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List and briefly discuss the major causes of visual impairment in Australia. List and briefly discuss the major causes of visual impairment in developing countries. - ✔✔In Australia 1.AMD cause of 50% of all blindness-less common in developing countries due to lower life expectancy 2.Glaucoma- 16% of blindness 3.Cataract-11% of blindness
- Diabetic retinopathy (+ other= 20%)- Most common cause of visual impairment in working age population
- 3% uncorrected refractive error Developing countries - uncorrected refractive errors, cataract- unavailable surgery, trachoma- river water parasite, glaucoma A teenage male attends your practice because he knows he is colour defective and he has been told that there are some professions where restrictions are placed on those with a colour vision problem. What advice would you give this patient? - ✔✔Careers with strict restrictions: ARMED SERVICES POLICE AIR TRAFFIC CONTROLER FIRE SERVICES Also have restrictions but candidate can work within some divisions: COMMERCIAL PILOT MARINE and MARINE PILOT etc; TRAIN DRIVER ELECTRICIAL ENGINERING ELECTRICAL TRADES COMMERCIAL ARTIST, HOSPITAL LABORATORY TECHNICIANS
PROFFESSIONAL TRANSPORT DRIVER- don't accept protanomaly- do accepy deuteranomoly Indicate the review cycle you would recommend for the following patients including your rationale behind the review cycle suggested a) a patient with mild background retinopathy annual review - ✔✔annual review Indicate the review cycle you would recommend for the following patients including your rationale behind the review cycle suggested a patient from whom you have just removed a superficial corneal foreign body - ✔✔1/52 to check for signs of infection/inflammation and healing process Indicate the review cycle you would recommend for the following patients including your rationale behind the review cycle suggested A patient with a branch retinal vein occlusion - ✔✔3/12 review- check for '90-day glaucoma' rubeosis iridis/neovascularistion and macular oedema Indicate the review cycle you would recommend for the following patients including your rationale behind the review cycle suggested a 6 year old child with hypermetropia and an alternating esotropia wear full cycloplegic rx - ✔✔review in 6 months if no amblyopia Indicate the review cycle you would recommend for the following patients including your rationale behind the review cycle suggested a patient with optic nerve head drusen - ✔✔3 years with medicare?
Pxs with iris fixed IOLs or pxs at risk of angle closure, pxs with known allergies to mydriatic agents, downs syndrome pxs? Define stereopsis. How would you measure stereopsis? What are normal values? - ✔✔the perception of depth produced by the reception in the brain of visual stimuli from both eyes in combination, combining areas in panums fusional area. TNO dependent on age 5 years, 140 seconds: 5 1/2 years, 100 seconds; 6 years, 80 seconds; 7 years, 60 seconds; 9 years, 40 seconds. Describe how you would assess whether a patient was suppressing an eye. - ✔✔Check if Vas are equal/ history of amblyopia/strabismus/surgery/patching/cover test are all useful factors to consider. Main test of suppression is worths 4 dot- if only 2-3 dots are seen then one eye is supressed i.e eye with red filter should see green dots, eye with green filter shot see red dot/ if unavailable can use mallet unit- polarisation filter means one eye sees 12 and 3 o'clock lines, one eye sees 6 and 9 o'clock lines. If one eye is suppressed only 2 of the four lines will be visible. Dry eye is a common disorder of the tear film caused by tear deficiency or excessive tear evaporation. What are the major causes of dry eye and how should dry eye be assessed? - ✔✔Causes of dry eye are related to:
- poor tear quality; i.e deficient lipid layer (MGD dysfunction- cause of 50% of dry eye), deficient mucous layer (e.g stevens-johnson syndrome which effects goblet cells)
- insufficient tear production
- environmental factors (e.g VDU users, contact lens wearer, air conditioning)
- systemic disease (e.g sjogrens syndrome)
- lid anomalies (e.g ectropion, bells palsy where there is not a complete blink)
Ways dry eye can be assessed: TBUT- instill fluorescein and observe using slit lamp NITBUT- oberve distortion of keratometer mires Schirmer Phenol red thread Tear prism height Patient questionnaire Discuss the course of the optic nerve. What type of visual deficit would you expect to see in the case of: a) An occipital lobe lesion b) A pituitary tumour c) A temporal lobe tumour d) Retinoblastoma - ✔✔a) An occipital lobe lesion homonymous haemianopia b) A pituitary tumour - bi temporal haemianopia c) A temporal lobe (meyers loop) tumour 'pie in the sky' sectoral defect- respecting vertical midline d) Retinoblastoma affecting the visual field of one eye only Describe the afferent pupil pathway. What conditions cause an afferent pupil defect and how do we test for an afferent pupil defect clinically. - ✔✔Swinging flashlight test- present light to one eye for 2- 3 seconds- then present light to other eye- eyes should present similar responses- and should constrict initially then dilate. If RAPD is present then second pupil will dilate. Afferent pupil pathway- from eye to brain Optic nerve, optic chiasm, pretectal nuclei, edinger- westphal nuclei Conditions causing afferent pupil defect
