Lecture 1Lecture 1

StrabismusStrabismus: : concominant, paralytic, heterophoriaconcominant, paralytic, heterophoria..NystagmusNystagmus. . Clinical picture, diagnostic, treatment, Clinical picture, diagnostic, treatment,

prophylaxis. Types of clinical prophylaxis. Types of clinical refractionrefraction. Gradual loss of . Gradual loss of visionvision. . Accommodative spasmAccommodative spasm. . Progressive myopia. Progressive myopia. Prophylaxis, methods of surgical and conservative Prophylaxis, methods of surgical and conservative

treatment. Presbyopia.treatment. Presbyopia.

Lecture is delivered byLecture is delivered byPh. D., assistant of professor Tabalyuk T.A.Ph. D., assistant of professor Tabalyuk T.A.

Visual organVisual organ consists from: consists from:

1) peripheral part – eyeball with ocular adnexa1) peripheral part – eyeball with ocular adnexa;;

2) guiding pathway – optic nerve, chiasm, optic 2) guiding pathway – optic nerve, chiasm, optic tracttract;;

3) undercortex centers – lateral geniculare 3) undercortex centers – lateral geniculare nucleus and optic radiationnucleus and optic radiation;;

4) higher visual centers in the occipital cortex.4) higher visual centers in the occipital cortex.

Structure of Visual Structure of Visual AnalisatorAnalisator1 - 1 - retinaretina,,

2 - 2 - optic nerve (non-crossed fibers)optic nerve (non-crossed fibers), ,

3 -  3 -  optic nerve (crossed fibers)optic nerve (crossed fibers), ,

4 - 4 - optic tractoptic tract, ,

5 -  5 -  lateral geniculare nucleuslateral geniculare nucleus,,

6 - radiatio optici,6 - radiatio optici,

7 - lobus opticus7 - lobus opticus

EYEBALLEYEBALLI. External (structural) layer – cornea & scleraI. External (structural) layer – cornea & sclera;;II. Middle (vascular) layer – iris, ciliary body & choroidII. Middle (vascular) layer – iris, ciliary body & choroid;;III. Internal layer – retina.III. Internal layer – retina.Internal nucleusInternal nucleus of the eye includes of the eye includes: : lens, vitreous & lens, vitreous &

aqueous humor, which fill in eye chambers.aqueous humor, which fill in eye chambers.The eyes lie within two bony cavities, or The eyes lie within two bony cavities, or orbitsorbits..

OCULAR ADNEXA OCULAR ADNEXA ::• Lacrimal gland & excretory systemLacrimal gland & excretory system• Oculomotor apparatusOculomotor apparatus• EyelidsEyelids• ConjunctivaConjunctiva

OPTICALOPTICAL SYSTEM of the EYESYSTEM of the EYE::• CorneaCornea• Aqueous humorAqueous humor• LensLens• VitreousVitreous

VISUAL FUNCTIONSVISUAL FUNCTIONS::

Peripheral vision (rods are response) includesPeripheral vision (rods are response) includes::

Light sensitivityLight sensitivityField of visionField of vision

Central vision (cones are response) includesCentral vision (cones are response) includes::

Visual acuityVisual acuityColour visionColour vision

Light sensitivityLight sensitivityEye adaptation to light lasts till 1 minute.Eye adaptation to light lasts till 1 minute.

Eye adaptation to dark lasts till 1 hour.Eye adaptation to dark lasts till 1 hour.

AdaptometrAdaptometr is a special equipment is a special equipment

with the help of which we can measure with the help of which we can measure

dark adaptation of the human eye.dark adaptation of the human eye.

The investigation durates 1 hour.The investigation durates 1 hour.

HemeralopiaHemeralopia is a light sensitivity disorder. is a light sensitivity disorder.

Functional hemeralopiaFunctional hemeralopia is usually is usually

caused by hypovitamonosis A.caused by hypovitamonosis A.

Symptomatic hemeralopiaSymptomatic hemeralopia is an index is an index

of rods condition and may be a of rods condition and may be a

symptom of retinitis pigmentosa, symptom of retinitis pigmentosa,

optic neuritis or glaucoma.optic neuritis or glaucoma.

