Pain Responses of Pascal

Mahiul Mk Muqit (1) , George R Marcellino (2) , Jane Cb Gray (1) , Rita Mclauchlan (1) , David B Henson (1) , Lorna B Young (1) , Niall Patton (1) , Stephen J Charles (1) , George S Turner (1) , Paulo E Stanga (1)

1 Manchester Royal Eye Hospital
2 Optimedica Corporation

Aims: To evaluate pain responses following Pascal® 20ms multi-spot and 100ms single-spot panretinal photocoagulation (PRP). Methods: Single-center randomized clinical trial. 40 eyes of 24 patients with treatment-naive proliferative diabetic retinopathy randomized to 20ms-PRP and 100ms-PRP under topical 0.4% oxybuprocaine. A masked grader used a pain questionnaire within one-hour (Numerical pain score: NPS) and one-month after treatment (Numerical headache score: NHS). Primary outcome measure was NPS immediately post-PRP. Secondary outcome measures were mean NHS scores and levels of photophobia reported within 4-weeks of primary PRP. Results: Mean laser fluence was significantly lower using 20ms-PRP (4.8J/cm2) compared to 100ms-PRP (11.8J/cm2; p<0.001). Mean NPS scores for treatment were 2.4±2.3 (mild) for 20ms-PRP group compared to 4.9±3.3 (moderate) in 100ms-PRP group, a significant difference (95%CI –4.3 to -0.68;p=0.006). Mean NHS score within 1-month was 1.5±2.7 in 20ms-PRP group compared to 3.2±3.5 in 100ms-PRP group (p<0.05). The median duration of photophobia after 20ms-PRP was 3-hours, and significantly less compared to 100ms-PRP after which 72-hours of photophobia was reported (p<0.001). Conclusions: Multi-spot 20ms-PRP was associated with significantly lower levels of anxiety, headache, pain, and photophobia compared to 100ms single-spot PRP treatment. Possible reasons include lower fluence, shorter-pulse duration, and spatial summation of laser nociception with multi-spot Pascal® technique.

Mots clés: Retina; Treatment Lasers; Clinical Trial

Mahiul Mk Muqit, George R Marcellino, Jane Cb Gray, Rita Mclauchlan, David B Henson, et al.. Pain Responses of Pascal. British Journal of Ophthalmology, 2010, 94 (11), pp.1493. ⟨10.1136/bjo.2009.176677⟩. ⟨hal-00557361⟩