Abstract
Purpose: :
To evaluate macular function in patients with diabetic macular edema treated with macular laser photocoagulation combined with intravitreal injection of 1.5 mg bevacizumab (IVB) or 4 mg triamcinolone acetonide (IVT).
Methods: :
11 patients (13 eyes) with DME were randomly assigned to one of three study groups: focal/grid macular laser (Laser; n=4), laser plus IVB (IVB; n=6), or laser plus IVT (IVT; n=3). Laser was performed 4 weeks after injection. Outcome measures included best-corrected visual acuity (BCVA), CSMT measured by optical coherence tomography, at baseline and at 4, 8 and 12 weeks after treatment. Macular sensitivity (MS), fixation stability (FS), and preferred retinal locus for fixation (PRL) were assessed by means of microperimetry (MAIA, Centervue - Padova, Italy) at baseline and 12 weeks after injection.
Results: :
At baseline, mean ± SE BCVA (logMAR) was 0.52 ± 0.28 (20/66); 0.53 ± 0.30 (20/68); 0.88 ± 0.24 (20/152) in the Laser, IVB, and IVT groups respectively (P= 0.2109). Statistically significant improvement of 0.21 ± 0.06 logMAR in BCVA was observed within IVT group comparing week 4 to baseline. However, intergroup analyses revealed no differences between BCVA changes in any of the groups throughout the study period. All eyes showed central fixation with mean PRL distance to the fovea of 1.91° ± 1.13°. At baseline, MS (dB) was 19.2 ± 3.0; 19.4 ± 2.1; 14.6 ± 0.8 in the Laser, IVB, and IVT groups respectively (P= 0.3877). Within or intergroup analyses revealed no significant MS changes in any of the groups. Similar results were found for FS, and PRL position. More about, there were no correlations between MS, FS or PRL position and BCVA improvement, or CSMT reduction (P>0.05). At baseline, mean ± SE CSMT (µm) was 372.25 ± 10.85; 434.83 + 67.93; 384.67 + 68.49 in the laser, IVB, and IVT groups, respectively (P= 0.7312). There was a significant reduction on CSMT in IVB group at 4th week but in any other group or study period.
Conclusions: :
The lack of correlations between MS and FS changes with BCVA or CSMT reduction might indicate that perifoveal function changes after these treatment modalities might be not correlated with visual acuity improvement. Assessing fixation stability and perifoveal sensitivity might reveal new data on functional improvement associated to the effects of IVB and IVT for DME.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00997191
Keywords: diabetic retinopathy • macula/fovea • perimetry