Field of vision Field of vision is a space which is seen is a space which is seen by non-moving eye (by non-moving eye (one eye, not one eye, not bothboth).).PerimetryPerimetry – projection of visual field on spherical concave – projection of visual field on spherical concave space, space,

which is concetric to retina.which is concetric to retina.

Left picture – ancient perimetr of FersterLeft picture – ancient perimetr of Ferster

Right picture – modern automatic computerized Right picture – modern automatic computerized spheroperimetrspheroperimetr

CampimetryCampimetry is a projection of visual field on a is a projection of visual field on a planeplaneThis method is useful to reveal and measure phisiological This method is useful to reveal and measure phisiological

scotoma – blind spot – projection in a space optic disc.scotoma – blind spot – projection in a space optic disc.

Usually Usually blind spotblind spot is found in temporal part of visual field 12-18 is found in temporal part of visual field 12-18 degrees of point of fixation (controposite nasal location of optic degrees of point of fixation (controposite nasal location of optic disc). Its vertical size - 8-9 degrees (10-11 sm), its horizontal disc). Its vertical size - 8-9 degrees (10-11 sm), its horizontal size – 5-7 degrees size – 5-7 degrees

(8-9 sm).(8-9 sm).

Normal bounders of visual field for Normal bounders of visual field for objects of different colourobjects of different colour

Visual field defectsVisual field defects1.Narroving of visual field bounders1.Narroving of visual field bounders:: concetric concetric (retinitis pigmentosa, optic atrophy, final (retinitis pigmentosa, optic atrophy, final

glaucoma)glaucoma) local (local (usual hemianopsia usual hemianopsia :: homonim - dextra or homonim - dextra or

sinistra & heteronim - binasal or bitemporal)sinistra & heteronim - binasal or bitemporal)

2. Patch loosing of visual field - scotoma2. Patch loosing of visual field - scotoma:: positive (with complaints) & negative (without positive (with complaints) & negative (without

complaints)complaints) absolute & relativeabsolute & relative physiological & pathologicalphysiological & pathological

I.e. blind spot is physiological, absolute & negative I.e. blind spot is physiological, absolute & negative scotomascotoma

Visual acuityVisual acuityVisual acuity is measured in relative units.Visual acuity is measured in relative units.visus=d/D,visus=d/D, where d-distance of investigationwhere d-distance of investigation; ; D-distance, from each normal eye can D-distance, from each normal eye can

definite signs of this line (is written in the left of each line of Sivtcev definite signs of this line (is written in the left of each line of Sivtcev table).table).

For example, the person reads first line of Sivtcev table from 5 m. Normal For example, the person reads first line of Sivtcev table from 5 m. Normal eye definites the signs of this line from 50 m. So, visus=5 m/50 m=0,1.eye definites the signs of this line from 50 m. So, visus=5 m/50 m=0,1.

If the person does not see optotypes of first line of Sivtcev table from 5 m, If the person does not see optotypes of first line of Sivtcev table from 5 m, we ask him to come more near to the table.we ask him to come more near to the table.

For example, the person reads first line of Sivtcev table from 3 m. Normal For example, the person reads first line of Sivtcev table from 3 m. Normal eye definites the signs of this line from 50 m. So, visus=3 m/50 m=0,06.eye definites the signs of this line from 50 m. So, visus=3 m/50 m=0,06.

If the person does not see optotypes of first line of Sivtcev table even from If the person does not see optotypes of first line of Sivtcev table even from 0,5 m, we project the light to his or her eye from different direcrion. If 0,5 m, we project the light to his or her eye from different direcrion. If the person gives correct answers, then his visus=1/∞the person gives correct answers, then his visus=1/∞ pr.l.certa. If the pr.l.certa. If the person see light, but gives not correct answers even in one direction, person see light, but gives not correct answers even in one direction, then his visus=1/∞then his visus=1/∞ pr.l.incerta.pr.l.incerta.

