Diabetic Macular Edema, Diabetic Retinopathy
Conditions
Keywords
Diabetic Macular Edema, Bevacizumab, Ranibizumab, Aflibercept, BCVA, OCT
Brief summary
PURPOSE: To evaluate the efficacy of switching from bevacizumab to ranibizumab (Lucentis; Genentech, South San Francisco, CA) or aflibercept (Eylea; Regeneron, Tarrytown, NY) in eyes with diabetic macular edema (DME) nonresponders to bevacizumab (Avastin; Genentech, South San Francisco, CA). METHODS: Single-center retrospective comparative study of patients with DME unresponsive to intravitreal bevacizumab that were switched to ranibizumab or aflibercept. Best-corrected visual acuity and central foveal thickness will be analysed prior to and 3 months after the switch. OCT biomarkers will also analyzed. A p value of 0.05 or less will be considered to be statistically significant. HYPOTHESIS: Patients will improve anatomically and functionally after switch.
Interventions
Sponsors
Study design
Eligibility
Inclusion criteria
* type 1 or type 2 diabetes mellitus patients * older than 18 years * with center-involved DME, defined as central subfield thickness (CST) of more than 300 µm on spectral-domain OCT (SD-OCT). * nonresponsive to bevacizumab, defined as having persistent intraretinal and/or subretinal fluid on optical coherence tomography (OCT), i.e CSF\>300µm after a minimum of 3 monthly injections, 4 months before switch, regardless of visual acuity (VA).
Exclusion criteria
* additional ocular diseases that could significantly affect the visual acuity such as: * significant vitreoretinal interface abnormality on SD-OCT that may contribute to macular edema * age-related macular degeneration * retinal vascular occlusion * central corneal opacity * amblyopia * advanced glaucoma * optic neuropathy * history of ocular trauma or surgery other than uncomplicated cataract extraction * cataract surgery within 3 months before or after bevacizumab switch * unable to provide written informed consent.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Anatomical change | Immediately before switch (one month after last bevacizumab intravitreal injection); 4 months after switch. Minimum of three intravitreal injections before and after switch. | The central foveal thickness (CFT), measured by Optical Coherence Tomography, was automatically measured by the software in the central 1 mm. A CFT \<250 µm or \>300 µm is considered pathological. A CFT between 200 and 300 µm is considered physiological. CFT has no defined minimum or maximum values. Since patients with diabetic macular edema usually have CFT \>300 µm the goal of treatment is to lower the CFT to values between 200 and 300 µm. A clinical significant anatomical improvement was considered for a change in CFT≥10%. |
| Functional change | Immediately before switch (one month after last bevacizumab intravitreal injection); 4 months after switch. Minimum of three intravitreal injections before and after switch. | Functional change was measure by the Early Treatment Diabetic Retinopathy Scale (ETDRS) which measures the best-corrected visual acuity with an ETDRS-like chart at 4 meters in number letters or at 1 meter when patients are unable to read any letters on the ETDRS chart at 4 meters. The ETDRS scale varies from 1 to 85 letters (85 letters correspond to a 20/20 in the Snellen scale). The higher the value the better the outcome. A clinical significant functional improvement was considered for a gain of ≥5 EDTRS letters. |