Soft contact lens complications Flashcards
how can we classify cl complications?
through aetiology or origin (mechanical) or by ocular structure effected
state 7 classifications of soft cl complications
- Metabolic influences (eg hypoxia)
- chemical influences(eg different ph with solution)
- toxic reactions (reactions with preservatives)
- allergic reaction (eg due to care regime or hypersenstivity to deposits)
- mechanical influences (breakages/modulus)
- tear deficiency (dehydration of lens)
- infection (eg bacterial)
what is a significant property of the cornea and how does it receive its nutrients?
cornea is avascular- nutrients supplied by aq humour and tears
state some corneal complications with soft lenses?
endothelial blebs,
microcysts,
oedema,
epithelial wrinkling,
staining,
neovascularisation,
endothelial bedewing,
how common is staining in a.) cl wear and b.) non cl wear
Common in up to 60% of contact lens wearers
Occurs in non-CL wearers (35%)
is staining asymptomatic?
can be asymptomatic
what are the 4 things to assess with corneal staining
Type, Location, Extent, Depth
what is three of describing CL staining pattern ?
- Puncate
- coalesced
- Confluent
what examples the locations of corneal staining
Location: e.g. central, peripheral, 3 o’clock to 4 o’clock
what are the two ‘extents’ to corneal staining
diffuse or localised
what are the depths of corneal staining
epithelial/superficial or stromal
what is SMILE staining?
located inferiorly, associated with dryness (eg dry environments) and incomplete blinks
how do we manage SMILE staining?
dry eye drops (preservative free), treat underlying MGD/bleph if present,modify environment, change lens type, blinking, 20/20/20, find underlying cause first
What can we do if SMILE staining is related to MGD?
we can re-review the px, to address the MGD
what is seen in mechanical corneal staining?
foreign body tracks
what can cause mechanical corneal staining
ABRASION - e.g. something caught under lens
how do we manage mechanical corneal staining?
- removal of lenses
- resume use once condition resolved,
- re-review px,
- lubrication (Eye drops etc),
- cl re-fit esp if tight
need to advise about hygiene ect, which to dailys if wearing monthlies
what does SEAL stand for?
superior epithelial arcuate lesion
what is SEAL normally associated with?
first generation siHy lenses
how do we manage SEAL
- removal of lenses,
- review px in 1 week,
- refit with lower modulus lens,
- consider rgp lenses : although this has a higher modulus, it is smaller.
how can we generally manage scl complications? general principles
- remove lenses,
- educate px on blinking eye drops,
- what to do in emergency (Seek medical attention),
- lubricating drops,
- prophylactic antibiotics,
- refer if severe staining (eg stromal),
- find underlying cause
causes of microcysts
hypoxia
what are microcysts and do they show reversed or unreversed illumination?
superficial epithelial vesicles, Show reversed illumination (not fluid filled)
where are vacuoles usually found?
Usually in mid-peripheral cornea
what can cause vacuoles?
chronic hypoxia
do vacuoles show reversed or unreversed illumination and why?
unREVERSED- as they are fluid filled
what is the average percentage of oedema we experience when sleeping?
4%
do daily or extended wear lenses cause more swelling
extended wear
what are the 3 different stages of oedema?
striae
Folds
Haze
what is the management for oedema?
remove lenses, manage wear time, change lenses
what is vascularisation?
normal vascular capillaries within cornea and limbus region-‘enroachment 0.2mm’- more common superiorly due to lack of O2
What is neovascularisation?
Formation of new blood vessels in areas which were previously avascular
what is vasoproliferation?
Increase in no. of vessels
what are the 3 theories as to why neovascularisation can occur?
Metabolic theory
Vasogenenic homeostasis model
Neural theory
what is the metabolic theory for neovasc?
- hypoxia causes production of VEGF
- lactic acid (hypoxia and or tight fit lens),
- stromal softening (chronic oedema) - reduces physical barrier for vessel to grow
- oedema (Excess fluid)
what is the vasogenic theory for neovasc?
local vasostimulatory factors= corneal vascularisation- creates conc that new vessels grow on, followed by inflam + leuokocytes- these may produce vasostimulatory factors
what is the neural theory for neovasc?
corneal nerves can play in vessel growth- cl wear associated with corneal nerves/sensitivity
what does neovasc appear as?
superficial or deep stromal
what is superficial neovasc and what is a complication?
vessels can leak an extra vascular lipid-like fluid and can cross line of sight
what is deep stromal neovasc?
- occurs at all levels of stroma
- numerous tortuous branches
- pattern of vessels may reflect breakdown in stromal tissue
- loss of vision occurs IF crosses line of sight
how can we manage neovasc?
cease cl wear
monitor recovery of px, -can leave ghost vessels
possible refit to siHy lenses
greater movement on fitting
earlier recall
characteristics of epithelial wrinkling?
rare cl complication,
painful,
VA usually affected (basically tight fit causes epithelial to wrinkle up)
how do we manage epithelial wrinkling?
stop cl wear, can resolve within 6 hrs but can take upto 1 wk
is px symptomatic with endothelial bedewing and why?
px can be symptomatic- redness, irritation, stinging, lens intolerance DUE TO inflam cells on endothelium
Does enothelial bedewing show reversed or unreversed illumination?
reversed-like epithelial microcysts
how can we manage endothelial bedewing?
rule out other possible things- PDS (pigment dispersion syndrome) or uveitis, then refit with dailies
what are endothelial blebs?
black non-reflecting ‘holes’, ‘transient change’ in corneal endothelium
when can endothelial blebs be seen?
in 10 mins of insertion- peak at 30 mins
how can we observe endothelial blebs? (technique)
specular mag technique- need high mag
what is aetiology of endothelial blebs?
