Week 6 - RGP Complications Flashcards
What is 3 and 9 O’clock corneal staining’s Aetiology?
• Poor edge design
• Thick edge design
• Edge clearance too large or too small
• Total diameter too large or too small
• Insufficient blinking
What are 3 and 9 O’clock corneal stainings symptoms?
• Can be asymptomatic
• Irritation/dryness
• Reduced wearing time
• Red eyes
What is 3 and 9 O’clock corneal staining’s signs?
• 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
What is 3 and 9 O’clock corneal staining’s management?
• 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
What is Vascularised Limbal Keratitis?
• 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
What are Vascularised Limbal Keratitis symptoms?
• Can be asymptomatic in the early stages
• Gradually increase in discomfort, can be painful if advanced
• Photophobia and lacrimation
• Increasing ocular redness
What are Vascularised Limbal Keratitis signs?
Appears as a limbal mass with blood vessels, usually opaque and elevated.
Associated conjunctival staining
How is Vascularised Limbal Keratitis managed?
• This can be reversed
• Stop CL wear
• Consider refitting with smaller/flatter lens
• Ocular lubricants
• Monitor with regular aftercare appointments
What is Dellen, and its risks?
• 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
What are Dellen Symptoms?
• 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
Dellen - Signs?
• Saucer-like depression
• Localised thinning of the cornea
• Can pool with fluorescein
• Epithelium usually intact
Dellen - management?
• 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
Corneal staining - Dimple Veil?
• 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
Corneal staining - dimple veil symptoms?
• Asymptomatic (usually)
Reduced vision if:
• Central
• Numerous
• Large
Corneal staining - dimple veil management?
• Will resolve slowly if lenses removed
• Prevent by altering fit
- Reducing edge clearance (steepen)
- Reducing central clearance (flatten)
How is staining classified by Type and depth?
• Type:
- Punctate
- Coalescent
- Patch
- Linear
- Arcuate
• Depth:
- Superficial epithelial
- Deep epithelial
- Stromal diffusion
How is staining classified by location?
• By quadrant or central
• And using an appropriate grading scale
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What causes a Foreign body track with CLs?
• Material trapped by CL
- Eyelashes
- Grit/sand
- Make up
- Back surface lens deposits
- Lid margin debris/flakes of skin
- Damaged lens
- Finger nail
What are symptoms and management of foreign body tracks?
• 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
What causes conjunctival staining with RGP’s?
Poor fitting:
• Excessive movement
• Decentration
• Large diameter
• Edge defects
• Incomplete/poor blinking
• Underlying dry eye disease
What can be done to improve if there is conjunctival staining?
• Improve CL fit
- Steepen the fit
• Lubrication during CL wear
• Blinking exercises
• Refit
does corneal oedema occur with RGP’s?
• 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
Does corneal vascularisation occur with RGP’s?
• 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
Is RGP adherence a thing?
• 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
How is RGP adherence managed?
• Revert to Daily wear
• Ocular lubricants in the morning
• Do not remove lens until it is mobile
• Reduce TD
What causes lens warpage?
• ‘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
What is lens warpage?
• Irregular mires on the keratometer or the focimeter
• No end-point on refraction or a very odd result
• Altered fit and fluorescein pattern
How is Lens warpage managed?
• Re-educate the patient
• Replace lens
• Increase the lens thickness
Ptosis with RGP’s?
• 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
What are possible causes of Ptosis with RGP?
• Mechanical interaction (lid riding over the CL edge)
• Oedema of the lid tissue and then gravity
• Inflammation
• Long time wear
How is ptosis with RGP’s managed?
• Stop lens wear temporarily
• Refit with SCLs
• Reduce CL thickness
• Regular after-care
• Make sure to rule out other causes
What is Acanthomoeba Keratitis, signs and symptoms and why is diagnosis important?
• 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
How is Acanthomaeba keratitis treated?
• Rare (thankfully)
• Sight threatening, it is a stubborn organism that is difficult to irradicate
• Must be treated by ophthalmology, corneal scraping required diagnosis
