Selective panretinal laser photocoagulation in ischemic central retinal vein occlusion

Abstract

To compare the effectiveness and safety of panretinal laser photocoagulation targeting far-periphery (sPRP) versus conventional panretinal laser photocoagulation (cPRP) in patients with ischemic central retinal vein occlusion (iCRVO) in terms of the degree of macular edema. The study included eight (5 males and 3 females, mean age 59.4±17.2 years) and seven (6 males and 1 female, mean age 75.7±9.1 years) patients in sPRP and cPRP groups, respectively. iCRVO was defined as a CRVO case with baseline best corrected visual acuity (BCVA) of <0.2, central retinal thickness (CRT) of >500 µm and severe intraretinal hemorrhages. sPRP included dense photocoagulation of far-periphery over 360˚ and standard photocoagulation of the mid-periphery. Primary outcome measures were CRT and macular volume at the end of the follow-up. BCVA served as the secondary outcome measure. The median of the follow-up period was 9.5 months (ranged from 1.5 to 19 months). In the sPRP group, at the end of the follow-up both CRT and macular volume significantly decreased from 892.0±149.4 µm to 391.8±131.2 µm (p<0.001) and from 16.6±4.1 mm3 to 9.7±1.4 mm3, respectively (p=0.008). In the cPRP group, at the end of the follow-up CRT and macular volume changes were statistically insignificant: from 761.0±162.1 µm to 705.0±181.8 µm (p=0.46) and from 13.6± 3.2 mm3 to 11.8±1.7 mm3, respectively (p=0.38). At the end of the follow-up, cPRP group did not have changes in BCVA, while in the sPRP group BCVA increased statistically significantly from 1.45±0.6 LogMAR (≈0.06) to 1.1±0.6 LogMAR (≈0.14) (p=0.03). There were no adverse events or complications associated with laser treatment in any of the study patients. This study demonstrates the superiority of sPRP compared with cPRP for treatment of patients with iCRVO, showing that selective laser treatment of the far-periphery results in significant reduction of macular edema associated with severe retinal ischemia.