Download MBBS Ophthalmology PPT 30 Diseases Of The Cornea 4 Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Ophthalmology PPT 30 Diseases Of The Cornea 4 Lecture Notes

DISEASES OF THE CORNEA

Department of Ophthalmology



Xerophthalmia

n Deficiency of vitamin A(dietary def. or

defective absorption)

n Young malnourished children often in the

1st year of life

n Usually bilateral

n Absence of inflammation

n Precipitated by acute systemic illness


Xerophthalmia

n XN night blindness

n X1A conj. Xerosis

n X1B Bitots spots

n X2 Corneal xerosis

n X3A Keratomalacia<1/3

n X3B Keratomalacia>1/3

n XS Corneal scarring

n XF Xerophthalmia fundus

Bitot's spots (X 1B)


Corneal xerosis(X2)

Keratomalacia (X3B)
Treatment of xerophthalmia/ keratomalacia

n Local ocular therapy

n Vitamin A therapy - XN X3B
> 1 year 200,000 IU orally/100,000 IM
on day 0, 1, 2 weeks later
6-12 months or < 8kg half the dose
<6 mths 50,000 IU
Treatment of underlying condition

Prophylaxis against xerophthalmia

WHO recommendations

6-12 mths/ < 8kg 100,000 IU orally 3-6

monthly

>1yr <6yrs 200,000 IU orally 6

monthly

Lactating mothers 20,000 IU orally at

delivery


WHAT IS AN EYE DONATION

n It is donation of transparent

glass (Cornea) from donor to

recipient having Corneal opacity

with normal posterior segment

Magnitude Of The Problem in India

n 20% of blind population of the world

n 15 million total blind in India

n 6-7 million are corneal blind

n 1 million bilateral blind

(90% below age 45 yrs including 60% children

below 12 yrs)
Magnitude of The Problem

n Required collection ? 2,00,000( 50% utilization)

n Current Collection 2017? 52960

EBAI- 2017 Stats for INDIA(Unpublished data)

Magnitude of the Problem in India

nRequired transplant ? 1,00,000 cornea

n Current transplants (2017) ? 25153



EBAI- 2017 Stats for INDIA(Unpublished data)
n We have achieved 0.25% of all deaths
- 25 donation / 10,000 deaths

n Target is 1% of total deaths
- 100 donation /10,000 deaths

With a goal of 100,000 transplants and utilization

of 50%

Causes of Corneal

Blindness




Corneal Infections

Vasculrized Corneas with

thinning




Sloughing Cornea with

Perforation

Vitamin A Deficiency


Traumatic Corneal Opacities

Chemical Burns


Corneal Dystrophies &

Degenerations

Congenital Corneal

Opacities




Surgical Trauma

Demand Vs supply of cornea

n 1 lakh Cornea needed per year

n 30-40,000 new Corneal blind are

added every year

n 50,000 eyes collected in India every

year

n 8-9 million death occur every year in

India

n To clear the backlog we need at

least 277,000 corneas
Eye Bank

n Is an organization which deals with

- Collection

- Storage

- Distribution
For the purpose of corneal grafting and

research

Functions of Eye Bank

n To promote eye donation

n Registration of pledger for eye

donation

n Collection and processing of eyes as

per Eye Bank standards

n To evaluate the quality of tissue

before use

n Preservation of Tissue

n Distribution of tissue

n Research activities




Assessment of Donor Cornea

Preparing a Corneo-Scleral

Button


Placing Donor Cornea in

MK Medium for Preservation


Keratoplasty

Types of keratoplasty

n Lamellar SALK
DALK
DSEK
DMEK

n Penetrating
optical
therapeutic
tectonic
n Rotational autografts


Removing diseased host corneal button

Donor corneal button


Placement of graft over the recepient eyeball

Corneal Graft in place
Refractive corneal surgeries

n Substraction procedures
- Photorefractive keratectomy (PRK):

eximer laser is used in the center optical

zone.





n Laser assisted in situ keratomileusis

(LASIK):

- 130-160micron flap is raised

- mid stromal tissue is ablated by eximer laser

n Clear lens extraction
n Addition procedures
- Epikeratoplasty ? corneal surface
- Intracorneal lenses ? corneal stroma
- Intracorneal rings ? peripheral cornea
- ICL ? Implantable collamer lens

- Piggy bag lens




Epikeratoplasty

Intra corneal lenses


Intracorneal lens for presbyopia

Intracorneal rings


ICL

Piggy bag IOL


n Relaxation procedures
- Radial Keratotomy - peripheral

corneal stroma (6D)

- Astigmatic keratatotomy ? peripheral

corneal stroma

Radial keratotomy


n Coagulation ? compression procedures
- Thermokeratoplasty : peripheral cornea
(4D of hyperopia)
- Compression sutures : peripheral cornea

Thermokeratoplasty
Myopia

n PRK ? 6D

n LASEK- Laser epithelial keratomileusis

n LASIK ? Laser in situ keratomileusis(8-12

D)

n Clear lens extraction

n Phakic posterior chamber contact lenses-

ICL(Implantable Collamer surgery) - -3 to -

15D

Hypermetropia

n PRK

n LASEK

n LASIK ? 4D

n Conductive keratoplasty(CK)

n Intracorneal inlays

n ICL
Astigmatism

n Limbal relaxing incisions

n PRK ? 3D

n LASEK- 3D

n LASIK- 5D

n TORIC IOL

n Conductive keratoplasty- 3D

Presbyopia

n IOL- multifocal, bifocal or accomodating

n LASER induced monovision

n LASIK- corneal multifocality

n Intracorneal inlays