- Optic neuritis
- Papilloedema
What visual problems might be experienced by younger presbyopic patients when using a computer screen within an office environment? In your answer outline briefly the advice you would give to patients about the advantages and disadvantages of each prescribing option. What lens designs can be used to creatively overcome these difficulties? Does this depend on the patient distance prescription? - ✔✔Patients will start to experience blurred vision and ast when on VDU. Often particularly worse after prolonged viewing or towards end the working day. Prescribing options include: a single vision pair of reading/VDU spectacles- advantages are that this has the widest field of vision and are easier to adapt to than varifocals. They are also inexpensive. Disadvantages are that the lens will be blurred on distance viewing- so spectacles will have to be removed. Varifocal spectacles- Advantages are that distance, intermediate and near prescriptions will be corrected enabling patient to multitask more without having to change between dv and sv specs. However lens takes longer to adapt to- px has to learn how to look through different areas on lens and 'point nose' to whatever they are wanting to focus on and get used to distortion areas in lens periphery. More expensive. Yes. Distance prescription will effect this. Pxs with a mild myopic rx may feel more comfortable viewing VDU without any specs. Emmetropic pxs may feel more comfortable with sv specs. Describe how an anti-reflection coating reduces reflections and when you would recommend an anti- reflection coating to a patient. (5 marks) - ✔✔Anti- reflection coatings work due to destructive interference- its thickness is equal to ¼ the wavelength of light. Reasons to recommend this to a patient would be due to cosmesis- eye is more visible when looking through spectacle lens- no visible reflections on photographs. Also for drivers, particularly helps to reduce reflections when driving at night. Patients with high index lenses, patients with cataract who suffer effects of increased light scatter esp. cortical cats
A patient who works in a chemistry department at a university and is a current spectacle wearer comes to you for advice about safety glasses to use in the laboratory. What advice would you give? (5 marks) - ✔✔ A presbyopic patient presents to you wanting to know the advantages and disadvantages of bifocals compared to progressive lenses. They also understand there are different types of progressive lenses available. Detail how would you discuss this issue with your patient. - ✔✔
- A patient is to be fitted with an RGP lens in one eye. Preliminary findings are: Ks 40.86 (8.26) @ 145 43.61 (7.74) @ 55 oc rx +0.25/-1.25x a) Based on these findings determine the amount and axis of the residual cylinder (3 marks) b) A spherical trial lens with BOZR of 8.05 mm and BVP of +1.00 is placed on the eye. (i) Calculate the resultant tear lens power when this spherical trial lens power is placed on the eye ( marks) (ii) What is the expected sphero-cylinder over refraction when this spherical lens is worn (4 marks) - ✔✔43.61-40.86=-2.75 2.75-1.25= - 1.50 x 145 ds (also 0.05mm k readings=0.25DS? this way= 2.6) b) i) 0.1mm difference in ks =0.50DS if fit is steeper then +ve lens power, if fit is flatter then - ve tear lens power Fit 0.2 steeper (8.26-8.05= 0.21) and 0.3 flatter (8.05-7.74=0.30) so +1.00/-1.50x 145 ii) Over refraction= spec rx-(contact lens power+ tear lens power+ difference in k reading between meridians) +0.25/1.25x145-, +1.00, +1.00-1.50x145, 2. +0.25-(1+1+2.75) Contact lenses may affect the anterior eye by causing
- Trichiasis Briefly discuss the contact lens options available for a presbyopic contact lens wearer. (5 marks) - ✔✔Options are- monovision (one eye dv rx one eye nv rx) Multifocals (which work on a basis of concentric circles of dv and nv) Dv rx only with reading glasses over top You are the locum in a busy rural practice and Mrs A, an elderly female patient, is attending with her carer (her daughter) for her yearly eye examination. The patient record has been temporarily mis-placed so the receptionist has briefed you on the patient's background. Mrs A has been undergoing treatment for metastatic breast cancer for several years with Tamoxifen (an antioestrogenic medicine that increases the risk of venous thromboembolism) and lost her right eye to choroidal melanoma about 15 years ago. The receptionist recalls Mrs A is short-sighted and that a French sounding name appears on the file "Charles Bonnet". a. Why is Mrs A attending the optometrist on a yearly basis? (3 marks) b. Which examination procedures