A vitreous hemorrhage can result in sudden, painless loss of vision. In patients with diabetes, the cause may be due to either a posterior vitreous detachment (PVD) or proliferative diabetic retinopathy (PDR). Remember, the proliferative phase of the diabetic retinopathy means that there are areas of neovascularization (abnormal blood vessel proliferation) on the surface of the retina.
In cases where a diabetic patient is diagnosed with a vitreous hemorrhage, my job is to ensure that the cause is not due to a retinal tear or a retinal detachment. This can be done by dilating the eye and examining.
Sometimes there is so much blood I can not see much or any of the retina. In these cases, we perform an ultrasound of the eye to make sure the retina is attached.
Sometimes, an ultrasound can locate a retinal tear. If there is no retinal tear, or retinal detachment, then I am pretty sure that the vitreous hemorrhage is due to the proliferative diabetic retinopathy.
Neovascular vessels are very fragile and may easily break open and bleed. This may occur with or without straining. The blood can fill the vitreous cavity causing sudden “loss” of sight. Vision is “lost” (not permanently) due to physical blockage of light.
Bleeding in the vitreous is benign. It causes no damage to the vision or to any part of the eye. On the other hand, as it physically blocks light, patients don’t see well.
Usually, when I am sure the bleeding is due to diabetic retinopathy, I recommend a period of doing nothing. We watch and wait. In doctor lingo, we are observing.
After a few weeks, or sometimes longer, we may decide to operate to remove the blood. Sometimes the blood absorbs on its own and sometimes it doesn’t. At some point, patients with non-absorbing blood in the eye become tired of the prolonged decreased vision. A vitrectomy is then scheduled to remove the blood.
What Does This Mean? The sudden loss of vision can be devastating for anyone. In cases when the loss of vision is due to a vitreous hemorrhage, we need to assess the threat of permanent vision loss due to other causes such as a retinal tear or retinal detachment.
If the eye is stable, that is, we can safely observe, it is sometimes tough to reassure patients that while they just “lost” their vision, the best idea is to do nothing! Their “lost” vision is temporary.
I often will have a patient return in a short week or two to reassess and help relieve anxiety.
Patients with proliferative diabetic retinopathy, if you remember, will require laser treatment (pan-retinal photocoagulation, aka PRP) to reverse the neovascularization.
While we are waiting for the hemorrhage to clear, at the same time we are mindful that laser treatment is ultimately needed. If the vitreous hemorrhage clears by itself, laser can be applied in the office. If we end up operating, the laser can be applied at the same time as the vitrectomy.