Preclin and Diseases - Study Flashcards
John, 18yr old. Blurry vision with 3 month old glasses. OD -6/-2.5x90 (6/9.5), OS -5.50/-4.00x85 (6/12). Previous optometrist only checked prescription and kept changing over last 3 visits.
What specific questions would you ask during history taking?
- LOFTSEA (location, onset, frequency, type/severity, self-treatment, exacerbating factors, associated symptoms)
- is blurry vision in both eyes? is it constant? What is the onset? anything makes it better/worse?
- anyone in family with high prescription, blindness, eye diseases?
- history of atopy (allergies)? eye rubbing?
- last full eye test?
- general health, medications?
John, 18yr old. Blurry vision with 3 month old glasses. OD -6/-2.5x90 (6/9.5), OS -5.50/-4.00x85 (6/12). Previous optometrist only checked prescription and kept changing over last 3 visits.
What specific screening tests will you perform for this patient? Explain why these tests are chosen
VA - overall indication of visual function
Pupils - neurological issues?
B.V (CT, NPA, NPC) – young patient, BV issues may give rise to blurry vision
Oc. Motil. - muscle balance/neurological issues
Confrontation - extent of FOV
CV Ishihara - male px: higher probability of CVD
Keratometry/Topography - high cyl, complains of frequent change in Rx
John reads 2/15 plates (OU) on the Ishihara. Describe how you can further evaluate his colour vision
Stage 1 (detection): Ishihara (RG), Lanthony (BY), Farnsworth (BY), Richmond HRR (RG and BY), City University (RG and BY)
Stage 2 (assess type/severity): Farnsworth D15, Lanthony desaturated D15, H16, Farnsworth Munsell M 100 hue, Oscar/Medmont C100
Describe in greater detail the process of diagnosing CVD
Start with detection (using ishihara, richmond, city uni, farnsworth f2 or lanthony album). A pass means normal or very mild CVD. If they fail detection: Farnsworth D15.
If pass Farnsworth D15: Do Lanthony desaturated D15, pass that = very mild defect, fail that = mild CVD)
If fail Farnsworth D15: then moderate/severe CVD. Do H16 test (pass = moderate, fail = severe). Also do Medmont C-100 to determine if protan or deutan
You suspect the px has keratoconus. Describe 3 techniques that you will perform and the signs that you will expect to observe.
Retinoscopy - scissors reflex
Keratometry and/or Topography - distorted K mires, steep cornea
Slit lamp exam - cornea thinning, prominent cornea nerves, munsun’s sign
John, 18yr old. Blurry vision with 3 month old glasses. OD -6/-2.5x90 (6/9.5), OS -5.50/-4.00x85 (6/12). Previous optometrist only checked prescription and kept changing over last 3 visits.
You decide to examine posterior eye. Between direct ophthalm, fundus and/or BIO, which technique/s do you choose? Explain
DFE (dilated fundus exam) indicated as px is high myope - increased risk of peripheral retinal abnormalities
Once dilated - perform both fundus lens (detailed view of ONH, BVs, Macula) and BIO (to look at peripheral abnormalities)
What are your instructions to the patient in a dilated fundus exam?
“I am going to have a look at the back of your eye to ensure that it’s healthy. This will involve shining a light into your eye. I will also need to put some drops in your eyes so we can have a thorough examination. These drops will make your pupils bigger and will blur your vision for a few hours. Things will get a bit blurry and the sun may be a bit glare-y. Did you drive today? Did you bring your sunglasses? Do you know if you are allergic to any drops?”
John, 18yr old. Blurry vision with 3 month old glasses. OD -6/-2.5x90 (6/9.5), OS -5.50/-4.00x85 (6/12). Previous optometrist only checked prescription and kept changing over last 3 visits.
You dilated the patient. What specific features might you expect to see in the fundus?
