BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

Bending LightPrism A triangular piece of glass, plastic, etc with an Apex & a Base

Light is bent (refracted) toward the base of the prismBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Light is bent or refracted as it moves through the eye. The cornea & lens act like prisms which bend & converge light rays.

Refractive LensesRefractive lenses are combinations of different shaped prisms

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Refractive lenses such as eye glasses or contact lens converge or diverge incoming light rays. Convex lenses converge light rays & Concave lenses diverge light rays.

Optics TerminologyParallel Light Rays Assumed to be parallel if they emanate from a distance source

Divergent Light Rays Appear to be spreading apart in relationship to their close proximity to the eye

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BAGIAN MATA FK UKI*Light rays enter the eye as parallel ray from a distant object or diverging rays from near objects.

Refractive Lens ConfigurationsBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Refractive lenses take on many configurations depending on the amount of refraction required.

Focal LengthThe distance from the center of the lens at which light rays Converge

The power of the lens is measured in Diopters (D)Higher power lens move the focal point closer to the lensBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Refractive power is determined by the configuration of the lens and is measured in Diopters. A 1 diopter convex lens has the ability to converge light rays 1 meter from the lens.

External Eye AnatomyBAGIAN MATA FK UKI

BAGIAN MATA FK UKI

Internal Eye AnatomyBAGIAN MATA FK UKI

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Corneal MorphologyBAGIAN MATA FK UKI

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Corneal CurvatureBAGIAN MATA FK UKI

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Index of RefractionAs light travels through glass, water or tissue, it slows downLight is bent as it strikes a material at an oblique angle

A higher Index yields greater refractionBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Index of refraction refers to the speed at which light moves through different materials. Materials with a greater Index of Refraction yield a higher power of refraction for a given lens configuration.

Tajam penglihatan dapat diperiksa dengan menggunakan :Kartu SnellenHitung jariSenter

AV : NLP/ No Light Perception1/~ proyeksi 1/3001/605/606/406/156/66/6 E

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

EmmetropiaDistance Vision Parallel (distant images)light is refracted by the Cornea & the LensLight is focused on the Fovea & images are clear BAGIAN MATA FK UKI

BAGIAN MATA FK UKI*An eye that has no refractive error is emmetorpic.

EmmetropiaNear VisionDivergent (near images) light rays focus behind the retinaThe lens changes shape (more convex) to focus near images on the retina (accommodation)BAGIAN MATA FK UKI

BAGIAN MATA FK UKI*An emmetropic eye focuses divergent light rays from near objects by changing the shape & location of the crystalline lens.

PresbyopiaDecreasing AccommodationThe lens can not accommodate enough to focus near imagesThe aging eye starts to lose its ability to accommodateBifocals or reading glasses are required

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI*As the eye ages, the crystalline lens is no longer capable of changing shape & can no longer focus on near objects. This age related loss of accommodation is referred to as presbyopia.

MyopiaNearsightednessParallel (distant images) rays are focused in front of the fovea The Cornea is too Steep &/or the eye is too Long for its refractive capabilityBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Myopia is a condition where the eye is too long d&/or the cornea is too steep. Distant images are focused in front of the retina.

Correcting MyopiaContact Lenses or Glasses

A CONCAVE lens diverges parallel light raysThe focal point moves back & distant images are clearBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Myopia is corrected by placing a concave lens in front or on the eye. The lens diverges the light rays moving the focal point further back in the eye.

Correcting MyopiaLaser Refractive Surgery

The cornea is reshaped, decreasing its convergent powerParallel rays of light focus on the fovea

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Myopia can also be corrected by changing the shape of the cornea through refractive surgery. Incisional refractive procedures flatten the cornea & laser refractive procedures reshape the cornea. The most popular laser refractive procedure is LASIK.

MyopiaNear VisionNearsighted people, without their glasses, can often focus near objects on the retina with little or no accommodationThe Divergent rays of objects near the eye are focused by the cornea & lensBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Most myopes have no difficulty reading because the divergent rays of near objects can be effectively focused by the lens. Many myopes may even be able to read as they become presbyopic depending on the degree of their myopia.

Most Myopic presbyopes with require reading glasses or bifocals as they age.

HyperopiaFarsightedness

The Cornea is too Flat &/or the eye is too ShortLight focuses in back of the FoveaBoth Distant & Near images are blurred

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BAGIAN MATA FK UKI*Hyperopoes or farsighted people have an eye that is too short &/or a cornea that is too flat. Parallel light rays focus behind the eye.

