Ocular Disease: Lecture 9: Cornea

Question 1

Cornea

1. It’s the most densely what in the body?
2. a. Length: Horizontally?
   b. Vertically?
   c. Thickness?
   d. Where is it thickest?

Answer 1

1. Most densely innervated tissue in the body
2. a. 12 mm
   b. 11.5 mm
   c. 540 microns thick
   d. in the Periphery

Question 2

Cornea: Layers

1. What are the 5 layers

Answer 2

1. Epithelium
2. Bowman’s Layer
3. Stroma
4. Descemet’s Membrane
5. Endothelium

Question 3

Cornea: Epithelium Layer

1. 3 Types of cells?

Answer 3

1. Columnar Basal Cells; Wing Cells; Surface Squamous Cells

Question 4

Cornea: Epithelium Layer

1. What are Columnar Basal Cells attached to?
2. What happens to the Surface Squamous Cells?

Answer 4

1. To the Basement Membrane

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

Question 5

Cornea: Bowman’s Layer

1. What is it?
2. What is it made of?

Answer 5

1. It’s an ACELLULAR Superficial Layer of the Stroma

2. Collagen Fibers

Question 6

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?

Answer 6

1. 90% of the corneal thickness
2. Regularly Oriented Layer of the Collagen Fibers
3. NO!
4. Modified Fibroblasts are INTERSPERSED

Question 7

Cornea: Descemet’s Membrane

1. What is it?
2. How many zones and what are the zones?

Answer 7

1. Sheet of Collagen Fibrils

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

Question 8

Cornea: Descemet’s Membrane: 2 Zones

1. Anterio Banded is what?
2. Posterior Non-Banded: What is it?
   a. Can it regenerate?

Answer 8

1. In-Utero
2. Endothelial Basement Membrane
   a. YES!!!

Question 9

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?

Answer 9

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

Question 10

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?

Answer 10

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

Question 11

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

Answer 11

1. PEE
2. PEK
3. SEI
4. SPK
5. Filaments
6. Edema
7. Neovascularization
8. Pannus

Question 12

Cornea: Superficial

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

Answer 12

1. of Epithelial Compromise

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

Question 13

Cornea: Superficial: PEE

1. Location may indicate cause? (5 different places)?

Answer 13

1. Central
2. Diffuse
3. Inferior
4. Interpalpebral
5. Superior

Question 14

Cornea: Superficial: PEK

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

Answer 14

Punctate Epithelial Keratitis (PEK)

1. Granular Swollen Epithelial Cells
2. YES
3. DISCRETE OPACITIES (Intra-Epithelial Infiltrates)

Question 15

Cornea: Superficial: PEK

1. Cases?

Answer 15

1. Non-Specific: Seen in a wide variety of Conditions

Question 16

Cornea: Superficial: SEI

1. What does SEI stand for?
2. What is it?
3. Where is it located?
4. Can you stain it?

Answer 16

1. Sub-epithelial Infiltrates (SEI)
2. Tiny Focal Inflammatory Infiltrates
3. They’re Just below the Surface
4. No. Non-Staining

Question 17

Cornea: Superficial: SEI

1. Causes? (4)

Answer 17

1. Acne Rosacea
2. Herpes Zoster
3. Prolonged Viral Infection
4. Other INFLAMMATORY CONDITIONS!!!

Question 18

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?

Answer 18

1. Superficial Punctate Keratitis
2. with THYGESON
3. Course Punctate Grayish white clusters of Epithelial Lesions
4. Central and Elevated
5. Possible Negative Staining

Question 19

Cornea: Superficial: SPK

More Recently:

1. Type of finding?
2. Used for what?
3. What type of disruption?

Answer 19

1. Common Non-specific Finding
2. Used for a Variety of Conditions/Disorders
3. Usually a Dot Like Epithelial Disruption

Question 20

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?

