There are two different laser treatments to treat diabetic retinopathy. One laser treatment is used to treat diabetic macular edema, the most common “complication” of diabetic retinopathy. The second laser treatment is used to treat proliferative diabetic retinopathy (aka PDR), yet far fewer people develop this potentially blinding stage of the disease.
Macular edema is treated with “focal” laser treatment. The laser is used to treat/burn/cauterize those areas of blood vessels that are leaking near the macula. The treatment is focused to treat certain specific areas, hence “focal” laser.
Proliferative diabetic retinopathy (PDR) is treated with “scatter” or “pan-retinal” photocoagulation (PRP). The peripheral retina is “scattered” with laser burns.
The timing of the treatment can be crucial. Treating the PDR (proliferative diabetic retinopathy) before the macular swelling is controlled, or treated, can lead to progressive loss of vision because the PRP (used to treat PDR) can worse the macular edema.
I prefer treating and controlling the macular swelling first, before treating the neovascular disease (PDR). Depending upon the situation, however, I don’t always have this luxury as sometimes the PDR is so advanced that we can not wait.
Remember, the neovascularization can cause blindness.
What Does This Mean? In most cases, patients need only one or the other treatment. Macular edema is treated with focal laser and PDR is treated with PRP. In the unlikely situation where patients need both…
When possible, I’ll treat the macular edema with focal and wait several weeks, or months, to treat with scatter laser. I don’t want the macular edema to worsen.
Macular fluid causes decreased vision (patients can tell). Worsening macular edema means lousy vision….and anxious patients.
Avastin, however, has improved my ability to treat those patients with both macular and proliferative disease. Avastin (or Lucentis) allows me to treat both the PDR and macular edema…it buys me time!