CLINICAL EXAMINATION OF EYE

[Total facility of aqueous outflow]

Tonography – is a noninvasive technique for determining the facility of aqueous outflow

Tonometry – is the assessment of the IOP of the eye and is one of the pillar stones of diagnosis of glaucoma

Tonography is a noninvasive technique for determining the facility of aqueous outflow.

Ref: Parson’s Diseases of The Eye, 18th Edition, Page 7226

Area of retina visualised under direct ophthalmoscope is 2DD. Image formed is virtual, erect and magnified 15 times.

Area of retina visualised under indirect ophthalmoscope is 8DD. Image formed is real, inverted and magnified 4-5 times.

 Indirect ophthalmoscopy:

• Done with indirect ophthalmoscope; and the position of the patient → Lying down.
•  Distance of the doctor → Arm length of the doctor
• Power of the holding lens →20D

Structures visualised are:

C i.e. Angle of anterior chamber 

Gonioscopy is examination of angle of anterior chamber Q.

B i.e. Lens 

Lens and cornea are avascular structures of eye Q that’s why fluorescein angiography can’t be used to identify lesions.

While fluorescein angiography (FA) is an excellent method of showing the retinal circulation against the uniform dark background of retinal pigmentary epithelium. It is not helpful in delineating choroidal circulation. In contrast Indocyanine green angiography is excellent in studying choroidal circulation & is a useful adjunct in investigation of macular disease.

D i.e. Posterior surface of lens 

B i.e. 2DD

B i.e. Periphery of retina

Indirect ophthalmoscopy is done for examination of periphery of retina upto ora serrata Q where as direct ophthalmoscopy can show slightly beyond equator.

Ans. Specular microscopy

Ans. Biomicroscope

Ans. Myopic

Ans. Pachymeter

Ans. Central serous retinopathy

Ans. A i.e. 22 cm

Distant direct ophthalmoscopy

• Used to get a preliminary idea about the status of the ocular media and fundu
• This should be done routinely before doing a direct ophthalmoscopy
• Equipment needed – self illuminated ophthalmoscope or plane mirror with a hole in centre
• Procedure

Should be performed in a semi dark room

The ophthalmoscope should be kept at a distance of 20-25 cm from the patient’s eye Normally a red reflex is seen at the pupillary area

• Uses
• Opacities in the ocular media are seen as dark spots in the red glow at the pupillar area
• The plane of the opacities can be assessed by asking the patient to move the eye from side to side while the examiner is observing the pupillary glow (based on parallax principle)
• opacities in front of the pupil move in the direction of eye movement
• opacities in the pupillary plane do not move
• opacities behind the pupillary plane move opposite the direction of eye movement
• To differentiate between a mole on the iris and a hole in the iris in oblique illumination, both appear dark in distant direct ophtalmoscopy
• mole – appears dark
• hole – red glow is seen
• To detect a retinal detachment or fundal mass

Both of them are visible as a grayish reflex

It is not possible to differentiate them in distant direct ophthalmoscopy

Ans. A. 5 times

• Done with indirect ophthalmoscope; and the position of the patient → Lying down.

• Distance of the doctor → Arm length of the doctor
• Power of the holding lens →20D

Structures visualised are:

• Can be seen until pars plana (that’s the farthest structure visualised)
• Pars Plicata cant be seen.

Quality of the image:

Pneumonic: (RIM) Real Inverted Magnified image & Magnification is 3 – 5 times the normal.

Ans. C: 15 times

The direct ophthalmoscope gives a magnification of approximately 15 times and a field of view of 6.5 to 10 degrees, This 15 times magnification makes the 1.5 mm disc appear much larger than it really is.

The image formed in direct ophthalmoscopy is always erect.

Ans. D: It has a large field of view

The image is erect and magnified about 15 times (more magnified than that of indirect ophthalmoscopy)

The area of the fundus which can be seen by the direct method varies with the distance of the observer from the eye and with the refraction. It increases as the eye is approached, is greatest in hypermetropia, least in myopia and intermediate in emmetropia.

Thus the largest area, least magnified, is seen in hypermetropia, and the least area, most magnified, in myopia.

Ans. is ‘a’ i.e., Keratometry

The `Keratometry’ or `ophthalmometry’ is an objective mehod of estimating the corneal astigmatism by measuring the curvature of central cornea.

Gonioscopy – Biomicroscopic examination of the angle of anterior chamber.

Perimetry – Procedure of estimating the extent of visual fields.

Tonography – Non – invasive technique for determining the facility of aqeous outflow (C – value).

Ans. is ‘a’ i.e., Tonometer

The exact measurement of intraocular pressure is done by an instrument called tonometer. Indentation (Schiotz tonometer) and applanation (e.g., Goldmann’s tonometer) tonometers are frequently used.

