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^ VI. The tasks below help you check your knowledge.

Task 1

During medical examination at a factory the ophthalmologist diagnosed that a patient was able to see the first line of Sivtsev chart with his right eye at only 1m distance.

What is the patient’s visual acuity?

A. 0,2.

B. 0,02.

C. 0,002.

D. 0,001.

E. 0,01.

Task 2

During military recruitment examination a conscript was diagnosed with 0, 07 (uncorrectable) visual acuity in his left eye and 1,0 in his right eye. The ophthalmologist could not explain reduced visual functions by objective changes. Vision acuity evaluation test showed that the left eye visual acuity was 0,3. The conscript was taken to a military hospital where his vision was examined with an objective technique.

What technique was used to evaluate the conscript visual acuity?

A. Golovin/Sivtsev charts.

B. Nystagmograph.

C. Optotypes.

D. Fingers.

E. Rabkin charts.

Task 3

An aged patient complained of a very bad vision in his left eye. Examination showed the left lens opacity. Visual acuity in the left eye equaled the light sensitivity with right light projection.

How to record the visual acuity findings in the patient’s file?

A. VOS=.pr. l. certa

B. VOS=.pr. l. incerta

C. VOS=.pr. l. dubia

D. VOS=0

E. VOS=0,005


Task 4

The patient complains of lost outside sections of visual fields. The patient has 0,9 (uncorrectable) of visual acuity in both eyes and bitemporal hemianopsia in the visual field. Both eyes are quiet, optical medium is transparent, optic nerve disks on the eye fundus are of normal size, pale, with clear borders.

Where is the pathological process causing bitemporal hemianopsia located?

A. Optic nerves.

B. Chiasma.

C. Optic tracts.

D. Graciole fascicle.

E. Cortical visual centers.

Task 5

A young man with a craniocerebral trauma had a course of treatment in neurosurgery department. A week after the trauma he noticed that his vision was deteriorating. Ophthalmologic examination revealed 0,9 uncorrectable vision acuity in his right eye, 0,8 uncorrectable in his left eye and equilateral hemianopsia in the field of vision. Both eyes are quiet, deep-seated medium is transparent, optic nerve disks are of normal size, pale, with clear borders.

What is equilateral hemianopsia characterized by?

A. Loss of temporal part of the visual field in one eye and nasal part in the other.

B. Loss of outward parts of visual field.

C. Loss of interior parts of visual field.

D. Appreciable narrowing of the visual field in the temporal sections of both eyes.

E. Appreciable narrowing of the visual field in nasal sections of both eyes.


^ VII. Brief work guidelines for the workshop activity

In the beginning of the workshop, the students’ basic knowledge is tested. Then the students individually examine visual functions in one another and in the patients. Then the students interpret the results obtained. The workshop ends with a concluding topical test.


^ Process chart of the workshop on

Examination techniques for evaluating visual functions; role of a physician in preventing vision disorders in children and adults



Stages

Time

(min)

Learning aids

Where held

Notes

Learning means

Facilities

1

Basic level checkout and adjustment test check

20

Target training tasks and reference answers




Study room




2

Independent examination of visual functions

1) Vision acuity testing with charts, Polyak’s optotypes from various distances
2) Qualitative examination of light perception with ophthalmoscope
3) Vision field examination with control method, perimeter, campimeter
4) Color perception examination with Rabkin’s charts

180

Logic structure graph,

Diagnostic algorithm


Roth’s apparatus, Polyak’s optotypes, Byelostotsky’s adaptometer, lamp, ophthalmoscope, Rabkin’s charts, perimeter, campimeter.
Vision filed forms.


Study room




3

Final test check

20

Set of tests




Study room




^ TECHNIQUES OF OCULAR EXAMINATION

I. Relevance of the topic. The subject is of great importance as many techniques trained during the workshop are used in the practice of various medical specialists. For instance, examination of eyelids is essential in diagnosing infectious, neurologic and parasitic diseases. Pupillary response to light and eyeball motility is very important for diagnosing neurologic and neurosurgical diseases.

Study and think over the objectives of the workshop on testing techniques for ocular examination.

