Changes of visual fields in treatment of proliferative diabetic retinopathy: a systematic review.

The aim of this systematic review was to compare certain side-effects [visual fields (VF), dark adaptation, colour vision (CV) and contrast sensitivity (CS)] of conventional panretinal photocoagulation (PRP) with those of other treatments in proliferative diabetic retinopathy (PDR). A systematic literature search was conducted on 30 November 2018 in PubMed and Embase. The search comprised the keywords 'proliferative diabetic retinopathy', 'laser', 'treatment' and 'anti-vegf'. We included prospective studies and randomized controlled trials that investigated certain side-effects (VF, dark adaptation, CV, CS) in treatment of PDR (primary outcome). In total, 1867 articles were screened, and 10 studies were included (2176 eyes of 2086 patients examined in the VF studies and 1360 eyes of 1360 patients examined in the CV and CS studies). Visual fields (VF) were investigated in 10 studies, CV in one study and CS in one study. Treatment modalities included conventional PRP, other modalities of laser treatment and vascular endothelial growth factor (VEGF) inhibitors. Four studies demonstrated a worse VF impact of PRP than VEGF inhibitors. Seven studies reported of an overall worsening in VF after laser with no differences between different laser approaches. No differences were found in CV or CS. Overall, we found a trend, confirmed in four large studies, towards VEGF inhibitors causing less harm to VF compared to conventional PRP. Whilst VF was generally depressed after laser, it did not differ between different treatment approaches. Furthermore, it was not possible to make certain conclusions of CV or CS, with only one study in each field.