If the person does not see light, then his visus=0. In such cases usually If the person does not see light, then his visus=0. In such cases usually direct light reaction of pupil is absent & during objective measuring of direct light reaction of pupil is absent & during objective measuring of visual acuity with the help of nystagmoaparat optokinetic nystagmus is visual acuity with the help of nystagmoaparat optokinetic nystagmus is absent.absent.

VISUAL ACUITY TEST (UKRAINIAN & FOREIGN VISUAL ACUITY TEST (UKRAINIAN & FOREIGN ONE)ONE)

Left picture – Left picture – Snellen chartSnellen chartRight picture – Right picture – Sivtcev tableSivtcev table

Visual acuity transcriptionVisual acuity transcription

20 feet 20 feet equivalentequivalent

(USA)(USA)

6 meter 6 meter equivalentequivalent

(Great Britain)(Great Britain)

5 meter 5 meter equivalentequivalent

(Ukraine)(Ukraine)

20/2020/20 6/66/6 1,01,0

20/2520/25 6/7.56/7.5 0,80,8

20/4020/40 6/126/12 0,50,5

20/6020/60 6/186/18 0,30,3

20/20020/200 6/606/60 0,10,1

Normal data of visual acuity in Normal data of visual acuity in childrenchildrenNewborns – 0,005Newborns – 0,005;;4 months – 0,014 months – 0,011 year – 0,1-0,31 year – 0,1-0,3;;2 years – 0,2-0,52 years – 0,2-0,5;;3 years – 0,3-0,63 years – 0,3-0,6;;4 years – 0,4-0,74 years – 0,4-0,7;;5 years – 0,5-0,95 years – 0,5-0,9;;6 years –0,7-1,06 years –0,7-1,0;;7-15 years – 1,07-15 years – 1,0

Colour visionColour visionPolichromatic Polichromatic Rabkins tablesRabkins tables are used for are used for

investigationinvestigation

Normal colour vision according to this method is called Normal colour vision according to this method is called

normal trichromasianormal trichromasia

Colour vision disordersColour vision disorders::

CongenitalCongenital usually bilateral usually bilateral

AquiredAquired usually monolateral usually monolateral

Defect of one of three main colours is called Defect of one of three main colours is called dichromasiadichromasia

White & black perceprion is called White & black perceprion is called monochromasiamonochromasia

Anomal perception of red – Anomal perception of red – protanomalyprotanomaly

Anomal perception of green – Anomal perception of green – deyteranomalydeyteranomaly

Anomal perception of blue - Anomal perception of blue - tritanomalytritanomaly

PHYSICAL REFRACTION of the EYEPHYSICAL REFRACTION of the EYE::

average refractive power of the eye is average refractive power of the eye is approximetly 60 Dapproximetly 60 D

individual indices fluctuate from 52 till 71 Dindividual indices fluctuate from 52 till 71 D

Average refractive power of optical mediums of Average refractive power of optical mediums of the eyethe eye::

Cornea – 40 DCornea – 40 D Lens - 19-20 DLens - 19-20 D Aqueous humor & vitreous – less then 1 DAqueous humor & vitreous – less then 1 DIn sum – 60 DIn sum – 60 D

CLINICAL REFRACTION of the EYECLINICAL REFRACTION of the EYE::correlation between refractive power of the eye & correlation between refractive power of the eye &

its lengthits length

EMMETROPIA & AMMETROPIAEMMETROPIA & AMMETROPIA:: MYOPIAMYOPIA HYPERMETROPIAHYPERMETROPIA ASTIGMATISMASTIGMATISM

EmmetropiaEmmetropia (E or Em) – refractive power of the eye (E or Em) – refractive power of the eye corresponds with its lengthcorresponds with its length, thus main focus is main focus is located on retinalocated on retina

Ammetropia Ammetropia – refractive errow, abnormal correlation – refractive errow, abnormal correlation between refractive power & length of the eyebetween refractive power & length of the eye::

MyopiaMyopia (M or My) – main focus is before retina (M or My) – main focus is before retina due to incresed refractive power or length of the eyedue to incresed refractive power or length of the eye

HypermetropiaHypermetropia (H or Hy) - main focus is behind (H or Hy) - main focus is behind retina due to decresed refractive power or length of retina due to decresed refractive power or length of the eyethe eye

AstigmatismAstigmatism – different refractive power in two – different refractive power in two perpendicular planes. Combination of different perpendicular planes. Combination of different clinical refraction or different degrees of one type of clinical refraction or different degrees of one type of clinical refraction in one eye is usually named clinical refraction in one eye is usually named astigmatism.astigmatism.

