Pain score of patients undergoing single spot, short pulse laser versus conventional laser for diabetic retinopathy.
BACKGROUND
To compare pain score of single spot short duration time (20 milliseconds) panretinal photocoagulation (PRP) with conventional (100 milliseconds) PRP in diabetic retinopathy.


METHODS
Sixty-six eyes from 33 patients with symmetrical severe non-proliferative diabetic retinopathy (non-PDR) or proliferative diabetic retinopathy (PDR) were enrolled in this prospective randomized controlled trial. One eye of each patient was randomized to undergo conventional and the other eye to undergo short time PRP. Spot size of 200 μm was used in both laser types, and energy was adjusted to achieve moderate burn on the retina. Patients were asked to mark the level of pain felt during the PRP session for each eye on the visual analog scale (VAS) and were examined at 1 week, and at 1, 2, 4 and 6 months.


RESULTS
Sixteen women and 17 men with mean age 58.9 ± 7.8 years were evaluated. The conventional method required a mean power of 273 ± 107 mW, whereas the short duration method needed 721 ± 406 mW (P = 0.001). An average of 1,218 ± 441 spots were delivered with the conventional method and an average of 2,125 ± 503 spots were required with the short duration method (P = 0.001). Average pain score was 7.5 ± 1.14 in conventional group and 1.75 ± 0.87 in the short duration group (P = 0.001). At 1 week, 1 month, and 4 months following PRP, the mean changes of central macular thickness (CMT) from baseline in the conventional group remained 29.2 μm (P = 0.008), 40.0 μm (P = 0.001), and 40.2 μm (P = 0.007) greater than the changes in CMT for short time group.


CONCLUSIONS
Patient acceptance of short time single spot PRP was high, and well-tolerated in a single session by all patients. Moreover, this method is significantly less painful than but just as effective as conventional laser during 6 months of follow-up. The CMT change was more following conventional laser than short time laser.
Farabi Eye Research Center, Department of ophthalmology, Tehran University of Medical Sciences, Quazvin Sq., 13366-16351 Tehran, Iran.
Ahmad
A
Mirshahi
Alireza
A
Lashay
Mehdi
M
Roozbahani
Masoud Aghsaei
MA
Fard
Saber
S
Molaie
Meysam
M
Mireshghi
Mohamad Mehdi
MM
Zaferani
D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000601:surgery*; D004311:Double-Blind Method; D058447:Eye Pain / Q000175:diagnosis*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D017075:Laser Coagulation / Q000379:methods*; D053844:Lasers, Solid-State / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D014792:Visual Acuity / Q000502:physiology
D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human