Three parameters interact to determine the delivered thermal load for effective coagulation: pulse durations (100-500 ms), beam diameter (100-500 µm), and pulse energy (100-750 mW).² To reduce retinal collateral damage, the application of shorter pulse durations and computer-guided patterned scanning systems (4-50 spots each delivered in 10- to 30-ms/pulse intervals) has been developed. Shorter pulse durations are associated with greater patient comfort,³ but require greater peak energy to achieve the desired coagulation goal, thus continuing to raise concerns about thermal damage. Micropulse (subvisible) coagulation (train of short pulses) has been shown to selectively photocoagulate the retinal pigment epithelium with less damage to adjacent structures.⁴ Interest in even shorter pulse technologies has led to the development of selective retinal therapy, an approach in which a train of ultra-short pulses (200 ns to 1.7 µs pulses) is applied, and the thermal load is confined to the photoreceptor layer with little damage to adjacent photoreceptors or the choriocapilaries).⁵....read more