- peripheral retinal tears/detachment, retinal holes, retinal degeneration (high myopes have higher risk)
- “white without pressure”: white patches in the periphery (happens for myopes)
- vitreous detachment
- tigroid fundus (myopia/degenerative myopia)
- choroidal/scleral crescent
- peripapillary atrophy (assoc. degenerative myopia)
- tilted disc? (assoc. with high astig)
So basically other than tilted disc, all these fundus signs are associated with high myopia (I guess KC doesn’t have many fundus signs in that case)
What does white without pressure mean?
You know how when you press your skin you get a white patch. It’s like this but in the eye and without pressure. White patches on the eye’s periphery
Explain how tigroid fundus occurs
as the eye enlarges (myopia), the RPE thins, resulting in a tessellated (checkered) appearance of the fundus and increased visibility of the choroidal vasculature
you get patches of bright dark bright (hence checkered)
You observed a feature on the BIO in the px’s left eye when he is looking up and towards to the ear. Which part of the retina is the feature located? How is the examiner and 20D lens oriented relative to the px?
- Superior temporal retina
- Examiner view from down and towards px’s nose
- Lens held perpendicular to examiner’s view
27 year old female with gritty sensation in right eye. It happened last night and is getting worse. Findings: VA: R 6/6 L 6/6+, N5@40cm CT: D+N: OrthoP, NPC: TTN, NPA: R+L 8D Confrontation + motility NAD
- List any questions that may assist you in your management (4 questions sufficient)
- Do you have dry eyes?
- Do you wear contact lenses? is grittiness same with/without?
- Any injury or trauma to the eye? (foreign bodies)
- Do you experience any pus or discharge coming from your eye
- Are there any eye drops that make it better?
27 year old female with gritty sensation in right eye. It happened last night and is getting worse. Findings: VA: R 6/6 L 6/6+, N5@40cm CT: D+N: OrthoP, NPC: TTN, NPA: R+L 8D Confrontation + motility NAD
- How would you investigate this further?
Slit lamp:
- fluoroscene staining with cobalt blue check TBUT
- lid eversion
- anterior chamber reaction: look for cells and flare
Pupil testing (could be irregular due to trauma)
Posterior segment examination (w/dilation. Assuming VH over 1 or normal gonio)
(half mark for tonometry to measure IOP)
27 year old female with gritty sensation in right eye. It happened last night and is getting worse. Findings: VA: R 6/6 L 6/6+, N5@40cm CT: D+N: OrthoP, NPC: TTN, NPA: R+L 8D Confrontation + motility NAD
- List your differentials and provide your provisional diagnosis
condition is unilateral and getting worse - therefore is progressive
- probably not dry eye (b/c it’s progessive)
- could be CL infection (b/c they can be unilateral)
- could be FB, trauma or infection (b/c progressive/getting worse)
27 year old female with gritty sensation in right eye. It happened last night and is getting worse. Findings: VA: R 6/6 L 6/6+, N5@40cm CT: D+N: OrthoP, NPC: TTN, NPA: R+L 8D Confrontation + motility NAD
How would you manage this patient?
- eye drops if dry eye (probably not dry eye though)
- if CL issue: stop using the contact lenses
- review px at later time
- if superficial FB: remove it (via referral to ophthalm)
You suspect a patient has glaucoma. What methods/techniques could you use to assess for this?
VA: to check progression of disease (open-angle tends to have good v.a in initial stages, whereas closed-angle will notice blurry vision)
Visual Field test: (check for typical gluacoma peripheral loss) - confrontation, red cap (check optic nerve, glaucoma can damage it)
Tonometry: check IOP (high in glaucoma, except NTG)
VH and Gonio: assess angle.
DFE: only if angle is ok! (if not just do undilated fundus)
- check for C/D ratio (large may imply glaucoma), NRR rim thinning, peripapillary atorphy, optic disc hemorrhage
- central corneal thickness: patients with thin corneas may show artificially low IOP readings
- OCT
Why would you check visual fields in a suspected glaucoma patient even though their v.a was fine?
because glaucoma involves peripheral visual field loss
