Shorter laser exposure just as effective as the conventional approach

Shortening of retinal laser exposure time is just as effective as conventional, longer laser exposure in patients undergoing laser photocoagulation, but is significantly less painful, according to a study published in the January issue of Eye.

Jonathan M. Gibson, MD, and colleagues at Birmingham Heartlands and Solihull NHS Trust, UK compared short exposure, high-energy laser settings with conventional settings, using a 532 nm, frequency doubled, Neodymium-Yag laser and assessed the patients in terms of pain experienced and effectiveness of treatment.

Twenty patients with proliferative retinopathy having panretinal photocoagulation (PRP) for the first time underwent random allocation to treatment of the superior and inferior hemi-retina. Treatment A used 'conventional' parameters: exposure time 0.1 s, power sufficient to produce visible grey-white burns, and a spot size of 300 µm. The other hemi-retina was treated with treatment B using exposure 0.02 s, 300 µm spot size and sufficient power to have similar endpoint. All patients underwent fundus photography and were followed up for 6 to 45 months.

Patients were asked to evaluate severity of pain on a visual analogue scale (0=no pain, 10=most severe pain), and pain scores were found to be significantly higher in the conventional group (treatment A) compared with the short exposure group (treatment B) — 5.1 versus 1.4, respectively. Further treatments, if required, were performed with treatment B parameters and long-term follow-up showed no evidence of under-treatment.

The researchers concluded that shortening exposure time of retinal laser is significantly less painful but equally effective as conventional parameters.