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Peripheral capillary non-perfusion in treatment-naïve proliferative diabetic retinopathy associates with postoperative disease activity 6 months after panretinal photocoagulation
  1. Thomas Lee Torp1,2,
  2. Ryo Kawasaki3,
  3. Tien Yin Wong4,
  4. Tunde Peto2,5,
  5. Jakob Grauslund1,2
  1. 1 Department of Ophthalmology, Odense University Hospital, Odense, Denmark
  2. 2 Department of Clinical Research, University of Southern Denmark, Odense, Denmark
  3. 3 Department of Vision Informatics, Osaka University Graduate School of Medicine, Osaka, Japan
  4. 4 Singapore National Eye Centre, Duke-NUS Medical School, National University of Singapore, Singapore
  5. 5 School of Medicine, Dentistry and Biomedical Sciences, Queen’s University Belfast, Belfast, UK
  1. Correspondence to Dr Thomas Lee Torp, Department of Ophthalmology, Odense University Hospital, Odense 5000, Denmark; thomas.lee.torp{at}


Background/aims With the perspective to provide individualised panretinal laser photocoagulation (PRP) for proliferative diabetic retinopathy (PDR), we evaluated if retinal peripheral capillary non-perfusion (PCNP) and oximetry, as non-invasive markers of retinal metabolism and function, could predict disease activity 6 months after PRP.

Methods We performed a prospective, interventional study of patients with treatment-naïve PDR. Retinal oximetry and ultra-widefield fluorescein angiography were performed at baseline (BL) and three (3M) and 6 months (6M) after PRP by a navigated laser system. At 6M follow-up, patients were divided according to disease activity: active or inactive.

Results We included 33 eyes, and 69.6% were men. At BL, the median age and duration of diabetes (with IQRs) were 51.6±23.4 and 20.0±15.0 years. Haemoglobin A1c was 63.0±17.0 mmol/mol and blood pressure was 152±37/82±24 mm Hg. At BL and M6, patients with postoperative disease activity (30.3.%, n=10) had a larger area with PCNP than those with inactive PDR (BL: 51%–75% vs 26%–50%, p=0.03; 6M: 51%–75% vs 26%–50%, p=0.03). The area of PCNP did not change from BL to 6M in either group (inactive PDR: p=0.38, active PDR: p=0.87). Changes in retinal oxygen saturation were not found to be clinical relevant.

Conclusion We found the area of PCNP at all timepoints to be statistically larger in patients with active PDR 6 months after PRP treatment. Therefore, the area of PCNP, at baseline, may serve as a potential predictive marker for PDR activity after treatment.

  • retina
  • clinical trial
  • imaging
  • neovascularisation
  • treatment lasers

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  • Contributors JG conceived the aims and overall design of the study. TLT acquired the data and did the writing of the different sections, tables and figures. JG and TLT did the literature search and statistical analyses. All authors were involved in the study design, data analyses, data interpretation and revision of the paper. TLT and JG had access to the full raw dataset. The corresponding author had the final responsibility to submit for publication.

  • Funding This study was funded by The Region of Southern Denmark, The Velux Foundation.

  • Competing Interests None declared.

  • Patient consent Obtained.

  • Ethics approval Regional Scientific Ethics Committee (ID S-20140046).

  • Provenance and peer review Not commissioned; externally peer reviewed.

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