^ II. Objective (general): to be able to carry out the globe and eye appendages examination, detect and evaluate the changes occurred.

Specific objectives

Specific objectives of basic level of knowledge and skills

TO BE ABLE TO

1. Examine the parts of the face around the orbit, eyelids and lacrimal apparatus; identify pathological changes.

Perform examination using the knowledge of normal anatomical and physiological parameters of eyelids, lacrimal apparatus, the orbit (Anatomy Dep. and Physiology Dep.)

2. Examine conjunctiva, cornea, anterior eye chamber and iris with focal illumination and biomicroscopy; identify pathological changes.

Apply to the knowledge about normal anatomical and physiological parameters of conjunctiva, cornea, anterior eye chamber and iris to correlate with the examination findings (Normal Anatomy Dep. and Normal Physiology Dep.).

3. Examine the lens and vitreous body with transmitted light and interpret the findings.

Know anatomical and physiological peculiarities of the lens and vitreous body structure (Normal Anatomy Dep.)

4. Perform ophthalmoscopic examination of the fundus.

Use the knowledge about normal anatomical and physiological parameters of the retina and optic nerve.

5. Examine tear secretion and tear drainage process

Know anatomy and physiology of lacrimal gland and tear drainage system (Normal Anatomy Dep.)

6. Identify the most informative signs of abnormalities obtained in the patient objective examination.

Perform objective examination of a patient (Surgery Dep.)

7.  Interpret the instrumental examination findings.

Assess the findings obtained in additional examination (Prop.Therapy Dep., Surgery Dep.)



^ III. You are supposed to do the two tasks below to check your basic level of knowledge and skills.


Task 1.

While examining the anterior eye section with focal illumination, the lamp light is focused with the help of loupe.

Question: At what distance should the 13D (diopters) loupe be held to aim the focus on the cornea?


Task 2.

The patient after a stroke was diagnosed with the lack of outward globe motility in the right eye.

Question: What is the most probable cause of this abnormality?

Reference answer to task 1:

7-8 сm away.


Reference answer to task 2:

Right abducent nerve palsy.


After the basic knowledge has been acquired, you may proceed to study the following:

1. Supplemental references to improve the basic level of knowledge:

Basic:

  1. Pryves M.G., Lysenkov N.K., Bushkovich V.I. Human anatomy.– SPb: Hippocrates, 1998.– pp. 656-670.

  2. Sinyachenko O.V., Ignatenko G.A. Propedeutics of internal diseases. Textbook.– Donetsk: Donetchyna, 1999.– pp. 22-44, С. 46-81, pp. 227-307.

  3. Smirnov O.V. Human physiology: Textbook.– М.: Medicine, 2002.– pp. 469-477.

Additional:

  1. Ivashchenko V.V. Selected lecturers in general surgery.– Donetsk «Weber», 2007.– pp. 86-112

  2. Zaiko N. N., Byts Yu.V., Ataman A.V. et al. Pathologic physiology: Textbook. – К.: «Logos», 1996.– pp. 576-609.

IV. Learning content.

Theory needed as a basis for target activities.

1. External examination. The state of periorbital sections. Eversion of the eyelid. The state of lacrimal apparatus and conjunctiva.

2. The size and shape of the eyeball, its position in the orbit and its motility.

3. Focal illumination. Sclera and cornea examination.

4. Transmitted light examination. Identifying opacity of lens cataract and vitreous body.

5. Biomicroophthalmoscopy. Detailed examination of conjunctiva, sclera, anterior chamber, iris. Gonioscopy.

6. Examination of tear production and tear drainage functions.

7. Approximate and instrument techniques for intraocular pressure evaluation.

8. Direct and indirect ophthalmoscopy. The picture of a normal fundus. Fundus picture in patients from various geographic regions.


Study the logic structure graph below.


