
- Rare, etiology unkown
- Men 3:1
- 20-40 yo most common
- any age possible
- Bilateral & symmetric
-
Non-inflammatory peripheral thinning with pannus
- Grey/white band 1-2mm width
- Starts supernasally & spreads circumferentially
- Fine punctate opacities in anterior stroma
- Rarely involves inferior limbus
- Epithelium remains intact
- Gutter forms between opacity & limbus
- Slowly progressive stromal thinning over many years
- Extends circumferentially or centrally
- Rarely causes perforation
- Easy perforation with mild trauma
- Lipid deposits at leading (central) edge of pannus
-
Types
-
Quiescent
- More common
- Older pt
- Painless lesions
-
Inflammatory
- Less common
- Younger pts
- Recurrent episodes of inflammation, episcleritis
-
Quiescent
-
Presentation
- Leading edge of lipid
- Steep central edge
- Sloping peripheral edge
- Intact epithelium
- Superficial vascularization
- High against the rule of oblique astigmatism
- Peripheral thinning from collagen degeneration
- May develop aqueous pockets
-
Symptoms
- Painless
- Blurred vision due to astigmatic changes
- Rare perforations
-
Treatment
- CL or spectacle correction
- Keratoplasty if risk of perforation
144
Q
Pellucid Marginal degeneration
- Characteristics?
- Signs?
- Tx?
A
- Bilateral
- Peripheral cornea ectatic disorder
- Characterized by a band of thinning 1-2mm typically in inferior cornea
- Inferior thinning at 4 & 8 o clock
- Max corneal protrusion usually just superior to area of thinning
- Protruding cornea is of NORMAL thickness
- No gender or racial predilection
- Present in 2nd-5th decade
- 2nd most common ectatic disorder
-
Signs
- Kissing doves, lobster claw
- Irregular astigmatism
- No iron rings
- No Striae
- Scarring at level of Descemet’s
- Hydrops possible
-
Treatment
- Same as KCN
147
Q
Review of Corneal Dystrophies
- Inheritance pattern
- Age of onset
- Presentation
- Sx
- Tx
A
151
Q
Epithelial Basement Membrane Dystrophy (EBMD)
- Other names?
- Characteristics?
- Symptoms?
- Treatment?
- Medical therapy?
- What surgery must be avoided?
A
- AKA: anterior basement membrane dystrophy, map-dot fingerprint dystrophy, Cogan dystrophy
-
Most common anterior corneal dystrophy
- Affects 2% of population
- Variable onset
- Microcyst formation in the epithelium with alterations in basement membrane
- Defect in formation & maintenance of epithelial basement membrane adhesion complex
- Leads to thickened, multilaminar or redundant, & misdirected into epithelium
-
Symptoms
- Spontaneous corneal erosion
- Blurred vision
- Variable
- Dry eye
- Photophobia
- Slowed healing time after surgery
-
Treatment
- None - most pts asymptomatic
- Bandage CL
- Lubrication
- Punctal occlusion
- Hypertonic solution
- RGP/Scleral lenses
-
Medical therapy
- FreshKote
- Steroids
- Restasis
- Low dose oral doxycycline
-
Surgical
- PTK
- Super-K
- ** Lasik NOT recommended due to increased risk of epithelial sloughing & other complications
153
Q
Corneal Farinata
A
- Innumberable centrally located tiny, dust-like grey dots & flecks in the deep stroma
- Flour-dust appearance
- Usually bilateral
- No decrease in VA
