屈光参差性弱视儿童治疗后双眼视觉输入平衡分析

Analysis of balance of binocular vision after successful treatment in anisometropia amblyopic children

目的探讨轻、中度屈光参差性弱视儿童经屈光矫正合并遮盖治疗弱视眼的视锐度恢复到相应正常水平后,双眼视觉输入是否达到平衡状态。方法选择成功治疗半年以上,视锐度恢复到相对稳定状态的轻、中度屈光参差性弱视儿童为弱视治疗组(n=15)。正常对照组选择相应年龄段的正常儿童(n=15)。受试者配戴立体眼镜,通过阈上双眼相位结合的方法对其进行双眼相互作用的检测。所有试验信息由计算机系统自动记录,最终进行模型分析得到双眼的有效对比度比,将其作为评价双眼视觉输入平衡的主要指标。结果弱视治疗组治疗后弱眼和强眼的视锐度分别为(-0.02±0.06)log MAR和(-0.05±0.05)log MAR,弱视治疗后双眼的视锐度差异无统计学意义(P>0.05)。与正常对照组相比,经屈光矫正合并遮盖治疗后,虽然屈光参差性弱视儿童弱眼的视锐度得到了较好的恢复,但是其双眼视觉输入依然不平衡。弱视治疗组弱眼的有效对比度比为0.27±0.09,正常对照组的有效对比度比为(0.95±0.07)。与正常对照组相比,弱视治疗组弱眼的平均有效对比度比降低了72%,差异有显著统计学意义(P<0.001)。结论经屈光矫正合并遮盖治疗视锐度恢复正常后的轻、中度屈光参差性弱视儿童,双眼输入的信号强度依然是不平衡的,双眼视觉功能依然存在缺陷。这种双眼输入信号强度的不平衡可能是儿童弱视易复发的一个潜在因素。

Objective To explore whether the binocular visual inputs are balance of mild o r m o derate aniso m etro pic am blyo pia children,who have been received the treatm ents o f co rrect refractive and o cclusio n,and who se visual acuities are recuperated to their co rrespo nding no rm al levels. Metho ds Mild o r m o derate aniso m etro pic am blyo pia children（ n = 15）w ho have been received the successful treatm ents fo r m o re than 6 m o nths and no rm al co ntro l children with co rrespo nding age（ n = 15） were cho sen. Subjects perceived the phase o f a cyclo pean sine wave thro ugh wearing a stereo glasses,and the balances o f their bino cular visual inputs were determ ined by the m etho d o f suprathresho ld bino cular sum m atio n. All experim ental info rm atio n was auto m atically reco rded by the co m puter system. Effective co ntrast ratio between the two eyes was determ ined by analysis phase info rm atio n o f baseline po sitio n,and was taken as the m ain indicato r o f bino cular visio n input balance. Results In the treatm ent gro up,the m ean value o f best co rrected visual acuities o f wake eye and stro ng eyes were（- 0. 02 ± 0. 06） log MARand（- 0. 05 ± 0. 05） log MAR,respectively,there was no significant difference between these two eyes（ P 〉 0. 05）. Co m pared with the co ntro l gro up,altho ugh the visual acuities o f aniso m etro pia am blyo pia children after treatm ent o f co rrect refractive and o cclusio n therapies were go tten a go o d reco very,their bino cular visual inputs were still im balance. The m ean effective co ntrast ratio o f am blyo pic eyes was 0. 27 ± 0. 09 and that o f the no rm al gro up was 0. 95 ± 0. 07. Co m pared with the no rm al co ntro l gro up,the m ean effective co ntrast ratio o f am blyo pic eyes was dro pped by abo ut 72 %,there was significant difference between these two gro ups（ P 〈 0. 001）. Conclusion Although the visual acuity of children who received treatment of correct refractive and occlusion therapies is recovery,the strength of binocular visual signal input is still imbalance and binocular visual function is still flaw ed. This binocular imbalance may be a potential factor for easy relapse of amblyopia.