Logical structure graph for

Techniques of ocular examination”




Basic reference sources:

  1. Logical structure graph

  2. Diagnostics algorithm

  3. Avetisov E.S., Avetisov S.E., Beloglazov V.G. et al. Ocular diseases: Textbook.– М.: Medicine, 2002.– pp. 129-152.

  4. Pavlyuchenko K.P., Oleynik T.V., Mogilevsky S.Yu. et. al. Ocular diseases: Study guide– Donetsk, 2007.– pp. 11-20.

Additional reference:

    1. Danilichev V.F. Modern ophthalmology.- SPb: Piter, 2000.- pp.24-25.

    2. Pavlyuchenko K.P., Oleynik T.V., Mogilevsky S.Yu. et. al. Ocular diseases: workbook– Donetsk, Anex, 2004, pp. 15-29.

After the basic knowledge has been acquired, use the following guiding procedure to check your ability to do the tasks.


V. Guiding procedure (GP)

The guiding procedure used to tackle the tasks and manage the patients is presented in the logic structure graph and diagnostics algorithm.


Diagnostics algorithm

«Techniques of ocular examination»





























Since the time of Hippocrates, the most learned and experienced physicians have always considered subjective case histories and patient’s complaints of priority importance.

Patient’ complaints.

А. Visual sensation.

  1. Most common complaint – reduced visual acuity. It is perceived in different ways: as a mist, cloudiness or blindness.

  2. Reduced visual acuity with reduced illumination (hemeralopy) is found with retina pigmental degeneration, A or B2 vitamin deficiency, and other cases though less common.

3. Vision disorders caused by visual field defects can bring about various complaints:

- running against objects while walking;

  • inability to see a whole line while reading;

  • a “spot” in the eye.

  1. Double vision occurs with paresis, palsy or injured eyeball external muscles.

  2. Metamorphopsia – image distortion of visible objects. It is found with posttraumatic corneal astigmatism, keratoconus, partial macular lesions and sometimes with retina detachment.

  3. Photopsy – visual sensation of lightnings, zigzagging lines, sparks etc. Such sensations can be attributed to inflammations of the eye nervous apparatus.

  4. Complaints of abnormal color perception can accompany various pathologies in the eyeglobe or optic nerve pathways.

В. Unpleasant sensations.

  1. Dryness, sharp or burning pain, foreign body sensation (typical for conjunctivitis or foreign bodies in cornea or conjunctiva).

  2. True pains are usually of diffuse character (sympathalgic) as with acute glaucoma, or have exact location (neuralgic pain).

  3. Heterotopic pain, for instance a headache, can be caused by inflammation in the eye associated with glaucoma.

Case history

Case history is collected during a patient investigation. Medical history data cannot be obtained from patients in bad state or children. Then the relatives are interrogated. Case history is needed to develop examination strategy, and sometimes enables to properly estimate the disease on the spot. Patient questioning is carried out according to a certain procedure. First of all, it is necessary to identify the onset and earliest signs of disease. Then, how the disease started – suddenly or gradually- what time of day it started, alleged causes (freezing, physical or visual exhaustion, emotional excitement). Next it is important to know the sequence of symptoms appearance and the treatment given. Also life history of the patient is taken, particularly if he has had other ocular diseases that could have caused certain ocular changes. Most ocular diseases are endogenous. Besides, general state of health influences the course of pathological processes in the eye. Therefore, it is essential to know what common diseases have been in the patient’s life before he applied to the ophthalmologist and which of those he is suffering at the moment. Questioning also helps find out the family medical history, work and household environment, occupational hazards, details of hereditary problems. Allergic history is mandatory.

^ General ocular inspection

In general inspection, the patient’s general appearance is estimated as well as his spatial orientation, manner of walking, position of the head, anatomic lesions adjacent to eye. Also it is necessary to examine his lids, orbit, lacrimal organs, the eye ball and its anterior part. A blind man walks unsteadily and carefully. His gait indicates a serious bilateral eye disease. A cornea disease is suspected if the patient covers his eyes with a hand or, due to photophobia, turns away from light.

Examination is carried out with good natural or artificial illumination, better with a desk lamp. At first, a healthy eye is examined and then the bad one.

