The Change of Multifocal Visual Evoked Potential in Unilateral Anisometropic Amblyopia before and after Occlusion Treatment

PURPOSE: To evaluate the change in multifocal visual evoked potential (mfVEP) in unilateral anisometropic amblyopia before and after occlusion treatment. METHODS: The mfVEP was performed using RETIscan(R) (Roland,Brandenburg, Germany) for patients with unilateral anisometropic amblyopia before and after occlusion treatment. Amplitude and latency values of mfVEP were analyzed according to the field divided by 6 rings or 4 sectors. RESULTS: The each amplitude of values of all 6 rings were not significantly different before treatment (p = 0.077) in amblyopic eyes. However, the value of ring 1 (p = 0.00) was significantly higher than the value of other rings after treatment. In fellow eyes, the values of ring 1 was consistently significantly higher than the value of other rings before (p = 0.014) and after (p = 0.049) occlusion treatment. Additionally, the amplitudes of ring 1 (p = 0.005) and ring 3 (p = 0.007) were significantly increased in amblyopic eyes after occlusion treatment. In fellow eyes, the values of all rings did not change significantly. The analysis of amplitudes with 4 sectors revealed no significant result. The analysis of latencies with 6 rings and 4 sectors revealed no significant result. CONCLUSIONS: The change in amplitude on the central field (ring 1) in amblyopic eyes can be a useful objective monitoring method observing the improvement progress in visual acuity.

The Change of Multifocal Visual Evoked Potential in Unilateral Anisometropic Amblyopia before and after Occlusion Treatment

PURPOSE: To evaluate the change in multifocal visual evoked potential (mfVEP) in unilateral anisometropic amblyopia before and after occlusion treatment. METHODS: The mfVEP was performed using RETIscan(R) (Roland,Brandenburg, Germany) for patients with unilateral anisometropic amblyopia before and after occlusion treatment. Amplitude and latency values of mfVEP were analyzed according to the field divided by 6 rings or 4 sectors. RESULTS: The each amplitude of values of all 6 rings were not significantly different before treatment (p = 0.077) in amblyopic eyes. However, the value of ring 1 (p = 0.00) was significantly higher than the value of other rings after treatment. In fellow eyes, the values of ring 1 was consistently significantly higher than the value of other rings before (p = 0.014) and after (p = 0.049) occlusion treatment. Additionally, the amplitudes of ring 1 (p = 0.005) and ring 3 (p = 0.007) were significantly increased in amblyopic eyes after occlusion treatment. In fellow eyes, the values of all rings did not change significantly. The analysis of amplitudes with 4 sectors revealed no significant result. The analysis of latencies with 6 rings and 4 sectors revealed no significant result. CONCLUSIONS: The change in amplitude on the central field (ring 1) in amblyopic eyes can be a useful objective monitoring method observing the improvement progress in visual acuity.

Outcomes of 6 Hour Part-time Occlusion Treatment Combined with Near Activities for Unilateral Amblyopia

PURPOSE: To evaluate the outcome of the part-time occlusion therapy with near activities in monocular amblyopic patients according to gender, age, severity of amblyopia, and the cause of amblyopia. METHODS: Fifty eight patients who were prescribed part-time occlusion therapy with near activity from July 1998 to October 2004, were included in this retrospective study. All patients were divided into groups by gender, age, severity of amblyopia, and the cause of amblyopia. Main outcome measures were best corrected visual acuity, line improvement, and success rate. RESULTS: At the end of patch therapy, visual acuity improved from baseline by an average of 3.2+/-2.5 lines (0.33+/-0.26 log MAR), and follow-up period was 19.71+/-14.61 months (1.62+/-1.20 years). At the last follow-up, visual acuity improved from baseline by an average of 3.7+/-2.4 lines (0.38+/-0.26 log MAR), and follow-up period was 37.41+/-25.83 months (3.08+/-2.12 years). The success rate was 86% (50 patients) at the end of patch therapy. In 44 patients out of 50 patients (88%), the visual acuity was maintained. While 43 patients out of 47 patients who were less than 7 years old (91%) achieved success, 7 patients out of 11 patients 7 years or older (64%) achieved success (p=0.035). CONCLUSIONS: Six-hour part-time occlusion treatment combined with near activities appears to be favorable in treating 58 children during follow-up of mean 3.08 years. The significant factor was the age at initial treatment.

Outcomes of 6 Hour Part-time Occlusion Treatment Combined with Near Activities for Unilateral Amblyopia

PURPOSE: To evaluate the outcome of the part-time occlusion therapy with near activities in monocular amblyopic patients according to gender, age, severity of amblyopia, and the cause of amblyopia. METHODS: Fifty eight patients who were prescribed part-time occlusion therapy with near activity from July 1998 to October 2004, were included in this retrospective study. All patients were divided into groups by gender, age, severity of amblyopia, and the cause of amblyopia. Main outcome measures were best corrected visual acuity, line improvement, and success rate. RESULTS: At the end of patch therapy, visual acuity improved from baseline by an average of 3.2+/-2.5 lines (0.33+/-0.26 log MAR), and follow-up period was 19.71+/-14.61 months (1.62+/-1.20 years). At the last follow-up, visual acuity improved from baseline by an average of 3.7+/-2.4 lines (0.38+/-0.26 log MAR), and follow-up period was 37.41+/-25.83 months (3.08+/-2.12 years). The success rate was 86% (50 patients) at the end of patch therapy. In 44 patients out of 50 patients (88%), the visual acuity was maintained. While 43 patients out of 47 patients who were less than 7 years old (91%) achieved success, 7 patients out of 11 patients 7 years or older (64%) achieved success (p=0.035). CONCLUSIONS: Six-hour part-time occlusion treatment combined with near activities appears to be favorable in treating 58 children during follow-up of mean 3.08 years. The significant factor was the age at initial treatment.

Evaluation of Factors Affecting the Outcome of Occlusion Treatment for Amblyopia

PURPOSE: To evaluate the factors affecting the outcome of occlusion treatment for amblyopia. METHODS: We analyzed 80 amblyopic patients who had been followed up more than 6 months after occlusion treatment according to the age at start of treatment, initial corrected visual acuity of amblyopic eye, difference of corrected visual acuity between two eyes, type of amblyopia, type of occlusion and patient compliance. RESULTS: Mean age was 6.01+/-1.76 (3~12) years at start of treatment and mean treatment period was 4.51+/-3.40 (2~12) months. Success of treatment was defined as optotype acuity of 0.5 or better in the amblyopic eye and less than one-line difference between the two eyes. The success rate was 74% (59/80) and the time for initial visual improvement was 1.57+/-0.77 months. The age at start of treatment did not correlate with the success rate and period of treatment. But the less the difference of corrected visual acuity between the two eyes and the greater the initial corrected visual acuity, the higher the success rate and the shorter the period of treatment. And the better the compliance, the higher the success rate. Aniosmetropic amblyopia and strabismic amblyopia had the higher success rate and shorter treatment of period than mixed type amblyopia. In anisometropic amblypia, hyperopic and astigmatic type had the shorter period of treatment than myopic type. In the group of the smaller difference in refractive error, the success rate was high and period of treatment was short. In strabismic amblyopia, exotropia had the higher success rate and shorter peroid of treatment than esotropia. But the prism diopter did not correlate with the success rate and period of treatment. CONCLUSIONS: For occlusion treatment of amblyopia, we must consider many factorsto establish the treatment plan and to predict the outcome of treatment.