we’ll get to lenses or retinal laser photocoagulation in a

1

Lenses for Retinal Laser PhotocoagulationWe’ll get toin a few. But first, let’s review a little bit…

2

The five modes of laser-tissue interaction:What are t ?

? ? ? ? ?

Lenses for Retinal Laser PhotocoagulationQ

3

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

The five modes of laser-tissue interaction:

aka photoactivation aka plasma-induced disruption

What are t ?

Lenses for Retinal Laser PhotocoagulationA

4

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

The five modes of laser-tissue interaction:

aka photoactivation aka plasma-induced disruption

What are t ?

Are these thrown up here rando, or are they in an order of some sort?

Lenses for Retinal Laser PhotocoagulationQ

5

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

The five modes of laser-tissue interaction:

aka photoactivation aka plasma-induced disruption

What are t ?

Are these thrown up here rando, or are they in an order of some sort?Not rando. Although there is some overlap (especially between plasma-induced ablation and photodisruption), overall these are listed in order of increasing intensity .

Lenses for Retinal Laser PhotocoagulationQ/A

6

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

The five modes of laser-tissue interaction:

aka photoactivation aka plasma-induced disruption

What are t ?

Are these thrown up here rando, or are they in an order of some sort?Not rando. Although there is some overlap (especially between plasma-induced ablation and photodisruption), overall these are listed in order of increasing intensity .

EnergyTime x area

Lenses for Retinal Laser PhotocoagulationA

7

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

The five modes of laser-tissue interaction:What are t ?

Of the modes, which is by far the most commonly employed during laser procedures involving the retina?

? ????

Lenses for Retinal Laser PhotocoagulationQ

8

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

The five modes of laser-tissue interaction:

Of the modes, which is by far the most commonly employed during laser procedures involving the retina?Thermal

Lenses for Retinal Laser PhotocoagulationA

9

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of thermal effects?----------

Lenses for Retinal Laser PhotocoagulationQ

10

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of thermal effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Lenses for Retinal Laser PhotocoagulationA

11

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of thermal effects?--Hyperthermia?--Coagulation?--Vaporization?--Carbonization?--Melting?

Which thermal effect is employed most frequently?

Lenses for Retinal Laser PhotocoagulationQ

12

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of thermal effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Which thermal effect is employed most frequently?Coagulation

Lenses for Retinal Laser PhotocoagulationA

13

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of tissue effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Which thermal effect is employed most frequently?Coagulation

What does it mean to say that tissue has ‘coagulated’?It means the proteins have been denatured

OK, what does it mean to say a protein has been ‘denatured’?It means the protein has been forced out of its native conformation by some sort of applied stress (in this case, heat). Because a protein’s function is inextricably tied to is shape, denatured proteins do not behave as they do in their native form.

Can you give an example of protein denaturation?Consider egg albumin. In its native state, it’s a clear liquid. But if sufficient heat is applied, it becomes a white solid. (And if sufficient salsa is applied to the white solid, it becomes delish.)

Lenses for Retinal Laser PhotocoagulationQ

14

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of tissue effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Which thermal effect is employed most frequently?Coagulation

What does it mean to say that tissue has ‘coagulated’?It means the proteins have been denatured

OK, what does it mean to say a protein has been ‘denatured’?It means the protein has been forced out of its native conformation by some sort of applied stress (in this case, heat). Because a protein’s function is inextricably tied to is shape, denatured proteins do not behave as they do in their native form.

Can you give an example of protein denaturation?Consider egg albumin. In its native state, it’s a clear liquid. But if sufficient heat is applied, it becomes a white solid. (And if sufficient salsa is applied to the white solid, it becomes delish.)

Lenses for Retinal Laser PhotocoagulationA

15

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of tissue effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Which thermal effect is employed most frequently?Coagulation

What does it mean to say that tissue has ‘coagulated’?It means the proteins have been denatured

OK, what does it mean to say a protein has been ‘denatured’?It means the protein has been forced out of its native conformation by some sort of applied stress (in this case, heat). Because a protein’s function is inextricably tied to is shape, denatured proteins do not behave as they do in their native form.