HyperopiaLatent or Manifest Hyperopes

Young farsighted people can use accommodation to focus distant objectsLatent or Manifest Hyperopes will eventually need distance & reading glasses as their accommodative potential decreases with age

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BAGIAN MATA FK UKI*Hyoperopes are classified as latent /manifest or absolute. Young Latent / Manifest hyperopes are able to use their accommodation to overcome their farsightedness.Unfortunately, this means they have little accommodation left for near vision & will require reading glasses at a young age.

Correcting HyperopiaAbsolute HyperopesFull accommodation does not have enough power to focus distant images on the retinaA Convex lens is required to converge light rays on the fovea

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BAGIAN MATA FK UKI*Absolute hyperopes have a significant amount of farsightedness & are unable to focus distance or near objects. A convex lens in glasses or contact lenses help converge light rays so images can be focused on the retina. All absolute hyperopes require reading glasses or bifocals.

Correcting HyperopiaLaser Vision CorrectionThe peripheral cornea is reshaped with the excimer laserA Convex lens is required to converge light rays on the fovea

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Hyperopia can also be corrected with laser refractive surgery. The laser steepens the central cornea allowing light rays to converge on the retina.

HyperopiaNear VisionLatent or Manifest Hyperopes usually need glasses to read because they have used all their accommodative potential to correct their distance vision

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BAGIAN MATA FK UKI*Manifest hyperopes usually require reading glasses in their late teens or early 20s when their accommodative potential can no longer correct their distance as well as their near vision.

Astigmatism

The Cornea is Steep in one axis & Flat in the otherMultiple focal points in the eyeImages are blurred &/or distorted

F1F2BAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Astigmatism is primarily a result of an aspheric cornea. Multiple focal points are created in the eye as a result of steeper & flatter refractive surfaces on the cornea.

Occasionally, the crystalline lens can also induce small degrees of astigmatism.

Astigmatism9018045 D42 D42.00 / 45.00 X090With-The-RuleAstigmatismSteep Axis Vertical9018042 D45 D42.00 / 45.00 X180Against-The-RuleAstigmatismSteep Axis Horizontal{Steep K & AxisBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Astigmatism is categorized as with the rule or against the rule. The curvature of the cornea is measured in refractive power or diopters. Corneas with more power in the vertical axis are with the rule & corneas with greater power in the horizontal axis are against the rule.

Types of AstigmatismBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Astigmatism is categorized by where the focal points occur in the eye. Simple astigmatism has one focal point on the retina & one, or more, focal points in front or behind the retina.

Mixed astigmatism has one focal point in front of the retina & one behind.

Types of AstigmatismBAGIAN MATA FK UKI

BAGIAN MATA FK UKI*Compound astigmatism occurs when both focal points are in front or behind the eye.

Astigmatisma:

with the rule - against the rule - irreguler astigmatismAnisometropia:

perbedaan sferis equivalenAniseikonia:

beda ukuran dan bentuk bayanganUnilateral aphakia:

hiperopik anisometropia koreksi kacamata aniseikonia 25%; KL 7%Akomodasi :

amplitudo ( perobahan kuat lensa dpt) - range of amplitudo (jarak titik jauh dari titik dekat)BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

Epidemiologi Bayi

3.0 dpt hiperopia 1 thn: 1.0 dpt bayi 6 thn panjang bulbus okuli > 5 mmMiopia:

5-7 thn 3%; 8-10 thn 8%; 11-12 thn 14%; 12-17 thn 25%Etnis cina miopia >>Juvenil onset (7-16 thn) 0,5 dpt/thn 75% stabil 15-16 thnAdult onset (20 thn) extensive near workGenetik - lingkunganEdukasi tinggi prevalens miopia >>Hiperopia: lower educational, 20% umur 40 an; 60% umur 60anPrevensi: tdk ada rekomendasi pasti

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BAGIAN MATA FK UKI

Refraksi klinisRefraksi objektif: retinoskopRefraksi subjektif

sferisAstigmat dial tehnik - Cross cylinder tehnikStrongest plus - weakest minus maximum visual acuityBalans binokularSikloplegik - nonOverrefraksi

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BAGIAN MATA FK UKI

Koreksi kacamata ametropiaLensa sferis titik jauh, jarak vertexKoreksi silinder

Anak koreksi penuhDewasa coba penuhKacamata anak:

bayangan jatuh pada retinaBalans optimal akkomodasi dan konvergensMiopia: kongenital / developmentalSikloplegik refraksiKoreksi penuh termasuk silinderOrang tua informasi progresivitas alamiHiperopia: rendah (-), silinder koreksi; esotropia koreksi penuh + sikloplegikAnisometropia: koreksi penuh; ambliopia th/ oklusiBAGIAN MATA FK UKI

