Week 6 - RGP Complications

Question 1

What is 3 and 9 O’clock corneal staining’s Aetiology?

Answer 1

• Poor edge design
• Thick edge design
• Edge clearance too large or too small
• Total diameter too large or too small
• Insufficient blinking

Question 2

What are 3 and 9 O’clock corneal stainings symptoms?

Answer 2

• Can be asymptomatic
• Irritation/dryness
• Reduced wearing time
• Red eyes

Question 3

What is 3 and 9 O’clock corneal staining’s signs?

Answer 3

• Usually bilateral
• Follows shape of lens (inner edge normally curved)
• Nasal and temporal punctate staining
• Can coalesce over time

• Bulbar redness nasal and temporal
• Can lead to:
- Neovascularization of the cornea
- Ulceration
- Scarring

Question 4

What is 3 and 9 O’clock corneal staining’s management?

Answer 4

• Refit with thinner edge design
• Refit with a GP toric lens if the cornea is >2DC
• Refit with Sily SCL
• Ocular lubricants
• Blinking exercises
• May need to reduce wearing time

Question 5

What is Vascularised Limbal Keratitis?

Answer 5

• A sequel to chronic 3 and 9 o’clock staining
• EW a risk factor
• Large diameter lenses/steep fit/narrow edge lift
• Mechanical irritation

• Rare

Question 6

What are Vascularised Limbal Keratitis symptoms?

Answer 6

• Can be asymptomatic in the early stages
• Gradually increase in discomfort, can be painful if advanced
• Photophobia and lacrimation
• Increasing ocular redness

Question 7

What are Vascularised Limbal Keratitis signs?

Answer 7

Appears as a limbal mass with blood vessels, usually opaque and elevated.
Associated conjunctival staining

Question 8

How is Vascularised Limbal Keratitis managed?

Answer 8

• This can be reversed
• Stop CL wear
• Consider refitting with smaller/flatter lens
• Ocular lubricants
• Monitor with regular aftercare appointments

Question 9

What is Dellen, and its risks?

Answer 9

• Dessication at the periphery of the cornea
• Due to dehydration of the cornea which causes the layers to compact together

• Risks
- Thick edge on CLs
- Increased tear evaporation
- Pinguecula/pterygium
- Post surgery

Question 10

What are Dellen Symptoms?

Answer 10

• Can be asymptomatic
• Can present with irritation and dryness
• May be symptoms of associated conditions such as 3 & 9 o’clock staining and dry eye disease

Question 11

Dellen - Signs?

Answer 11

• Saucer-like depression
• Localised thinning of the cornea
• Can pool with fluorescein
• Epithelium usually intact

Question 12

Dellen - management?

Answer 12

• Manage any associated 3&9 o’clock staining or dry eye disease
• Removing lens wear usually leads to resolution of the depression in a few days, scaring may remain
• But need to solve underlying problem
- Re-wetting drops
- Blinking exercises
- Reduce wearing time
- Refit with soft lenses

Question 13

Corneal staining - Dimple Veil?

Answer 13

• Gas bubbles trapped in tear film, break up into multiple small bubbles with pressure
• Leaves small pits in epithelium
• “pools” with fluroscein
• Caused by excessive corneal clearance/edge clearance so can be due to a steep or flat lens

Question 14

Corneal staining - dimple veil symptoms?

Answer 14

• Asymptomatic (usually)

Reduced vision if:
• Central
• Numerous
• Large

Question 15

Corneal staining - dimple veil management?

Answer 15

• Will resolve slowly if lenses removed

• Prevent by altering fit
- Reducing edge clearance (steepen)
- Reducing central clearance (flatten)

Question 16

How is staining classified by Type and depth?

Answer 16

• Type:
- Punctate
- Coalescent
- Patch
- Linear
- Arcuate

• Depth:
- Superficial epithelial
- Deep epithelial
- Stromal diffusion

Question 17

How is staining classified by location?

Answer 17

• By quadrant or central
• And using an appropriate grading scale

Question 18

LEFT OFF PAGE 23

Question 19

What causes a Foreign body track with CLs?

