OVERVIEW
Primary or true erythrocytosis. Rare in China, generally believed to be caused by the bone marrow hematopoiesis hyperfunction, compensatory (or relative) erythrocytosis, is a compensatory reflection of the arterial blood oxygen pressure reduction. Due to the body’s oxygenation disorder, the bone marrow is stimulated to produce more red blood cells and hemoglobin to compensate for the original lack. Primary individuals tend to have fundus changes in adult males, accounting for about 32.5% of cases. In secondary cases, the disease is more common in those with congenital heart disease and those who live in highland areas. It can occur in both men and women at any age, with early onset in congenital heart disease.
Causes
Any type of erythrocytosis can be accompanied by the same fundus changes when the red blood cell count is more than 8 x 1012/L and the hemoglobin exceeds 125 g/L. The important changes in the fundus are as follows:
1. All blood vessels in the fundus not only dilate but also lengthen due to increased blood volume. The retinal vessels are confined to the retinal area, and the growing vessels become tortuous, with the veins being the most prominent highly dilated and tortuous veins, and the blood columns are dark purple or a mature purple-grape color. The arterioles are also enlarged, and the column loses its bright red color due to the increase in reduced hemoglobin, becoming a dark red color similar to that of normal veins. This is seen not only in the large branches but also in the small terminal branches, and the veins appear to be more numerous than usual under fluoroscopy. The diameter of the veins is sometimes uneven, and in severe cases, the veins may look like salami.
2. Due to the increase in the amount of red blood cells and hemoglobin, high blood viscosity and blood stagnation, the whole fundus of the eye turns from the normal orange-red color to purplish-red color, i.e., the retina becomes cyanotic.
3. When the blood vessels are generally dilated and tortuous and there is no great obstruction to the blood flow, there is no other complication in the retina except cyanosis; if the wall of the blood vessel itself is changed or the degree of blood viscosity is particularly serious, the circulatory obstruction will cause retinal hemorrhage, and even cause the obstruction of the central retinal vein trunk or branch.
4. In erythrocytosis with normal or slightly reddened optic disc color, congestion and edema may also occur. The cause of optic disc edema, with other blood diseases or other diseases, mostly due to increased intracranial pressure in addition to erythrocytosis due to cerebral vasodilatation and cerebral edema, or cerebral hemorrhage can make the intracranial pressure rise should not be ignored, there may be the existence of intracranial space-occupying lesions, in particular, we must be vigilant against cerebellar hemangioblastoma. This type of intracranial pressure damage can sometimes lead to relative erythrocytosis.
Symptoms
1. Ocular symptoms
Visual acuity may be normal, or there may be transient blurring or transient darkness, and there may be photophobia, visual fatigue, flash hallucination, mosquito phantom vision, night vision disorder, black or dark spots in front of the eyes, visual field defect and diplopia, etc. The above symptoms may be accompanied by fundus changes. The above symptoms may be accompanied by fundus changes. If there are no fundus changes but the above symptoms, it should be considered that there may be retrobulbar lesions or intracranial lesions, such as cerebral hemorrhage or intracerebral thrombosis.
2. Fundus changes
(1) Changes of optic disc may include blurred boundaries of optic disc, congestion, and blurring of physiological depression caused by dilation of capillaries on the surface of optic disc. Sometimes there may be optic disc edema, which can be as high as 2 to 3 diopters. The cause of optic disc edema may be increased blood viscosity, slow blood flow, resulting in optic disc small blood vessel blockage. The occurrence and extent of optic disc changes are directly proportional to the increase in the number of red blood cells.
(2) Retinal vascular changes The retinal arteries are generally unremarkable, and in a few cases arterial spasm may be present Retinal vein changes are the most prominent and common sign of the disease, and increase with the increase in red blood cell count. The retinal veins are highly tortuous and dilated with purplish red or purplish black coloration, especially at the intersection of the arterioles and veins, and the vein diameter is not uniform. The distal veins of the intersection are enlarged, and can be beaded or sausage-shaped, and the color is ripe purple grapes, the vein diameter becomes thicker, and can be 2-3 times wider than the original diameter, and the ratio of arterial veins can be 1:3. Severe obstruction of blood flow can produce central retinal vein obstruction or branch obstruction of the capillaries are full and dilated, and it seems as if the whole retina is covered with blood vessels. As the choroidal blood vessels are also dilated and filled and darkened, the whole fundus of the eye shows cyanosis, which is called retinal cyanosis.
(3) Retinal hemorrhage and exudation are rare, the hemorrhage can be small dots or flakes, mostly superficial hemorrhage, occasionally hemorrhage into the vitreous body, exudation is even more rare.
3. Other ocular changes
In addition to changes in the fundus, the eyelids may be purplish-red, and the conjunctiva may be dilated and filled with blood vessels, and small hemorrhages may be seen. Conjunctival vasodilatation, especially in the terminal blood vessels, can be spiral expansion and scattered small hemorrhagic spots superficial scleral blood vessels can also be seen dilated. Iris vasodilatation and filling, resulting in iris tissue thickening, ciliary zone iris crypt and folds become shallow or flat.
4. Systemic manifestations
The patient shows cyanosis, especially cyanosis of lips and tongue, mucous membrane and limbs are also cyanotic. The spleen is enlarged due to congestion. Patients may have headache and dizziness, tinnitus, tingling of hands and feet, insomnia and other symptoms.
Examination
1. Laboratory examination
Routine blood test to clarify the number of red blood cells and hemoglobin level Blood rheology test to clarify the viscosity of the blood.
2. Other auxiliary examinations
Funduscopic examination to clarify fundus lesions. Cranial CT scan or MRI examination to exclude intracranial space-occupying lesions and intracranial pressure elevation caused by hemorrhage.
Diagnosis
The disease is diagnosed according to the results of routine blood tests and fundus manifestations.
Complications
Bleeding and exudation of the central retinal vein or branches obstructing the retina, etc.
Treatment
Primary patients can be treated with X-ray or 32P, or repeated phlebotomy and bloodletting, or blood-thinning therapy, or giving oxygen and trying blood-activating and blood-sludging traditional Chinese medicines; those with congenital heart disease can be operated; those who are poisoned by drugs can terminate the use of drugs; and those who live in the plateau should be detached from the plateau area.
Prognosis
Retinal cyanosis caused by erythrocytosis has little effect on vision. When combined with hemorrhage, the degree of impairment varies depending on the amount and location of the hemorrhage. If the patient complains of blurred vision or blindness that cannot be explained by fundus changes, visual pathway damage such as intracranial complications, cerebral hemorrhage, or cerebral thrombosis should be considered.