Abstract
Purpose:
Subfoveal choroidal thickness (CT) has been reported to be reduced in diabetic macular edema eyes (DME) and that intravitreal injections of ranibizumab reduce retinal thickness (RT) by reducing vascular permeability with significant functional improvement although no information is still available regarding possible influence on CT. The purpose of this study was to explore CT changes and their relationship with functional changes in DME eyes after three injections 1 month apart (loading phase) of ranibizumab 0.5 mg in comparison with the fellow eye.
Methods:
BCVA measurement with ETDRS charts, biomicroscopy, IOP measurement, ophthalmoscopy and RT measurement were performed at baseline and then monthly until 1 month after the loading phase. In addition CT measurement using enhanced depth imaging optical coherence tomography (EDI-OCT, Spectralis; Heidelberg Engineering GmbH, Heidelberg, Germany) and MP1 microperimetry (Nidek Technologies, Padova, Italy) were performed at baseline and 1 month after the loading phase, as systolic and diastolic pressure and heart rate measurement.
Results:
23 DME eyes of 23 patients with diabetes (14 males, 9 females, mean age 66.2±8.3 years) were included. Mean diabetes and macular edema duration was 16.13±8.5 and 3±1.7 years, respectively. After the loading phase mean BCVA significantly improved from 60.6±12.3 to 66.4±12.4 letters (p<.0001) and central RT significantly reduced from 583.4±141.5 to 434.4±136.3 μm (p<.0001). Not significant changes were found in mean retinal sensitivity throughout the follow-up (10.9±5.3 vs 11±5.03 dB, p=0.83). CT was found to be different between treated and fellow eye at baseline (185.4± 49.9 vs 210.04±41.03, respectively) and while after the loading phase an increase of 21.2±56 μm (11.4%, from 185.4±49.9 to 206.6±60.6 μm) was found in the treated eye, no changes were found in the fellow eye. BCVA changes from baseline were found not be related to either central RT (R2 0.11, p=0.1) or CT changes (R2 0.05, p=0.28). No significant relationship was also found between central RT and CT at any visit as between their changes from baseline. No relationship was found between refraction, IOP, systemic pressure and CT changes.
Conclusions:
Loading phase of ranibizumab in DME eyes determines an increase of choroidal thickness associated with an improvement of visual acuity and a reduction of retinal thickness.
Keywords: 452 choroid •
498 diabetes