白化病儿童视功能特征及其评估方法的临床研究

Evaluation method and visual function of 84 children with albinism

目的 探讨白化病患儿视功能特征及其评估方法.方法 收集2015年2月至2021年5月在首都医科大学附属北京儿童医院眼科就诊的白化病患儿84例(168只眼)和健康儿童25例(50只眼)的病例资料.其中,男性71例(142只眼),女性38例(76只眼);年龄2~167个月,平均年龄(35.6±27.5)个月.按照疾病诊断,分为白化病组,健康儿童归为对照组.对患儿进行眼部常规检查、光学相干断层扫描(OCT)、单通道闪光视觉诱发电位(F-VEP)检测,并经基因检测判定基因突变类型.最佳矫正视力、F-VEP P2波潜伏期及振幅等数据以(x)±s表示,组间比较采用独立样本t检验;F-VEP指标与视力、发病时间及黄斑中心凹发育不良分级之间的相关性采用Pearson或者Spearman相关性分析.结果 白化病组患儿男性54例(108只眼),女性30例(60只眼);对照组儿童男性17例(34只眼),女性8例(16只眼),其差异无统计学意义(x2=0.12,P>0.05).白化病组和对照组儿童平均年龄分别为(39.05±32.20)个月和(32.20±22.70)个月,其差异无统计学意义(Z=-0.49,P>0.05).60例完成基因检测.其中,阴性者3例,占5.00%;皮肤型白化病(OCA)者48例,占80.00%;单纯眼型白化病(OA)者3例,占5.00%;HPS者6例,占10.00%.本研究患儿基因突变均为致病性变异.30例(60眼)白化病患儿完成视力检查,右眼、左眼及双眼的裸眼视力分别为(0.21±0.19)logMAR、(0.21± 0.20)logMAR及(0.21±0.19)logMAR;右眼、左眼及双眼的最佳矫正视力分别为(0.33±0.27)logMAR、(0.31±0.24)logMAR及(0.32±0.25)logMAR.矫正后视力均略有提高且与裸眼视力的差异均具有统计学意义(t=-3.77,-4.29,-5.64;P<0.05).60例(120只眼)白化病患儿完成屈光度检查,平均等效球镜为(+1.09±3.13)D.其中,散光57例(113只眼),平均等效球镜为(-2.37±1.19)D.68例(136只眼)白化病组和对照组患儿右眼及左眼F-VEP P2波的潜伏期分别为(118.25±37.39)ms及(117.63±32.33)ms 和(108.68±15.05)ms 及(111.89±17.61)ms,差异无统计学意义(t=1.24,0.84;P>0.05).白化病组和对照组患儿右眼及左眼的振幅分别为(17.39±9.08)uV及(15.55±8.75)uV和(17.39±9.08)uV及(15.55±8.75)uV.后者振幅大于前者,其差异有统计学意义(t=-2.13,-2.16;P<0.05).白化病患儿右眼与左眼的F-VEP P2波潜伏期差异无统计学意义(t=0.18,P>0.05).白化病患儿右眼与左眼振幅不对称,其差异有统计学意义(t=2.10,P<0.05).36例(72只眼)白化病患儿完成了 OCT检查,黄斑发育不良分级正常、1级、2级、3级及4级分别为2例(4只眼)、3例(6只眼)、6例(12只眼)、13例(25只眼)及13例(25只眼).黄斑发育不良分级与最佳矫正视力呈负相关性且有统计学意义(r=-0.60,P<0.05);与FVEP振幅呈负相关性具有统计学意义(r=-0.34,P<0.05).结论 白化病患儿OCA基因突变居多,双眼散光多见,视力损伤明显,矫正后可轻度改善.单通道F-VEP检测P2振幅的两眼间不对称,双眼矫正视力与F-VEP振幅呈正相关;白化病患儿的黄斑中心凹发育不良明显,且与F-VEP的振幅呈负相关.白化病患儿的视功能发育情况评估需要综合因素考量.

