Rubeosis iridis is a disease characterized by the appearance of newly formed vessels on the anterior surface of the iris. Clinical symptoms are represented by visual discomfort, a slight decrease in visual acuity, photophobia, the appearance of “fog” in front of the eyes. To make a diagnosis, biomicroscopy of the eye, gonioscopy, tonography, ophthalmoscopy and retinal angiography are performed. Conservative therapy is effective in the early stages. The use of angioprotectors, glucocorticosteroids is shown. Surgical treatment is based on the use of panretinal photocoagulation and surgical removal of newly formed vessels.
Rubeosis iridis is a widespread pathological condition in ophthalmology. According to statistics, in 21% of cases, rubeosis develops against the background of thrombosis of the central retinal vein. Newly formed vessels in the iris are detected in 4-8% of patients with diabetes mellitus, however, with a decompensated form of metabolic disorders, this indicator increases to 80%. In most cases, the disease is diagnosed in patients older than 40 years. Ophthalmopathology is more common among male patients. Geographical features of distribution are not noted.
Causes of rubeosis iridis
The etiology of rubeosis iridis is not fully understood. Activation of the neovascularization process is provoked by a number of internal and external factors. The main causes of the development of rubeosis include:
- Metabolic disorders. Rubeosis often occurs a second time against the background of diabetic retinopathy in patients with a decompensated form of diabetes mellitus.
- Occlusion of retinal veins. Thrombosis of the central vein of the inner lining of the eye leads to ischemia, which increases vascular proliferation.
- Detachment of the retina. Normally, the inner shell of the eyeball provides the trophism of the iris. Retinal detachment or its degenerative-dystrophic changes underlie regional hypoxia, which provokes angiogenesis.
- Pathology of the orbital artery. Damage to the vessels feeding the eyeball, as a result of a prolonged course of atherosclerosis or arteritis, leads to increased angiogenesis, the appearance of iris rubeosis and corneal neovascularization.
Vascular proliferation is a compensatory reaction to hypoxia of surrounding tissues. Oxygen starvation potentiates the synthesis of nitric oxide, which belongs to the number of vasodilators. Increased angiogenesis is caused by ischemia of the membranes of the eye caused by insufficient blood supply or the presence of an organic barrier in the path of blood flow in the orbital artery. The secretion of vasoconstrictive substances, mainly endothelial growth factor, the expansion of arterioles and venules, the activation of plasminogen provoke the formation of endotheliocytes, and in the future – the formation of blood vessels.
Normally, the structure of the iris contains a large number of capillaries located under the anterior boundary membrane and pigment epithelium. The growth of newly formed vessels begins with the internal parts of the iris, followed by spreading to the periphery and corner of the anterior chamber. FCA obturation is accompanied by an increase in ophthalmotonus. The formed capillaries have a thin wall and have increased fragility. A slight increase in intraocular pressure or the action of traumatic agents leads to their damage and the development of bleeding.
Rubeosis iridis is an acquired pathology. Signs of the congenital form are often associated with intrauterine fetal hypoxia, but they have no practical significance, because they are leveled independently in the neonatal period. From a clinical point of view , the following types of iris rubeosis are distinguished:
- Pupillary. It is characterized by enhanced angiogenesis in the region of the pupillary edge of the iris.
- Angular. A typical manifestation of this variant of the disease is the detection of newly formed vascular plexuses in the area of the angle of the anterior chamber of the eye.
- Combined. In this form, pathological vascular plexuses are determined in the FCA and central divisions.
- Total. It is characterized by a widespread lesion of the entire anterior part of the iris.
Patients complain of discomfort in the orbit area with prolonged visual load. Symptoms of the disease are photophobia, the appearance of “fog” or “shroud” in front of the eyes. Visual acuity decreases slightly. Visual dysfunction is caused by a spasm of accommodation and is reversible. Narrowing of the visual fields leads to deterioration of peripheral vision, which is manifested by a weakly pronounced violation of orientation in space. Clinical manifestations of rubeosis can disappear on their own, provided that the patient does not show signs of ophthalmohypertension. Patients report frequent headaches. With an extensive lesion, dilated blood vessels in the form of red spots are visualized on the surface of the iris, which leads to a cosmetic defect.
