Secondary cataract is a complication after cataract extraction characterized by secondary closure of the posterior capsulorexis area by connective tissue. Clinically, the disease is manifested by a progressive decrease in visual acuity, deterioration of color perception, violation of dark adaptation, diplopia, “blurring” of vision. To confirm the diagnosis, visometry, biomicroscopy of the eye, ultrasound, OPT are performed. Additionally, laboratory diagnostics are carried out. To eliminate the clinical symptoms of secondary cataract, an automated aspiration-irrigation system or a laser dissection method is used.
H26.4 Secondary cataract
Secondary cataract is the most common complication of surgical interventions performed in connection with all types of cataracts. According to statistics, the frequency of development ranges from 0.5 to 95%. The wide range of data is due to the use of different surgical techniques, the age of patients and the presence of concomitant diseases. Ophthalmopathology is equally common among men and women. An increase in the titer of anti-crustal antibodies in pediatric patients correlates with a 75% risk of secondary cataract formation after extraction or phacoemulsification. There is no information about geographical or seasonal features.
This disease occurs several months or years after surgery and is manifested by fibrous changes in the posterior capsule of the lens. Etiopathogenesis has not been studied enough. The main causes are:
- Fibrosis of the posterior capsule. The development of fibrosis is preceded by inflammatory processes in the surrounding tissue, so the risk factors for secondary cataracts are uveitis and metabolic disorders (diabetes mellitus).
- Migration of hyperplastic epithelial cells. The reason for the formation of spherical Adamyuk-Elschnig cell conglomerates in the epithelium of the lens capsule is excessive regeneration of the epithelium after cataract extraction.
- Incorrect implantation of IOL. Secondary cataract develops more often with the introduction of an anterior chamber IOL, exceeding the diameter of its optical part (more than 7 mm) or fixing the lens in the area of the ciliary furrow.
The development of secondary cataracts is based on inflammatory processes that potentiate the synthesis of mediators and promote their penetration through the hematophthalmic barrier. In response to the formation of inflammatory mediators, cellular proliferation increases. Pro-inflammatory cytokines and a number of extracellular proteins act as growth factors. Against the background of the pathological course of the postoperative period and reduced resistance of the body, there is an increased risk of activation of infectious agents. This entails excessive stimulation of reparative processes and synthesis of connective tissue in the posterior capsule area. Fibrous transformation is immune-dependent. The response to the synthesis of lens antigens is the formation of a tissue-specific immune response.
According to another pathogenetic theory, the formation of a secondary cataract film is an adaptive reaction of the eyeball to the implantation of an intraocular lens (IOL). When the lens is inserted, the monocyte-macrophage system is activated, since the body perceives the implant as a foreign body. The deposition of fibroblasts on the surface of the IOL subsequently leads to the formation of a dense connective tissue shell. Intraoperative damage to the iris stimulates an additional transition of pigment cells to the lens area. Cell components (mostly protein) play a role in the formation of the prelental membrane and turbidity of the posterior capsule.
The classification is based on the cellular composition of the film and its effect on the clinical course of the disease. From a morphological point of view, the following forms of secondary cataract are distinguished in ophthalmology:
Fibrous. Characterized by fibrous transformation of the posterior capsule. Connective tissue elements predominate in the cellular composition of the film. The fibrotic type is diagnosed in the first 3 months after the onset of the pathology.
Proliferative. In this variant of the disease, specific cells are detected-Adamyuk-Elschnig balls, Semmering rings, which indicates a prolonged course of the disease (3 or more months).
Thickening of the lens capsule. According to the classification, this is a separate nosological type, since, unlike other variants, the thickening of the capsule is not accompanied by a loss of its transparency. It is rarely diagnosed, the etiology and pathogenesis have not been established.
For a long period of time, the main complaint of patients is a progressive decrease in visual acuity that occurred in the postoperative period. After the restoration of normal visual acuity, the increasing visual dysfunction cannot be eliminated using classical correction methods. The violation manifests itself both when looking into the distance and up close. The progression of pathology leads to a disorder of dark adaptation, a decrease in contrast sensitivity, less often a deterioration in color perception (a decrease in the brightness of the image in front of the eyes).
