Anti-vascular endothelial growth factor (VEGF) treatments, either alone or combined with a laser treatment, appear to improve visual outcomes and treatment stability in patients with type 1 diabetes (T1D) and central diabetic macular edema (DME), according to a long-term, real-world study published in BMC Ophthalmology.
Researchers conducted a population-based cohort and follow-up on all adult patients who presented at the Oulu University Hospital with T1D and DME between June 1, 2006 and December 31, 2020. The primary outcome measures included age, gender, duration of T1D at DME onset, stage of retinopathy, treatment of DME (observation, laser, intravitreal treatments, combination), and visual outcomes.
Patients with central DME within 500 μm from the fovea mainly underwent intravitreal anti-VEGF treatment. In cases of subsequent central and extrafoveal edema, patients underwent combination treatment with anti-VEGF and macular laser.
A total of 304 eyes from 206 patients (121 men, 85 women) with T1D and DME were included in the study cohort. The average age at the time of T1D diagnosis was 23.4±16.5 years (range: 1-79 years). The average age at DME onset was 47.4±14.4 years (range: 18-85 years). During the time of diagnosis of DME, 155 patients (75%) had non-proliferative diabetic retinopathy (NPDR) and 51 patients (25%) had PDR. In total, 45 DME episodes (15%) were observed, 41% underwent intravitreal anti-VEGF, 33% underwent macular laser, and 12% underwent a combination of laser and intravitreal injections.
After the initial DME episode, patients in anti-VEGF and in combination groups gained 4.9 and 5.5 Early Treatment of Diabetic Retinopathy Study (ETDRS) letters (P <.001 and P <.001), respectively. In addition, patients in anti-VEGF and in combination groups gained statistically significant long-term improvements of 4.1 (P <.001) and 5.1 (P <.001) ETDRS letters, respectively.
The observation and laser groups had an initial gain of 0.1 (P >.90) and loss of 0.4 ETDRS letter (P =.61), respectively. After the follow-up, a 3.7 letter decrease was noted in the observation group (P >.90) and a 1.1 (P =.14) letter decrease in the laser group.
At the initiation of treatment, eyes that underwent anti-VEGF alone or in combination with laser had lower visual acuity compared with eyes that underwent observation or macular laser. The average of a 6.1±4.8 anti-VEGF injections were required to dry DME. During the 15-year period, visual impairment due to DME decreased from 2.4% to 1.0%.
During the average follow-up period of 65 months, the recurrence of DME occurred in 91% of cases in the observation group, 65% of cases in the anti-VEGF group, 59% of cases in the laser group, and 37% of cases in the combination group of laser and anti-VEGF.
“Anti-VEGF alone or in combination with macular laser seems to be beneficial in terms of visual outcomes and treatment stability in T1D patients with central DME,” according to the researchers. “A low rate of DME recurrences and the beneficial effect on contrast sensitivity highlights the importance of timely anti-VEGF in maintaining good visual function in patients with DME.”
Limitations of the study included its retrospective design and data did not include intraocular lens status and patients treated with intravitreal corticosteroids.
Wirkkala J, Kubin A-M, Ohtonen P, Ylisela J, Siik T, Hautala N. Visual outcomes of observation, macular laser and anti-VEGF in diabetic macular edema in type 1 diabetes: a real-world study. BMC Ophthalmol. Published online June 9, 2022. doi:10.1186/s12886-022-02482-z