BAGIAN MATA FK UKI

Problem akkomodasiPresbyopia: respons akomodasi elastisitas lensa

Kontak lensaBeda dari kacamata:

Jarak vertex pendekPerbatasan lensa - kornea: airmata bukan udaraLapangan pandang: lebih besarBesar bayangan: minus lebih besar; plus lebih kecilAnisometopia: lebih kecilAkomodasi: miopia akomodasi >>; plus akomodasi

Pemeriksaan pasien KLPalpebra, pergerakan palpebra, kedipan, film airmata, neovaskularisasi kornea, allergiSeleksi: soft-hard soft: adaptasi cepat, kenyamanan >>Problem:

Kornea: abrasi, keratitis pungtata, pewarnaan jam 9 & 3, infiltrat steril, keratokonjungtivitis superior limbik KL, keratitis dendritik, neovaskularisasi kornea, corneal warpage, ptosis.Mata merah: pengepasan kurang, hipoxia, deposit , KL rusak, toksik / alergi larutan KL, dry eyeTransmisi HIV: desinfeksi trial lens:

Hard: hidrogen peroxid, desinfeksi panas (78*-80*/10 min)RGP: idem kecuali desinfeksi panasSoft: idemBAGIAN MATA FK UKI

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

BAGIAN MATA FK UKI

*Light is bent or refracted as it moves through the eye. The cornea & lens act like prisms which bend & converge light rays.*Refractive lenses such as eye glasses or contact lens converge or diverge incoming light rays. Convex lenses converge light rays & Concave lenses diverge light rays.*Light rays enter the eye as parallel ray from a distant object or diverging rays from near objects.*Refractive lenses take on many configurations depending on the amount of refraction required.*Refractive power is determined by the configuration of the lens and is measured in Diopters. A 1 diopter convex lens has the ability to converge light rays 1 meter from the lens.*Index of refraction refers to the speed at which light moves through different materials. Materials with a greater Index of Refraction yield a higher power of refraction for a given lens configuration. *An eye that has no refractive error is emmetorpic.*An emmetropic eye focuses divergent light rays from near objects by changing the shape & location of the crystalline lens.*As the eye ages, the crystalline lens is no longer capable of changing shape & can no longer focus on near objects. This age related loss of accommodation is referred to as presbyopia.

*Myopia is a condition where the eye is too long d&/or the cornea is too steep. Distant images are focused in front of the retina.*Myopia is corrected by placing a concave lens in front or on the eye. The lens diverges the light rays moving the focal point further back in the eye.*Myopia can also be corrected by changing the shape of the cornea through refractive surgery. Incisional refractive procedures flatten the cornea & laser refractive procedures reshape the cornea. The most popular laser refractive procedure is LASIK.*Most myopes have no difficulty reading because the divergent rays of near objects can be effectively focused by the lens. Many myopes may even be able to read as they become presbyopic depending on the degree of their myopia.

Most Myopic presbyopes with require reading glasses or bifocals as they age. *Hyperopoes or farsighted people have an eye that is too short &/or a cornea that is too flat. Parallel light rays focus behind the eye.*Hyoperopes are classified as latent /manifest or absolute. Young Latent / Manifest hyperopes are able to use their accommodation to overcome their farsightedness.Unfortunately, this means they have little accommodation left for near vision & will require reading glasses at a young age. *Absolute hyperopes have a significant amount of farsightedness & are unable to focus distance or near objects. A convex lens in glasses or contact lenses help converge light rays so images can be focused on the retina. All absolute hyperopes require reading glasses or bifocals.*Hyperopia can also be corrected with laser refractive surgery. The laser steepens the central cornea allowing light rays to converge on the retina.*Manifest hyperopes usually require reading glasses in their late teens or early 20s when their accommodative potential can no longer correct their distance as well as their near vision.*Astigmatism is primarily a result of an aspheric cornea. Multiple focal points are created in the eye as a result of steeper & flatter refractive surfaces on the cornea.

Occasionally, the crystalline lens can also induce small degrees of astigmatism.*Astigmatism is categorized as with the rule or against the rule. The curvature of the cornea is measured in refractive power or diopters. Corneas with more power in the vertical axis are with the rule & corneas with greater power in the horizontal axis are against the rule. *Astigmatism is categorized by where the focal points occur in the eye. Simple astigmatism has one focal point on the retina & one, or more, focal points in front or behind the retina.

Mixed astigmatism has one focal point in front of the retina & one behind.*Compound astigmatism occurs when both focal points are in front or behind the eye.