Contrast sensitivity evaluation in high risk proliferative diabetic retinopathy treated with panretinal photocoagulation associated or not with intravitreal bevacizumab injections: a randomised clinical trial

Br J Ophthalmol. 2013 Jul;97(7):885-9. doi: 10.1136/bjophthalmol-2012-302675. Epub 2013 May 17.


Purpose: To compare the effect on contrast sensitivity (CS) measurements of panretinal photocoagulation (PRP) associated with intravitreal bevacizumab (IVB) injections versus PRP alone in high risk proliferative diabetic retinopathy (HR-PDR).

Design: Prospective, randomised, masked, controlled trial.

Participants: 42 patients with HR-PDR with visual acuity ≥20/200.

Methods: Eyes were randomised to one of two groups: one underwent PRP and IVB injections (study group) and the other PRP alone (control group). PRP was performed three times during the study and IVB injection was administered twice.

Main outcome measures: Mean change in CS threshold scores between and within groups, from baseline to 6 months.

Results: Seven patients presented with vitreous haemorrhage and were removed from the study. Mean results for CS threshold (at 1.5, 3, 6, 12 and 18 cycles per degree (cpd) frequencies) for patients with and without diabetic macular oedema showed no significant differences (p>0.05 for all comparisons) between the two groups. In 35 eyes in the control group, compared with baseline values, there was significant worsening (p<0.05) of CS at 1.5, 12 and 18 cpd after 1 month, at 12 cpd after 3 months, and at 6 and 12 cpd after 6 months. In the study group, there was significant improvement in CS at 3 cpd, 3 months after treatment.

Conclusions: In eyes with HR-PDR, PRP treatment is associated with deterioration of CS while adjuvant use of bevacizumab prevents such deterioration. CS evaluation seems to support the adjuvant use of bevacizumab when using PRP for the treatment of HR-PDR. Identifier NCT 01389505.

Trial registration: NCT01389505.

Keywords: Angiogenesis; Retina; Treatment Lasers; Treatment Medical; Visual perception.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Angiogenesis Inhibitors / therapeutic use*
  • Antibodies, Monoclonal, Humanized / therapeutic use*
  • Bevacizumab
  • Combined Modality Therapy
  • Contrast Sensitivity / physiology*
  • Diabetic Retinopathy / drug therapy
  • Diabetic Retinopathy / physiopathology
  • Diabetic Retinopathy / surgery
  • Diabetic Retinopathy / therapy*
  • Double-Blind Method
  • Female
  • Fluorescein Angiography
  • Humans
  • Intravitreal Injections
  • Laser Coagulation*
  • Male
  • Middle Aged
  • Prospective Studies
  • Risk Factors
  • Tomography, Optical Coherence
  • Vascular Endothelial Growth Factor A / antagonists & inhibitors
  • Visual Acuity / physiology


  • Angiogenesis Inhibitors
  • Antibodies, Monoclonal, Humanized
  • VEGFA protein, human
  • Vascular Endothelial Growth Factor A
  • Bevacizumab

Associated data