Soft contact lenses: aftercare and problem solving Flashcards
Disinfection
routine lens care - disinfection and cleaning required
3 methods of disinfection for soft lenses:
- chemical
- oxidative (hydrogen peroxide)
- thermal
-daily disposable lenses require no care regimen
chemical disinfection - multipurpose solutions
combines cleaning, rinsing, and disinfection
simple, cost-effective
preservatives: thimerosal and chlorhexidine
sensitivity to preservative: dryness, itching, burning, injection, dereased wearing time, and discomfort
multipurpose nonkeratitis - normal ext. findings but complains of ocular dryness -> go to preservative-free hydrogen peroxide cleaners
microbial efficacy of these systems is based on entire regimen -> rubbing, rinsing, and disinfection
ex. opti-free, biotrue
save the last lens
by purge: place in vial of distilled saline for 8 hrs and repeat this for 3 cycles, follow each cycle with disinfection in nonpreserved system
purge: put in nonpreserved distilled for 8 hours followed with disinfection with nonpreserved system for 3 CYCLES
acanthamoeba
fungal infection
extended wear, noncompliance, and poor lens compliance increase chance of fungal infection
tap water use, swilling use of hot tubs and showering w/ contact lens on - inc. risk
digital rubbing and rinsing - remove up to 99% acanthamoeba
ring ulcer, feather edges, painful
oxidative disinfection (hydrogen peroxide)
3% hydrogen peroxide solution with neutralizing tablet or disc, case vial, and saline
vial should be replaced each time you replace bottle or every 3 months
preservative free, required soaking time
hydrogen peroxide have less staining or inflammatory responses
removes protein, lipid, and trapped debri
efective against fungi, acanthoamoeba, HIV, and aspergillus
very acidic - if cornea contact, cause chemical burn
red cap - dont put in eye
clearcare - 6hrs
peroxiclear (recalled) - 4 hrs
thermal disinfection
least expensive, most effective
bakes deposits onto cl instead of clean -> lens life shortened
complications occur: GPC, red-eye reactions
effective against all forms of bacteria - pseudomonas, acanthamoeba, HIV
not popular, usually in office
saline
sterile solution used to rinse lenses -> not to disinfect
preserved and nonpreserved saline type
used for filling scleral lenses
do not use homade saline
deposits
deposits due to hydrophilic surface, patient tear film, environment, and lens handling
deposited lens result in reduction in effectiveness of preservatives, oxygen transmission, surface wettability, vision, and wearing time
silicone hydrogel lenses more prone to lipid deposits than hydrogel lenses
types of deposits
protein - white opaque film on lens surface
pigment deposits - melanin polymer in tears
fungi/yeast - various colors in filamentary appearance
lipid deposits - smeared, greasy appearance
rust spot - circular, orange deposits
mascara, hairspray, lotion, soaps, and suntan lotion - greasy, iridescent, and filmy
patient education
noncompliance comes from poor education/poor instructions
verbally review all instructions
patient compliance
wash hands with soap and water before handling cl
store lenses in recommended solution
rub and rinse lenses before disinfection
wear lenses according to schedule
always discard used solution -> use fresh solution
replace case every 3 months
no tap water
no swimming or showering in lenses
insertion and removal
make sure lenses is not inside out - taco method or flared edges
place cl on finger and place lens on sclera
remove by holding lens, sliding onto sclera and pinch off
cl and hygiene
washing hands with mild soap
clean lens case
closed solution bottles
cl problem solving
common problems: reduced vision, discomfort, photophobia, dryness, excessive movement, foggy/hazy vision
reduced vision
reasons: lens contamination, uncorrected RE, defective lens material, improper lens to cornea fitting relationship, excessive tearing, corneal abnormalities, intraocular abnormalities, inverted lens, abrasion, edema, defective lens
solve:
- measure va w/o correctionwith glasses, then cl => baseline
- determine onset and duration, and whether reduced va is present when spectacls worn
- pinhole va
discomfort
remove immediately
classified in 4 categories:
immediately on insertion - torn lens, sensitivity to solution, prism ballast of toric lens, alcohol from hand sanitizer, trapped debris
after removal: typically cornea abrasion, infection, ulcer, inflammation
constant: poor fit, corneal edema, lens deposit, compression
after wear time: trapped foreign body, corneal abrasion
burning
most common problen related to lens solution sensitivity
also problem with:
- preservative sensitivity
- non-buffered solution
- inappropriate care regimen
- residual cleaner on lens
- incomplete neutralization of hydrogen peroxide
- improper solution use
photophobia
pathological condition when pain occurs when light eneters eye
dazzling - sensation of discomfort as result of excessive light usually not associated with pain
ask about discharge
cause:
- epithelial abrasion
- moderate lens overwear
- blunt trauma
- uncorrected RE ad residual astigmatism
dryness
causes:
- poor tear quality/quantity
- pregnancy
- incomplete blink
- medications
- environment
- computer use
excessive lens movment
deposited lens
less frequently on daily disposables
dehydration of lens
inverted lens
flat lens - inferior lens decentration, edge lift more than 1.5 mm and minor discomfort
if deposited lens -> replace lens
if inverted lens -> educate on proper lens position
flat lens -> refit or change BCR/dia
foggy hazy vision
may result from coated lens or corneal edema
symptoms: appearance of halos around or distortion of bright light sources
slit lamp eval. required
ask of frequency of cleaning, method of disinfection, moisturizers, age of lenses, how often removed
treat: change type of lens, cleaner, or add hydrogen perozide
clinical signs grading
0 to 4 0 not present 1 minimal 2 mild 3 moderate 4 severe
clinical signs
corneal neovascularization
superior epithelial arcuate leasion
contect lens solution toxicity
corneal edema
most with conventional hydrogels - overwearing
clinically apparent at 6%
striae and epithelial edema noticed wit mild edema
- microcystic edema: midperipheral, apparent 3 weeks after beginning wear of hydrogel material
- <50 microcysts: discontinue wear
- > 50 microcysts: discontinue and fit pt into silicone hydrogel
descemet membrane fold noticed with moderate to severe edema
“tight-lens” syndrome
signs/symptoms: reduced va, foggy/hazy vision, inc. in myopia, generlized loss of corneal transparency, striae, microcysts, folds of descemet membrane, endothelial changes, possible steepening of keratometry readings
injection
related to cl:
damaged lens
edema
solution sensitivity
tight lens
deposited lens
contaminated lens
trapped foreign body
poor-fitting lens
improper use of solutions
contact lens acute red eye
need thorough history: injection observed? continue after removal? recent or chronic? irritated, burning or itching? mucous, watery, or stringy? sectorial injection - damage of lens, pinguecula, episcleritis
corneal vascularization
sign of cl intolerance - result of tight lens fit, limbal compression, corneal edema, or excessive wear
more than 1.0 mm of growth past limbus, engorgement, looping or tortuous growth, leakage, edema surrounding area
3 stages:
- filling of pre-existing limbal capillyary plexus
- new vessel growth in form of endothelial spikes or sprouts extend from limbal arcades toward central cornea
- true vessels that may be at any depth
ghost vessel remain
treatment: remove lens and fit into silicone hydrogen or flatter lens
GPC (giant papillary conjunctivitis)
most often associated with cl wear
clinical signs: conjunctival hyperemia, excess mucus, giant papillae on upper tarsal conj., inc. col movement
lid eversion is a must
inflammatory rxn
treatment: decrease wear time, change material, replace more frequently, disinfectiong, hydrogen peroxide cleaners, mild steroid ophthalmic sol. in moderate to severe cases, mast cell stabilizers in more chronic conditions