Can you give an example of protein denaturation?Consider egg albumin. In its native state, it’s a clear liquid. But if sufficient heat is applied, it becomes a white solid. (And if sufficient salsa is applied to the white solid, it becomes delish.)

Lenses for Retinal Laser PhotocoagulationQ

16

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of tissue effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Which thermal effect is employed most frequently?Coagulation

What does it mean to say that tissue has ‘coagulated’?It means the proteins have been denatured

OK, what does it mean to say a protein has been ‘denatured’?It means the protein has been forced out of its native conformation by some sort of applied stress (in this case, heat). Because a protein’s function is inextricably tied to its shape, denatured proteins do not behave as they do in their native form.

Can you give an example of protein denaturation?Consider egg albumin. In its native state, it’s a clear liquid. But if sufficient heat is applied, it becomes a white solid. (And if sufficient salsa is applied to the white solid, it becomes delish.)

Lenses for Retinal Laser PhotocoagulationA

17

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of tissue effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Which thermal effect is employed most frequently?Coagulation

What does it mean to say that tissue has ‘coagulated’?It means the proteins have been denatured

OK, what does it mean to say a protein has been ‘denatured’?It means the protein has been forced out of its native conformation by some sort of applied stress (in this case, heat). Because a protein’s function is inextricably tied to its shape, denatured proteins do not behave as they do in their native form.

Can you give an example of protein denaturation?Consider egg albumin. In its native state, it’s a clear liquid. But if sufficient heat is applied, it becomes a white solid. (And if sufficient salsa is applied to the white solid, it becomes delish.)

Lenses for Retinal Laser PhotocoagulationQ

18

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of tissue effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Which thermal effect is employed most frequently?Coagulation

What does it mean to say that tissue has ‘coagulated’?It means the proteins have been denatured

OK, what does it mean to say a protein has been ‘denatured’?It means the protein has been forced out of its native conformation by some sort of applied stress (in this case, heat). Because a protein’s function is inextricably tied to its shape, denatured proteins do not behave as they do in their native form.

Can you give an example of protein denaturation?Consider egg albumin. In its native state, it’s a clear liquid. But if sufficient heat is applied, it becomes a white solid. (And if sufficient salsa is applied to the white solid, it becomes delish.)

Lenses for Retinal Laser PhotocoagulationA

19

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of tissue effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Which thermal effect is employed most frequently?Coagulation

What does it mean to say that tissue has ‘coagulated’?It means the proteins have been denatured

OK, what does it mean to say a protein has been ‘denatured’?It means the protein has been forced out of its native conformation by some sort of applied stress (in this case, heat). Because a protein’s function is inextricably tied to is shape, denatured proteins do not behave as they do in their native form.

Can you give an example of protein denaturation?Consider egg albumin. In its native state, it’s a clear liquid. But if sufficient heat is applied, it becomes a white solid. (And if sufficient salsa is applied to the white solid, it becomes delish.)

At what temperature does retinal tissue start to coagulate?65oC

Lenses for Retinal Laser PhotocoagulationQ

20

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruptionaka plasma-

induced disruption

The five modes of laser-tissue interaction:

Thermal effects on tissue exist on a continuum. What are the five degrees (see what I did there?) of tissue effects?--Hyperthermia--Coagulation--Vaporization--Carbonization--Melting

Which thermal effect is employed most frequently?Coagulation

What does it mean to say that tissue has ‘coagulated’?It means the proteins have been denatured

OK, what does it mean to say a protein has been ‘denatured’?It means the protein has been forced out of its native conformation by some sort of applied stress (in this case, heat). Because a protein’s function is inextricably tied to is shape, denatured proteins do not behave as they do in their native form.

Can you give an example of protein denaturation?Consider egg albumin. In its native state, it’s a clear liquid. But if sufficient heat is applied, it becomes a white solid. (And if sufficient salsa is applied to the white solid, it becomes delish.)

At what temperature does retinal tissue start to coagulate?65oC

Lenses for Retinal Laser PhotocoagulationA

21

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

Laser energy is absorbed

transforms into heat

local thermal damage

aka plasma-induced disruption

The five modes of laser-tissue interaction:

In a nutshell, what is the process by which laser photocoagulation proceeds?

