Ocular Disease: Lecture 9: Cornea Flashcards

1
Q

Cornea

  1. It’s the most densely what in the body?
  2. a. Length: Horizontally?
    b. Vertically?
    c. Thickness?
    d. Where is it thickest?
A
  1. Most densely innervated tissue in the body
  2. a. 12 mm
    b. 11.5 mm
    c. 540 microns thick
    d. in the Periphery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cornea: Layers

  1. What are the 5 layers
A
  1. Epithelium
  2. Bowman’s Layer
  3. Stroma
  4. Descemet’s Membrane
  5. Endothelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cornea: Epithelium Layer

  1. 3 Types of cells?
A
  1. Columnar Basal Cells; Wing Cells; Surface Squamous Cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cornea: Epithelium Layer

  1. What are Columnar Basal Cells attached to?
  2. What happens to the Surface Squamous Cells?
A
  1. To the Basement Membrane

2. They’re SHED into the TEAR FILM after 2-3 Days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Cornea: Bowman’s Layer

  1. What is it?
  2. What is it made of?
A
  1. It’s an ACELLULAR Superficial Layer of the Stroma

2. Collagen Fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cornea: Stroma

  1. % of the thickness of the Cornea?
  2. Type of orientation of the Collagen Fibers?
  3. Does it regenerate?
  4. What else is found here?
A
  1. 90% of the corneal thickness
  2. Regularly Oriented Layer of the Collagen Fibers
  3. NO!
  4. Modified Fibroblasts are INTERSPERSED
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cornea: Descemet’s Membrane

  1. What is it?
  2. How many zones and what are the zones?
A
  1. Sheet of Collagen Fibrils

2. 2 Zones: Anterior Banded, and Posterior Non-Banded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cornea: Descemet’s Membrane: 2 Zones

  1. Anterio Banded is what?
  2. Posterior Non-Banded: What is it?
    a. Can it regenerate?
A
  1. In-Utero
  2. Endothelial Basement Membrane
    a. YES!!!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cornea: Endothelium

  1. Type of Cells and layers?
  2. What does it help Maintain?
  3. Number of Cells /mm^2?
    a. How many are lost each Year?
  4. What happens when you get 500 cells/mm^2?
A
  1. Single Layer of POLYGONAL CELLS
  2. The State of Corneal Hydration! (Pumps fluid OUT of the Cornea)
  3. 2500 cells/mm^2
    a. About 0.6% each year
  4. Corneal Edema and Decreased Transparency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cornea: 6th Layer?

  1. How long ago was it discovered?
  2. Discovered by whom?
  3. What do they think it is?
    a. Cellular?
    b. Thickness?
  4. How was it discovered?
  5. What do they think it’s important for?
A
  1. It’s a RECENTLY described “New” Layer. Called the DUA’s LAYER
  2. Harminder Dua and Perry Binder
  3. Very Strong Pre-Descemet’s Layer
    a. Acellular
    b. 10-15 microns Thick
  4. Using the Big Bubble Technique
  5. For Lamellar Surgeries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Cornea: A lot of Important Clinical Findings? (8)

A
  1. PEE
  2. PEK
  3. SEI
  4. SPK
  5. Filaments
  6. Edema
  7. Neovascularization
  8. Pannus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cornea: Superficial

  1. Punctate Epithelial Erosions (PEE): It’s an Early sign of what?
  2. What is it?
A
  1. of Epithelial Compromise

2. Tiny Defects (NaFl; Rose Bengal are the way to see them!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cornea: Superficial: PEE

  1. Location may indicate cause? (5 different places)?
A
  1. Central
  2. Diffuse
  3. Inferior
  4. Interpalpebral
  5. Superior
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Cornea: Superficial: PEK

  1. What is it?
  2. Can you see it w/o Staining?
  3. What will you see?
A

Punctate Epithelial Keratitis (PEK)

  1. Granular Swollen Epithelial Cells
  2. YES
  3. DISCRETE OPACITIES (Intra-Epithelial Infiltrates)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Cornea: Superficial: PEK

  1. Cases?
A
  1. Non-Specific: Seen in a wide variety of Conditions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cornea: Superficial: SEI

  1. What does SEI stand for?
  2. What is it?
  3. Where is it located?
  4. Can you stain it?
A
  1. Sub-epithelial Infiltrates (SEI)
  2. Tiny Focal Inflammatory Infiltrates
  3. They’re Just below the Surface
  4. No. Non-Staining
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Cornea: Superficial: SEI

  1. Causes? (4)
A
  1. Acne Rosacea
  2. Herpes Zoster
  3. Prolonged Viral Infection
  4. Other INFLAMMATORY CONDITIONS!!!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Cornea: Superficial: SPK

  1. What does SPK stand for?
  2. ONLY refers to LESIONS ASSOCIATED with what?
  3. What is it?
  4. Where is it found?
  5. Staining?
A
  1. Superficial Punctate Keratitis
  2. with THYGESON
  3. Course Punctate Grayish white clusters of Epithelial Lesions
  4. Central and Elevated
  5. Possible Negative Staining
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cornea: Superficial: SPK

