Head elevation lets the blood settle
In proliferative diabetic retinopathy, chronic ischemia of the retina stimulates growth of fragile new blood vessels (neovascularization) on the retina and into the vitreous. These vessels bleed easily, and blood in the vitreous causes sudden dark floaters and hazy vision. While the hemorrhage clears, the client rests with the head of the bed raised, in a semi-Fowler's position. Gravity lets the blood settle into the lower part of the vitreous cavity, below the visual axis, so central vision clears sooner and the retina can be examined.
Why the other positions do not help
Lying flat on her back lets the blood spread across the back of the eye, including the macula and the visual axis. Lying flat with the legs raised adds to venous pressure in the head and still does not let the blood settle. Lying on her side with the bed flat moves the blood to one side but does not keep it below the line of sight. Only head elevation uses gravity to pull the blood down and away from central vision.
| Position | Effect on vitreous blood |
|---|
| Head of bed raised (semi-Fowler's) | Settles low, clears the visual axis |
| Flat on back | Spreads over the back of the eye |
| Flat with legs raised | Raises venous pressure; no settling |
| Side-lying, bed flat | Does not keep blood below the line of sight |
Other teaching while it clears
She is taught to avoid strenuous activity, heavy lifting, bending with the head below the waist, and straining, all of which raise venous pressure in the head and can cause more bleeding. She should keep her blood glucose and blood pressure controlled, since both affect retinopathy progression. She should seek care at once for a sudden increase in floaters, flashes of light, or a shadow or curtain across her vision, which can signal retinal detachment. Laser or vitrectomy may be needed if the hemorrhage does not clear.
Link to her history
Twelve years of diabetes and eight years of hypertension both damage retinal vessels. The nurse reinforces regular dilated eye examinations, glucose and blood pressure control, and smoking avoidance as long-term measures.
Exam takeaway
Key point Vitreous hemorrhage: head of bed elevated so blood settles below the visual axis, and avoid strenuous activity.