CL 2-8: GP Lens Complications Flashcards
Fit Related Complications (6)
- Binding
- Corneal Edema
- Corneal Warpage
- Central Staining
- Dimple Veiling
- 3 and 9 Staining
Dimple Veiling (1)
- Etiology
a. Poor Fitting relationship b/w what?
b. Indentations are formed by AIR BUBBLES that are trapped b/w what?
c. FORMS IN AREAS of what?
d. Can also be due to the use of what?
- a. b/w Lens-Cornea
b. b/w Back Surface of Lens and Epithelium
c. of EXCESSIVE POOLING
d. to the use of Aerosol Saline
Dimple Veiling (2)
- Is it true corneal staining?
- How does it resolve?
- May interfere with what?
- What do we need to look at?
- How do you MANAGE IT?
- No.
- by removing the lens
- with Vision
- Look at the Fit AND Patient’s Symptoms to decide whether a change is needed.
- Adjust Fit to REDUCE POOLING in are of Dimple Veiling
Binding/Lens Adherence (1)
- Cause?
- You get thinning of what?
a. Especially during what?
b. Occurs in what % of Patients in GP LENS EXTENDED WEAR?
- Lens-Cornea Adherence in the ABSENCE of Lens movement with blink. (SUCTION EFFECT)
- thinning of post lens tear film
a. esp. during sleep
b. in 50% of Patients in GP lens EW.
Binding/Lens Adherence (2)
- Lenses bind/Adhere due to what?
a. 2 Places this can happen?
- due to insufficient tear flow.
a. tear flow can be impeded in the PERIPHERY or in the MID-PERIPHERY
Binding/Lens Adherence (3)
- Major Clue that a Lens is bound?
- What other 2 things are clues?
- NO MOVEMENT!
- a. Areas of Heavy bearing where TEARS are COMPLETELY ABSENT!
b. Tear exchange could be cut off in the Periphery or Mid-Periphery
Binding/Lens Adherence (4)
- Management
a. Improve what?
b. If LENS is TOO STEEP?
c. If BC is OKAY, but the PERIPHERAL SYSTEM is TOO TIGHT, what do you do?
- a. improve tear exchange
b. FLATTEN the BC. (All peripheral curves will be flattened as well)
c. LOOSEN the Peripheral Curves
Central Staining (1)
- Type of Lens that causes this?
- What is occurring b/w this lens and the Cornea that causes central staining?
- Flat Fitting Lens
2. Mechanical Force of LENS AGAINST the APEX of the Cornea ERODES the Corneal Surface
3 and 9 Staining (1)
- Corneal staining where?
a. Caused by what?
b. Why is it important to know about it?
- in the peripheral Cornea at 3 o’clock and/or 9 o’clock position
a. DESSICATION associated w/GP CL Wear
b. cuz it’s the MOST PREVALENT COMPLICATION of GP CL Wear
3 and 9 Staining (2)
- What?
- Why?
- Patient Symptoms?
- Superficial Microerosions of the Corneal Epithelium JUST LATERAL to CL EDGES!
- INADEQUATE CORNEAL WETTING!
- Usually none, but could be MILD IRRITATION, or Localized Conjunctival Injection
3 and 9 Staining (3): Management
- Aimed at Specific Cause
a. Treat what?
b. Improve what on CL?
c. what else can be IMPROVED?
d. How can you IMPROVE EDGE DESIGN?
- a. Treat DES and/or MGD
b. Lens movement if insufficient
c. CENTRATION so PERIPHERY of LENS is ALIGNED to the PERIPHERY of the CORNEA (Low riding lenses especially)
d. Decrease Edge Thickness and Change Peripheral Curve Radius/Width to either Increase or Decrease Peripheral Clearance
3 and 9 Staining (4)
So what can cause it?
- Periphery of Lens is NOT aligned w/Periphery of Cornea
- Insufficient Edge Clearance can lead to 3 and 9 staining
as well as Excessive Edge Clearance
3 and 9 Staining (5)
- Long term Complications of 3 & 9 Staining: (Chronic/Severe cases can lead to what 3 things?)
- Vascularized Limbal Keratitis (VLK)
- Dellen
- Infection
3 and 9 Staining (6)
- VLK
a. What is it?
b. AKA?
c. 4 major signs?
d. 5 Major symptoms?
- a. Inflammatory Complication Unique to GPs
b. Pseudo-Pterygium
c. Corneal Vascularization; Localized Conjunctival Injection; Semi-opaque Epithelial Elevation; Surrounding Tissue Stains with NaFl
d. Cosmetic concern; Lacrimation; Lens Awareness; Lens Discomfort; Photophobia
3 and 9 Staining (7)
- Management of VLK
a. Improve fit using what?
b. What topical can reduce Redness?
c. What topical may reduce inflammation?
- a. using Guidelines for 3&9 Staining
b. Topical Decongestants (Rebound Redness)
c. Topical Corticosteroid (Not a Long-term solution)
3 and 9 Staining (8)
- Dellen
a. It’s a Localized Excavation of the Cornea near what?
b. Local Dehydration of the STROMA leads to what?
c. Can occur as a result of what 3 things?
- a. near the Limbus with Intact Overlying Epithelium
b. that leads to a Compression of its Lamellae
c. of Surgery, Swelling of the Limbus (like in Episcleritis or Pterygium), or due to AGING
Corneal Warpage (1)
- Relative Flattening of Cornea underlying what?
a. High Riding Lenses = ?
b. Low Riding Lenses = ?
c. This can occur with what type of CL?
- the Resting area of the CL.
a. Superior Flattening (Keratoconus-like Pattern)
b. Inferior Flattening
c. any type of CL (more common w/GPs)
Corneal Warpage (2)
- Symptoms (1)?
- Signs (4)
- Spectacle Blur
- a. Corneal Cyl does not equal Refractive Cyl
b. Decreased Myopia
c. Distorted Keratometry Mires
d. Topographic Changes (Corneal Flattening, Irregular Astigmatism)
Corneal Warpage (3)
- Treatment
a. Main thing to do?
b. GP Warpage takes how long to Normalize?
c. CAUTION with what?
d. Repeat Topography how often?
- a. DISCONTINUE CL WEAR!
b. about 10 wks to normalize (but can take up to 6 months)
c. with Refractive Surgery!
d. every 2-4 weeks
Corneal Warpage (4)
- Differentiating Warpage and Keratoconus: KERATOCONIC EYES Have what 5 things?
- Corneal Warpage: On Topographer can have what?
- a. Greater Corneal Toricity
b. Posterior Elevation Map Changes (Orbscan, Pentacam)
c. Slit lamp signs of the disease (usually)
d. Steeper K Values
e. Thinner Corneal Pachymetry - can have an INFERIOR “Smile” Pattern
Corneal Edema/Central Corneal Clouding (CCC) (1)
- Corneal Edema Secondary to what?
a. What 4 things can cause this? - 4 Major Symptoms?
- to Chronic Hypoxia
a. Insufficient Tear Exchange, Lens overwear and/or EW, Low Dk Material, Thick Lens - a. Haloes
b. Photophobia
c. Spectacle Blur
d. Stinging, Burning, Pain
Corneal Edema/Central Corneal Clouding (CCC) (2)
- Differential Diagnoses for Corneal Clouding? (7)
- Birth Trauma
- Congenital Hereditary Endothelial Dystrophy (CHED)
- Dermoid Tumors
- Infectious/inflammatory Processes
- Mucopolysaccharidoses
- Peters Anomaly
- Sclerocornea