In proliferative diabetic retinopathy, panretinal photocoagulation (PRP) reduces neovascularisation primarily by which mechanism?

• A Directly ablating new vessels on the retinal surface
• B Destroying ischaemic outer retina, thereby reducing VEGF production ✓
• C Increasing choroidal blood flow to the inner retina
• D Creating chorioretinal adhesions that prevent vitreous traction

Explanation

PRP destroys the metabolically active but ischaemic photoreceptors and outer retinal cells in the mid-peripheral retina. This reduces the ischaemic stimulus and thereby decreases VEGF production by the remaining retinal tissue, causing regression of neovascularisation. PRP does not directly burn the new vessels. While chorioretinal adhesions occur as a secondary effect, this is not the primary anti-angiogenic mechanism. Choroidal perfusion is not significantly altered by PRP.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.