I have no financial relationship with any · •Lubricates the surface •Maintains a smooth...

$: I have no financial relationship with any · •Lubricates the surface •Maintains a smooth refracting surface on the cornea •Provides nutrients and oxygen to cornea •Contains$

“…I have no financial relationship with any

commercial interests related to the

content of this activities…”

Apivat Mavichak, M.D.

EPIDEMIOLOGY IN OPHTHALMOLOGY

• Global estimates : 285 M people (4.25%) are affected by visual impairment

• Low vision : 246 M (86%)

• Blindness : 39 M (14%)

• 80% of visual impairment is avoidable (preventable or cured)

EPIDEMIOLOGY IN OPHTHALMOLOGY

WHAT IS EYESIGHT ?

IS 20/20 PERFECT VISION ?

EYESIGHT

• The “EYESIGHT” : The ability to see

• Clarity (visual acuity)

• Visual field

• Alignment / Distortion

• Color vision

• Contrast sensitivity

• Dark adaptation

• Other visual quality (glare / halo / aberration / visual cognitive / super vision, etc.)

THE HUMAN VISUAL PATHWAY

THE HUMAN VISUAL PATHWAY

• Tear Film

• Refraction / Refractive error

• Cornea

• Anterior chamber

• Iris

• Lens

• Vitreous body

• Vitreo-retinal interface

• Retina

• Optic disc / Glaucoma

• Optic nerve

• Optic tract

• Brain

ANTERIOR SEGMENT

• Tear film

• Refraction

• Cornea

• Lens

THE TEAR FILM

THE TEAR FILM

• Two types of tear

• Basal / normal tear : accessory lacrimal gland and goblet cell

• Reflex / emotional tear : main lacrimal gland

THE TEAR FILM

• The roles of tear film

• Maintains a moist / Preventing the epithelial cells from damage

• Lubricates the surface

• Maintains a smooth refracting surface on the cornea

• Provides nutrients and oxygen to cornea

• Contains enzymes, antibodies and phagocytic cells (defensive system)

• Removes waste products, foreign bodies from cornea

• Protects cornea against adverse atmosphere conditions (chemical, pH, temperature)

THE TEAR FILM

• Problem of tear film

• Dry eye : loss of homeostasis of tear film

Tear film instability Hyperosmolarity

Ocular surface damage / inflammation

Neurosensory change

Dry eye

THE TEAR FILM

THE TEAR FILM

• Artificial tear supplementary

• Gel / Ointment

• Contains high viscosity and high concentration material

• Good choice for suffering dry eye in the morning

• Blurry vision

• Preservative VS Non-preservative

• Benzalkonium chloride (BAK) : damages corneal nerve, delays healing, tear instability, inflammation

• Should not be used more than 6 times/days

THE TEAR FILM

• New generation of artificial tear

• Sodium hyaluronate (HA)

• Increases tear stability (both lipid tear deficiency and aqueous tear deficiency)

• Decreases cell damage

• Decreases inflammation

• Higher molecular weight (> 1,000,000 Da)

• Increases viscosity and coating ability

• Higher concentration

• Increases viscosity

• Hypotonicity

• Dilutes hyperosmolarity of tear film

THE TEAR FILM

• Diquafosol sodium

• P2Y2 receptor agonist

• Meibomian gland

• Conjunctiva epithelium

• Goblet cell

• Adverse effect

• Irritation

• Eye discharge

• Conjunctival injection

REFRACTION / REFRACTIVE ERROR


• Refractive error corrections

• Glasses / spectacles

• Contact lens

• Excimer laser

• Lens surgery


• Glasses : Monofocal / Bifocal / Progressive / High-precision progressive lens

• High precision progressive lens

• Wavefront technology

• 3D technology

• Personalization (free form progressive lens)

• Improved materials


• Contact lens

• Refractive contact lens

• Cosmetic contact lens

• Refractive contact lens

• Soft lens (daily / bi-weekly / monthly / yearly / permanent)

• Rigid gas permeable lens (RGP)


• New technologies of contact lens

• 3D-Printer contact lens crafting

• OCT assisted custom-made contact lens crafting

• Telescopic contact lens

• VR contact lens

• Glucose monitoring CL

• Drug delivery CL


• Excimer laser

• “Excited dimer” laser

• Generated from noble gas (Argon / Krypton / Xenon) + Reactive gas (Fluorine / Chlorine)

• Ultraviolet wave length

• Photo-ablation


• Excimer laser

• PRK (Photorefractive keratectomy)

• LASIK (Laser In-Situ Keratomileusis)


• Femtosecond laser

• Ultra-short pulse laser (1/1015 second)

• Photodisruption effect

• Tissue separation


• Femtosecond laser assisted LASIK


• Small Incision Lenticular Extraction (SMILE)

• More precision

• Minimal invasive surgery (2 mm incision)