are likely to need to be repeated at this visit? Why? (3 marks) c. What symptoms should Mrs A and her carer be alert for and why? (4 marks) - ✔✔a) due to her age and poor vision (which is likely if she is experiencing Charles bonnet). Also as the patient is monocular and possible recurrence of choroidal melanoma b) slit lamp anterior eye examination- check for corneal and lens opacities related to tamoxifen, colour vision- can be defect related to tamoxifen, amsler- maculopathy related to drug, dilated fundus examination- thoroughly check for signs of melanoma and any other pathology including maculopthy, pupil reflexes- possible afferent pupillary defect in choroidal melanoma, VAs and refraction- must always be taken c. Any sudden change in vision must be investigated, visual hallucinations, px must be reassured that this is a common occurance for pxs with poor vision and to not be alarmed. Your patient is a 12 year old boy who has been referred to you for advice following the detection of a colour vision problem with the Ishihara plate test at a school vision screening. He passed the other tests of visual performance at the screening.
a. List the tests that should be performed to determine the nature and characteristics of the colour vision problem in this patient. (4 marks) - ✔✔Ishihara- best for screening of defect Medmont c-best for classification of defect btw protan/deutan Farnsworth munsell D- 15 - best for grading severity of defect- mild defects may pass the test What is the most common type of inherited colour vision defect in males? (1 mark) - ✔✔deutaronomalous trichromachy Your patient has the most common type of inherited colour vision defect that appears in males. List in point form the most important advice that should be provided to this patient. (5 marks) - ✔✔• Px may confuse greens,reds and yellows- problems with 'green cone pigment' in retina
- Issues at school- teacher should be made aware may need help on activities which involve colour coding and matching, bar charts, colour coded maps, art etc.
- Day to day life e.g judging when meat is cooked, fruit is ripe
- Reassurance- depending on severitiy many pxs learn to adapt well, this will not worsen with age Careers (Careers with strict restrictions: ARMED SERVICES POLICE AIR TRAFFIC CONTROLER FIRE SERVICES Also have restrictions but candidate can work within some divisions: COMMERCIAL PILOT MARINE and MARINE PILOT etc; TRAIN DRIVER ELECTRICIAL ENGINERING ELECTRICAL TRADES COMMERCIAL ARTIST, HOSPITAL LABORATORY TECHNICIANS PROFFESSIONAL TRANSPORT DRIVER- don't accept protanomaly- do accepy deuteranomoly )
corrected from an early age otherwise one eye will likely be supressed and good vision will not develop because brain relies on the 'good' eye
- astigmatism- front surface of eye is unevenly curved 'like a rugby ball, not round like a football' meaning vision in left eye will be very blurred
- full time wear of spectacles from an early age improves prognosis and development of good binocular vision A 31 year old female patient presents to you complaining of 'itchy eyes'. List clinical procedures that you would use to investigate this complaint, in the order that you would perform them in your consultatation, and briefly describe the rationale for using the procedures. - ✔✔- Slit lamp examination- lids and adnexa, diffuse beam low mag- check for lid inflammation, blepharitis, conjunctival redness/chemosis/discharge. Increase mag 16x parallelepiped beam to check cornea, check upper (evert) and lower lids for signs of papillae/follicles, instil fluorescein to check for staining Case history- atopic skin conditions and allergies? Your 22 year old female patient has presented with a red eye. This was present on waking the previous day, with a prickling feeling sensation in the eye. She now has some light discomfort and watering in this eye which was not presented previously. General health is reported as normal. Biomicroscopy reveals a clear cornea and anterior chamber. There is a marked red appearance to the nasal conjunctiva, with hyperaemia and dilated episcleral vessels. The vessels blanch with phenylephrine. The palpebral and tarsal conjunctivae are normal. Pupil reactions are normal. Visual acuity is 6/6 each eye. a) What is a likely diagnosis? b) The patient is concerned regarding the redness and discomfort. How might this be treated? Assume unrestricted access to therapeutics in your answer. c) If this was the third occurance rather than the first of this condition, how might management differ? - ✔✔a) What is a likely diagnosis? episcleritis (b) The patient is concerned regarding the redness and discomfort. How might this be treated? Assume unrestricted access to therapeutics in your answer. May be treated with ocular lubricants, inflammation may be controlled with NSAIDs e.g flurbiprofen, cold compresses may provide further symptomatic relief- possible mild topical steroid c) If this was the third occurance rather than the first of this condition, how might management differ?
