Tractional retinal detachment ('crunch' phenomenon) from intravitreal anti-vascular endothelial growth factor injection in central retinal vein occlusion

Tractional retinal detachment is an uncommon complication of intravitreal anti-vascular endothelial growth factor (VEGF) injection wherein the drug triggers tractional retinal detachment as a result of fibrovascular membrane contraction. We present a case of a 42-year-old hypertensive woman diagnosed with chronic central retinal vein occlusion on both eyes. The right eye had total retinal detachment and neovascular glaucoma, while the left eye had retinal neovascularisation. Panretinal photocoagulation and intravitreal anti-VEGF injection was started on the left eye. However, she was lost to follow-up. She returned 4 months later with extensive tractional retinal detachment involving the macula on the left eye. She subsequently underwent vitrectomy with endolaser and silicone oil tamponade on the left eye. The anti-VEGF 'crunch' results from regression of fibrovascular proliferation with a concurrent increase in fibrosis, resulting in worsening retinal traction. With the widespread use of anti-VEGF agents, ophthalmologists need to be aware of this vision-threatening complication.