Abstract
Purpose:
Large epidemiological studies suggest that the co-existence of choroidal neovascularization in patients with diabetic retinopathy is uncommon. We describe a case series of patients in whom the two pathologies co-exist and propose a hypothesis for the underlying pathophysiology.
Methods:
Retrospective case note, fundal photography, ocular coherence tomography (OCT) and fluorescein angiography review.
Results:
Three eyes of 3 patients under the care of the hospital eye service with chronic diabetic macular oedema and proliferative retinopathy developed choroidal neovascularization, confirmed on OCT and fluorescein angiography. All patients were male of Asian ethnicity, with mean age 66 years (range 54-77 years). All eyes were treated for diabetic macular oedema over mean 5 years (range 6 months-10 years) with mean 5 sessions of macular laser (range 1-12). One eye had quiescent treated proliferative and 2 active new proliferative diabetic retinopathy at the time of diagnosis with choroidal neovascular membrane. Visual acuity pre-treatment with intravitreal ranibizumab was LogMAR 1.02. At 1 year follow up, mean number of injections was 6 (range 3-10) and visual acuity was LogMAR 1.30.
Conclusions:
Elevated levels of vascular endothelial growth factor in eyes with chronic diabetic macular oedema and ischaemia are likely to be implicated in choroidal neovascular membrane formation. Asian ethnicity and male sex may be risk factors, and prognosis despite treatment with anti-VEGF agents appears to be poor. It is important to consider choroidal neovascularization as a co-existent diagnosis in patients with treated diabetic macular oedema or proliferative diabetic retinopathy who have a drop in visual acuity. This will enable prompt treatment that may improve final visual outcome.
Keywords: 499 diabetic retinopathy •
412 age-related macular degeneration •
748 vascular endothelial growth factor