Examination includes: superciliary zone, nasal arch, upper jaw anterior wall, temporal region and malar bone, aural glands region. Skin state is also evaluated: hyperemia, edema, subcutaneous hemorrhage, swellings. Palpation is used to examine orbit bone edges, detect soft tissues infiltration, painful areas. Then, eye position in the orbit is to be estimated. Normal eyeball hardly ever projects from the eye socket plane and is proximate to the outside edge. Normal eyeball projection is 17-19mm. There are pathologic dislocations forward (exophthalmus), backward (enophthalmos), rightward or leftward from the orbit anteroposterior axis (lateral dislocation), upward or downward. Combination of exophthalmus and a lateral dislocation may be indicative of a reduced eyesocket cavity (tumor). Vertical or horizontal dislocation of an eye is called strabismus. Eyeballs motility and range of motions are examined. With maximum outward dislocation the outside cornea edge reaches the external lids commissure, with maximum inward dislocation it reaches the region of lacrimal caruncle. When the gaze is directed downwards, the bigger half of cornea is to be below the low lid edge; with upward gaze, cornea goes 2mm under the upper lid. Sometimes nystagmus is detected when the eyeball is in extreme positions.

During ocular convergence examination the patient is required to look at the finger point being gradually moved to his eyes strictly along the centerline. Visual lines should all the time converge at the point of fixation and only diverge very close to the eyes. In affected eyes, divergence of visual lines occurs even at a great distance from the eyes. Defects of associated eye movements can be the result of paralysis of gaze when the patient fails to align his both eyes while looking in the same direction but each of his eyes can follow the object independently.

Next is the eyelids examination. It includes examining the skin particularly at the ciliary edge – hyperemia, thickening, scales-, the way eyelashes grow, eyelids position – entropion or ectroption-, palpebral fissure length and width, which is to be 30mm and 10-12mm respectively (upper lid covers cornea over 2mm, lower lid is 1mm below the cornea). These data are important to evaluate eyelids motility defects: ptosis, i.e. drooping of the upper eyelids, and lagophthalmos, i.e. incomplete closure of eyelids). They also help diagnose exophthalmus and enophthalmos.

Lacrimal apparatus examination includes assessing the lacrimal openings size and relative position against the lacrimal lake. Pressing the lacrimal sac region enables to detect discharge of abnormal contents from lacrimal ducts and sac through the openings. Palpebral part of the lacrimal gland can be examined when the upper eyelid is lifted up and outwards and the patient is asked to look at his nose tip.

^ Schirmer test is the assessment criterion for tear production. A blotting paper strip of 1x5cm is placed behind the lower eyelid. The free end of the strip lies outside on the lid skin. With normal tear production the paper will get soaked in 5 min as far as 15-18mm from the lid edge. Less than 15mm soaking indicates reduced tear production.

Canaliculus test is used to examine the functioning of lacrimal ducts. After placing 1-2 drops of 2% collargol solution behind the lower lid the patient is required to do several frequent winks. If lacrimal openings and duct function normally, collargol disappears from conjunctival sac in 0.5-2 min, which can be recognized by whitening of the eyeball. Then the test is positive. With negative test the eyeball is colored brown for a long time.

^ Nasal test helps detect any obstructions of the nasolacrimal duct. Emergence of collargol in the nose (a light blow from the nose on a small piece of cotton wad) 5 minutes after 1-2 drops of the 2% solution have been placed in the conjunctival sac indicates that the passage is not blocked. If it takes more than 10 minutes for collargol to appear in the nose, there is some obstruction in the passage. If collargol does not emerge even 30 minutes later, the obstruction is complete.

Irrigation of lacrimal drainage system enables to determine passive anatomic obstruction. For irrigation a 2-ml syringe with a blunt and not very thin needle is used. Sterile saline is used. At first, a lacrimal opening is dilated with a cone-shaped probe, and then the syringe needle is inserted 5-6mm deep into the lacrimal duct. Saline is injected slowly. With no obstruction in the duct saline trickles out through the nose.

