Macular grid photocoagulation in persistent macular edema due to central retinal vein occlusion

Macular edema is still the main cause of poor visual prognosis in central retinal vein occlusion (CRVO). This study was designed to establish whether grid photocoagulation is effective in the management of this disorder.

The records of 16 patients who had undergone macular grid photocoagulation for persistent macular edema due to CRVO were reviewed retrospectively. Pre-treatment visual acuity ranged from 20/400 to 20/40, and laser treatment was done six months or more after the onset of the disease.

Biomicroscopy and fluorescein angiography showed the improvement or disappearance of macular edema in 14/16 patients (87.5%). Improved visual acuity was observed in eight (50%) and no improvement or reduced vision in the other eight (50%). A poorer prognosis was statistically correlated with older age (p < 0.03), macular ischemia (p < 0.001), foveal avascular zone larger than 1/2 disc diameter (p < 0.05) and pigmentary clumps in the foveal area (p < 0.05). Laser treatment was ineffective for most patients with systemic vascular risk factors and pre-treatment visual acuity below 20/200.

Macular grid photocoagulation may be effective for drying up, or at least reducing, macular edema due to CRVO and some improvement of vision can be expected in half the cases.