wk2: CL/M - CL Prelim Exam Lens application/removal Flashcards
Come up with some important history questions to ask a patient who wants contact lenses? (9. Based on student responses, I picked the good ones)
What are they for? (e.g. cosmetic)
How often will you wear them?
Have you tried CLs before?
Have you had any eye infections?
Do you wear glasses?
Do you have dry eyes?
Do you work in an environment with lots of dust?
Visual requirements?
Sore/itchy, alergies, lazy eyes, injuries, medications
What are the 3 basic key aims/objectives of a preliminary examination for a patient who wants contact lenses?
- inform patient to set expectations
- assess px suitability
- obtain baseline information
What considerations should you inform your patient (who wants to get CLs) of? (5)
Time taken in clinic (incl. fitting sessions and fitting fees)
expense
Types of CLs
Need for aftercare visits
Need for CL special storage + maintenance
Adaptation
What factors can influence suitability for CLs? (4)
Motivation
Ocular indications/contraindications
Personal indications/contraindications
Systemic factors
What personal indications are there for CL suitability? (5)
Cosmetic reasons
Highly motivated px
Sport
Occupation
Large refractive error
What personal contraindications are there for CL suitability? (8)
Environment (e.g. dusty)
Occupation
Low refractive error
Monocular wear
Poor hygiene
Poor manual dexterity
Sensitive eyes (fear of touching eyes)
Poor motivation
Why might people with trichiasis benefit from CL wear?
CL will protect the ocular surface and make it more comfortable
Why might people with nystagmus benefit from CL wear?
May dampen nystagmus symptoms
What ocular indications are there for CL wear? (15)
High Rx
Anisometropia
Aphakia
Trchiasis (bandage)
Dry eye syndrome
Exposure keratitis
Nystagmus (kids)
Recurrent erosions (bandage)
Bullous keratopathy (bandage)
Ocular disfigurement
Unsuccessful refractive surgery
Post-keratoplasty
Keratoconus
Is self-esteem in children an indication for CL wear?
yes
What type of CLs would you consider for a patient with recurrent corneal erosions or bullous keratopathy?
Bandage contact lenses
What type of CLs would you consider for a patient with either keratoconus, post-keratoplasty or unsucessful refractive surgery? What does this achieve?
Hard contact lenses. Corrects for cornea shape, which is different/can be different in these situations
What should you consider when assessing CL suitability for a patient with recurrent corneal erosions or bullous keratopathy?
we don’t want to reduce oxygen too much because we don’t want to slow the healing response too much
Why may CLs be indicated for dry eye syndrome patients?
can keep the cornea moist by using the right CLs in cases of severe dry eye
What is a bandage contact lens?
is a contact lens designed to protect an injure or diseased cornea from the mechanical rubbing of the blinking eyelids, therefore allowing it to heal. The bandage lens often makes the eye feel more comfortable
Is a bandage lens soft or hard?
It’s usually a soft contact lens, but not always.
What is Bullous keratopathy?
is the presence of corneal epithelial bullae, resulting from corneal endothelial disease caused by edema of the cornea, resulting from failure of the corneal endothelium to maintain the normally dehydrated state of the cornea. (I.e. endothelial pump failure causes this)
List 11 ocular indications where extra care may be required when considering CLs
Cosmetically noticeable strabismus
Conjunctivitis
Dry eye
Glaucoma
History of keratitis (e.g. herpes simplex)
Ocular allergies/hayfever/atopy
Decreased corneal sensitivity
Pingueculae
Lid conditions (chalazion, hordeoleum, acute blepharitis)
Pterygia
Uveitis
What might be a problem when fitting CLs in a patient with strabismus? (2)
CL might not sit at optical centre
Changing the power in CLs (due to no vertex distance) from specs with high prescription may make STRAB more obvious
Why might glaucoma be a problem for CL wear in a patient? What might you advise patients in this scenario?
Eye drop tx for glaucoma may be less effective with CLs. Perhaps advise px to wait 15 minutes after eye drop before putting on CLs
What should you consider when giving CLs to a patient with blepharitis?
the gunk might get trapped between the CL and the eye
What systemic factors can influence CL wear? (9)
General Health
Smoking
Chronic sinusitis
Allergies
Skin problems
Endocrine changes
Thyroid disease
Pregnancy
Medication
(basically any condition that alters tear flow, production, anterior surface properties)
How can general health affect CL wear?
if health is poor then contact lens tolerance may be affected
How can smoking affect CL wear? (2)
Dry eye
Particulate matter
How can chronic sinusitis affect CL wear? (2)
Increased mucous in tears
More lens deposits
How can allergies affect CL wear? (3)
Hayfever
Increased risk of poor tolerance
Hypersensitivity to solutions/contact lens materials
How can skin problems affect CL wear? (3)
Acne rosacea
Atopic eczema
Increased irritation with CLs poor tolerance
How can endocrine changes affect CL wear? (1)
Dry eye
How can thyroid disease affect CL wear? (4)
Dry eye
Exophthalmos
Reduced blinking
Less tearflow
How can pregnancy affect CL wear? (2)
Less stable tear film
Increased chance of tolerance
How can medication affect CL wear?
Use of topical medications for other eye problems
List 6 issues associated with CL wear and diabetes
Blepharitis
Dry eye
Epithelial fragility + reduced healing rate
Higher risk of keratitis (bacterial fungal, and herpes simplex)
Unstable refraction
Reduced corneal sensitivity
Can people with diabetes wear extended wear CLs
No. They should not be fitted with these. I.e. they should NOT sleep in their lenses
Outline the order of a preliminary work up for CLs (5)
- Complete Hx
- Refraction
- External eye examination (ocular parameters)
- Slit lamp
- Keratomery (or corneal topography)
What 6 key areas should you cover when performing history for an aspiring CL wearer?
Motivation
Ocular hx
Occupation
Systemic/allergic history
Medications (incl. Q about smoking)
Intended wearing time (affects type of CL you’d give them, and can give you an idea on compliance)
What ocular parameters should be assessed in an external eye examination as part of a preliminary workup for CLs? (5)
Corneal diameter (HVID)
Pupil diameter (in low illumination)
Palpebral aperture
Lids tight/flaccid - high/low
Corneal sensitivity (often not measured if not indicated)
What must you assess in slit lamp as part of a preliminary workup for CLs? (4)
Thorough anterior eye examination
Lid eversion
Fluorescein staining
TBUT
What is the standard grading scale we use for findings in slit lamp?
Effron scale (scale grading from 0-4)
Why must you do lid eversion in slit lamp as part of a preliminary workup for CLs?
want to check for any bumps. People with allergies can have papillae there and the number of papillae will increase with CL wear
What 2 main techniques can you use to measure corneal curvature?
Keratometry
Corneal topography
What is the main difference between keratometry and corneal topography?
Keratometry = only central part of cornea is measured
Corneal topography = measures whole cornea
Where should patient’s look when you insert a hard CL?
at a fixation target
Which lid is the stronger blinking lid? upper or lower?
upper
In CL insertion, once you’ve applanated the CL onto the eye, which lid should you release first?
release the lower lid first
List the 3 methods of hard CL removal by the patient
Blink method
Lid method
Suctino up
Where should the patient look when you insert a soft contact lens?
Direct the patient’s gaze nasally to expose the bulbar conjunctiva
What should you do if there is discomfort after SCL insertion? (2)
Scleral swish (i.e. look all around)
If discomfort persists, remove lens, rinse and retry