Referral to medical practitioner for systemic workup is indicated. Recurrent epidodes may be related to; IBD, rheum. Arthritis, lupus, crohns, ulcerative colitis, herpes virus You are examining a 25 year old man who is noticing episodes of vertical diplopia more frequently over the past few months, and worse when reading. He also tilts his head to one side. Motility testing shows depression of the right eye is restricted when looking down and to the right, and his right eye deviates in left gaze. Heterophoria testing reveals an 8prism dioptre R hypertropia in the primary position. a) What extraocular muscle is most likely affected? Inferior rectus b) What other clinical testing could confirm this? Hess, Lees charts c) Explain why the left eye elevates in right gaze due to muscle sequelae??? (doesn't make sense) d) What is his likely habitual head tilt? To the right?? - ✔✔a) What extraocular muscle is most likely affected? Inferior rectus b) What other clinical testing could confirm this? Hess, Lees charts c) Explain why the left eye elevates in right gaze due to muscle sequelae??? (doesn't make sense) d) What is his likely habitual head tilt? To the right??
- a) Explain how you would set up a slit lamp biomicroscope to examine the corneal endothelium 40x magnification, focus on posterior cornea, use specular reflection- illumination system and microscope so angle of incidence= angle of reflection b) Describe the changes that you would expect to see in the endothelium in: i) Fuch's endothelial dystrophy- ii) long term wear of low water content, low oxygen permeable contact lenses - ✔✔Fuch's endothelial dystrophy- would likely see spaces in corneal endothelium- guttata ii) long term wear of low water content, low oxygen permeable contact lenses polymegathism, polymorphism The two most commonly used ocular stains are rose Bengal and sodium fluorescein
Schirmer Phenol red thread Tear prism height Patient questionnaire A patient presents with a history of a tumour of the left temporal lobe a) Use well labelled diagrams to illustrate the visual field results you would expect to find in this patient. b) Explain your answer with reference to your understanding of the anatomy of visual pathways - ✔✔'pie in the sky' incongruous (asymmetrical) homonymous superior quadrantanopia homonymous because post optic chiasm lesion, superior defect as more inferior retinal fibres in Meyers loop/parietal lobe? Where does an inferior homonymous quadrantanopia indicate a legin? - ✔✔Upper optic radiations The case history is very important for a child with vision related learning problems. Disscuss some of the chief complaints/concerns and symptoms and signs that may be associated with learning problems - ✔✔difficulty reading, missing and mixing up words, difficulty following on from one line to the other, read slowly, difficulty seeing board at school, diplopia, difficulty switching from dv to nv
- ast, headaches, blurred vision
- reported eye turn from parents/teacher
- reduced VA distance and near, refractive error, poor accommodative-amplitude response, facility, saccades (inaccurate), poor convergence, symptomatic phoria dissociated/ assocoated Outline essential examination procedures that you would include to evaluate a child who presents to your practice with a history of learning difficulties - ✔✔Vas, refraction, NPC- pen to nose, accomodation amplitude test RAF rule, dynamic ret, +/-2.00 flippers to measure accommodative facility, cover test, mallet unit Kays pictures, crowded logmar, Leas etc. depending on age, ophthalmoscopy
A 59 year old male presents to your practice for examination complaining of difficulty with distance vision over the past few weeks. However he has no difficulty reading books and other near tasks. His vision with his current multifocals is R6/12 and L6/9. Refraction shows that his R distance prescription has altered by - 0.75/-0.50x75 and his L distance prescription has altered by - 0.75/-0.25x90 to give a VA of R6/5and L6/5. His near addition remains unchanged. a) Indicate possible differential diagnoses cataracts causing myopic shift, change in rx b) What other information might be necessary from the case history to assist managing this patient? c) What further tests or actions would be appropriate to differentially diagnose and manage this patient.