Conjunctiva examination through an open palpebral fissure enables to see only a small part of mucosa. This is the conjunctiva that covers sclera. Lower eyelid conjunctiva can be examined by pulling the lid downwards (while the patient looks up). This makes possible to see the lower lid conjunctiva, lower interjacent fold, and the eyeball lower part conjunctiva. To examine the upper eyelid it should be everted. The patient is required to look down. The physician holds the eyelid by the edge with his left-hand thumb and index finger, pulls it slightly down and then quickly turns it around the right-hand thumb placed some 1.5cm over the lid edge at the tarsal upper level. The same can be done with a glass stick or Desmarres retractor. To examine the upper interjacent fold it is necessary to double-evert the upper eyelid. Healthy eyelid conjunctiva is pink-pale, smooth, transparent, wet. Vasculature pattern is well seen, glands deep in the tarsal tissue can be visible.

Conjunctiva and eyeball diseases manifest with hyperemia, i.e. eye reddening of various severity and localization, superficial (conjunctival) or deep (pericorneal, ciliary) injection. Superficial injection indicates conjunctiva inflammation; deep injection is indicative of pathological cornea, iris or ciliary body. With conjunctival injection the mucus is bright red and hyperemia is the most severe in the region of interjacent folds. Vessels loaded with blood can be well observed. Finally, instillation of adrenaline drops into conjunctival sac leads to a brief apparent reduction of conjunctival hyperemia. With pericorneal injection, there is a dilation of anterior ciliary vessels and their episcleral branches that make up a marginal loop plexus of blood vessels around the cornea. In ciliary injection, the conjunctiva looks like a violet–pink crown around the cornea. Injection decreases towards the fornices. Injected area does not shift with injection dislocation. Adrenaline does not reduce ciliary hyperemia.

The next step after conjunctiva examination is the eyeball examination. This includes cornea, sclera, anterior chamber, iris, pupil region.

Lateral (focal) illumination and biomicroscopy are useful for detail examinations of anterior chamber.

^ Focal illumination. Examination is performed in a dark room with an electric lamp. The patient sits on the left of the table; the lamp is 40-60cm away on his left and a little in front of him at his eye level. The patient’s face is illuminated from the side and the front. Ophthalmologic kit is available for examinations. It includes two magnifying glasses (lenses) of 13 and 20 diopters and a mirror ophthalmoscope. A bundle of light beams is directed from the lamp with the help of one of the lenses, which is held with the right-hand thumb and index finger. To obtain the brightest illumination the lens should be at a distance of its principal focus from the eye, i.e. 8cm and 5cm respectively. The examination should be performed at the largest possible angle to the beams directed into the eyes. Illuminated area is well seen against the shadowed areas.

^ Combined examination. In this examination, the ophthalmologist holds the second lens of the kit in his left hand sets it at the focal distance from the patient’s eye and examines a magnified image of the anterior eye part.

Biomicroscopy. In ophthalmological centers, the slit lamp, i.e. biomicroscopy, is used for ocular examinations rather than combined examination. This is based on the light contrast effect (Tyndall phenomenon).

The patient is examined in a dark room. A bright homogeneous beam of light generated by the slit lamp is directed towards various eyeball areas. The illumination contrast enables to detect any minor changes caused by an injury or disease. Slit lamp is a combination of a powerful light source and a binocular microscope. Biomicroscopy enables a precise examination of conjunctiva, cornea, anterior chamber, iris, pupil, lens, vitreous body, which is essential for differentiating opacity of the posterior capsule of lens from opacity of vitreous body. It is also useful in ophthalmoscope assessment of the eye fundus with a scattering glass. In addition, gonioscopy of the anterior chamber angle with the slit lamp can be performed. It is made with gonioscope, an instrument that deflects the beam of light towards the anterior chamber angle.

Cornea examination is performed to assess if normal properties of the cornea persist. Healthy cornea is transparent, with shining smooth surface. Cornea horizontal diameter is 11mm and the vertical diameter is 10mm. It is spherical and of high sensitivity. Deviation of any of these parameters is indicative of pathological changes in the cornea. Cornea inflammation results into impaired transparency: infiltrates associated with other signs of inflammation (photophobia, lacrimation, pain, pericorneal injection). Traumas and inflammatory processes may be accompanied by epithelium damage. There is a lack of brightness and smoothness in pathological regions in the cornea.

