A study published in Acta Opthalmologica explored what factors impact the progression of neurovascular age-related macular degeneration (nAMD), and identified predictive factors that can estimate the duration of intravitreal treatments.
Give me some background first.
In 2019, an estimated 18.34 million Americans were reported to have early age-related macular degeneration (AMD)—and of that, 1.49 million had the late-stage vision-threatening form of AMD.
While the emergence of intravitreal anti vascular endothelial growth factor (VEGF) therapies has improved visual outcomes for patients and is now considered the standard of care, researchers note that those vision gains in clinical trials are not always seen in daily clinical practice.
This may be due to insufficient treatment, as anti VEGF therapies require frequent intravitreal injections to maintain clinical benefits—which can be burdensome for patients, investigators have noted.
Now, talk about the study.
This retrospective real-world study collected data from 421 nAMD patients treated at the Kuopio University Hospital (KUH) from 2007 to 2021.
Who was included in the study?
Participants were only included in the study if they had:
- Received treatment for nAMD at KUH from 2007 to 2021
- Enough information for each corresponding analysis
- No signs of other retinal diseases
The median age for nAMD diagnosis was:
- 76 years for heavy smokers (p < 0.001)
- 80 years for nonsmokers (p < 0.001)
In cases where only one eye of the patient was affected by nAMD, it was selected as the study eye.
If both eyes were affected by nAMD, the eye with a longer treatment history was selected unless it had exhibited signs of fibrotic late-stage nAMD.
And what data was collected?
Data included:
- Demographics
- Treatment history
- Visual acuity (VA)
- Retinal biomarker analysis
Researchers then analyzed:
- Impact of baseline factors on age at diagnosis
- Treatment duration
- Received treatment intensity
- VA gains
These statistical analyses were explorative and descriptive, as the researchers stated their goal was not to confirm or reject predefined hypotheses.
Continuous variables were determined by absolute values and only included patients receiving yearly treatment in their calculations for the median number of injections.
How were participants examined?
Participants underwent:
- Biomicroscopy examination
- Fundus photographs
- And/or optical coherence tomography (OCT)
- Fluorescein angiography (FAG) (when needed)
Findings?
Heavy smoking and a high body mass index (BMI) were linked to earlier diagnosis of nAMD. Patients who used anticoagulation and antiplatelet medication were linked to later onset of nAMD.
The presence of intraretinal fluid (IRF) resulted in a faster progression of the disease. The researchers also observed a link between IRF and the appearance of subretinal drusenoid deposits, hyperreflective foci (HRF), and increased retinal atrophy.
And the data?
In patients with anticoagulation medication, investigators found:
- Progression of nAMD was delayed
- p = 0.001, age 78.1 vs. 81 years, no med. vs. med. resp.
- A high percentage of these patients remained in treatment during the second and third year
- Year 2: p = 0.003, 59.7% vs. 74.2%, no med. vs. med. resp
- Year 3: p = 0.006, 45.3% vs. 51.6%, no med. vs. med. resp.
Go on …
Later onset nAMD also occurred in patients on antiplatelet (p = 0.024, 78 vs. 79.7 years no med. vs. med. resp.) and blood pressure medication (p = 0.032, 76.9 vs. 79.2 years no med. vs. med. resp.)
Lastly, high BMI was linked with earlier onset of nAMD (p = 0.006, 76.5 years vs. 79.4 years BMI ≥30 vs. BMI <25 resp.)
What about in relation to IRF and SRF?
Findings related to IRF and subretinal fluid (SRF) were:
- IRF only patients showed higher occurrences of subretinal drusenoid deposits (43.5% vs. 15%, p = 0.04) when compared to subretinal fluid SRF only patients
- In all patients with IRF, more hyperreflective foci (HRF) and complete RPE and outer retinal atrophy (cRORA; 20.7% vs. 5%, p = 0.02) were observed when compared to SRF patients
Limitations?
The researchers stated that real-world recording practices may have caused limitations to the study due to data being collected from real-world patients.
Additionally, they excluded patients who lacked sufficient information in their records, causing the patient population of the study to be smaller than the true population in the clinic. Therefore, the data presented may not be representative of the whole population.
Lastly, the researchers noted that, as treatment practices have evolved over the years, their data may not reflect current treatment practices.
Expert opinion?
The study authors stated their study underlines the importance of keeping in mind the potential role of disturbed vasculature function during the disease duration of nAMD.
They also recommended future studies to utilize a larger data set in order to better understand why anticoagulation and antiplatelet medication may affect the disease course.
Take home.
Practitioners may be able to utilize the results of this study when determining an individual’s risk for disease progression, with the added potential to draw attention to early lifestyle intervention to delay nAMD onset.