METHOD FOR RESTORING BIFOVEAL FUSION IN THE CASE OF ANISOMOTILITY

Abstract

The method relates to the field of ophthalmology and is intended for postoperative restoring bifoveal fusion in patients, inter alia in children, following concomitant esotropia surgery, with use of liquid crystal glasses. The technical effect of the invention is restoration of bifoveal fusion in accordance with individual ocular motility parameters, using anharmonical alternating of liquid crystal glasses. The technical effect is achieved by the approach during which for patients with a residual angle of deviation of less than 10 degrees after esotropia surgery, a duration of the fixative eye movement of the eyeball (t in ms) is determined for each eye using a Gazelab video eye tracking device produced by BCN Innova (Spain), a duration of occlusion is then calculated in ms for each eye, using the formula: t=40+U, where t is the duration of occlusion in ms; 40 is the minimum time required for visualization between alternations in ms; U is the duration of the fixative eye movement in ms, and the duration of occlusion is set for each eye on liquid crystal glasses that are worn for 6-8 hours a day during 6 to 12 months.

Claims

1. A method for restoring bifoveal fusion in the case of anisomotility of patients with a residual angle of deviation less than 10 degrees after esotropia surgery, the method comprising determining a duration of the refixation eyeball movement with the use of a video eye tracking device, characterized in that the duration of the fixative eye movement is determined for each eye in ms, a duration of occlusion is then calculated in ms for each eye, by the formula:
t=40+U, where t is the duration of occlusion (ms); 40 is the minimum time (ms) required for visualization between alternations; U is the duration of the fixative eye movement (ms), and the duration of occlusion is set for each eye on liquid crystal glasses that are worn for 6 to 8 hours a day during 6 to 12 months.

Description

[0016] Example 1. Patient K., 4 years old, after surgical treatment of congenital non-accommodative esotropia. The postsurgical angle of deviation was 4 degrees. The visual acuity in both the right and left eyes was 1.0. The postsurgical examination by a synoptophore has diagnosed absence of sensory fusion for the patient. The vision character assessed by the Worth 4-dot test at 5 meters was simultaneous. By video-oculography it has been found that the fixative eye movements of the right and left eye have the durations of 180 ms and 220 ms, respectively. Using the formula, the required duration of occlusion has been calculated at 220 and 260 ms for the right-eye and left-eye lenses of liquid crystal glasses, respectively. This duration has been set on the liquid crystal glasses. Wearing the liquid crystal glasses for 6 hours a day during 6 months has provided successful restoration of the sensory fusion as well as, by further diploptic treatment, of the binocular vision.

[0017] Example 2. Patient L., 22 years old, after surgical treatment of non-accommodative esotropia. The angle of deviation was 8 degrees. The visual acuity was 0.8 in the right eye after correction and 1.0 in the left eye. The postsurgical examination by a synoptophore has diagnosed absence of sensory fusion of the patient. The vision character assessed by the Worth 4-dot test at 5 meters was simultaneous. By video-oculography it has been found that the refixation movements of the right and left eyes have the durations of 160 ms and 230 ms, respectively. Using the formula, the required duration of occlusion has been calculated at 200 and 270 ms for the right-eye and left-eye lenses of liquid crystal glasses, respectively. This duration has been set on the liquid crystal glasses. Wearing the liquid crystal glasses for 8 hours a day during 12 months has provided successful restoration of the sensory fusion.

[0018] Example 3. Patient M., 3 years old, after surgical treatment of congenital non-accommodative esotropia. The postsurgical angle of deviation was 6 degrees. The visual acuity in both the right and left eyes was 0.8-1.0. The postsurgical examination by a synoptophore has diagnosed absence of sensory fusion of the patient. The vision character assessed by the Worth 4-dot test at 5 meters was simultaneous. By video-oculography it has been found that the refixation movements of the right and left eyes have the durations of 160 ms and 180 ms, respectively. Using the formula, the required duration of occlusion has been calculated at 200 and 220 ms for the right-eye and left-eye lenses of liquid crystal glasses, respectively. This duration has been set on the liquid crystal glasses. Wearing the liquid crystal glasses for 6 hours a day during 9 months has provided successful restoration of the sensory fusion as well as, after further diploptic treatment, of the binocular vision.