- ✔✔Cataract Cornea (keratoconus/corneal oedema) Inflammation Transient cillary body contraction due to medication Medications, Ocular history, is patient a driver, smoker? Exposure to sunlight, e.g occupation does px work outside? Family ocular history Summarise findings that would support each differential diagnosis Pinhole, slit lamp assessment anterior and biomicroscopy to examine fundus. A 42 year old man presents for routine examination complaining of near vision difficulties over the past 6 months. He reports no other symptoms. He reports he has had blows to the eye which caused significant 'black eyes', on a number of occasions during the playing of contact sports and as his occupation as a police officer. Apart from the need of presbyopic correction, refractive and binocular vision assessment was unremarkable. Unaided distance vision was R 6/6 L 6/6. Colour vision was normal. a) List potential areas for concern from this patient's history.
c) On slit-lamp examination you find an umbilcated nodule on the superior lid margin. What is the most likely diagnosis? d) What would be your management plan? - ✔✔Viral conjunctivitis, chlamydial, conjunctivitis medicomentosa (contact conjunctivitis), EKC, molluscus contagiosum Viral Conjunctivitis- cold symptoms/ URTI, contact with other infected individuals, type of 'irritation' burning sensation/grittiness? EKC (epidemic keretoconjunctivitus- same as above plus photophobia and blurred vision Chamydial- any knowledge of STI/vaginitis/ urethritis? Sexually active? Molluscus contagiosum Advise self limiting- referral to ophthalmlology for excision, cold compresses, hygiene to prevent infection A 50 year old female patient consults you. She reports that she is currently being treated for a pituitary tumour. She asks whether she will currently be eligible for driving a private vehicle. a) What are the legal requirements for driving in Australia? b) What tests would you undertake to determine her eligibility to drive for driving and what aspects of her condition are most likely to be important in relation to driving ability? - ✔✔Vas 6/12, horizontal visual fields 110 degrees horizontally, 10 degrees vertically above and below horizontal midline Visual Fields, VAs
- A 60 year old male patient presents to you with a 3 day history of flashes and floaters a) Outline the specific examination techniques that you would use for exploring the cause of these symptoms in this patient. b) Name the 2 potential causes of these symptoms and your management plan for each of them, including your advice to the patient and relative urgency of your referral or review P - ✔✔VAs, Fields, pupil reactions, dilated fundus biomicroscopy, IOPs, slit lamp for tobacco dust in anterior vitreous VD- discharge patient reassure and give advice of any increase in sx, curtain/shadows in vision go straight to eye emergency RD- emergency referral to opthalmology What factors would you consider when determining whether to refer a patient to an ophthalmologist for pterygium removal? - ✔✔Symptoms: reduced/blurry vision, discomfort, signs: Reduced visual acuity, lesion close to visual axis, high astigmatism difficult to correct c glasses, lesion will probably regrow after surgery
- A 60 year old male patient consults you and you diagnose primary open angle glaucoma. His visual fields show a small arcuate loss in both eyes and on ophthlomoscopy you observe an arcuate nerve fibre defect. His intro-ocular pressures are 27mmHg in each eye. This man also suffers from athsma, is a diabetic and has an allergy the sulphur drugs a) What anti glaucoma medications could be prescribed? b) How can their effectiveness be assessed? c) Are any medications contraindicated here and why? - ✔✔Prostaglandin analogues eg. Latanoprost, alpha 2- agonists e.g brimonidine Check for reduction in IOP, expected 30-35% reduction in Pas and 25% in alpha2A Beta blockers (timolol) caronic anhydrase inhibitors (sulphur drugs) (e.g. dorzolamide) A 10 year-old girl is brought to your practice as she is reporting difficulty in seeing the board at school. You suspect that the child may be malingering.