ObjectiveThe aim of this study is to evaluate the visual function of children with albinism.MethodsA total of 84 children with albinism (168 eyes) and 25 healthy children (50 eyes) who visited the ophthalmology department of Beijing Children′s Hospital affiliated with Capital Medical University from February 2015 to May 2021 were enrolled. There were 71 males (142 eyes) and 38 females (76 eyes) with an average age of (35.6±27.5) months (ranged from 2 to 167 months). According to disease diagnosis, children with albinism are classified as the albinism group, while healthy children are classified as the control group. The routine eye examinations, optical coherence tomography (OCT), and single channel flash visual evoked potential (F-VEP) testing on the affected child were performed, and the type of genetic mutation disease through genetic testing was determined. The best corrected visual acuity, F-VEP P2 wave latency, amplitude and other quantitative data are expressed as ±s, and compared by independent sample t-test for inter group. The correlation between F-VEP indicators and visual acuity, onset time, and grading of macular fovea dysplasia was used to analyze by Pearson or Spearman correlation analysisResultsThere were 54 males (108 eyes) and 30 females (60 eyes) in the albinism group, and 17 males (34 eyes) and 8 females (16 eyes) in the control group. The difference was not statistically significant difference between them(χ2=0.12, P>0.05). The average age of the albinism group and the control group were (39.05±32.20) months and (32.20±22.70) months, respectively. After rank sum test, the difference was not statistically significant (Z=-0.49, P>0.05). 60 cases completed genetic testing. Among them, there were 3 cases with negative, 48 cases of cutaneous albinism (OCA), 3 cases of simple ocular albinism (OA), 6 case of HPS, accounting for 5.00%, 80.00%, 5.00%, 10.00%, respectively. All genetic mutations in the patients in this study were pathogenic mutations. 30 cases (60 eyes) of children with albinism completed visual acuity examinations. The naked eye visual acuity of the right eye, left eye, and both eyes were (0.21±0.19)(logarithm of the minimum angle of resolution, logMAR), (0.21±0.20)logMAR, and (0.21±0.19)logMAR, respectively. The corrected visual acuity for the right eye, left eye, and both eyes were (0.33±0.27) logMAR, (0.31±0.24)logMAR, and (0.32±0.25)logMAR, respectively. After correction, the visual acuity slightly improved, and the differences compared to naked eye vision were statistically significant (t=-3.77, -4.29, -5.64;P<0.05). 60 children (120 eyes) with albinism completed refractive tests, with an average spherical equivalent of (+ 1.09±3.13)D. Among them, 57 cases (113 eyes) had astigmatism, with an average spherical equivalent of (-2.37±1.19)D. 16 children (32 eyes) in the normal control group completed visual acuity examinations, and the average visual acuity in the right eye was (0.80±0.20)logMAR. The average visual acuity of the left eye was (0.83±0.18)logMAR. The latent periods of the right and left eyes of 68 children with albinism (136 eyes) were (118.25±37.39)ms and (117.63±32.33)ms, respectively. The incubation periods of the right and left eyes in the control group were (108.68±15.05)ms and (111.89±17.61)ms, respectively, and there was no statistically significant difference between them (t=1.24, 0.84;P>0.05). The amplitudes of the right and left eyes of children with albinism are (17.39±9.08)uV and (15.55±8.75)uV, respectively. The amplitudes of the right and left eyes in the control group were (17.39±9.08)uV and (15.55±8.75)uV, respectively. The amplitude of the control group was greater than that of the albinism group, with statistical significance (t=-2.1, P<0.05). 36 patients (72 eyes) completed OCT examination. The grading of macular dysplasia was normal, with 2 cases (4 eyes), 3 cases (6 eyes), 6 cases (12 eyes), 13 cases (25 eyes), and 13 cases (25 eyes), respectively. There is a negative correlation between the grading of macular dysplasia and corrected visual acuity, with statistical significance (r=-0.60, P<0.05), and a negative correlation with FVEP amplitude, with statistical significance (r=-0.34, P<0.05).ConclusionsAmong 84 children with albinism, OCA is more common, astigmatism is more common in both eyes, and visual impairment is significant. After correction, mild improvement can be achieved. The abnormal manifestation of using single channel F-VEP is mainly the asymmetry between the two eyes during the P2 amplitude. The corrected visual acuity of both eyes is positively correlated with the amplitude of F-VEP. Patients with albinism have significantly underdeveloped macular fovea, which is negatively correlated with the amplitude of F-VEP. The evaluation of visual function development in children with albinism requires comprehensive consideration of factors.