• Less flap related complication

• Less dry eye

• Faster wound healing

THE CORNEA

• The cornea layers

• Epithelium

• Bowman’s layer

• Stroma

• Descemet’s membrane

• Endothelium

THE CORNEA

• Corneal opacity

• Prevalence 2.3-3.7 %

• Blindness corneal opacity 0.12 %

• 4 % of total visual impairment patient

• Corneal scar

• Infection

• Corneal degeneration / dystrophy

THE CORNEA

• Penetrating keratoplasty (PKP)

• Full thickness

• Donor : recipient = 1 : 1

• Waiting time : 4-6 years

THE CORNEA

• Partial thickness (lamellar) keratoplasty (LK)

• Donor : recipient = 1 : 2

• Improved shortage of donor

THE CORNEA

• Keratoprosthesis (K-Pro) : Artificial cornea

• Boston Keratoprosthesis (Type 1, 2) : poly(methyl methacrylate) (PMMA)

• AlphaCor : poly(2-hydroxyethyl methacrylate)

• KeraKlear : hydrophilic acrylic

THE LENS

THE LENS

• Cataract : Clouding of the lens in the eye

THE LENS

Ancient time

“Couching”

1748

Intracapsularcataract extraction

1949

Extracapsular cataract extraction

IOL implantation

Not known : “Needling”

1967 Phaco-

emulsification

1978

Foldable IOL

THE LENS

• Phacoemulsification

• Standard treatment

• Fast visual recovery

• Small incision

• Less complication

• Cost / investment

• Technology-dependent

• Hard lens

• Extracapsular Cataract Extraction

• Low-cost

• Less instrument

• Hard lens

• Longer recovery time

• Large incision

• More complication

THE LENS

• Manual Small Incision Cataract Surgery (MSICS / SISC)

Phaco-

emulsification

Extracapsular

Cataract Extraction

Small incision

Less complication

Less instrument

Low cost

Hard lens

- Corneal edema

- Iris injury

- Posterior Capsular Opacity

THE LENS

• Femtosecond Laser Assisted-Cataract Surgery (FLACS)

• Incision making

• Capsulorhexis

• Nucleus disassembly

• Corneal relaxing incision

THE LENS

• Intraoperative aberrometry

• ORATM (Alcon, USA)

• Intraoperative IOL calculation

• More accuracy

• Markerless toric IOL implantation

• CallistoTM Cataract Suite (Zeiss, Germany)

• VerionTM Image Guide System (Alcon, USA)

• Markerless for toric IOL implantation

THE LENS

• Intraocular lens

1948

-Sir Harold Ridley

-Rigid intraocular lens

-PMMA (Polymethyl-methacrylate)

1978

-Foldable lens

-Acrylic / silicone

-Small incision

1998

-Toric lens

-Correct corneal astigmatism

Ancient time : Aphakia

Present time :

-Multifocal lens

-Multifocal-toric lens

-Accommodating lens

-Light adjustable lens

THE POSTERIOR SEGMENT

• Vitreous / vitreoretinal interface / retina

• Vitreous

• Vitreoretinal interface

• Retina


• Rhegmatogenous

retinal detachment


• Retina detachment surgery

• Pre-1850 : Gold standard in retinal detachment surgery = ?

Salt-free diet (promoting subretinal fluid absorption)

• 1850 : Drain subretinal fluid by puncture the sclera with knife (James Ware)

• 1860 : Drain subretinal fluid by puncture the retina in side the eye (von Graefe)

• 1871 : Suture retina with sclera

• 1895 : Inject the material into vitreous cavity (Deutschmann)

• 1912 : Success rate = 1 : 1,000



• 1920-1950 : Diathermy is a standard for retinopexy

• 1930 : Scleral buckling procedure

• 1940 : Intraocular gas

• 1960 : Cryo retinopexy

• 1962 : Silicone oil

• 1970 : Laser retinopexy

• Vitreous cutter / surgery

• 1912 : Von Hippel : Intraocular vitreous cutter

• 1970 : pars plana vitrectomy (PPV)



• Cryopneumatic retinopexy

• Scleral buckling procedure

• Pars plana vitrectomy

• Laser retinopexy

• Intraocular gas / silicone oil


• Head-up retina surgery

• Maximize contrast and magnification

• Teaching / demonstration

• Readiness for the teams / nurse

• Posterior segment / anterior segment


• Artificial Retina

• ARGUS-II

• 60 electrodes

• 200 x 200 microns

• VA 20/1200 (23%)

THE SHAPE OF THING TO COME

TAKE HOME MESSAGE

• Eyesight is not just VA

• VA / VF / alignment / color / contrast / night vision / others

• All visual pathway can effect eyesight

• From refraction - to the brain

I have no financial relationship with any · •Lubricates the surface •Maintains a smooth...

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