Patients note increased fatigue when performing visual work. Asthenopic complaints are not accompanied by pain syndrome. Frequent signs of pathology are double vision, distortion of the shape of objects. These manifestations are caused by a violation of binocular vision. The appearance of a “veil” or “fog” in front of the eyes is characteristic. It is not possible to eliminate the symptoms by using contact lenses or glasses. There may be glare, flashes or colored halos around the light source. There are no visual changes on the part of the visual organ. The first symptoms develop no earlier than 3 months after surgery.
Prolonged course of secondary cataract leads to irreversible loss of vision, which is not amenable to classical methods of correction. Intraoperative corneal damage not only complicates the course of the underlying pathology, but is also associated with a high probability of the development of disperse syndrome and pigmented glaucoma. The inflammatory process underlying the pathogenesis of the disease often provokes the development of uveitis, scleritis, endophthalmitis. The proliferative type of secondary cataract and the thickening of the lens capsule stimulate an increase in intraocular pressure, which is manifested by the clinic of ophthalmic hypertension.
Secondary cataract is a difficult to diagnose pathology, for the detection of which a complex of instrumental and laboratory research methods is used. Ophthalmological examination includes:
- Visometry. The technique allows you to determine the degree of visual acuity reduction with and without correction.
- Biomicroscopy of the eye. The procedure is used to visualize the opacity of optical media, degenerative-dystrophic changes in the anterior part of the eyes.
- Ultrasound of the eye in A- and B-modes. The method makes it possible to evaluate the anatomical and physiological features of the structure of the organ of vision, the position of the IOL.
- Optical coherence tomography (OCT). The technique is used for additional study of the topography of the eyeball and intraorbital structures. Examination is indicated to identify pathological changes in the posterior chamber (dense connective tissue film and accumulation of Semmering rings, Adamyuk-Elschnig cellular elements).
- Instrumental diagnostics is informative only with pronounced changes in the lens capsule. Laboratory methods are used in the early stages or to predict the risk of nosology. Additionally , with secondary cataract , it is shown:
- Measurement of the level of anti-inflammatory cytokines. The study is carried out by hybridization and immunofluorescence. The determination of an elevated cytokine titer in the blood serum correlates with the severity of inflammation at the postoperative stage.
- Investigation of the titer of antibodies to the lens. An increase in the titer of antibodies in the blood or lacrimal fluid is associated with a high risk of secondary cataract formation.
- Cytological examination of the film. The detection of Adamyuk-Elschnig cells and Semmering rings is possible no earlier than 90 days after the initial surgical exposure, indicating a long course of the disease.
Timely therapeutic measures make it possible to completely eliminate the clinical manifestations of pathology and restore visual functions. Conservative therapy has not been developed. The following surgical methods of treatment are used:
Laser dissection of secondary cataract. The technique of laser capsulotomy is reduced to the application of small perforations, followed by the complete removal of connective tissue growths. Surgical intervention is performed under regional anesthesia and does not limit the patient’s ability to work.
Cataract removal using an aspiration-irrigation system. Automated bimanual aspiration-irrigation technique allows to remove the proliferating lens epithelium by forming two paracentesis in the cornea, the introduction of viscoelastic and mobilization of IOL. Additionally, capsule ring implantation or capsulorexis can be performed under an intraocular lens.
Prognosis and prevention
The prognosis for the timely diagnosis and treatment of secondary cataracts is favorable for life and work capacity. The lack of adequate therapy is the cause of frequent relapses, in the future irreversible loss of visual functions is possible. Surgical prevention is reduced to an individual approach to the choice of the model, material and design of the edge of the intraocular lens, taking into account the anatomical and physiological features of the structure of the eye. Drug preventive measures require local and oral administration of nonsteroidal anti-inflammatory drugs and glucocorticosteroids in the pre- and postoperative period. Modern trends in the prevention of secondary cataracts involve the use of photodynamic therapy and monoclonal antibodies to lens epithelial cells.