title: Optos-guided pattern scan laser (Pascal)-targeted retinal photocoagulation in proliferative diabetic retinopathy.
abstract: OBJECTIVE
  To investigate the clinical effects and safety of targeted pattern scan laser (Pascal) retinal photocoagulation (TRP) in proliferative diabetic retinopathy (PDR).
  
  
  METHODS
  Prospective and non-randomized study of 28 eyes with treatment-naive proliferative diabetic retinopathy (PDR). Single-session 20-ms-Pascal TRP strategy applied 1500 burns to zones of retinal capillary non-perfusion and intermediate retinal ischaemia guided by wide-field fluorescein angiography (Optos). Main outcome measures at 12 and 24 weeks included; PDR grade (assessed by two masked retina specialists); central retinal thickness (CRT); mean deviation (MD) using 24-2 Swedish interactive threshold algorithm (SITA)-standard visual fields (VF); and ETDRS visual acuity (VA).
  
  
  RESULTS
  Following primary TRP, there was PDR regression in 76% of patients at 12 weeks (κ = 0.70; p < 0.001). No laser re-treatment was required at 4 weeks, and 10 eyes underwent repeat TRP at 12 weeks. Wide-field Optos angiography at 24 weeks showed complete disease regression in 37% and partial regression in 33%. Additional panretinal laser photocoagulation (PRP) was planned for active PDR in 30%. There were significant reductions in CRT over time (10.4 μm at 12-weeks, p = 0.007; 12.1 μm at 24-weeks, p = 0.0003). The MD on VFs improved after 12 weeks (+1.25 dB; p = 0.015) and 24 weeks (+1.26 dB, p = 0.01). The VA increased by +3 letters at 24 weeks (95% CI, 1.74-5.01; p < 0.0001).
  
  
  CONCLUSIONS
  This pilot study reports that Optos-guided Pascal 20-ms TRP using 1500 burns for treatment-naive PDR is a promising procedure with favourable safety profile.
authors.affiliation: Manchester Royal Eye Hospital, Manchester, UK.
authors.forename: Mahiul M K
authors.initials: MM
authors.lastname: Muqit
authors.forename: George R
authors.initials: GR
authors.lastname: Marcellino
authors.forename: David B
authors.initials: DB
authors.lastname: Henson
authors.forename: Lorna B
authors.initials: LB
authors.lastname: Young
authors.forename: Niall
authors.initials: N
authors.lastname: Patton
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Charles
authors.forename: George S
authors.initials: GS
authors.lastname: Turner
authors.forename: Paulo E
authors.initials: PE
authors.lastname: Stanga
mesh_terms: D000328:Adult; D000465:Algorithms; D001786:Blood Glucose / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005451:Fluorescein Angiography; D005583:Fourier Analysis; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D017075:Laser Coagulation / Q000379:methods*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015861:Retinal Neovascularization / Q000503:physiopathology / Q000601:surgery*; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human