1 Lenses for Retinal Laser Photocoagulation We’ll get to in a few. But first, let’s review a little bit…
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