MyopiaMyopia is subdivided into is subdivided into::

Light degree – till minus 2,75 DLight degree – till minus 2,75 D;;Middle degree – from minus 3,0 till 5,75 DMiddle degree – from minus 3,0 till 5,75 D;;High degree – minus 6,0 D and moreHigh degree – minus 6,0 D and more

HypermetropiaHypermetropia is subdivided into is subdivided into::

Light degree – till plus 1,75 DLight degree – till plus 1,75 D;;Middle degree – from plus 2,0 till 4,75 DMiddle degree – from plus 2,0 till 4,75 D;;High degree – plus 5,0 D and moreHigh degree – plus 5,0 D and more

AnisometropiaAnisometropia

is different refraction of both eyes more then 1,0 dptris different refraction of both eyes more then 1,0 dptr

TYPES of ASTIGMATISMTYPES of ASTIGMATISM::I.I. 1. 1. SimpleSimple – – combination of emmetropia in one meridian & combination of emmetropia in one meridian &

ammetropia in perpendicular oneammetropia in perpendicular one.. A. Simple myopic - A. Simple myopic - combination of emmetropiacombination of emmetropia & myopia in two

perpendicular planes; B. Simple hypermetropic - Simple hypermetropic - combination of emmetropiacombination of emmetropia &

hypermetropia in two perpendicular planes. 2. Complex Complex – – combination of different degrees of one type of combination of different degrees of one type of

ammetropia in two meridians.ammetropia in two meridians. A. Complex myopic - A. Complex myopic - combination of different degrees of combination of different degrees of myopia in

two perpendicular planes; B. Comlex hypermetropic - Comlex hypermetropic - combination of different degrees of combination of different degrees of

hypermetropia hypermetropia in two perpendicular planes. 3. Mixt – combination of myopia & hypermetropia in perpendicular

planes of one eye.

II. 1. Direct – refractive power of vertical meridian is stronger then horizontal one

2. Indirect - refractive power of horizontal meridian is stronger then vertical one

III. 1. Regular - refractive power of hole meridian is the same 2. Irregular - refractive power in one meridian is different due to

corneal diseases, i.e. keratoconus, scars etc.

METHODS of MEASURING the REFRACTION METHODS of MEASURING the REFRACTION

I. Objective methodsI. Objective methods::

• sciascopy or retinoscopysciascopy or retinoscopy

• refractometryrefractometry

• autorefractometryautorefractometry

• ophtalmometryophtalmometry

II. Subjective method II. Subjective method according to improving the visual acuity with trial glassesaccording to improving the visual acuity with trial glasses

Retinoscopy, refractometry, Retinoscopy, refractometry, autorefractometryautorefractometry

Ophthalmometry, corneal topographyOphthalmometry, corneal topography

NORMAL DEVELOPMENT of REFRACTION in NORMAL DEVELOPMENT of REFRACTION in CHILDRENCHILDREN

Newborns – Hm 3,0-5,0 dptrNewborns – Hm 3,0-5,0 dptr;;

1 year – Hm 3,5 dptr1 year – Hm 3,5 dptr;;

2 years – Hm 3,0 dptr2 years – Hm 3,0 dptr;;

3 years – Hm 2,5 dptr3 years – Hm 2,5 dptr;;

4 years – Hm 2,0 dptr4 years – Hm 2,0 dptr;;

5 years – Hm 1,5 dptr5 years – Hm 1,5 dptr;;

6 years – Hm 1,0 dptr6 years – Hm 1,0 dptr;;

7-8 years – Hm 0,75 dptr7-8 years – Hm 0,75 dptr;;

9-15 years – Hm 0,5 dptr9-15 years – Hm 0,5 dptr;;

EXAMPLESEXAMPLES::

1. The results of refractometry of both eyes1. The results of refractometry of both eyes::90 degrees –My (-) 5,0 dptr90 degrees –My (-) 5,0 dptr;;180 180 degrees – My (-) 5,0 dptrdegrees – My (-) 5,0 dptrIt's middle degree myopia OU.It's middle degree myopia OU.