More Recently:

  1. Type of finding?
  2. Used for what?
  3. What type of disruption?
A
  1. Common Non-specific Finding
  2. Used for a Variety of Conditions/Disorders
  3. Usually a Dot Like Epithelial Disruption
20
Q

Cornea: Superficial: Filaments

  1. What are they?
  2. What cells do they consist of?
  3. How are they attached to the Cornea?
  4. What do they STAIN with?
  5. Unattached END Moves around with what?
    a. Can cause what problem?
A
  1. Mucus Strands
  2. Mucus and Epithelial Cells
  3. To the Corneal Surface at One End
  4. Rose Bengal
  5. Moves around with each BLINK
    a. Can cause an Epithelial Defect
21
Q

Cornea: Superficial: Filaments

Causes

  1. What do they come from?
    a. What 4 conditions?
A
  1. They Arise from ABERRANT HEALING of the Epithelium
    a. Blepharospasm
    b. Dry Eye
    c. Recurrent Corneal Erosion
    d. SLK
22
Q

Cornea: Superficial: Epithelial Edema

  1. What is it?
  2. How may it present?
  3. In a more severe case, what will you see? (2)
A
  1. Edema of the Epithelium
  2. with a LOSS of Corneal Luster
  3. Tiny Epithelial Vesicles (called SADDLER VEIL)

and BULLAE

23
Q

Cornea: Superficial: Filaments

Causes

  1. Main Cause?
    a. Why does this happen?
  2. What’s the other main cause?
A
  1. Prolonged Contact Lens Wear
    a. Corneal Epithelium becomes Hypoxic
  2. Elevated IOP
24
Q

Cornea: Superficial: Superficial Neovascularization

  1. Where are vessels located?
    a. This is due to what?
A
  1. In Peripheral Anterior Corneal Surface

a. Due to CHRONIC Ocular Surface Irritation or Hypoxia

25
Q

Cornea: Superficial: Pannus

  1. What is it?
A
  1. Superficial Neovascularization that’s accompanied by Connective Tissue
26
Q

Cornea: Superficial: Deep

  1. What are the 6 deep findings we talked about?
A
  1. Infiltrates
  2. Ulcer
  3. Vascularization
  4. Descemet Fold
  5. Descemetocele
  6. Break in Descemet
27
Q

Cornea: Superficial: Deep: Infiltrates

  1. What is it?
  2. Caused by what cells?
  3. What type of Debris do we see?
  4. 2 forms?
A
  1. Acute Stromal Inflammation
  2. Inflammatory Cells
  3. Cellular and Extracellular Debris
  4. Sterile and Infective
28
Q

Cornea: Superficial: Deep: Infiltrates

Infective

  1. Size?
  2. Progression?
  3. Epithelial Defect?
  4. Pain?
  5. Discharge?
  6. Single or Multiple?
  7. Unilateral or Bilateral?
  8. Anterior Chamber Reaction?
  9. Location?
  10. Adjacent Corneal Reaction?
A
  1. Usually larger
  2. Rapid
  3. Very Common and LARGER when Present
  4. Moderate-Severe
  5. Purulent
  6. Typically Single
  7. Unilateral
  8. Severe
  9. Often Central
  10. Extensive
29
Q

Cornea: Superficial: Deep: Infiltrates

Sterile

  1. Size?
  2. Progression?
  3. Epithelial Defect?
  4. Pain?
  5. Discharge?
  6. Single or Multiple?
  7. Unilateral or Bilateral?
  8. Anterior Chamber Reaction?
  9. Location?
  10. Adjacent Corneal Reaction?
A
  1. Tend to be Smaller
  2. Slow
  3. Much less common and if present, tends to be small
  4. Mild
  5. Mucopurulent
  6. Usually Multiple
  7. Usually Bilateral
  8. Mild
  9. Typically Peripheral
  10. Limited
30
Q

Cornea: Superficial: Deep: Ulcer

  1. What is it?
  2. Involves what defect?
A
  1. Tissue Excavation

2. an Epithelial Defect

31
Q

Cornea: Superficial: Deep: Vascularization

  1. Where is it commonly seen?
  2. Due to what 4 things?
A
  1. Anterior or Deep Stroma
  2. a. Chronic Inflammation or Infection
    b. Graft Rejection
    c. Hypoxia
    d. Wound
32
Q

Cornea: Superficial: Deep: Descemet Folds

  1. What are they?
  2. Associated with what 3 things?
A
  1. Wrinkles of Descemets Membrane
  2. a. Edema
    b. Hypotony
    c. Keratoconus
33
Q

Cornea: Superficial: Deep: Descemetocele

  1. What is it?
  2. May be due to what 2 things?
A
  1. Herniation of Descemet Membrane
  2. a. Corneal Trauma
    b. Ulcer
34
Q