When epithelium damage is suspected, a drop of 1% fluorescein solution is instilled in the conjunctival sac and then irrigated with any eye drops based on sodium chloride isotonic saline. De-epithelized areas remain stained. Pathologic changes in the cornea are often accompanied by hyposelaphesia or apselaphesia. The latter phenomenon is tested by touching cornea with the tip of a twisted strip of cotton wad or with calibrated hairs. With normal sensation, the eyelids quickly close. When tactile sensation is lacking, cornea wink reflex is absent. .

^ In the examination of anterior eye chamber, the chamber depth and content should be considered. The depth corresponds to the distance between light reflexes on the cornea and iris. Average chamber depth is 3-3.5mm. In various pathological states the depth may be various: lack of chamber in penetrating wounds; shallow chamber due to detached choroid, perforated cornea ulcer; unsteady depth of chamber due to lens dislocation or adhesions; deep chamber due to aphakia (lack of lens). Humor in healthy chamber is transparent; in pathological states suppuration (hypopyon) and blood (hyphema) can emerge in it.

In iris examination, the color, pattern and state of iris pigment borders are assessed. Iris color can be light blue to dark brown. Iris pattern is made of trabecules (radial stripes) and crypts (depressions). An inflammatory process smoothes the iris pattern, changes the color, occasionally gives rise to synechia (posterior iris-lens adhesions or anterior adhesion to the posterior corneal surface). Iris coloboma (defects), iridodialysis (iris detachment at the root), iridodonesis (iris tremor) may be detected.

^ Healthy pupil is oval; its diameter in both eyes is the same (2-4mm on the average). Pupil contracts when light falls into the eye; this is a direct pupillary response to light. The pupil also contracts when light falls onto the other eye; this is a consensual, or indirect pupillary reaction to light. Pupillary constriction (miosis) can result from iris inflammations, failures of sympathetic innervation, miotics instillation (constrictive drops).

Mydriasis (pupil dilation) is observed after instillation of mydriatics (pupil dilative drops), in oculomotor nerve lesions, traumas. Inequality of the pupils of the eye is called anisocoria. With lateral illumination, the pupil region looks black, which is suggestive of the lens transparency. Pupil region of gray color is indicative of the lens opacity.

Final judgment can be made after the pupil dilation and examination with transmitted light and biomicroscopy.

^ Transmitted light examination is performed in a dark room. The source of light (60-100W matted electric bulb) is placed a little behind the patient on his left. The examiner sitting in front of the patient sets the mirror ophthalmoscope against the patient’s right eye, moves it 20-30cm to the patient and directs the reflected light into the pupil to investigate the eye through the ophthalmoscope aperture. If the light beam meets no obstruction in the passage to the eye fundus, the pupil shines red. The light reflected from the choroid vessels explains the red color. Focal opacities in the eye optical medium retain the light beam and are visible as dark spots against the red background of the pupil. Cornea opacity is easily detected in external examination and lateral illumination.

Lens opacities shift with the eye movement and they are compact. Motility is common with the vitreous body opacity. In the eye fixed still after some voluntary movements the vitreous body opacity keeps moving while the lens opacity comes to a stop. Opacity located in the pupil plane shifts in the direction of the eye movement. Opacity moves in the opposite direction to the eye movement if located behind the pupil plane. When lens opacity is complete and vitreous body is filled with blood or exudate, the pupil does not shine in transmitted light.

^ Indirect ophthalmoscopy is useful for examining the fundus. Ophthalmologist, sitting 40-50 cm away from the patient, holds mirror ophthalmoscope in his right hand and 13,0D loupe in his left hand. The loupe is placed 7-8 cm away from the patient’s eye after the red reflex is obtained in transmitted light. The aperture of ophthalmoscope mirror, loupe center and the patient’s pupil should be in line. True reverse and magnified image of the fundus is seen between the loupe and the tester’s eye. The loupe (13,0D) enables a 5-fold magnification. Indirect binocular ophthalmoscopy is the best examination procedure for detecting retina detachment.

