STUDY GUIDE BASIC CLINICAL SKILL OPHTHALMOLOGY
CONTENTS: 1. Subjective visual examination
2. External inspection: Eyelid
Conjunctiva Sclera
Lachrymal apparatus Pupil
Light reflex and convergence Cornea
Camera Oculi Anterior Iris
Lens 3. Intra Ocular Pressure
Palpation Tonometry Schiotz
4. Therapeutic Skill Eyelid eversion
Eye drops installation Eye ointment installation
Applying eye dressing Removal conjunctiva foreign body
Removal corneal foreign body with cotton bud
I. SUBJECTIVE VISUAL EXAMINATION Eye Examination:
• Visual Acuity
• Visual field examination with confrontation test, perimetry kinetic and static
• Dark adaptation – measurement of least luminance required to produce a visual
sensation •
Contrast sensitivity – is measurement of the smallest distinguishable contrast, it is assessment of quality of vision
• Colour vision –with lantern test Edridge green lantern and Isochromatic charts
Subjective examination of the function of eye Definition. It is defined as the measurement of the smallest retinal image which can be
appreciated with reference to its shape and size. it is actually measure of form sense. •
Central or direct vision •
Distance vision with Snellen test type •
Near vision with Snellen test type or Jaeger’s test type •
The principal of assessment is measurement of spatial resolution of the eye i.e. an estimation of ability of eye to discriminate between two points.
DISTANCE VISION Two distant points can be visible as separate only when they subtend an angle of 1 minute
at the nodal point of eye.
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Principle
• Each individual letter subtends an angle of 5 minutes and each component of letter
subtends an angle of 1 minute at the nodal point of eye from the distance in meters written as numerical.
• Snellen chart is having different number of letters in different rows and the letter at
top line should be read clearly at distance of 60 m. similarly the letters at subsequent lines as are read at 36, 24,18,12,9,6,5mts respectively
• Numerical convention is used for recording visual acuity. In fraction, the numerator is
the distance at which the patient is sitting from chart and the denominator is the distance at which person with normal vision should be able to read the last line that
person is able to read.
Procedure of testing
• Patient is seated at the distance of 6 meters from Snellen’s chart distance of 6 mts
is taken as at this distance it is assumed that the rays are almost parallel and patient exert minimum accommodation
• The chart should be properly illuminated at minimum of 20 feet candles. Patient is
asked to wear trial frame. It is adjusted according to patient inter pupillary distance. •
Ask the patient to read with one eye from the top letter while the contra lateral eye is closed gently with the patient palm or with occulder in the trial frame.
• Now patient is asked to reads the Snellen’s chart from top letter to smaller letter, and
depending upon the smallest line that the patient can read from distance of 6mt. His vision is recorded as 66, 69, 612,618, 624, 636, 660.
• But if patient is not able to see the top line from 6mts he is asked to count the
examiner finger at 5,4, 3, 2, 1 mts or reverse, from 1 to 5 mts and noted as
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560,460,360,260,160 respectively or CF=counting finger 1m, CF 2m, CF 3m,CF 4m, CF 5m
• If patient not able to count examiner finger close to face then examiner waves or
moves his hand in about 25 cm from the patient eye and asks patient whether he is able to see hand movement or not. Visual acuity then recorded as HM+ or 1300.
• When patient cannot distinguish hand movements, the examiner use penlight in front
of the patient eye ± 20 – 25cm and notes whether the patient can perceive light or not. If he perceive light it is noted as LP light perception +ve otherwise as LP-ve.
The examiner then reflect the penlight from four directions nasal, superior, temporal, inferior and asked the patient to mention the direction of the light.
• Record accordingly if present patient perceive light from all directions it is marked as
PR Projection of rays present or else mark as absent or defective. The test is repeated for the other eye in similar fashion
Pin hole test Method
• Place the pin hole occluder in front of the eye with reduced vision
• Ask the patient to move their eye and head until some letters can be read on the
letter chart •
Ask the patient to read the lowest line of letters he can see looking through the pinhol
Interpretation
• If patient vision is improved with pin hole it means the poor acuity is due to
refractive errors. eg. 612 PH 66 means visual acuity 612 can be improved with pinhole until 66
• If static acuity means may be due to structural or organic cause.eg.612 NI PH =
non improved PH means the visual acuity still 612 with non improvement with pin hole
• If reduced the poor visual acuity may be due to corneal opacity or lenticular
opacity occupying papillary area or macular pathology. Charts for testing near vision are :
1 Snellen near vision chart 2 Jaeger chart
3 Roman test type
Method of recording near vision
• Ask the patient to sit with his back to the light
• If the patient is using glasses for distance the same number will be put on the
trial frame. Occlude one eye with an occulder •
Ask the patient to hold the near vision by his right hand at a distance of 25 to 33 cms.
• Note the near vision as per the letter read
• Repeat the test for the other eye.
II. EXTERNAL INSPECTION