‘acidic shift’ CO2/lactic acid
name some CL ocular conditions in relation to eyelid
lid wiper epitheliopathy(LWE),
incomplete blinking,
MGD
What is CL induced Ptosis?
more common in rgp wearers, can be due to abnormal insertion and removal- stretch levator and weaken muscle,
CAUSED BY weak levator aponeurosis or abnormal force
name disorders of the conjunctiva?
hyperaemia,
lid wiper epitheliopathy (LWE)
lid parallel conjunctival folds (LIPCOF)
staining
papillary conjunctivits (CLPC)
conjunctival epithelial flap
state some palpebral changes?
hyperaemia, papillae, follicles and concretions
what is the difference of follicles and papillae
follicles - not CL related, sign of viral infection
papillae - have central blood vessel , can be sign of GPC
what do concretions look like?
pale yellow accumulations beneath the palpebral conjunctival epithelium
what symptoms do you get with concretions?
foreign body sensation
what are signs of CL associated papillary conjunctivitis?
Papillae
Hyperaemia
Mucus discharge-
Lens deposition-protein- can affect comfort
Excessive movement- rgps
what is the first sign of inflammation?
hyperaemia
what are symptoms of cl associated papillary conjunctivitis?
blurred vision (lens deposits, mucus)
itching
FB sensation
what are causes of cl associated papillary conjunctivits?
allergic, mechanical, hypersensitiy, stiffer material SCL, sensitivty to solutions or preservatives, MGD
how do we manage cl associated papillary conjunctivits (short-term)?
remove source- eg if mechanical or protein deposits- cease cl wear or change solution, allow to resolve- can take a few months, preservative free lubricants
how do we manage cl associated papillary conjunctivits (long-term)?
Improve lens care regime
Daily disposables
Alter lens design or material- refit after grade 1, Manage any lid margin disease
what are disorders associated with limbus?
redness and Superior limbic keratoconjunctivitis
what is limbal hyperaemia?
series of blood vessels within the limbus
how can we treat limbal hyperaemia?
Record-use grading scale
Cease lens wear
Refit with high Dk lens/SiH
Reduce WT
Alter lens fit
Review care regime
what is the aetiology of limbal hyperaemia?
Hypoxia
Infection / Inflammation
Trauma
Solution toxicity/ hypersensitivity
Lens deposits
Mechanical- answer if px wears sihy- as can’t by hypoxia
characteristics of superior limbic keratoconjunctivitis?
Involves corneal epithelium, stroma, limbus, bulbar and tarsal conjunctiva,
associated with cl solution toxicity
Hypoxia, thought to be an aggravating factor
what can sectoral conjunctival hyperamia be associated with?
likely to be specific cause eg infilitrate,
what can interpalpebral conjunctival hyperamia be associated with?
chronic dryness and RGP wear
Can be an allergic and/or mechanical cause
what can bulbar hyperaemia be associated with?
Common with soft CL wear, but also a sign associated with many other serious eye conditions
what are the 3 types of conj hyperaemia?
sectorial, interpalpebral and bulbar
how do we manage conj hyperaemia?
Identify and address cause
Refit- change lens design
Refit-change lens material e.g. different modulus or Dk
Refit- more frequent replacement
Review care regime
Ocular lubricants
Consider environmental factors
what is a lens indentation?
Lens indentation (furrow staining)
Pressure from superior lid
what is a conjunctival epithelial flap?
loose conj tissue in area of lens indentation- can be superior or inferior, assoiciated with sihy cl wear, – cause superficial layers of conjunctival cells to break down
- found in GP wearers-esp if poor fit and going across inferior limbus
How do we manage conj epithelial flap?
- cease cl wear
- lower modulus lens
- reduce overnight wear
What can diffuse punctate staining covering the limbus, cornea and conjunctiva be a sign of?
toxicity
What is the managment of a toxcity reaction?
- stay out of lenses until resolved
- review in 2-3 days
- address cause (e.g. change solution)
Where is conjunctival epithelial flaps found in the most?
GP lens - poor fit and going across the inferior limbus
what do concretions look like?
pale yellow accumulations beneath the palpebral conjunctival epithelium
management of conj epithelial flap?
cease lens wear
lower modulus
reduce overnight wear
what deposits are these?
protein
what material are protein deposits attracted to?
hydrogel
when you have protein deposits what other signs do you see?
papillary conjunctivitis
management of protein deposits?
- review care routine
- increase lens replacement frequency
- change material
what deposits are these?
Lipids
what materials are lipid deposits attracted to?
group 2 and SiHy lenses
what symptoms does the px get with lipid deposits?
smeary vision
colour fringes
toric lens may destabilise
management of lipid deposits
- review care routine
- increase lens replacement frequency
- change material
- treat any MGD
what deposits are these?
Fungal
why do you get fungal deposits on lenses?
contamination of lens by fungus
what are fungal deposits associated with?
intermittent wearers and long-term lens storage
poor hygiene
management of Fingal deposits
- need to replace lens
- review hygiene
- care regimen
- switch to dailies
what are jelly bumps?
- focal gelatinous lumps
- mucous lipid protein and calcium build up
What deposits are these?
Jelly bumps
what symptoms does the patient present with if they have jelly bumps?
no/moderate discomfort
management of jelly bumps?
- review care routine
- increase lens replacement frequency
- change material to low water content lens
what are mucin balls?
- focal accumulation of mucus and lipids under the lens which causes an indentation in the epithelium
what material are mucin balls associated with?
extended wear of SiHy lenses
what symptoms do patients present with if they have mucin balls?
asymptomatic
what deposits are these?
Mucin balls
Management of mucin balls?
- monitor
- review lens material or modality if possible
- ocular lubricants