Answer 20

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

Question 21

Cornea: Superficial: Filaments

Causes

1. What do they come from?
   a. What 4 conditions?

Answer 21

1. They Arise from ABERRANT HEALING of the Epithelium
   a. Blepharospasm
   b. Dry Eye
   c. Recurrent Corneal Erosion
   d. SLK

Question 22

Cornea: Superficial: Epithelial Edema

1. What is it?
2. How may it present?
3. In a more severe case, what will you see? (2)

Answer 22

1. Edema of the Epithelium
2. with a LOSS of Corneal Luster
3. Tiny Epithelial Vesicles (called SADDLER VEIL)

and BULLAE

Question 23

Cornea: Superficial: Filaments

Causes

1. Main Cause?
   a. Why does this happen?
2. What’s the other main cause?

Answer 23

1. Prolonged Contact Lens Wear
   a. Corneal Epithelium becomes Hypoxic
2. Elevated IOP

Question 24

Cornea: Superficial: Superficial Neovascularization

1. Where are vessels located?
   a. This is due to what?

Answer 24

1. In Peripheral Anterior Corneal Surface

a. Due to CHRONIC Ocular Surface Irritation or Hypoxia

Question 25

Cornea: Superficial: Pannus 1. What is it?

Answer 25

1. Superficial Neovascularization that's accompanied by Connective Tissue

Question 26

Cornea: Superficial: Deep 1. What are the 6 deep findings we talked about?

Answer 26

1. Infiltrates 2. Ulcer 3. Vascularization 4. Descemet Fold 5. Descemetocele 6. Break in Descemet

Question 27

Cornea: Superficial: Deep: Infiltrates 1. What is it? 2. Caused by what cells? 3. What type of Debris do we see? 4. 2 forms?

Answer 27

1. Acute Stromal Inflammation 2. Inflammatory Cells 3. Cellular and Extracellular Debris 4. Sterile and Infective

Question 28

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?

Answer 28

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

Question 29

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?

Answer 29

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

Question 30

Cornea: Superficial: Deep: Ulcer 1. What is it? 2. Involves what defect?

Answer 30

1. Tissue Excavation | 2. an Epithelial Defect

Question 31

Cornea: Superficial: Deep: Vascularization 1. Where is it commonly seen? 2. Due to what 4 things?

Answer 31

1. Anterior or Deep Stroma 2. a. Chronic Inflammation or Infection b. Graft Rejection c. Hypoxia d. Wound

Question 32

Cornea: Superficial: Deep: Descemet Folds 1. What are they? 2. Associated with what 3 things?

Answer 32

1. Wrinkles of Descemets Membrane 2. a. Edema b. Hypotony c. Keratoconus

Question 33

Cornea: Superficial: Deep: Descemetocele 1. What is it? 2. May be due to what 2 things?

Answer 33

1. Herniation of Descemet Membrane 2. a. Corneal Trauma b. Ulcer

Question 34

Cornea: Superficial: Deep: Break in Descemets 1. Due to what 3 things and give example of each?

Answer 34

1. Trauma a. Forceps at Birth b. Vertical Striae 2. Glaucoma a. Haabb Striae b. Horizontal Striae 3. Distortion a. Keratoconus

Question 35

Cornea: Superficial: Congenital Anomalies 1. 7 Congenital Anomalies

Answer 35

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

Question 36

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?

Answer 36

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

Question 37

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?

Answer 37

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

Question 38

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?

Answer 38

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

Question 39

Cornea: Congenital Corneal Anomalies Megalocornea 1. IOP levels? Associations 2. Pigment Dispersion (what 2 things) 3. Lens Subluxation (what stretches)? 4. Linked to what 4 syndromes?

Answer 39

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

Question 40

Cornea: Congenital Corneal Anomalies Megalocornea 1. Treatment a. What do we manage? b. What do we monitor for?

Answer 40

1. a. Manage refractive Error | b. Glaucoma and other complications

Question 41

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?

Answer 41

1. VERY RARE a. Mild b. SEVERE 2. Bilateral 3. Peripheral Corneal Opacification and Vascularization 4. The Entire Cornea

Question 42

Cornea: Congenital Corneal Anomalies Sclerocornea 1. What 4 things is it associated with? 2. Treatment?

Answer 42

1. a. Cornea Plana b. Glaucoma c. Iris Abnormalities (Aniridia, Coloboma) d. Microphthalmos 2. Uni: Monitor? * Bilateral: PKP (poor prognosis)

Question 43

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?

Answer 43

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

Question 44

Cornea: Congenital Corneal Anomalies Cornea Plana 1. Associated with what 5 things?

Answer 44

1. Aniridia 2. Glaucoma 3. High Hyperopia 4. Microcornea 5. Shallow Anterior Chamber

Question 45

Cornea: Congenital Corneal Anomalies Corneal Plana 1. Treatment a. Correct what? b. Monitor for what?

Answer 45

1. a. Refractive error | b. for Glaucoma and other Complications