Abstract
Purpose:
To evaluate and compare the safety, usablity and retinal effects of the recently introduced 577 nm yellow navigated laser with/without navigated microsecond pulsing (MSP) versus 532 nm green navigated laser.
Methods:
An initial case series of 14 eyes of 12 consecutive patients having center-involving DME. Nine eyes were treated with Navilas 532 nm (5 eyes) and 577 nm (4 eyes) continous wave (CW) laser photocoagulation to a barely visible effect. Five additional eyes were treated with OCT-guided 577 nm navigated microsecond pulsing therapy (confluent pattern, 100 micron, 100 μs pulses, 5% duty cycle, 100 ms envelope pulse duration, titration with CW to barely visible effect, power values doubled/ switch to MSP). Microperimetry analysis of retinal sensitivity was conducted on individual effect locations following registration with Navilas treatment documentation.
Results:
Required laser power settings for a barely visible effect were 98 (±9,25) mW for 532nm and 84 (±19,86) mW for 577 nm. Effect boundaries appeared slightly more defined with 577 nm. Mean power setting for microsecond pulsing was 170 (± 32,84) mW after doubling. At 5% duty cycle no visible effects could be observed. Retinal sensitivity changes were 2.8±2.7 with 532 nm, -0.5±24.3 with 577 nm and 0.05±4.0 with 577 nm MSP. No adverse effects were observed.
Conclusions:
All navigated laser modalities could safely and easily be applied in a standard clinical setting. Navigated yellow 577 nm laser required less laser power to create a barely visible effect than 532 nm laser and appears less detrimental to retinal function. Navigated microsecond pulsed laser does not produce visible effects and does not appear to affect retinal function at 5% duty cycle. Therefore it represents a tissue friendly option in the management of retinal disease warranting further investigation into its efficacy.