Iridodialysis is a pathology of the iris, accompanied by its separation from the ciliary body at the root. The main clinical manifestations are pain at the time of injury, decreased visual acuity, photophobia, monocular diplopia. The examination of the patient includes an objective examination, visometry, biomicroscopy, non-contact eye tonometry, electronic tonography, ophthalmoscopy. Correction of iridodialysis is carried out in an open way (through intraoperative access). The closed technique allows to eliminate the defect through a small limbal tunnel puncture.
H21.5 Other types of adhesions and ruptures of the iris and ciliary body
Iridodialysis is a limited area of separation of the iris from the root. The first attempt to introduce reconstructive surgery to correct this defect was made by the Arab ophthalmologist Amedi in 1866. In the general structure of iris lesions, iridodialysis occurs in 8.6% of cases. Among the injuries of the anterior segment of the eyeball, the partial separation of the iris accounts for 23.2%. The disease is often diagnosed at the age of 31 to 40 years (30.6%). In men, the disease occurs 1.5 times more often than in women, which is associated with more frequent traumatization of the visual organ in males. Pathology is widespread everywhere.
Congenital separation of the iris from the root should be considered as a developmental anomaly. Scientists do not exclude that the likely etiological factors are the influence of teratogenic factors during pregnancy and eye damage during childbirth. In the case of the acquired form, there is a clear relationship between the impact of a traumatic agent and the formation of a defect. The main causes of the disease:
- Contusion of the eye. The separation of the iris is one of the manifestations of a 3-4 degree contusion. At the moment of impact of the shock wave, there is a sharp increase in intraocular pressure and compression of the structures of the anterior pole of the eyeball. Pressure reduction is accompanied by partial or complete separation.
- Eye injury. Iridodialysis occurs against the background of a blunt blow to the eye socket. Characteristic triggers: punch, tennis ball, bottle stopper. A high-pressure jet of water directed into the eye can cause pathology. Less often, the disease is a complication of a penetrating injury to the eyeball.
- Iatrogenic intervention. The most frequent cases of postoperative iridodialysis are noted with intracapsular cataract extraction. Less often, pathology occurs during endovitreal surgical interventions. Any microsurgical operations on the anterior pole of the eye are considered as a possible provoking factor.
- Partial atrophy of the iris. In rare cases, gonioscopy can reveal a small area of atrophy of the iris along its base. A slight shock or an increase in intraocular pressure leads to the formation of a defect visible to the naked eye.
- Tumor of the ciliary body. Neoplasms of the ciliary body, increasing in size, shift towards the angle of the anterior chamber (FCA). The iris gradually separates from the root, which becomes a prerequisite for the development of spontaneous iridodialysis.
In the mechanism of pathology development, a leading role is assigned to a sharp increase in intraocular pressure, which is subsequently replaced by hypotension. This leads to a forward shift of the iris. The subsequent dislocation posteriorly causes its separation at the root. When more than 1/2 of the iris circumference is detached, a post-traumatic inversion is observed. This potentiates a significant change in the shape of the pupil. Due to excessive light entering the retina, visual acuity decreases. The process of accommodation is sharply disrupted.
Limited separation of the iris is a unilateral pathology. The disease is accompanied by an intense pain syndrome. With spontaneous iridodialysis, patients note the sudden occurrence of sharp pain in the eye. If the area of damage is located in the lumen of the eye slit, patients complain of visual impairment, severe photophobia and double vision. To reduce the severity of symptoms, the patient squints or completely closes the eye on the side of the lesion.
If the defect is covered by the upper eyelid, the only symptom of iris detachment is gradually subsiding pain. Symptoms may be absent with a small size of the defect, which is hidden behind the hyphae or deep anterior chamber of the eye. As blood or exudate resorption occurs, fibrin deposits appear in the area of the iris root. Patients note discomfort in the eyes when looking at a light source. The use of sunglasses or colored lenses eliminates unpleasant sensations.
The defeat of the iris in most cases is accompanied by degenerative-dystrophic changes on the part of the cornea. Patients with post-traumatic iridodialysis are at risk of developing retinal detachment. Often there is such a formidable complication as cystic macular edema. Scarring in the area of the CPC and violation of the circulation of watery moisture causes secondary glaucoma in 12% of patients. Violation of the light scattering process with damage to the iris leads to a decrease in visual acuity.
Examination of a patient with iridodialysis is carried out by a specialist in the field of modern ophthalmology, includes anamnesis collection, visual examination and special research methods. From anamnestic information, it is necessary to clarify the circumstances and time of injury. An objective examination reveals the irregular shape of the pupillary opening and the area of the defect. Basic diagnostic methods:
- Visometry. The degree of visual impairment is directly proportional to the area of the defect. With a small area of separation of the iris, vision can reach 0.3-0.7. In most patients, the average visual acuity is 0.25 ± 0.06.
- Biomicroscopy of the eye. When examining the anterior part of the eyeball with a slit lamp, an irregularly shaped pupil opening is visualized. Dialysis has the appearance of a dark biconvex area near the limb. The injection of conjunctival vessels is determined.
- Non-contact tonometry of the eye. The average values of intraocular pressure (IOP) are 20.31 mm Hg. In this pathology, it is necessary to regularly measure IOP due to the high risk of developing ophthalmohypertension and secondary glaucoma. At the same time, in 4% of cases there is a tendency to hypotension.
- Electronic tonography. Iridodialysis is characterized by high figures of the coefficient “C” and low values of the coefficient “F”. Features of intraocular hydrodynamics indicate a decrease in the secretion of watery moisture, which is caused by damage to the ciliary body.
- Ophthalmoscopy. Examination of the fundus in case of traumatic damage to the organ of vision allows you to identify the first signs of retinal detachment and macular edema, hemorrhage foci. With hemophthalmos, the posterior segment remains inaccessible for examination.
Elimination of the iris defect is possible only surgically. Surgical intervention should be performed at an early date. This is due to the fact that atrophic changes are progressing in the area of separation, after a long period of time, the restoration of the normal structure of the iris and the shape of the pupil becomes impossible. There are the following methods of correction of iridodialysis:
- Open. It is carried out using intraoperative access. It is used for severe injuries and contusions, accompanied by the need to remove a traumatic cataract, implantation of an intraocular lens or vitreoretinal intervention. This method is associated with the risk of synechiae formation, impaired regulation of intraocular pressure and the development of dystrophic changes in the cornea.
- Private. It is made through a small puncture. This technique is preferred with pronounced hyphema, hypotension of the eye or the presence of general contraindications to performing surgery. Often, the operation is performed in a closed way if iridodialysis was detected a few days after the injury or became an accidental diagnostic finding.
Prognosis and prevention
With timely surgical intervention, it is often possible to completely restore the structure and functions of the iris. With a defect length of more than 120 degrees along the circumference of the limb or delayed surgery, it is impossible to achieve a pupil reaction to light and normalize the process of accommodation. To prevent the spontaneous development of pathology, it is recommended to undergo an annual examination by an ophthalmologist. Specific preventive measures have not been developed. Non-specific prevention is reduced to the use of personal protective equipment (masks, glasses) when working in production.