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Ruth Hogg PhD Lecturer CEM  Anatomy of the eye  Symptoms  Clinical signs  Tools of the trade  Slit-lamp practical  Ophthalmoscopy.

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Presentation on theme: "Ruth Hogg PhD Lecturer CEM  Anatomy of the eye  Symptoms  Clinical signs  Tools of the trade  Slit-lamp practical  Ophthalmoscopy."— Presentation transcript:

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2 Ruth Hogg PhD Lecturer CEM

3  Anatomy of the eye  Symptoms  Clinical signs  Tools of the trade  Slit-lamp practical  Ophthalmoscopy

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5 Cardiovascular disease Diabetes Hypertension Stroke

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9  Presenting complaint, ask supplementary Q  Past history (including ocular surgery or treatment)  Medical history (ocular manifestations, etc)  Drug therapy (ocular drug side effects)  Trauma  Family history (diabetes, hypertension, myopia, strabismus, amblyopia and glaucoma)  Occupation and hobbies Observe the patient!

10  Decreased vision-distance vs near  Pain in the eye-  Redness of the eye  Discharge  Diplopia- constant, intermittent, self- treatment  Metamorphopsia  Floaters  Flashing lights

11 ◦ II (Optic Nerve)  Visual acuity  Colour Vision  Visual Field  Fundoscopy – optic disc ◦ III, IV, VI ◦ Pupils  Parasympathetic – constriction (III nerve)  Sympathetic - dilation

12 Distance patient is from chart (6m) ---------------------------- -------------- Distance a symbol of a given size can be seen by an eye with standard acuity 6/6 Normal Vision 6/10Driving vision 6/6010% vision 3/60Blind Registered

13  Unaided VA, often called vision  Habitual VA, with the patient’s own spectacles or contact lenses  BCVA - Best corrected VA, with the best refractive correction I.e. after subjective refraction

14  Distance crucial (spectacle plane)  Encourage guessing.  Discourage cheating.  Unaided, then aided and pinhole.

15  Assesses the potential acuity in the absence of optical defects.

16  Unaided= 6/18  Pinhole= 6/6 Uncorrected refractive error present.

17  Unaided= 6/18  Aided=6/9  Pinhole= 6/6 Uncorrected refractive error present may need an updated Rx.

18  Aided=6/18  Pinhole= 6/18 Deficit must be neural in origin. Ambylopia

19  Readily available  Snellen notation of VA widely understood  Can be produced in a compact format  Useful for patients with good VA

20  Few larger letters to accurately assess poor VA  Single letter identification much easier to undertake than multiple-letter presentations (crowding effect)  Less sensitive to amblyopia and other uniocular VA loss  Legibility ratings vary greatly between letters  Reduced sensitivity in the upper range (6/60 – 6/24)  Irregular geometric progression from top to bottom  More logical to have letter sizes increase as a regular logarithmic progression

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22  Logarithmic progression of letter sizes  5 letters on each row, more larger letters  Spaces between letters are equal to one letter width  Letters of similar legibility  Design principles allow each letter to be given the same value  VA scored as 0.1 logMAR for each row and 0.02 logMAR for each letter  Letter score improves reliability

23 No of letters read at 1m logMAR scoreSnellen equivalent 51.66/240 101.56/192 151.46/150 201.36/120 251.26/96 301.16/75 351.06/60 400.96/48 450.86/36 500.76/30 550.66/24 600.56/18 650.46/15 700.36/12 750.26/9 800.16/7.5 850.06/6 90-0.16/4.5 95-0.26/3.75 100-0.36/3

24  In cases where VA is less than 6/60, common practice within the UK is to use the terms Counting Fingers (CF) Hand Movements(HM) Perception of Light(PL) No perception of Light(NPL)  However - much better to use closer distance! E.g. 3/60, 1/60, 0.5/60  Use of CF (counting fingers) should be discouraged as Finger width, distance from the patient, finger separation and target- surround contrast vary greatly

25  Those with VA less than 1/60 (or 0.5/60) can be classified using the following test sequence:  Hand movements: HM @ ‘Y’cm  Perception of light: PL  No perception of light: NPL

26  Identify numbers or trace lines.  Just red-green NOT blue yellow defects.  Screening test.

27  Sphincter pupillae ◦ Circular muscle constricts pupil (MIOSIS) ◦ Parasympathetic from Edinger-Westphal nucleus via III  Dilator pupillae ◦ Radial muscle dilates pupil (MYDRIASIS) ◦ Sympathetic via:  Hypothalamus  Ciliospinal center of Budge and Waller

28 Constriction – III nerve (parasympathetic) Dilatation – sympathetic

29 INSPECT ◦ Size, shape, symmetry ◦ Look at lids (ptosis), eye position 1. Direct Response 2. Consensual Response 3. Swinging Flash Light 4. Accommodation (Near response) (Lid and eye movements)

30  Have the patient look at a distant object  Look at size, shape and symmetry of pupils.  LIGHT RESPONSE - Shine a light into each eye and observe constriction of pupil. ◦ Flash a light on one pupil and watch it contract briskly (DIRECT REFLEX). ◦ Flash the light again and watch the opposite pupil constrict (CONSENSUAL REFLEX). ◦ Repeat this procedure on the opposite eye.  SWINGING FLASH LIGHT TEST  ACCOMODATION RESPONSE ◦ Ask the patient to fixate on distance target ◦ Then follow your finger or accommodative target as you bring it toward the bridge of his nose. ◦ Note the convergence of the eyes and pupillary constriction. ◦ Normal: Convergence should be sustainable to within 5-8 cm and both pupils constrict

31  Patient is not looking at distance target  Fixing on light or examiner  Accommodation stimulated  Findings will be inaccurate

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33 unilateral lesion in the afferent visual pathway anterior to the chiasm

34 Normal:  Pupils are subtle, mild anisocoria (unequal in size) by itself is not necessarily an abnormal findings.  Pupil size is 3-5 mm in diameter.  They react briskly to light, constrict consensually and constrict with accommodation.  No Relative Afferent Pupillary Defect (RAPD)

35  Used to dilate the pupil, most also act on accommodation at the same time.  Improve the view of the fundus and images particularly in older people whose pupils tend to be small.  1% tropicamide This anticholinergic (parasympathetic antagonistic) preparation blocks the responses of the sphincter muscle of the iris and the ciliary muscle to cholinergic stimulation, dilating the pupil (mydriasis). The stronger preparation (1%) also paralyzes accommodation.

36  VI - lateral rectus  IV - superior oblique  III - everything else ◦ MR, SR, IR, IO ◦ Levator paplpebrae superioris LR6 SO4 Right Eye

37  Instruct Patient ◦ Keep head still ◦ To follow target ◦ Say ‘YES’ if at anytime they have double vision  Assess range of ocular movements  Target approx. 50cm from patient

38 Visual Pathway

39 ◦ Position yourself in front of the patient  Same level  Approx. 1m away ◦ The nose normally cuts off the medial field of vision - so compare the patient's right eye to your left eye and vice versa. ◦ Instruct the patient to cover eye. ◦ Examiner covers/closes opposite eye ◦ Instruct the patient to look straight at your eye and not to move their eyes. ◦ Instruct patient to say ‘YES’ when finger moves. ◦ Present upright index finger to each quadrant of field of vision ◦ Some like to have the patient count fingers, i.e., 1, 2 or 5. ◦ Test one quadrant at a time. ◦ Compare your field of vision with the subject's. ◦ Test all four quadrants in a similar fashion.

40 If patient continues to not fixate on your eye and looks at finger – suspect field defect which they are trying to compensate for.


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