Ans. is ‘a’ i.e., Ophthalmoscopy

The procedure of determining and correcting refractive errors is termed as refraction. The refraction comprises two complementary methods : ‑

A) Objective methods : Objective methods of refraction include :- (i) Retinoscopy, (ii) Refractometry, (iii) Keratometry.

B) Subjective methods : These are :- (i) Subjective verification of refraction, (ii) Subjective refining of refraction, (iii) Subjective binocular balancing.

Ans. is ‘c’ i.e., Aesthesiometer

Measurement of Corneal Sensitivity

• Corneal sensitivity may be tested by touching it in various places with a wisp of cotton-wool twisted to a fine point and comparing the effect with that on the other, normal cornea. There is in general a brisk reflex closure of the lids.
• Corneal sensations are often diminished after any gross disorder, but the change is of diagnostic significance in certain cases, particularly herpes keratitis where minimal corneal changes are accompanied by a gross diminution of sensation.
• Quantification of the corneal sensation is possible to some degree by the use of a corneal aesthesiometer in which a single horse hair of varying length is used instead of a wisp of cotton-wool. The longest length which induces blinking is a measure of the threshold of corneal sensitivity.

Ans. is ‘d’ i.e., Useful in hazy media

Ans. is ‘d’ i.e., Slit lamp bio-microscope

Corneal Endothelium:

• It consists of single layer of polygonal (mainly hexagonal cells).
• They are visualized by slit lamp bio-microscope and appear like mosaic.
• The cell density is 3000 cells/ mm2 in young adults and deceases with age.
• These cells contain active pump mechanism.

Note: Confocal microscope can be used to study all layers of retina.

Ans. is ‘a’ i.e., Cornea

Important corneal examinations

• Keratometry, Corneal topography
• Specular microscopy
• Slit lamp
• Pachymeter
• Placido’s disc
• Fluorescein, Alacian blue & Bengal rose stain
• Window reflex, slit lamp biomicroscopy, Placidos’ disc

Used for

• Curvature of cornea
• Corneal endothelial density
• Corneal opacity
• Thickness of cornea
• Corneal sheen
• Corneal staining
• Corneal surface

The Instrument shown is a Gonioscope 

• Gonioscopy is using a goniolens (also known as a gonioscope) together with a slit lamp or operating microscope to view the iridocorneal angle or the anatomical angle formed between the eye’s cornea and iris.
• Its use is important in diagnosing and monitoring various eye conditions associated with glaucoma.

Ans:B.)Indirect Ophthalmoscope

Ophthalmoscopy, also called fundoscopy

• It is a test that allows to see inside the fundus of the eye and other structures using an ophthalmoscope (or fundoscope). It is crucial in determining the health of the retina, optic disc, and vitreous humor.
• It is of two major types:
  • Direct ophthalmoscopy : produces an upright, or unreversed, image of approximately 15 times magnification.
  • Indirect ophthalmoscopy: produces an inverted, or reversed, direct image of 2 to 5 times magnification.

• Each type of ophthalmoscopy has a special type of ophthalmoscope:
  • The direct ophthalmoscope is an instrument about the size of a small flashlight (torch) with several lenses that can magnify up to about 15 times. This type of ophthalmoscope is most commonly used during a routine physical examination.
  • An indirect ophthalmoscope, on the other hand, constitutes a light attached to a headband, in addition to a small handheld lens. It provides a wider view of the inside of the eye.
    •  It allows a better view of the fundus of the eye, even if the lens is clouded by cataracts.
    •  An indirect ophthalmoscope can be either monocular or binocular. It is used for peripheral viewing of the retina.

• Fluorescein angiography is useful in all conditions.

 Fluorescein angiography is used in :‑

1. Diabetic retinopathy
2. Neoplasm
3. Papilloedema
4. Central serous retinopathy
5. Retinitis pigmentosa and other retinal degeneration
6. Choroidal diseases : Choroidal neovascularization
7. Vascular occlusions (CRVO, CRAO)
8. Eale’s disease
9. Cystoid macular edema

Ans. is ‘d’ i.e., Binocular balancing

Refraction

• The procedure of determining and correcting refractive errors is termed as refraction. The refraction comprises two complementary methods : ‑

Objective methods

• These are used to measure the error of refraction.

1. These tests are :-
2. Retinoscopy
3. Keratometry
4. Refractometry

Subjective refraction

• Subjective refraction is meant for finding out the most suitable lenses to be prescribed. The proper subjective

1. refraction includes three steps.
2. Subjective verification of refraction
3. Subjective refining of refraction
4. Subjective binocular balancing