| Title:
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How Laser Physical Parameters affect Lesion Size in Retinal Photocoagulation Surgery: Clinical OCT Study
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| Author(s):
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Rasta S.H.*,Soleimani A., Banaei T., Asgharsharghi Bonab A.
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| Presentation Type:
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Oral
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| Subject:
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Retina and Retinal Cell Biology
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| Others:
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Presenting Author:
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| Name:
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Seyed hossein Rasta
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| Affiliation :(optional)
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Department of Medical Bioengineering, Tabriz University of Medical Sciences. University of Aberdeen
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| E mail:
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s.h.rasta@abdn.ac.uk
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| Phone:
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Mobile: |
09370630833
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Abstract (Max 200 words)
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| Purpose:
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The aim of the present study was to determine burn intensity in
retinal laser photocoagulation based on laser parameters; wavelength, power, beam
size and pulse duration, using Optical Coherence Tomography (OCT), fundus camera,
physical eye model and computer simulation in a clinical study.
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| Methods:
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Participants were 10 adult patients between 50-80
years with proliferative diabetic retinopathy. A multicolor-photo coagulator with 532
nm green and 672 nm red for retina photocoagulation in diabetic retinopathy was
used to investigate the participants. Lesion size was measured for spot sizes 50 and
100 μm, with 100 and 150 mW laser power, and pulse duration 50 and 100 ms by
OCT. Artificial eye and Zemax-optical design software were used with the same laser
parameters.
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| Results:
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Appearance of OCT and fundus images showed direct relationship
between retina burn size and lesion intensity with exposure time and power and also
reverse relationship with laser spot size. Compared to red wavelength, burn size and
lesion intensity increased in green wavelength. On the other hand, results from physical
eye model were the same as clinical examination shown. Laser spot size in retina
with Zemax simulation demonstrated that red wavelength was greater than green one.
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| Conclusion:
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This study showed shorter pulses provide decrease in duration of laser
surgery with significantly reduced pain. Results and calculations described in this
article can help clinicians adjusting the required total coagulated area, the number of
lesions and pattern density.
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| Attachment:
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