Yellow Micropulse Laser 577-nm vs Infrared Diode Micropulse Laser 810-nm for the Treatment of Diabetic Macular Edema
Phase: PHASE4
Conditions: Diabetic Retinopathy, Macula Edema
Sponsor: Cairo University

 
 
 
 
Yellow Micropulse Laser 577-nm vs 
Infrared Diode Micropulse Laser 810-nm 
For the Treatment of Diabetic Macular 
Edema 
Protocol 
 
12-10-2017 
 

Faculty of Medicine, Cairo University Postgraduate 
Research Program Template 
 
1- Proposed study Title: 
Yellow Micropulse Laser 577-nm vs Infrared Diode Micropulse Laser 810-nm For the Treatment of 
Diabetic Macular Edema 
2- Degree: MSc 
3-Candidate Name: 
 Farida Omar Mohamed El Zawahry. 
4-Date of registration:  
April 2016 
 5- Occupation: 
 Ophthalmology Resident in Kasr Al Ainy Hospital. 
6-Full Mailing address:  
4 Roshdy Street, Cairo, Egypt 11511. 
7- Phone Number: 00201001409852 
8- E-mail Address: farida.zawahry6@gmail.com 
9- Investigators Contact Information: 
a- Principal investigator: 
Professor Dr. Hany Hamza 
b- Department Name: 
Prof. Dr. Omar El Zawahry Unit, Ophthalmology Depatment. 
c- Full mailing address: 
82 Mohi Eldin Abul Ezz Street Dokki Cairo Egypt. 
d- Phone Number: 
+201222199879. 
e- E-mail address: 
hhamza1@yahoo.com 
f- Other Investigators: 
Lecturer Dr.Ahmed Abd Albaki. 
   
 

 
10- Background and Rationale: 
Diabetic eye disease refers to a group of eye problems that people with diabetes may face as a 
complication of this disease. All can cause severe vision loss or even blindness. Diabetic eye 
disease may include:Diabetic retinopathy, Cataract, Glaucoma. (1) 
Diabetic macular edema (DME) is one of the main causes of vision disturbance in diabetic 
retinopathy, which is a clinically significant microvascular complication of diabetes. Anti-
vascular endothelial growth factor (VEGF) therapy is becoming the mainstay of treatment for 
DME. However, to achieve sustained long-term improvement in visual acuity, conventional 
laser photocoagulation, vitrectomy and steroid therapy are also expected to play a role in the 
treatment of DME. (2) 
Pattern scan laser in proliferative diabetic retinopathy and diabetic macular edema allows 
laser treatment that is less time consuming and less painful. Now, it is possible to deliver a 
subthreshold micropulse laser that is above the threshold of biochemical effect but below the 
threshold of a visible, destructive lesion thereby preventing collateral damage. The yellow 
pattern 577-nm micropulse laser converts each laser shot into a “pulse envelope” consisting 
of a sequence of extremely short pulses of laser (10–20 ms) with intervening periods of zero 
laser energy to the treatment site. When the multi-spot pattern mode is used, the pulses are 
not produced simultaneously; however, they formed in rapid succession with low-energy 
pulses during each laser shot. Laser generated in this way is typically 10–25% of the visible 
threshold power. Previous studies have shown that subthreshold laser performed in this way 
was sufficient to show a consistent retinal pigment epithelium-confined photothermal effect, 
and also to allow the inner retinal temperature to remain below the threshold of coagulative 
damage, sparing the transparency of the retina and lowering the risk of hemorrhage.(3)(4) 
The commercially available diode lasers emit at a wavelength of 810 nm, which is in the 
near-infrared range of the spectrum. A feature of the 810-nm wavelength is its deep 
penetration into the choroid, but it is not clear if this characteristic is relevant in micropulse 
treatment. For all indications requiring a treatment near the foveal avascular zone, the 810-
nm laser has the advantage that the laser energy will relatively spare the inner neurosensory 
retina and affect mainly the deeper layers.(5)(6)(7)(8) 
The use of micropulse laser in Diabetic Macular Edema DME was initiated by Friberg and 
Karatza in 1997. Luttrell and colleagues in 2005 published, for the first time an account of 
their experience of using subthreshold MP 810 nm diode laser for DME with complete and 
contiguous treatment of the entire edematous area without tissue damage. Micropulse laser 
has been demonstrated to be as efficacious as the conventional laser. (9)(10)(11)(12)(13) 
11- Objectives:   
To detect the effect of Yellow Micropulse Laser 577-nm vs Infrared Diode Micropulse Laser 810-nm 
In the Treatment of Diabetic Macular Edema 
12- Study Design: 
Prospective comparative study. 
 