2. The results of refractometry of both eyes2. The results of refractometry of both eyes::90 degrees – Hm (+) 2,0 dptr90 degrees – Hm (+) 2,0 dptr;;180 180 degrees – Hm (+) 2,0 dptrdegrees – Hm (+) 2,0 dptrIt's middle degree hypermetropia OU.It's middle degree hypermetropia OU.Pay attention for patients'Pay attention for patients' age! It may be age! It may be

physiological refraction!physiological refraction!

3. The results of refractometry of right eye3. The results of refractometry of right eye::90 degrees –My (-) 5,0 dptr90 degrees –My (-) 5,0 dptr;;180 180 degrees – Emdegrees – EmIt's simple myopic direct astigmatism OD.It's simple myopic direct astigmatism OD.

EXAMPLESEXAMPLES::

4. The results of refractometry of left eye4. The results of refractometry of left eye::90 degrees – Hm (+) 5,0 dptr90 degrees – Hm (+) 5,0 dptr;;180 degrees – Hm (+) 10, 0 dptr180 degrees – Hm (+) 10, 0 dptrIt's complex hypermetropic indirect astigmatism OS.It's complex hypermetropic indirect astigmatism OS.

5. The results of refractometry of both eyes5. The results of refractometry of both eyes::90 degrees – My (-) 2,0 dptr90 degrees – My (-) 2,0 dptr;;180 degrees – Hm (+) 3,0 dptr180 degrees – Hm (+) 3,0 dptrIt's mixt direct astigmatism OU.It's mixt direct astigmatism OU.

6. 6. The results of refractometry of right eyeThe results of refractometry of right eye::90 degrees –My (-) 2,0 dptr90 degrees –My (-) 2,0 dptr;;180 180 degrees – My (-) 2,0 dptrdegrees – My (-) 2,0 dptrThe results of refractometry of left eyeThe results of refractometry of left eye::90 degrees – Hm (+) 5,0 dptr90 degrees – Hm (+) 5,0 dptr;;180 degrees – Hm (+) 5, 0 dptr180 degrees – Hm (+) 5, 0 dptr

It's anisometropia. Light degree myopia OD. High degree It's anisometropia. Light degree myopia OD. High degree hyperopia OS.hyperopia OS.

METHODS of AMMETROPIA CORRECTION:

1. GLASSES2. CONTACT LENSES3. SURGICAL, i.e. EXIMER LASER4. ORTHOKERATOLOGY in light & middle myopia

Glasses is the most simple, most Glasses is the most simple, most ancient method of correction, but not ancient method of correction, but not always the most effectivealways the most effective

Sph concave for myopiaSph concave for myopia

Sph convex for hyperopiaSph convex for hyperopia

Cyl for simple astigmatismCyl for simple astigmatism

Sph-cyl for complex & Sph-cyl for complex &

mixt astigmatismmixt astigmatism

SOFT & HARD CONTACT LENSSOFT & HARD CONTACT LENS

Contact lenses give the better & more Contact lenses give the better & more natural vision, but the patient have to be natural vision, but the patient have to be under a special doctors controlunder a special doctors control

Medical indications for contact Medical indications for contact correctioncorrection::

High myopiaHigh myopiaHigh astigmatismHigh astigmatismAphakiaAphakiaIrregular cornea, i.e. in keratoconusIrregular cornea, i.e. in keratoconusAnisometropiaAnisometropia

Lasik surgery – changing of cornea Lasik surgery – changing of cornea shapeshape

Implantation of phakic intraocular Implantation of phakic intraocular lenseslenses in high myopia & astigmatism in high myopia & astigmatism

ORTHOKERATOLOGY – changing of corneal shape in light & middle myopia with the help of special contact lenses to stop myopia progression in children & in cases when laser surgery is contrindicated (i.e. thin cornea)

