title: Pilot randomised clinical trial of Pascal TargETEd Retinal versus variable fluence PANretinal 20 ms laser in diabetic retinopathy: PETER PAN study.
abstract: OBJECTIVE
  To investigate the short-term effects of high-density 20-ms laser on macular thickness using Pascal-targeted retinal photocoagulation (TRP) and reduced fluence/minimally-traumatic panretinal photocoagulation (MT-PRP) compared to standard-intensity PRP (SI-PRP) in proliferative diabetic retinopathy (PDR).
  
  
  METHODS
  Prospective randomised clinical trial. Treatment-naive PDR was treated with single-session 20-ms Pascal 2500 burns photocoagulation randomised to one of three treatment arms (TRP:MT-PRP:SI-PRP). Primary outcome measure was change in central retinal thickness (CRT) on OCT. Secondary outcomes at 4 and 12 weeks post-laser included: OCT peripapillary nerve fibre layer (NFL) thickness; PDR disease regression on Optos angiography; SITA-Std visual fields (VF); and, visual acuity (VA).
  
  
  RESULTS
  30 eyes of 24 patients were studied, ten eyes/arm. At 12 weeks, there were significant reductions in CRT after TRP (9.6 µm; 95% CI, 1.84 to 17.36; p=0.021) and MT-PRP (17.1 µm; 95% CI, 11 to 23.2; p=0.001), versus SI-PRP (+5.9 µm; 95% CI, -6.75 to 18.55; p=0.32). PDR regression was similar between groups (TRP 70%; MT-PRP 70%; SI-PRP 90%; κ=0.76). No significant changes in VA and NFL thickness developed between groups. The VF mean deviation scores increased significantly in all groups at 12 weeks ([TRP, +0.70dB; 95% CI, 0.07 to 1.48; p=0.07], [MT-PRP, +0.63dB; 95% CI, 0.12 to 1.15; p=0.02], [SI-PRP, +1.0dB; 95% CI, 0.19 to 1.74; p=0.02]). There were no laser-related ocular complications.
  
  
  CONCLUSIONS
  This pilot study reports that high-density 20-ms Pascal TRP and MT-PRP using 2500 burns did not produce increased macular thickness or any ocular adverse events during the short-term.
authors.affiliation: Oxford Eye Hospital, Oxford, UK.
authors.forename: Mahiul M K
authors.initials: MM
authors.lastname: Muqit
authors.forename: Lorna B
authors.initials: LB
authors.lastname: Young
authors.forename: Rod
authors.initials: R
authors.lastname: McKenzie
authors.forename: Binu
authors.initials: B
authors.lastname: John
authors.forename: George R
authors.initials: GR
authors.lastname: Marcellino
authors.forename: David B
authors.initials: DB
authors.lastname: Henson
authors.forename: George S
authors.initials: GS
authors.lastname: Turner
authors.forename: Paulo E
authors.initials: PE
authors.lastname: Stanga
mesh_terms: D000328:Adult; D003930:Diabetic Retinopathy / Q000473:pathology / Q000601:surgery*; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005654:Fundus Oculi; D006801:Humans; D017075:Laser Coagulation / Q000295:instrumentation*; D007834:Lasers; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D012160:Retina / Q000473:pathology / Q000601:surgery*; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014792:Visual Acuity