1st

2nd

3rd

Coagulation

?

Lenses for Retinal Laser PhotocoagulationQ

(What happens first)

22

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

Laser energy is absorbed

transforms into heat

local thermal damage

aka plasma-induced disruption

The five modes of laser-tissue interaction:

In a nutshell, what is the process by which laser photocoagulation proceeds?

1st

2nd

3rd

Coagulation

Lenses for Retinal Laser PhotocoagulationA

23

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

Laser energy is absorbed

transforms into heat

local thermal damage

aka plasma-induced disruption

The five modes of laser-tissue interaction:

In a nutshell, what is the process by which laser photocoagulation proceeds?

1st

2nd

3rd

Coagulation

?

Lenses for Retinal Laser PhotocoagulationQ

(What had happen next)

24

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

Laser energy is absorbed

transforms into heat

local thermal damage

aka plasma-induced disruption

The five modes of laser-tissue interaction:

In a nutshell, what is the process by which laser photocoagulation proceeds?

1st

2nd

3rd

Coagulation

Lenses for Retinal Laser PhotocoagulationA

25

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

Laser energy is absorbed

transforms into heat

local thermal damage

aka plasma-induced disruption

The five modes of laser-tissue interaction:

In a nutshell, what is the process by which laser photocoagulation proceeds?

1st

2nd

3rd

Coagulation

?

Lenses for Retinal Laser PhotocoagulationQ

(The result)

26

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

Laser energy is absorbed

transforms into heat

local thermal damage

aka plasma-induced disruption

The five modes of laser-tissue interaction:

In a nutshell, what is the process by which laser photocoagulation proceeds?

1st

2nd

3rd

Coagulation

Lenses for Retinal Laser PhotocoagulationA

27

Photo-chemical Thermal Photo-

ablationPlasma-induced

ablationPhoto-

disruption

Laser energy is absorbed

transforms into heat

local thermal damage

aka plasma-induced disruption

The five modes of laser-tissue interaction:

In a nutshell, what is the process by which laser photocoagulation proceeds?

1st

2nd

3rd

For more on Lasers, see slide-set FELT26

Coagulation

Lenses for Retinal Laser Photocoagulation

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

28

?

?

Lenses for Retinal Laser PhotocoagulationQ(Finally!)

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

29

Lenses for Retinal Laser PhotocoagulationA

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

30

?

?

Lenses for Retinal Laser PhotocoagulationQ

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

31

Lenses for Retinal Laser PhotocoagulationA

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

32

?

?

Lenses for Retinal Laser PhotocoagulationQ

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

33

Lenses for Retinal Laser PhotocoagulationA

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

34

?

?

Lenses for Retinal Laser PhotocoagulationQ

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

35

Lenses for Retinal Laser PhotocoagulationA

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

36

?

?

Lenses for Retinal Laser PhotocoagulationQ

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

37

Lenses for Retinal Laser PhotocoagulationA

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

sizeThis constellation of features makes planoconcave lensesthe preferred choice for what common retinal laser procedure?FML

38

Lenses for Retinal Laser PhotocoagulationQ

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

sizeThis constellation of features makes planoconcave lensesthe preferred choice for what common retinal laser procedure?Focal macular laser (FML)

39

Lenses for Retinal Laser PhotocoagulationA

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

This constellation of features makes high-plus lenses thepreferred choice for what common retinal laser procedure?PRP

40

Lenses for Retinal Laser PhotocoagulationQ

Two basic types of lenses

employed

Image orientation (upright vsinverted)

Resolution (superior vs

inferior)

Field of view (wide vs small)

Burn size (relative to size set on

laser)

Plano-concave

(high-minus)Upright Superior Small Same as

set

High-Plus-Power Inverted Inferior Wide 1.5-2x set

size

This constellation of features makes high-plus lenses thepreferred choice for what common retinal laser procedure?Panretinal photocoagulation (PRP)

41

Lenses for Retinal Laser PhotocoagulationA