Clinical Study
Eye (2008) 22, 96–99; doi:10.1038/sj.eye.6703026; published online 23 November 2007
Pain response and follow-up of patients undergoing panretinal laser photocoagulation with reduced exposure times
S Al-Hussainy1, P M Dodson1 and J M Gibson1
1Department of Ophthalmology, Birmingham Heartlands and Solihull NHS Trust, Bordesley Green East, Birmingham, UK
Correspondence: JM Gibson, Department of Ophthalmology, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK Tel: +44 121 424 3010; Fax: +44 121 711 4040; E-mail: gibsonj@heartofengland.nhs.uk
Received 21 May 2007; Accepted 2 October 2007; Published online 23 November 2007.
Abstract
Purpose
We performed a study of laser panretinal photocoagulation in 20 patients with proliferative retinopathy. We 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.
Methods
Twenty patients having panretinal photocoagulation 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 a visible grey-white burns, spot size 300
m. The other hemi- retina was treated with treatment B using exposure 0.02 s, 300
m and sufficient power to have similar endpoint. All patients were asked to evaluate severity of pain on a visual analogue scale. (0=no pain, 10=most severe pain). All patients were masked as to the type of treatment and the order of carrying out the treatment on each patient was randomised. Patients underwent fundus photography and were followed up for 6–45 months.
Results
Seventeen patients had proliferative diabetic retinopathy, two had ischaemic central retinal vein occlusion and one had ocular ischaemic syndrome. The mean response to treatment A was 5.11, compared to 1.40 treatment B, on the visual analogue scale, which was statistically significant (P=0.001). All patients preferred treatment B. Further treatments, if required, were performed with treatment B parameters and long-term follow-up has shown no evidence of undertreatment.
Conclusions
Shortening exposure time of retinal laser is significantly less painful but equally effective as conventional parameters.
Keywords:
laser photocoagulation, retina, pain

