Purpose
To establish the effects of Panretinal Photocoagulation (PRP) and parameters of laser in the different retinopathies treated. To compare the treatment of PRP with Anti VEGF (Avastin) versus PRP alone.
Methods
Retrospective cohort study of all the patients than received PRP for retina ischemic disease, between February 2010 and December 2012 in the Hospital Dr. Elias Santana, Dominican Republic. The variables were: visual acuity, retinal pathology, cataract LOCS classification, laser parameters and Anti-VEGF. Statistical Analysis: Percentage, median and quartiles, Spearman R, the Chi 2 test and Wilcoxon test in SPSS.
Results
799 record and 2472 laser session were reviewed; of them 549 eyes met the inclusion criteria. Of all studied patients that received PRP, 61% (282 eyes) were treated for proliferative diabetic retinopathy (PDR), 39% (180 eyes) for nonproliferative diabetic retinopathy, 7.2% (39 eyes) for central retina venous occlusion (CRVO), 3% (16 eyes) for branch retina vein occlusion (BRVO) and 2.6% (19 eyes) others disease. The parameters of the laser were similar for all diseases, with the laser power median of 250mW (with exception of CRVO who has 300mW), duration median of 200msec, and a total number of spots median of 1100 (with exception of BRVO with median of 680 spots). It was necessary to increase the power of the laser 10% for each increase in level of cataract opacity (LOCS classification) p value < 0.001. The PRP treatment maintained stable visual acuity for a follow of 2 years. The 70% that completed PRP therapy had double the number of spots compared to those that did not complete therapy (median 1300 vs 720 spots). The cases of PDR treated with a combination of PRP with Anti VEGF therapy have a higher rate of stabilization of disease (71.4% vs 54.9 %) than those that received only PRP.
Conclusions
Proliferative Diabetic Retinopathy treated with PRP and Anti VEGF had a higher rate of stabilization of disease than with PRP alone. All the diseases studied needed similar PRP parameters except for CRVO that needed higher power settings, and BRVO than needed fewer spots. For each level of increased opacity in cataract, we needed to increase the power of the laser by 10%. Differences in laser settings was not associated with higher stabilization. Patients receiving more than 1100 spots of PRP stabilized similarly, but the highest levels of stabilization were only associated with completion of PRP and use of Anti VEGF therapy.
Keywords: 499 diabetic retinopathy •
748 vascular endothelial growth factor •
578 laser