Short presentation discus the Laser and its use in Ophthalmology field

2. QAnd A
By
Dr.MohamedFElbarghathi

3. What is laser ?
Little bit of physics
How laser produced ?
How laser interact with tissue ?
What are the applications of laser in
ophthalmology ?

5. Light
R
E
S
A
L
Amplification (by)
Stimulated
Emission (of)
Radiation
Term coined by Gordon Gould
Lase means to absorb energy in one
form and to emit a new form of
light energy which is more useful

6. Light as electromagnetic waves, emitting radiant
energy in tiny package called ‘quanta’/photon.
Each photon has a characteristic frequency and
its energy is proportional to its frequency.
1 minute

7. Visible light
Ultraviolet Infrared
400 nm 750 nm
Nd:YAG
1064 nm
DIODE
680 nm
Argon
488-514 nm
ArF
193 nm
Femto
1053 nm
HeNe
632 nm

9. Higher energy level
Lower energy level
Photon Excited Electron
An excited electron falls back to its
lower energy level, releasing a photon
in a random direction
Electron
Released
Photon

10. Higher energy level
Lower energy level
A photon strikes an excited
electron. The electron falls to its
lower energy level, releasing a
photon that is going in the same
direction and in exact phase with,
the original photon.
Released
Photon
Photon Excited Electron Electron

12. Nd: YAG Solid state laser Illustration
Photon Electron
• Input 6 photon .
• Output 12 photon .
Flash lamp ( pump source )
Nd:YAG Crystal ( Laser medium)
Highly
reflective
mirror
Partially
reflective
mirror
Optical resonator

14. Argon Retinal Photocoagulation
Excimer laser , LASIK, PRK, PTK
YAG laser

15. Slit-lamp Indirect ophthalmoscope Endo photocoagulation

16. l

17. Diagnostic Therapeutic
Optical coherence tomography (OCT)
useful in the evaluation of retinal
pathology, corneal pathologies
and optic nerve head evaluation
in glaucoma .
Treatment of glaucoma
Treatment of retinal ischemia
Treatment of PCO ( After cataract)
Correction of refractive error.
Treatment of corneal diseases.

18. 1-Laser peripheral iridotomy
Used in
1-Closed angle glaucoma
2-Pupillary Block
3-Prophylaxis in other eye of
ACG patients
Laser type
1-Nd:YAG Laser.
2-Argon laser.

19. Nd: YAG laser
PI

20. 2- Argon laser trabeculoplasty ALT and selective laser trabeculoplasty
SLT
Used in
1-Open angle glaucoma
2-Pseudoexfoliation syndrome
Laser type
1-Nd:YAG Laser. SLT
2-Argon laser. ALT

21. 2- Selective laser trabeculoplasty SLT

22. 2- Trans scleral Cyclophotocoagulation
Used in
Refractory Glaucoma like (NVG), Traumatic
Glaucoma and uveitic glaucoma

24. 1- Proliferative diabetic retinopathy
Pan retinal photocoagulation
Argon laser ----- Frequency doubled YAG Laser

25. 2- Central retinal vein occlusion (CRVO)
Pan retinal photocoagulation

26. Diabetic retinopathy (Diabetic macular edema)

27. 3- Diabetic retinopathy (Diabetic macular edema)
Focal laser photocoagulation

28. 4- Retinal tear
Laser Retinopexy

29. 1-Laser Posterior capsulotomy

30. Nd: YAG laser
Capsulotomy

31. 2-Femto laser assistant cataract surgery
Femto anterior capsulotomy Femto lens fragmentation

32. 1-Correction of refractive error
PRK LASIK

33. 1-Correction of refractive error
FEMTO LASIK

34. 2-Femto DALK

35. 1-The following are true regarding properties of laser
except :
A. It is entirely polychromatic
B. Produced by simulated emission
C. All the photons have the same wavelengths
D. The waves of light are parallel

36. 2. Regarding the Nd-YAG laser which is false :
A. it emits infrared radiation
B. it is visible
C. it is used to create iridotomy
D. Used to treat PCO( After cataract)
Visible light
Ultraviolet Infrared
400 nm 750 nm
Nd:YAG
1064 nm
DIODE
680 nm
Argon
488-514 nm
ArF
193 nm
Femto
1053 nm
HeNe
632 nm

37. 3. All of the following conditions managed with Trans
scleral Cyclophotocoagulation except
A. Traumatic Glaucoma
B. Uveitic glaucoma
C. Neovascular glaucoma
D. Treatment of choice in POAG

38. 4. All of the following Are methods for laser delivery into
patient’s eye except
A. Slit lamp
B. Direct ophthalmoscope
C. Optical fiber endolaser cable in PPV
D. Indirect ophthalmoscope

39. 5. True / false regarding Laser used in retinal
photocoagulation
A. Argon laser True False
C. Frequency doubled Yag laser
B. Argon fluorine
D. Nd:YAG
True False
True False
True False

40. Scan code
ETDRS trial was a multisite, randomized clinical
trial designed to evaluate argon laser
photocoagulation and aspirin treatment in the
management of patients with early proliferative
diabetic retinopathy.

41. Question & answer
By Mohamed F Elbarghathi Thanks ..