Abstract
Purpose:
Assess the effectiveness and safety of SRFLPT in patients with diabetic CSME.
Methods:
142 patients (216 eyes) with ETDRS defined CSME were enrolled in this prospective study. ETDRS visual acuity, SD-OCT volume (central 6X6mm), F/A and ICG were obtained at baseline and at months 3, 6, 9, and 12. ICG findings were used to identify focal leakage from larger retinal microaneurysms that were individually treated with direct bare threshold (light blanching) focal laser application. On the other hand, F/A findings were used to determine areas of diffuse capillary leakage that were treated with a further reduced invisible sub-threshold grid laser photocoagulation. A spot size of 100µm and a duration of 20msec were selected. The Heidelberg SD-OCT was used to monitor central macular volume.
Results:
Average total fluence was 2720 J/cm2. Visual acuity improved on average 6.1±5.2, 5.6±5.7, 6.3±5.8 and 9.7±7.1 ETDRS letters after 3, 6, 9 and 12 months respectively ( p<0.05 for all points). 24% of the patients (51) exhibited a gain of more than 10 letters, when 5% (11 eyes) lost 15 or more letters. Macular volume at baseline was 8.6±5.5mm3, which showed a statistically significant improvement to 8.3±5.6, 8.1±5.5, 8.2±0.5 and 7.7±0.5 at the four follow-up data points.
Conclusions:
The ETDRS defined parameters remain the gold standard for CSME laser treatment. By using F/A and ICG guided SRFLPT there appears to be a statistically significant reduction in the total amount of energy needed to achieve improvement in both visual acuity and volumetric reduction of macular edema. By minimizing the total energy used, theoretically less collateral damage and inflammation occurs and this may be responsible for the speed and extend of the clinical improvement observed in our study. However, long term follow-up and a larger controlled randomized trial is necessary to better assess the effectiveness of this treatment.
Keywords: 578 laser •
499 diabetic retinopathy •
585 macula/fovea