Cornea: Superficial: Deep: Break in Descemets

  1. Due to what 3 things and give example of each?
A
  1. Trauma
    a. Forceps at Birth
    b. Vertical Striae
  2. Glaucoma
    a. Haabb Striae
    b. Horizontal Striae
  3. Distortion
    a. Keratoconus
35
Q

Cornea: Superficial: Congenital Anomalies

  1. 7 Congenital Anomalies
A
  1. Axenfeld-Rieger Syndrome
  2. Cornea Plana
  3. Megalocornea
  4. Microcornea
  5. Peters Anomaly
  6. Posterior Embryotoxan
  7. Sclerocornea
36
Q

Cornea: Congenital Corneal Anomalies:

Microcornea

  1. How common is it?
    a. Genetic disorder type?
  2. Uni or Bilateral?
  3. The adult HORIZONTAL Diameter is what?
  4. Deep or Shallow Anterior Chamber?
  5. Linked to what 2 diseases?
  6. What else happens?
A
  1. RARE
    a. Autosomal Dominant
  2. can be EITHER
  3. Has a Diameter of 10mm or LESS
  4. SHALLOW
  5. Ehlers-Danlos and Fetal Alcohol Syndrome
  6. Hyperopia
37
Q

Cornea: Congenital Corneal Anomalies

Microcornea

  1. Associations: What 7 diseases is it associated with? (in other words, usually presents along with one or more of these)
  2. Treatment
    a. Manage what?
    b. Monitor for what?
A
  1. a. CORNEAL PLANA
    b. Congenital Cataract
    c. Glaucoma (open and closed angle)
    d. Leukoma
    e. Microphakia
    f. Optic Nerve Hypoplasia
    g. Rieger’s Anomaly
  2. a. Refractive Error
    b. for Glaucoma and Other Complications
38
Q

Cornea: Congenital Corneal Anomalies

Megalocornea

  1. How common is it?
  2. Uni or Bilateral?
  3. Is it a PROGRESSIVE disease?
  4. Corneal Diameters of what?
  5. Anterior Chamber: Deep or Shallow?
  6. What 2 things are associated with it? (eye sight errors)
  7. It’s due to what?
A
  1. RARE
  2. BILATERAL
  3. Non-Progressive
  4. of 13 mm or greater
  5. Deep
  6. Astigmatism and HIGH Myopia
  7. Defective Growth of Optic Cup
39
Q

Cornea: Congenital Corneal Anomalies

Megalocornea

  1. IOP levels?

Associations

  1. Pigment Dispersion (what 2 things)
  2. Lens Subluxation (what stretches)?
  3. Linked to what 4 syndromes?
A
  1. NORMAL
  2. a. Krukenberg Spindle
    b. Trabecular Hyperpigmentation
  3. Zonular Stretching
  4. a. Alport Syndrome
    b. Ehlers Danlos Syndrome
    c. Down Syndrome
    d. Marfan’s Syndrome
40
Q

Cornea: Congenital Corneal Anomalies

Megalocornea

  1. Treatment
    a. What do we manage?

b. What do we monitor for?

A
  1. a. Manage refractive Error

b. Glaucoma and other complications

41
Q

Cornea: Congenital Corneal Anomalies

Sclerocornea

  1. How common is it?
    a. If it’s Autosomal Dominant (severity)?
    b. and Autosomal Recessive?
  2. Uni or bi?
  3. What happens to the Periphery of the Cornea?
  4. May involve what?
A
  1. VERY RARE
    a. Mild
    b. SEVERE
  2. Bilateral
  3. Peripheral Corneal Opacification and Vascularization
  4. The Entire Cornea
42
Q

Cornea: Congenital Corneal Anomalies

Sclerocornea

  1. What 4 things is it associated with?
  2. Treatment?
A
  1. a. Cornea Plana
    b. Glaucoma
    c. Iris Abnormalities (Aniridia, Coloboma)
    d. Microphthalmos
  2. Uni: Monitor?
    * Bilateral: PKP (poor prognosis)
43
Q

Cornea: Congenital Corneal Anomalies

Cornea Plana

  1. How common is it?
  2. Uni or bi?
  3. What is it?
  4. 2 types: What genetic abnormality and refractive power of cornea for each?
A
  1. RARE
  2. BILATERAL
  3. It’s a FLAT CORNEA
  4. a. Cornea Plana 1: Auto. Dom.; Power = 38-42
    b. Cornea Plana 2: Auto Recess.; Power: 23-35
44
Q

Cornea: Congenital Corneal Anomalies

Cornea Plana

  1. Associated with what 5 things?
A
  1. Aniridia
  2. Glaucoma
  3. High Hyperopia
  4. Microcornea
  5. Shallow Anterior Chamber
45
Q

Cornea: Congenital Corneal Anomalies

Corneal Plana

  1. Treatment
    a. Correct what?
    b. Monitor for what?
A
  1. a. Refractive error

b. for Glaucoma and other Complications