Answer 19

• Material trapped by CL
- Eyelashes
- Grit/sand
- Make up
- Back surface lens deposits
- Lid margin debris/flakes of skin
- Damaged lens
- Finger nail

Question 20

What are symptoms and management of foreign body tracks?

Answer 20

• Symptoms range from asymptomatic to sharp pain with associated lacrimation
• Irrigation if still uncomfortable once lens removed
• Need to thoroughly examine the eye including lid eversion

Management
• Remove lens for 24-48 hours to allow healing
• Prophylactic antibiotic?
• Sunglasses/eye protection
• Replace damaged lens
• Conversation around I&R

Question 21

What causes conjunctival staining with RGP’s?

Answer 21

Poor fitting:
• Excessive movement
• Decentration
• Large diameter
• Edge defects

• Incomplete/poor blinking

• Underlying dry eye disease

Question 22

What can be done to improve if there is conjunctival staining?

Answer 22

• Improve CL fit
- Steepen the fit
• Lubrication during CL wear
• Blinking exercises
• Refit

Question 23

does corneal oedema occur with RGP’s?

Answer 23

• Less common than with SCLs due to the high Dk of RGPs (though some modern SCLs also have high Dk)
• See the slides from Soft Complications
• Can be more subtle with RGPs
• Manage by stopping any EW and reducing wear time
• Maximise Dk
• Err on the flat side when fitting

Question 24

Does corneal vascularisation occur with RGP’s?

Answer 24

• Again, review the slides in SCL Complications
• Due to inadequate oxygen supply or a decentred lens over the limbus or a tight fitting lens or dellen

• Manage by increasing Dk/t
• Optimise CL fit, ensuring adequate movement but with good
centration

Question 25

Is RGP adherence a thing?

Answer 25

• Rare in DW but very common in EW • The main cause is believed to be a thinning of the tear film and eyelid pressure during sleep • Can be asymptomatic • Symptoms include - Foreign body sensation - Blurred vision with and without the lens - Dryness

Question 26

How is RGP adherence managed?

Answer 26

• Revert to Daily wear • Ocular lubricants in the morning • Do not remove lens until it is mobile • Reduce TD

Question 27

What causes lens warpage?

Answer 27

• 'heavy handling' e.g. cleaning between thumb and forefinger • Flat base on the lens case • Pressed into the lens case • Allowed to dry out • Thin lens design Symptoms - reduced vision, discomfort, reduced wear time

Question 28

What is lens warpage?

Answer 28

• Irregular mires on the keratometer or the focimeter • No end-point on refraction or a very odd result • Altered fit and fluorescein pattern

Question 29

How is Lens warpage managed?

Answer 29

• Re-educate the patient • Replace lens • Increase the lens thickness

Question 30

Ptosis with RGP’s?

Answer 30

• Long term gas permeable wear • Upper lid rests in a lower than normal position • Typically bilateral • Can be accompanied by thickening and reddening of upper lid

Question 31

What are possible causes of Ptosis with RGP?

Answer 31

• Mechanical interaction (lid riding over the CL edge) • Oedema of the lid tissue and then gravity • Inflammation • Long time wear

Question 32

How is ptosis with RGP’s managed?

Answer 32

• Stop lens wear temporarily • Refit with SCLs • Reduce CL thickness • Regular after-care • Make sure to rule out other causes

Question 33

What is Acanthomoeba Keratitis, signs and symptoms and why is diagnosis important?

Answer 33

• Protozoan MK • Acanthomoeba are found in tap water, increased risk with CL wear • Clinical signs are disproportionate to symptoms - Patient will report pain and possibly lacrimation, blurred vision, photophobia - Signs are non specific in the early stages. Possibly infiltrates or a pseudo-dendrite appearance (similar to Herpes). A ring defect will appear in due course • Diagnosis often delayed • Be aware of this in a CL wearer

Question 34

How is Acanthomaeba keratitis treated?

Answer 34

• Rare (thankfully) • Sight threatening, it is a stubborn organism that is difficult to irradicate • Must be treated by ophthalmology, corneal scraping required diagnosis