What happens in the retina
The retinal vessels are normally separated from the tissue by a dense barrier that does not allow fluid and proteins to pass through. When this barrier is damaged, plasma escapes and accumulates between the layers of the retina, forming small cavities similar to a honeycomb. The macula thickens one and a half to two times, the distance between the photoreceptors changes, and the brain receives a distorted image. While the cells are alive, recovery is possible, but with prolonged swelling they gradually die, and vision does not return even after the fluid is completely eliminated.
- Cystic edema—fluid cavities in the layers of the retina
- Diffuse edema - uniform thickening of the macula
- Neuroepithelial detachment - fluid under the retina
- Edema with traction when stretched by the vitreous
- Prolonged swelling leads to irreversible cell death
Reasons
The most common cause is diabetes: with high sugar levels, the walls of the retinal capillaries are damaged and begin to leak fluid. The second most important factor is retinal vein thrombosis, when the outflow of blood is impaired and the pressure in the capillaries increases. Swelling often develops after cataract surgery, usually several weeks after surgery. Other causes are uveitis, wet age-related macular degeneration, vitreous tension on the retina, hereditary dystrophies and side effects of certain drugs.
- Diabetic retinopathy
- Retinal vein thrombosis
- Condition after cataract surgery
- Uveitis and inflammatory diseases of the eye
- Wet macular degeneration
- Vitreomacular traction, hereditary dystrophies
Symptoms
Complaints specifically concern the center of vision. The text blurs, letters creep on top of each other, and the faces of people at a distance are more difficult to recognize. Metamorphopsia is very characteristic: bars on a window, a door frame, lines in a book look curved or broken. Some patients note that objects appear smaller in one eye than in the other. Colors become dull and it feels like you are looking through cloudy glass. There is no pain, the eye is externally calm, and peripheral vision remains normal.
- Blurred central vision
- Curvature of straight lines
- Gray or dark spot in the center
- Changing the perception of the size of objects
- Dull colors
- Difficulty reading and working with small parts
Diagnostics
The main method is optical coherence tomography: it shows the retina layer by layer, measures the thickness of the macula in micrometers and identifies cavities with fluid. It is OCT that evaluates the effect of treatment. Examination of the fundus with a dilated pupil helps to see the cause: hemorrhages, altered veins, newly formed vessels. Fluorescein angiography shows exactly where the vessels are leaking fluid. A simple Amsler test allows the patient himself to monitor the curvature of the lines at home. Be sure to check your sugar levels and blood pressure.
- Optical coherence tomography of the retina
- Fundus examination with pupil dilation
- Amsler test for self-control
- Fluorescein angiography according to indications
- Computer perimetry
- Glycated hemoglobin, blood glucose, blood pressure control
Treatment
Modern treatment of macular edema has changed the prognosis: what previously led to a persistent decrease in vision is now reversible in many cases. The main method is intravitreal injections of drugs that block vascular growth factor; they are administered in a course, with regular OCT monitoring. In case of insufficient effect or inflammatory nature, long-acting hormonal implants are used. Laser treatment is used for certain forms of diabetic edema. Swelling after cataract surgery usually responds well to anti-inflammatory drops. If the retina is pulled by the vitreous body, vitrectomy is performed. At the same time, diabetes and hypertension must be treated.
- Intravitreal injections as prescribed by a doctor
- Hormonal implants for the inflammatory nature of edema
- Laser coagulation for certain forms
- Anti-inflammatory drops after cataract surgery
- Vitrectomy for vitreous tension
- Strict control of sugar, blood pressure and cholesterol
