Humans have the physiological function of dominant eye gaze, i.e., the dominant eye plays the main gaze role when binocular gaze is used.
The purpose of the masking method is to cover the dominant eye and force the amblyopic eye to gaze in order to eliminate the competitive inhibition of the dominant eye on the amblyopic eye.
The masking method can be divided into the complete masking method and the partial masking method. Complete masking method: refers to full-day masking, except for removal during sleep, to be covered on immediately after waking up. Partial masking method: refers to daily masking for several hours.
Specific methods are as follows.
1, monocular amblyopia, pay attention to follow the age principle:.
(1) Infant masking treatment: mainly used for the treatment of constant strabismus and monocular cataract post-operative lens-less eyes. Using alternate masking and de-masking of the healthy eye monocular partial masking method.
①＜3 months, the masking time of the healthy eye is 25% of the waking time.
②3-6 months, the masking time of the healthy eye is 50% of the waking time
③6-12 months, the masking time of the healthy eye is 75% of the waking time.
(2) Children after the age of 1 year: Covering the amblyopic eye by complete masking with alternate masking of both eyes can prevent the loss of vision in the dominant eye. This is because covering the amblyopic eye actively promotes the function of the dominant eye and also prevents the competitive inhibition of the amblyopic eye due to opening both eyes.
①At 1-2 years of age, the 3:1 principle is used, i.e., cover the healthy eye for 3 days and the amblyopic eye for 1 day, with weekly review.
②3-4 years old, the 4:1 principle was adopted, i.e., the healthy eye was covered for 4 days and the amblyopic eye was covered for 1 day, with biweekly review.
③≥5 years old, using the principle of 6:1, that is, covering the healthy eye for 6 days and covering the amblyopic eye for 1 day, with monthly re-examination.
④≥8 years old, the method of simply covering the healthy eye and not covering the amblyopic eye was used, i.e., the healthy eye was not removed from the coverage and reviewed half a month. If the visual acuity of the primary eye decreases.
Take a break first and adjust the glasses prescription of the primary eye appropriately to see if the vision is restored. Because the primary eye that was covered may not be able to adapt to the adequately corrected lens for a while after the sudden removal of the cover, resulting in a loss of vision.
If the vision still does not recover after the above measures, the recovery is based on the principle of 6:1, i.e., cover the healthy eye for 6 days, cover the amblyopic eye for 1 day, and review it monthly.
2. Complete masking method with alternate masking of both eyes is used for children with binocular amblyopia.
(1) According to the degree of unequal visual acuity, the masking ratio can be 5:2, 4:3, 3:3, etc.
(2) To follow the age principle: <5 years old, monocular masking ≤3 days; ≥5 years old, monocular masking ≤6 days.
3.In the amblyopia consolidation period and children who cannot cooperate with masking treatment, short masking can be used, i.e., 1-4 hours of masking per day.
4.Pay attention to the changes in visual acuity and the nature of gaze at the time of review.
5.Children undergoing masking treatment should receive care from doctors, parents, teachers, classmates and society to prevent certain psychological problems in order to facilitate the healthy physical and mental growth of children.