Clinical Features and Management of Diabetic Retinopathy

Introduction to Diabetic Retinopathy

Diabetic retinopathy progresses through distinct stages characterized by specific retinal vascular abnormalities, with nonproliferative disease showing microaneurysms, hemorrhages, and exudates, while proliferative disease demonstrates neovascularization that threatens vision through bleeding and retinal detachment 1, 2

The American Academy of Ophthalmology classifies NPDR severity using the "4-2-1 rule" for severe NPDR, which includes criteria such as microaneurysms, hemorrhages, and venous beading 7
Eyes with intraretinal microvascular abnormalities (IRMA) have a 1.77-fold increased risk of progressing to proliferative disease, while those with 4-quadrant dot-blot hemorrhages have a 3.84-fold increased risk of vitreous hemorrhage 8
NPDR is characterized by retinal vascular abnormalities without neovascularization, including microaneurysms, intraretinal hemorrhages, venous dilation, and cotton wool spots 1, 2

PDR represents the advanced stage characterized by neovascularization in response to global retinal ischemia, with high-risk characteristics including NVD equaling or exceeding one-quarter to one-third disc area, and vitreous or preretinal hemorrhage with any NVD or NVE equaling or exceeding one-quarter disc area 1, 2, 4, 5
High-risk PDR requires prompt panretinal photocoagulation and consideration of anti-VEGF therapy 1
Worse baseline levels of PDR are associated with a 3.97-fold increased risk of progression regardless of treatment modality 8

DME can occur at any stage of diabetic retinopathy and represents a separate vision-threatening manifestation, characterized by retinal thickening and hard exudates 1, 2, 3, 9
Clinically Significant Macular Edema (CSME) requires prompt treatment consideration, particularly when center-involved, and is defined by retinal thickening and/or adjacent hard exudates that involve the center of the macula or threaten to involve it 1, 6