13- Laser Procedure: 

A 7×7 Pattern laser will be used to paint the retina. A 160 µm will be used to increase the treatment 
area, ensuring therapeutic delivery to all of the targeted tissue. A 5% duty cycle  meaning that each 
MicroPulse of energy is “on” for 100 µs followed by 1900 µs in the “off” mode. To ensure there is 
enough time for the surrounding tissues to cool to eliminate the possibility of thermal damage to the 
inner retina. This cycle is repeated multiple times within one laser shot. 
14- Ethical Committee approval: 
Yes  
15- Study Methods: 
a- Population of study & disease condition: 
 Diabetics (type1 or 2) more than 10 years durations. 
B-Inclusion Criteria: 
 Diabetics (type 1 or type 2) more than 10 years durations with bilateral DME 
Age: 20-80 years                    
c- Exclusion criteria: 
Any non diabetic macular edema 
Corneal opacities  
Significant cataract  
Intraocular surgery within the past 6 months 
Previous intravitreal injections of any drug within the past 6 months 
 
 
 d- Methodology: 
All patients meeting inclusion criteria in outpatient retina clinic, will have a full 
ophthalmological assessment including: 
Past and present History. 
Full Slit lamp examination. 
Fundus examination. 
OCT Macula Bilaterally 
One eye of the same patient (randomly selected) will undergo laser treatment with Yellow 
Micropulse Laser 577-nm and the other eye (randomly selected) with Diode Micropulse 
Laser 810-nm. 
 e- Possible Risk: 
None. 
f- Primary Outcomes: 

To detect the effect of Yellow Micropulse Laser 577 vs Infrared Diode Micropulse Laser 810 and 
their effect On Diabetic Macular Edema 
As regards: 
Visual acuity  
Macular thickness via OCT 
G-Secondary Outcomes: 
 
h- Sample Size: 
30 diabetic patients from outpatient retina clinic in Cairo university hospital. 
 
 i- Source of Funding: 
 Private-funding 
 16- Time Plan 
Start Date:  December 2017 for 6 months. 
 
17. References: 
(1) Don't Lose Sight of Diabetic Eye Disease. From: www.webmd.com/diabetes/diabetic-
eye-disease#1 
 (2) Management of diabetic macular edema in Japan: a review and expert opinion. Jpn J 
Ophthalmol. 2017 Dec 5. doi: 10.1007/s10384-017-0537-6. 
(3) Recent developments in retinal lasers and delivery systems. Indian J Ophthalmol. 2014 
Jan; 62(1): 50–54.  
(4) Vujosevic S, Martini F, Longhin E, Convento E, Cavarzeran F, Midena E. Subthreshold 
micropulse yellow laser versus subthreshold micropulse infrared laser in center-involving 
diabetic macular rdema: morphologic and functional safety. Retina. 2015;35:1594–1603. 
 (5) McHugh J, Marshall J, Ffytche T, Hamilton A, Raven A. Macular photocagulation of 
human retina with a diode laser: a comparative histopathological study. Lasers Light 
Ophthalmol. 1990;3(1):11–28. 
 (6) Vogel A, Birngruber R. Temperature profiles in human retina and choroid during laser 
coagulation with different wavelengths ranging from 514 to 810 nm. Lasers Light 
Ophthalmol. 1992;5(1):9–16. 
 (7) Peyman GA, Raichand M, Zeimer RC. Ocular effects of various laser wavelengths. Surv 
Ophthalmol. 1984;28(5):391–404. doi: 10.1016/0039-6257(84)90244-3. 
(8) Friberg TR, Karatza EC. The treatment of macular disease using a micropulsed and 
continuous wave 810-nm diode laser. Ophthalmology. 1997;104(12):2030–2038. doi: 
10.1016/S0161-6420(97)30061-X. 
(9) Friberg TR, Karatza EC. The treatment of macular disease using a micropulsed and 
continuous wave 810-nm diode laser. Ophthalmology. 1997;104:2030–8. 

(10) Luttrull JK, Musch DC, Mainster MA. Subthreshold diode micropulse photocoagulation 
for the treatment of clinically significant diabetic macular oedema. Br J Ophthalmol. 
2005;89:74–80. 
(11) Akduman L, Olk RJ. Subthreshold (invisible) modified grid diode laser photocoagulation 
in diffuse diabetic macular edema (DDME) Ophthalmic Surg Lasers. 1999;30:706–14. 
(12) Figueira J, Khan J, Nunes S, Sivaprasad S, Rosa A, de Abreu JF, et al. Prospective 
randomized controlled trial comparing sub-threshold micropulse diode laser 
photocoagulation and conventional green laser for clinically significant diabetic macular 
oedema. Br J Ophthalmol. 2009;93:1341–4. 
(13) Ulbig MW, McHugh DA, Hamilton AM. Diode laser photocoagulation for diabetic 
macular oedema. Br J Ophthalmol. 1995;79:318–21.