Direct ophthalmoscopy is performed in a dark room with electric ophthalmoscope, as a rule after pupil dilation. The light beam from ophthalmoscope is directed into the patient’s pupil from the distance of 0.5-2 cm. The fifteen-fold direct image of the fundus is obtained. To obtain a clearer picture of the fundus, the tester and the patient have to have relaxed accommodation and certain refraction ratio in their eyes, which enables the beams from the patient’s eye converge on the tester’s retina. Up-to-date ophthalmoscope disks are provided with various dioptric glasses (from –10,0 D to +10,0D ). Rotating the disk, it is possible to adjust the glass so that a clear fundus picture is obtained.

^ Ophthalmoscopic picture of the fundus. Optic nerve disk (OND) lies inwards from the eye pole (the patient should turn his eye 12-15 towards his nose). Optic nerve disk has clear borders and looks pink or yellowish-red color against the red background of the fundus. Nasal part of the disk contains a massive papillomacular funicle of nerve fibers and is better supplied with blood. Therefore, the templar part always looks lighter. Normally optic nerve disk is round or lengthwise oval; seldom may it be crosswise oval. Horizontally the disk is 1.5-1.7 mm. OND may have a flush coverage with the fundus or it may have a funnel-shape depression in the center (physiological excavation).

It is the disk center where central retina artery comes out and central retina artery comes in. On the OND surface and retina, the arteries dichotomically divide into multiple branches. The arteries are red; the veins are cherry-red. The artery-vein size ratio is 2:3. There is a yellow spot in (macula lutea) near the posterior pole. It is a red oval bordered with a shining strip – macular reflex, which appears due to a cushion-like swelling along the yellow spot border. Macular reflex is more pronounced in younger people, particularly in children. The size of macula lutea may vary significantly. Horizontal diameter may be from 0,6 to 2,9mm. In the center of macula lutea, there is a darker round depression (fovea centralis) with a light point (foveola) in the middle. Average diameter of the central depression is 0.4mm.

More detailed picture of the fundus can be obtained with a large reflexless ophthalmoscope. Replaceable eyepieces enable to magnify the fundus image 10, 20 and 27 times.

Diaphanoscopy is a special examination technique used for differential diagnosing between true and false intraocular tumors. Diaphanoscope is a powerful electric lamp enclosed in a lightproof case with a probe shaped like a bent truncate cone housing a light condencer. A narrow concentrated light beam is fed through the probe.

Diaphanoscopy is performed in a dark room. The lamp tip is set vertically against the eyeball after epibulbar anesthesia with 0.5% tetracaine. The patient’s other eye looks aside. Pupillary region shines red as the light goes through the eyeball tunics. Then the tip moves parallel to the ball equator exciting the pupillary region shine from various directions. The area, where a dense opaque tissue (tumor) occurs in the light way, is darkened.

^ In fluorescent angiography, vascular opacification at the posterior pole of the eye is used to diagnose fundus diseases.

Ultrasound diagnostics is useful for detecting tumors, intraocular foreign bodies, changes in the optical medium, retina detachment; it also enables to accurately assess parameters of the eyeglobe and its internal structures.

^ Ultrasound dopplerography is the method of assessing blood flow in arteries supplying eye and the appendages.

Measuring intraocular pressure. Intraocular pressure may be normal, elevated (with glaucoma and ocular hypertension) or reduced (ocular hypotension). Palpation is an approximate evaluation of intraocular pressure. A patient is asked to look down while the examiner gently presses the eye over the upper lid cartilage with the both index fingers by turns. The fingertips feel rigidity of the eyeball. The higher the pressure, the more rigid the eye is. With low pressure, the ball is soft and flexible. Normal pressure is marked with TN. There are 3 degrees of elevated intraocular pressure in palpation: Т+1 – moderate elevation of the eye tone; Т+2 – marked elevation, Т+3 – sharp elevation; and 3 degrees of reduction, respectively Т-1, Т-2 and Т-3. Palpation method is useful for determining intraocular pressure when tonometry is contraindicated (corneal ulcer, keratitis). In this procedure, the tone of one eye is compared with the other.