Accommodation - Accommodation -   adjustment of the   adjustment of the

eye for eye for vision in different vision in different distancesdistances • .. InIn short short distances distances - - ciliary ciliary

musclemuscleccontractontracts – zonula ciliaris relax s – zonula ciliaris relax – lens becomes more convex – – lens becomes more convex – refractive power of lens refractive power of lens increasesincreases

InIn longlong distances distances - - ciliary ciliary musclemusclerelaxes – tensio of zonula relaxes – tensio of zonula ciliaris increases – lens ciliaris increases – lens becomes more concave – becomes more concave – refractive power of lens refractive power of lens decreasesdecreases

PRESBYOPIAPRESBYOPIA – age loosing of – age loosing of accommodationaccommodationTo correct it special multifocal glasses To correct it special multifocal glasses

(progressive) or glasses for near (progressive) or glasses for near distance are prescribed. Approximetlydistance are prescribed. Approximetly::

40 years – sph convex (+) 1,0 dptr40 years – sph convex (+) 1,0 dptr45 years – sph convex (+) 1,5 dptr45 years – sph convex (+) 1,5 dptr50 years – sph convex (+) 2,0 dptr50 years – sph convex (+) 2,0 dptr55 years – sph convex (+) 2,5 dptr55 years – sph convex (+) 2,5 dptr60 years – sph convex (+) 3,0 dptr60 years – sph convex (+) 3,0 dptrover 60 years – sph convex (+) 3,5 dptrover 60 years – sph convex (+) 3,5 dptr

STRABISMUSSTRABISMUS

HIRSHBERG TEST HIRSHBERG TEST

is used to determine angle of strabismusis used to determine angle of strabismus

Differentiation of neurologycal & Differentiation of neurologycal & ophthalmological srabismusophthalmological srabismus

Paralytic Paralytic (nonconcominant) (nonconcominant)

strabismusstrabismus

ConcominantConcominant

(nonparalytic) (nonparalytic) strabismusstrabismus

Decreasing or absence of Decreasing or absence of eye movements in any eye movements in any

directiondirection

Full amount of eye Full amount of eye movementsmovements

Primary & secondary Primary & secondary angle of strabismus are angle of strabismus are

differentdifferent

Primary & secondary Primary & secondary angle of strabismusangle of strabismus

are equalare equal

DiplopiaDiplopia Diplopia is absebtDiplopia is absebt

Types of concominant srabismusTypes of concominant srabismus

Accommodative Accommodative strabismusstrabismus

Nonaccommodative Nonaccommodative strabismusstrabismus

Angle of srabismus is visible Angle of srabismus is visible only for near distance (if it is only for near distance (if it is

esotropia) or only for far esotropia) or only for far distance (if it is exotropia) distance (if it is exotropia)

Angle of srabismus is present Angle of srabismus is present constantly (for far & near constantly (for far & near

distances) distances)

Using of cycloplegic agents (S. Using of cycloplegic agents (S. atropini, Mydriacili or atropini, Mydriacili or

Tropicamide) corect angle of Tropicamide) corect angle of srabismus (if it is esotropia) or srabismus (if it is esotropia) or increases it (if it is exotropia) increases it (if it is exotropia)

Using of cycloplegic agents (S. Using of cycloplegic agents (S. atropini, Mydriacili or atropini, Mydriacili or

Tropicamide) Tropicamide)

does not influence on angle of does not influence on angle of srabismus srabismus

Glasses corect angle of Glasses corect angle of srabismussrabismus::

sph convex if it is esotropiasph convex if it is esotropia

sph concave if it is exotropiasph concave if it is exotropia

Glasses does not influence on Glasses does not influence on angle of srabismus angle of srabismus

TREATMENT of NONACCOMMODATIVE TREATMENT of NONACCOMMODATIVE STRABISMUS only SURGICALSTRABISMUS only SURGICAL

RecessionRecession

(weakening of eye muscle)(weakening of eye muscle)

& &

ResectionResection

(strenthening of eye muscle)(strenthening of eye muscle)

THANK YOU FOR THANK YOU FOR ATTENTION!ATTENTION!