EST: CL COMPLICATIONS AND MANAGEMENT Flashcards
what are the 5 things that make up ideal CL?
- provide normal vision
- provide sufficient O2 for normal corneal metabolism
- able to avoid ocular complications
- allow for unlimited CL wear
- allow for safe and comfortable CL wear
what are the 3 main types of CL complications
- corneal edema
- infections and inflammations
- lens and lens fit related
what causes CL induced edema? what are some signs and symptoms
hypoxia
Dk/t related
ssx:
- hazy tissue
- central cornea more affected compared to periphery
- generally asymptomatic unless significant corneal swelling
- reduced vision
- haziness
- halos
- spectacle blur
what is the management for corneal edema?
increase dk/t
reduce wearing time
monitoring
what are the types/ signs of corneal edema from least to most severe?
striae 8% edema folds 10-15% edema corneal haze > 15% edema microcysts vacuoles endothelial polymegathism corneal neovas
what is endothelial polymegathism caused by
chronic hypoxia induced by long term CL wear
slow progression, asymptomatic
what are some ssx of corneal neovas? cause? what is the management?
Signs: extending of limbal blood vessels into cornea, location usually superiorly under the lids or correspond to the lens thicker area
cause: : Hypoxia with Lower Dk lenses
management:
Switch to SiHy lenses (higher dk/t)
Strictly Daily wear (no sleeping in lenses)
what are some ssx of CL induced papillary conjunctivitis? cause? what is the management?
ssx:
Lens awareness, discharge in the morning, itch after removing lens, blurry vision if lens is deposited heavily, stinging/burning sensation upon insertion
enlarged papillae, palpebral redness
cause: : Allergy towards the lens deposits
management:
1) Refer to get Mast Cell Stabiliser eye drop to relieve symptoms (from GP or pharmacist). Cease lens wear if GPC grade 3 or 4
2) Schedule review to check of recovery
3) Switch to DD or RGP, or to add enzymatic cleaner into the
what are some ssx of microbial keratitis? cause? what is the management?
ssx:
Severe pain, photophobia, tearing
lids are swollen, corneal ulcers with staining and hyperaemia
cause: Due to contaminated CL/lens case/solutions, soft extended wear, poor hygiene and non-compliance and corneal hypoxia.
* *infection!!
management:
1) Immediate referral to eye specialist/ A & E
2) Review compliance
3) Switch to DD or RGP but strictly DW
what are 6 risk factors of MK
- exposure to organism (contaminated water)
- smoking
- corneal trauma
- online purchasing of CL
- swimming
- contact lens wear
what are some ssx of CL induced peripheral ulcer? cause? what is the management?
ssx:
Some redness, some tearing , may be pain, unable to wear lenses
small round peripheral corneal epithelial defects (ulcer), some limbal and conjunctiva hyperaemia near the ulcer.
cause:
Non infectious/sterile inflammatory response to bacteria toxins. Often seen in Px who sleep in SCL
management:
1) Assume it is infectious , refer to GP/eye specialist
2) Review the next day
3) Cease lens wear until fully recovered
4) Switch to DD or RGP
5) review compliance
how to differentiate MK and CLPU?
MK is due to infection and CLPU is due to inflammation
PEDAL sign!
what are some ssx of corneal infiltrative events? cause? what is the management?
ssx:
Small diffuse infiltrates, are usually found, near the periphery of cornea, and, at the layer of, epithelial, sub-epithelial, or, stromal, staining is absent.
cause:
hypoxia, lens fitting, or lens care issues, bacteria toxins trapped beneath the contact lenses and patient compliance, can be a predecessor of an infection
management:
change in the type of lenses, for example, to increase oxygen permeability, Px compliance
what are some ssx of CL acute red eye CLARE? cause? what is the management?
ssx:
Painful red eye upon waking (with CL), teary, some discharge
moderate to severe ocular redness, (punctate) cornea staining with infiltrates (accumulation of white blood cells) at periphery or mid periphery
cause: : Immune response to bacteria toxin or lens deposits during overnight lens wear
management:
1) Cease lens wear. Assume infectious and immediate refer to GP/Eye specialist.
2) Review the next day if seeing GP
3) Switch to RGP if DW is not feasible
4) Review lens care routines
what causes arcuate staining? what are the two types of arcuate staining and what causes them?