Tonometry is an objective method of determining intraocular pressure. Since 1884, Maklakov’s tonometry has been used. It uses the principle of flattening the cornea. Tonometer of 10g weight is used (there are weights of 5; 7.5; 10 and 15g). Tonometer is a hollow metal cylinder with a lead weight inside and 1cm diameter polished matt glasses at the end. Before examination, the tonometer glasses are cleaned with alcohol and covered with a thin layer of dye (mixture of collargol, glycerin and distilled water). Tonometry is performed 3-5 minutes after topical epibulbar anesthesia (0,5% dicaine twice). The patient lies on the back, face up; the examiner’s is at the patient’s head. The patient is asked to fix his glance at the index finger of his raised hand to make the eye cornea horizontal. The examiner with the left hand moves the eyelids away fixing them at the orbit edges. With the right hand he lowers the tonometer precisely on the corneal center. In the contact area, the dye from the tonometer passes to cornea. The dye remains on the glass edges, and in the center there is an undyed disk. The higher the pressure, the less is the tonometer contact with the cornea and so is the diameter of the white disk. And vice versa, the white disk diameter is larger when the tone is low. Disk diameter is measured with Polyak’s scale calibrated in mm Hg to read IOP.

Tonography is used for determining the intraocular fluid production and outflow.


^ VI. The tasks below help you check your knowledge.

Task 1

The patient complains of excessive tearing and stinging pain in the right eye after, as he says, a speck has hit in it. The doctor removed the speck from conjunctival sac.

What testing technique can prove the absence of a foreign body in the cornea?

A. External examination.

B. Palpation.

C. Lateral illumination.

D. Transmitted light examination.

E. Ophthalmoscopy.

Task 2

The patient after a blunt trauma of the head applied to ophthalmologist with complains of redness of the external part of the left eyeball. Vision acuity in both eyes is 1,0; field of vision in both eyes is normal. The patient was diagnosed with subconjunctival hemorrhage in the left eyeball.

What testing technique is more accurate in examination of the eyeball conjunctiva?

A. External examination.

B. Lateral illumination.

C. Lateral illumination with 20 D.

D. Biomicroscopy.

E. Transmitted light examination.

Task 3

General practitioner referred a patient with suspected bilateral glaucoma to ophthalmological consultation. Ophthalmologist has to examine the anterior chamber angle to adjust the diagnosis.

What examination enables to investigate the anterior chamber angle?

A. Lateral illumination.

B. Combination method.

C. Gonioscopy.

D. Transmitted light examination.

E. Ophthalmoscopy.

Task 4

In examination of a 70-year-old patient, opacity of the lens nucleus was detected. Other optic media were transparent. No pathological changes were found in the fundus.

What examination method can differentiate between lens and vitreous body opacities?

A. Lateral illumination.

B. Combination method.

C. Ophthalmoscopy.

D. Biomicroscopy.

E. Diaphanoscopy.

Task 5

A 30-year-old patient complains of sudden loss of vision in his right eye. Hypertension in his medical history. Right eye visual acuity is 0,01 uncorrectable, the left eye is 1,0. Field of vision in both eyes is normal. Objective examination: edematous right eye, pale optic nerve disk.

Which of the methods below is the most accurate for examining optic nerve disk?

A. Transmitted light examination.

B. Indirect ophthalmoscopy.

C. Direct ophthalmoscopy.

D. Combination method.

E.  Diaphanoscopy.


^ VII. Brief work guidelines for the workshop on “Techniques of ocular examination”.

In the beginning of the workshop, the students’ knowledge is tested through a case study approach (in writing). Then using the theory, the graph of logical structure and algorithm, the students examine each other and the patients.

After the tasks have been done, the students analyze the results of their independent work and write a test.

^ Process chart of the workshop on «Techniques of ocular examination»



Stages

Time

(min)

Learning aids

Where held

Notes

Learning means

Facilities

1

Initial level checkout and adjustment

20

Target training tasks and reference answers




Study room




2

Independent work
1) Training on each other
2) Patients’ examination

180

Logic structure graph, diagnostic algorithm

lamp, direct ophthalmoscope, mirror ophthalmoscope , biomicroscope, Roth’s apparatus, 13D loupe

Study room




3

Final test

20

Set of tests




Study room



1   2   3   4   5   6   7   8   9   ...   14

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