“Persna” is a method of –
**Core Concept**
Persna is a method of assessing the severity of diabetic retinopathy, specifically the extent of retinal non-perfusion.
**Why the Correct Answer is Right**
Persna is a quantitative method that uses fluorescein angiography to estimate the percentage of retinal non-perfusion, which is an indicator of diabetic retinopathy severity. This method helps in assessing the risk of progression to proliferative diabetic retinopathy. The Persna score is calculated by analyzing the areas of non-perfusion in the retinal arteries and veins.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as Persna is not a method for assessing the severity of diabetic macular edema.
**Option B:** This option is incorrect as Persna is not a method for assessing the severity of glaucoma.
**Option C:** This option is incorrect as Persna is not a method for assessing the severity of age-related macular degeneration.
**Clinical Pearl / High-Yield Fact**
The Persna method is a useful tool for assessing the risk of progression to proliferative diabetic retinopathy, and it helps in making informed decisions about the need for laser photocoagulation or other treatments.
**Correct Answer:** D. Persna method.