In this pathology, the process of neovascularization extends to the angle of the anterior chamber (FCA) of the eye, which leads to the appearance of a network of newly formed vessels and a violation of the outflow of intraocular fluid. Therefore, the most severe complication of rubeosis is neovascular glaucoma, which is characterized by a severe course and resistance to drug therapy. Newly formed vessels have a tendency to increased fragility, which often leads to hemorrhage in the anterior chamber of the eyeball or vitreous. A common complication of neovascularization is amblyopia, which is caused by a spasm of accommodation.
Diagnosis requires an objective examination of the patient. At the beginning of the development of pathology, changes are not detected with the naked eye. With a prolonged course of the disease, pathological changes have the form of a lace pattern. A special complex of ophthalmological examination includes:
- Biomicroscopy of the eye. The technique allows you to identify slightly dilated capillaries and red formations on the periphery of the pupil. The direction of growth of newly formed venules and arterioles is from the central parts to the iridocorneal angle.
- Gonioscopy. With a prolonged course of rubeosis, signs of enhanced angiogenesis are visualized in the anterior chamber area. In some cases, FCA is affected before involvement in the pathological process of the iris.
- Non-contact tonometry. At the beginning of the disease, intraocular pressure (IOP) is within the physiological norm. The progression of rubeosis leads to an increase in ophthalmotonus.
- Electronic tonography of the eye. The study makes it possible not only to measure IOP, but also to study the features of the hydrodynamics of the eye (volume of intraocular fluid, outflow coefficient). Tonography is indicated with a high probability of developing neovascular glaucoma and in persons with a history of ophthalmohypertension.
- Ophthalmoscopy. Examination of the fundus is carried out in order to detect detachment of the inner shell.
- Retinal angiography. Diagnostics is performed to study the features of blood flow in the vessels of the retina, to detect signs of venous thrombosis.
- Visometry. Prolonged course of the disease leads to the development of accommodation spasm and secondary decrease in visual acuity.
- Perimetry. The technique allows you to visualize the narrowing of the visual field.
Treatment of rubeosis iridis
The tactics of managing patients with iris rubeosis is determined by the duration of the course and the severity of clinical manifestations of the disease. Etiotropic therapy is based on the elimination of the underlying pathology. The main methods of treatment:
- Conservative therapy. It is recommended to use medicines from the group of angioprotectors, glucocorticosteroids, vitamins B and C. It is used at an early stage of the disease.
- Panretinal photocoagulation (laser coagulation). The technique stimulates regression of newly formed capillaries. Photocoagulation is recommended for the first manifestations of neovascularization in people with a high risk of secondary glaucoma. The use of laser coagulation is more effective in superficial lesions.
- Surgical treatment. Surgical intervention is indicated if rubeosis has arisen against the background of metabolic disorders. Vascular removal is performed surgically due to the high risk of retinal detachment when performing photocoagulation in patients at risk.
The possibility of using anti-VEGF therapy in ophthalmology is being studied. The developed drugs bind to the endothelial growth factor, thereby blocking its effect on the vascular wall. Scientists believe that the drugs will be administered in the form of retro- or parabulbar injections.
Prognosis and prevention
The prognosis for life and work capacity in the case of iris rubeosis is favorable. Timely treatment of the disease allows you to avoid the development of dangerous complications and restore visual functions. No specific preventive measures have been developed. Non-specific methods of prevention are reduced to the control of intraocular pressure and blood glucose levels. Patients with a history of diabetes should be examined by an ophthalmologist 2 times a year in order to diagnose signs of diabetic retinopathy. If a retinal detachment is suspected, it is necessary to urgently seek help from a specialist.