unit 4 Flashcards
Physiological considerations for lens selection
-HVID
-Recurrent corneal erosino
-Poor tear layer stability
-Corneal scarring
-Corneal disease
-Lid margins
- GPC
-Vertical palpebral aperture
-Pupil size
-Corneal shape
-High ametropia
-Lenticular vs corneal astigmatism
-Systemic disease
-Handling problems
Considerations for HVID
Large or small cornea = may require custom soft lens
-GP lens must be smaller than HVID
Considerations for recurrent corneal erosion
-Must heal before fitting
-Possible therapeutic bandage lens
Considerations for poor tear layer stability
-Dry eye can benefit from scleras
-Dry eye could be good GP candidate (mild and borderline)
Considerations for corneal scarring
Good candidate for GP or hybrid
Considerations for corneal disease (kerataconus)
good cadidate for GP or hybrid
Considerations for lid margins
Treat prior to fitting
consider if their lid margin is small or large
Consideration for GPC
Treat prior to fitting
Consideration for vertical palpebral aperture
May impact size of lens of lens design (hybrid may be difficult to insert with small VPA)
Considerations for pupil sizw
Can affect MF contact lens, GP lens BOZD
Consideration for corneal shape (prolate vs oblate ; eccentricity)
-Oblate needs reverse geometry GP lens
-Eccentricity will affect sagittal depth
Considerations of high ametropia
High plus
High minus
High cylinder
Considerations for handling problems
a px with arthritis would not be good to wear CLs because they may struggle inserting and removing CLs or cleaning the CLs
Ocular medication considerations
Usually wait 10-15 mins after instilling drops before inserting soft contact lenses (always read medications instructions)
Systemic meds associate w/ dry eye considerations
Antihistamines, decongestants, blood pressure, tranquilizers, parkinsons meds, antidepressants, birth control, and horome replacement therpay
Side effects of Rifampin therapy
When taken causes contact lenses to discolor to a pink color. This drug is often used to treat tuberculosis
Ocular health considerations
-Last eye exam and last CL exam
-CL wearing time
-Modality of wear
-Previous CL wear and solutions
-Allergies to solutions
-History of eye disease or infections
-Pregnancy
Types of tinted lenses
-Handling tint
-Cosmetic tint
-Prosthetic lenses
-Therapeutic tinted lenses
-Performance enhancing tints
-Theatrical lenses
Sports lens considerations
-Cold
-Wind
-Altitude
-Dusty environment
-Aquatic sports
-Outdoor UV effects
Types of overnight extended wear
-Overnight wear of soft CL
-Overnight wear of GP CL
-Overnight wear of ortho K lenses
Extended wear complications
Risk of infection
Corneal ulcer
Inflammation
Superior epithelial arcuate lesions
Corneal edema
Hypoxia
What is hypoxia
lack of oxygen
What is corneal edema
Swelling of cornea
types of inflammation from extended wear
Corneal infiltrative events
Giant pupillary conjunctivitis
Contact lens acute red eye
what does Lavendar tint CL do
Migraine/headache relief
Reduces eye strain
Photophobia (especially in fluroescent and outdoor lights)
Red tint purpose
migraine relief
reduces glare
improves contrast
enhances perception
purpose of cobalt blue tint
reduces glare
may help reduce seizures related to photosensitive epilepsy
