Real-world treatment outcomes of proliferative diabetic retinopathy and diabetic macular edema

Thesis event information

Date and time of the thesis defence

Place of the thesis defence

Leena Palotie auditorium (101A) of the Faculty of Medicine (Aapistie 5 A)

Topic of the dissertation

Real-world treatment outcomes of proliferative diabetic retinopathy and diabetic macular edema

Doctoral candidate

Licentiate of medicine Joonas Wirkkala

Faculty and unit

University of Oulu Graduate School, Faculty of Medicine, Research Unit of Clinical Medicine

Subject of study



Docent Kati Kinnunen, Kuopio University Hospital


Professor Nina Hautala, University of Oulu

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Treatment oucomes of proliferative diabetic retinopathy and diabetic macular edema

Diabetic retinopathy is a vision-threatening complication of diabetes and a leading cause of blindness globally. Complications are a major burden to the healthcare system. This study was carried out to evaluate the real-world treatment outcomes of proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME).

The first study (I) included 103 patients with type 1 (T1D) or type 2 diabetes and PDR with vitreous hemorrhage (VH). Intravitreal anti-vascular endothelial growth factor (anti-VEGF) agent bevacizumab showed superiority to panretinal photocoagulation, pars plana vitrectomy and observation alone in shortening the time for clearance of VH (p<0.0001). An average of 1.7±1.1 injections were needed to clear the VH, and the reinjection interval was 7.2±3.9 weeks. In addition, during the 5-year period, patients had 2.2±2.7 VH recurrences and the number of vitrectomies decreased 72% (p<0.0001).

To evaluate functional vision and health-related quality of life (HRQoL) after 35-year duration of T1D, 29 patients with PDR from the population-based cohort with T1D since childhood were re-evaluated in 2019 (II). The visual acuity was 73–77 ETDRS letters and only two patients were visually impaired. Visual field sensitivity and reaction time were impaired in patients with PDR compared to healthy controls, (23.2±3.9 dB vs. 26.9±1.0 dB, and 14.9±5.6 dB vs. 21.0±2.0 dB, respectively, p<0.001). However, contrast sensitivity was not significantly affected (490.5 ms vs. 462.8 ms, p=0.004). HRQoL remained good despite declined functional vision.

The third study (III) consisted of a population-based cohort of 206 patients diagnosed with T1D and DME. Anti-VEGF or a combination of anti-VEGF and laser seemed to be beneficial in terms of visual gain after the initial episode of DME (+4.9 and +5.5 ETDRS letters, p<0.001 and p<0.001, respectively) and long-term treatment stability (+4.1 and +5.1 ETDRS letters, p<0.001 and p<0.001, respectively). The visual impairment due to DME decreased from 2.4% to 1.0% during the 15-year period.

In conclusion, these results underline the importance of timely and effective treatment of PDR and DME in preventing visual impairment in patients with diabetes. Furthermore, modern treatment of DR with intravitreal anti-VEGF agents has revealed promising results in real-life setting and greatly improved the visual prognosis in patients with diabetes.
Last updated: 26.5.2023