- lens edges
- tight fit
- deposits on posterior lens surface
1.SMILE staining:
in lower third of cornea
lens dehydration
poor or incomplete blinking
- superior epithelial arcuate lesion (SEAL)
thought to be caused by SiHy (has higher modulus)
causes discomfort
what are the ssx of SEAL? cause? management?
ssx:
asymptomatic or some lens awareness
cause:
eye lid pressure + high modulus Material + high minus power (mechanical)
management:
1) Cease lens wear
2) Schedule review to check on recovery
3) switch to third generation SiHy / check with website for the published modulus value before refitting
what causes central staining?
poorly fitted lens
- solution or material allergies
- toxic reaction
what causes punctate staining?
- Corneal desiccation
- Poor blinking
- Solution / toxic reaction
what causes irregular staining?
- poorly fitted lens
- damaged lens
- poor I&R technique
what are the ssx of solution induced corneal staining? cause? management?
ssx: Redness and foreign body sensation/ stinging upon insertion, gets better in the afternoon
cause: Toxicity from disinfectants in solution when combining SiHy with PHMB
combining group 4 lenses with sorbitol solution
management:
1) Stop lens wear until cornea fully recovered
2) Schedule review
3) switch to H2O2 or non-PHMB solution
what are the ssx of 3 and 9 o clock staining? cause? management? ! RGP ISSUE!
ssx:
Cornea and Conjunctiva staining at 3 & 9 o’clock,
Some discomfort or dryness complaints, conjunctiva redness and inferiorly decentered RGP
cause:
desiccation of corneal and conjunctival surface (tear not distributed to that area during blinks)
management:
1) Improve RGP centration
2) Prescribe wetting drops
3) switch to SCL as last option
what is dry eye? what causes it in CL?
tears aren’t able to provide adequate lubrication for your eyes
tear film in CL wear separates the tears into the Pre-Lens Tear Film(PrLTF) and Post-Lens Tear Film(PoLTF)
This disruption in the tear structure causes unstable tear film that lead to DE.
what causes increased SCL evaporation rate? what does SCL evaporation lead to?
i) lower humidity
ii) higher air temperature
iii) higher water content materials
iV) thinner SCL
causes SCL dehydration and thus Hyperosmotic PoLTF
how does Hyperosmotic PoLTF cause dry eyes?
Hyperosmotic PoLTF stimulates corneal nerve endings, activates ocular immune response, and elicits dry-eye symptoms.
describe the events leading to CL induced dry eyes
- separation of tear film, tear composition changes and unstable tearfilm
- increased evaporation of pre lens tear film
- reduced tear vol. in eye (pre and post tear film)
- stagnant PoLTF, tear hyperosmolarity, increased friction between lens and ocular suraface
what are 5 ssx of dry eyes that px will experience?
- stinging/burning
- excessive tearing
- sandy/gritty sensation (end of day discomfort)
- episodes of blurred vision
- redness
what are 5 clinical signs of CL induced DE?
- ‘sluggish’ movement of tear debris (observed using Slit lamp) may indicate an aqueous-deficient, mucus-rich and/or lipid-rich tear film, and the amount of debris provides an indication of the level of contamination of the tears.
2, Lens surface haziness indicating lens surface becoming “non-wettable” due to deposits.
- Reduced TBUT indicating unstable tear film.
- NaFl staining of ocular surfaces (cornea, bulbar conjunctiva and Lid-wiper) indicating ocular surface tissues damages.
- Hyperosmolarity of tear film indicating the unusually high salt content in tears. Osmolarity measurement has been shown to be the gold standard test in diagnosis of DE.
what are 8 managements for DE?
- Re-wetting eye drop (always consider product backed by latest research findings).
- Refit with Daily disposable for best hygiene and also to prevent other complications.
- Switch to H2O2 if using MPS previously
- Switch to DW if previously in EW.
- Omega 3 and omega 6 supplement which have anti-inflammatory effect.
- Switch to Proclear 1 day (FDA approved to treat CL induced DE) or low water content materials like SiHy.
- Reduce wearing hours and limit digital device usage (when wearing CL).
- Switch to RGP corneal lens as the last resort.
what are 7 ways to prevent CL complications?
- Patient selection – motivated, health, compliant
- Patient Education – CL care, handling & hygiene
- Lens and wearing regime selection
- Aftercare is important
- Careful questioning of Px
- Meticulous ocular examination
- CL induced complications knowledge
how often should we perform after care?
1st session: after 1 week
2nd session: after 1 month of first aftercare
subsequently ever 3-6 months
