Nonstrabismic binocular vision abnormalities_ inadequate collection

Nonstrabismic binocular vision abnormalities: inadequate collection

People want to see objects clearly, to be able to maintain binocular vision in any direction of gaze, at any distance, and to have a highly accurate and fully coordinated mechanism. When an object moves from a distance to a near place, in order to maintain the position of the object in the macula of the retina in both eyes, both eyes must be turned inward at the same time, so that the object image returns to the macula. Similarly, when an object is moving from near to far, both eyes must be turned outward at the same time, which is a convergence and divergence reaction. In the same way, people need to see objects at different distances, and they also need to focus according to the distance needs, that is, to perform knots, adjust the refractive power of the eye to see foreign objects clearly, and the adjustment is organically linked to the set. External objects at different distances have certain requirements for the vision system, and must achieve a certain collection and adjustment in order to maintain clear, comfortable and long-lasting vision. Strabismus is easy to diagnose and treat clinically because it destroys binocular monovision; Non-strabismus binocular abnormalities, insidious conditions, clinically due to various reasons resulting in abnormal collection function, abnormal accommodative function, and binocular fusion disorders, may make patients show symptoms such as visual fatigue, visual double vision, orbital tenderness, headache, font jumping, and diplopia in visual behavior. Detection and attention to non-strabismic binocular vision abnormalities, and active and effective treatment and training can reduce or eliminate the patient's eye discomfort symptoms. Convergence is an indispensable anisotropic movement function of binocular vision, in order to adjust the angle of sight between the two eyes to align with external objects, to achieve binocular monovision, so as to obtain optimal stereoscopic vision. Convergence insufficiency (CI) is a common binocular visual dysfunction, which reflects the disharmony between the need for near reading and the actual ability to use eyes. Patients may present with exotropia when they see near and emmetropia or exoheterosis with less amplitude than near vision when they see at a distance, with a low AC/A Lk rate, and symptoms can be very mild to very intense, which generally tends to occur in primary school students, college students or occupational groups with more eyes. Most patients with deficit collection may also have accommodative dysfunction, and many people have symptoms of deficit collection that become more and more obvious with the onset of presbyopia. Among all people with non-strabismus binocular abnormalities, collection deficiency is common and easy to attract attention, and the incidence of collection deficiency accounts for about 3%-5% of the total population. 1. Symptomatic patients will experience the following conditions after a period of continuous reading. 1. There is a sense of double vision and double vision when looking at near objects. 2. The font on the book flows and jumps. 3. Stretching and tension in the eyes. 4. Soreness of the eyeballs and inability to use the eyes. 5. Pain around the eyes after reading or using the computer. 6. Blurred vision and difficulty focusing during near vision. 7. Inability to concentrate. 8. You want to avoid reading up close as much as possible. 2. Signs 1. Enlargement of the convergence near point, generally greater than 6 cm, such as when placing red glass in front of the eye for the convergence near point test, diplopia will soon appear. 2. Exotropia occurs during nearsightedness, generally greater than 6~8△, and even intermittent exotropia occurs during nearsightedness. 3. When the horizontal heterogeneity is measured in the near use, the degree of external heterogeneity is greater than the degree of the occlusion test. 4. According to Sheard's rule, the reserve of aggregation and dispersion capacity should be twice the amount of concealment, so that the patient has no obvious complaining symptoms; However, in patients with insufficient convergence, the ability to converge and disperse is relatively low. The 5.AC/A value is low (4/1 normal). 6. The flexibility of adjustment is reduced, and it is difficult to eliminate blurred images when the positive lens is placed in front of both eyes. 7. Negative relativity regulation (NRA) decreases and positive relativity regulation (PRA) increases (under normal conditions, NRA is +2.50 and PRA is -3.50). 8. Accommodative dysfunction, patients may have a series of manifestations, and the flexibility and amplitude of monocular accommodation are abnormal. 3. Diagnosis 1. Ask about medical history: understand the patient's age, reading habits, symptom severity, triggers when symptoms occur, accompanying symptoms, alleviating factors, general conditions, etc. 2. General eye examination. 3. Refractive examination: If the patient has uncorrected refractive error, refractive correction will be performed first, and binocular vision function test will be performed on the basis of refractive correction. 4. It is necessary to understand the binocular vision situation when the vision is far away: to rule out excessive separation and exophoria, intermittent exotropia, etc. 5. Near binocular vision function measurement: This is the main basis for diagnosis, including occlusion test, near horizontal heterogram measurement, convergence near point measurement, AC/A, fusion convergence range, adjustment flexibility, adjustment amplitude measurement, etc. 6. Others: Diagnosis can be made according to the medical history and examination results that meet the above signs of collection insufficiency. 4. Differential diagnosis 1. Uncorrected refractive error Farsightedness, myopia, astigmatism, especially anisometropia in both eyes, will affect the effectiveness of reading. After identifying and correcting a refractive error that needs to be corrected, the patient's symptoms improved significantly. In addition, except for refractive error, the patient had no obvious abnormalities such as convergence proximity. 2. Pseudo-collection insufficiency The primary problem of the patient is insufficient accommodative function, and the collection insufficiency is a secondary factor. At this time, wearing positive lenses, after solving the lack of accommodative function, the symptoms of insufficient convergence will naturally improve, if there are still symptoms, further visual training and treatment must be carried out. 3. Exotropia Relatively large exotropia, the degree of distance and near vision is the same, and occasionally intermittent exotropia occurs. If there is intermittent exotropia and the patient has significant symptoms, vision therapy is necessary, and sometimes prism is worn to improve the symptoms. 4. Excessive separation: The patient presents with exotropia heterotropia and/or exotropia greater than that of near vision. 5.Convergence paralysis is a sudden onset, with normal function of inward conversion in one eye, normal motor function in the same direction of both eyes, and symptoms such as diplopia due to the inability of both eyes to converge only in near distance, and may be accompanied by some neurological symptoms in addition to ocular symptoms. 6. Hyperthyroidism: Due to extraocular muscle infiltration, edema and other factors, it causes eye muscle movement disorders, secondary collection function is insufficient, and patients may also have symptoms such as proptosis, eyelid insufficiency, diplopia, and blurred vision. 7. Vertical heterophoria Some vertical heterophoria, due to the imbalance of the vertical direction, can also lead to secondary binocular vision dysfunction, and patients with vertical heterophoria may have a compensated head position, which is helpful for identification. 5. Treatment and treatment 1. Refractive correction Although it is not the best method for insufficient collection, refractive correction can improve the effectiveness of vision and eliminate some symptoms. 2. Additional lenses If the lenses are corrected for reading, they can improve the symptoms of patients with inadequate accommodation. 3. Application of prisms The use of BI lenses can improve the patient's symptoms. 4. Training, such as propulsion training, Brock line method, etc., can change the convergence proxima and improve the symptoms of insufficient convergence.。