Soft contact lenses: aftercare and problem solving

Question 1

Disinfection

Answer 1

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

Question 2

chemical disinfection - multipurpose solutions

Answer 2

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

Question 3

save the last lens

Answer 3

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

Question 4

acanthamoeba

Answer 4

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

Question 5

oxidative disinfection (hydrogen peroxide)

Answer 5

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

Question 6

thermal disinfection

Answer 6

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

Question 7

saline

Answer 7

sterile solution used to rinse lenses -> not to disinfect

preserved and nonpreserved saline type

used for filling scleral lenses

do not use homade saline

Question 8

deposits

Answer 8

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

Question 9

types of deposits

Answer 9

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

Question 10

patient education

Answer 10

noncompliance comes from poor education/poor instructions

verbally review all instructions

Question 11

patient compliance

Answer 11

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

Question 12

insertion and removal

Answer 12

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

Question 13

cl and hygiene

Answer 13

washing hands with mild soap

clean lens case

closed solution bottles

Question 14

cl problem solving

Answer 14

common problems: reduced vision, discomfort, photophobia, dryness, excessive movement, foggy/hazy vision

Question 15

reduced vision

Answer 15

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

Question 16

discomfort

Answer 16

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

Question 17

burning

Answer 17

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

Question 18

photophobia

Answer 18

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

Question 19

dryness

Answer 19

causes:
- poor tear quality/quantity
- pregnancy
- incomplete blink
- medications
- environment
- computer use

Question 20

excessive lens movment

Answer 20

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

Question 21

foggy hazy vision

Answer 21

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

Question 22

clinical signs grading

Answer 22

0 to 4
0 not present
1 minimal
2 mild
3 moderate
4 severe

Question 23

clinical signs

Answer 23

corneal neovascularization

superior epithelial arcuate leasion

contect lens solution toxicity

Question 24

corneal edema

Answer 24

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

Question 25

injection

Answer 25

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

Question 26

corneal vascularization

Answer 26

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:

1. filling of pre-existing limbal capillyary plexus
2. new vessel growth in form of endothelial spikes or sprouts extend from limbal arcades toward central cornea
3. true vessels that may be at any depth

ghost vessel remain

treatment: remove lens and fit into silicone hydrogen or flatter lens

Question 27

GPC (giant papillary conjunctivitis)

Answer 27

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