病理性近视眼的黄斑形态和功能变化特征

Observation on morphology and function of macular in pathologic myopia

目的综合分析眼底检查、相干光断层扫描（OCT）、多焦视网膜电图（mERG）检查结果并了解病理性近视眼（PM）的黄斑形态和功能变化特征。方法系列病例报告。确诊且连续观察的病理性近视眼患者共31例（36只眼），按眼轴长度分为两组：A组10例（12只眼），眼轴长度≥30．00mm；B组21例（24只眼），眼轴长度〈30．00mm。对所有患者进行A、B超检查、显然验光，眼底检查，黄斑区OCT（包括黄斑区神经上皮层厚度分析）和mERG检查。应用SPSS11．5统计学软件进行数据分析。两组病理性近视眼的屈光度数、最佳矫正视力及mERG检测的黄斑中心（0°）、颞下、鼻下、鼻上象限P1波平均反应密度（Amp—P1）值的比较，采用独立样本t检验；OCT与眼底检查黄斑病变和后巩膜葡萄肿的阳性检出率比较，采用x^2检验；两组患者黄斑部1—9区视网膜神经上皮层厚度的比较，采用混合效应模型，以分组和区域作为固定效应，受试者作为随机效应；mERG检测的黄斑中心Amp—P1值、眼轴长度、最佳矫正视力及屈光度数间的相关性，采用多元相关分析及多元回归分析。以P〈0．05作为差异有统计学意义。结果A组：眼轴长度为（31．77±1．27）mm，屈光度数为（-22．92±7．10）D，矫正视力为（0．31±0．25）。B组：眼轴长度为（28．64±1．17）mm，屈光度数为（-14．03±5．37）D，矫正视力为（0．55±0．35）。两组间屈光度数（t=4．20，P〈0．01）和矫正视力（t=-2．28，P〈0．05）比较，差异均有统计学意义。OCT检查结果显示黄斑分区中1—5区视网膜神经上皮层厚度A组小于B组，差异有统计学意义（P=0．016，0．032，0．048，0．009，0．002）。两组mERG黄斑中心（0°）、鼻上、鼻下、颞上、颞下象限Amp—P1值差异有统计学意义（t=3．63，2．71，2．21，2．32，2．64；均P〈0．05）。相关分析结果显示mERG黄斑区Amp—P1值与眼轴呈负相关（r=-0．498，P〈0．01），与矫正视力呈正相关（r=0．468，P〈0．01）；眼轴长度与屈光度数呈正相关（r=0．800，P〈0．01），与矫正视力呈负相关（r=-0．605，P〈0．01）；屈光度数与矫正视力呈负相关（r=-0．616，P〈0．01）。结论病理性近视眼患者眼轴的延长、屈光度数的增加、眼底病变发生率的上升、矫正视力的下降、黄斑部视网膜神经上皮层的变薄，均可导致视功能逐渐下降。综合应用眼底检查、OCT检查、mERG检测能较早发现患者病变并监测病情进展。

Objective To observe the morphology and function of the macular in pathologic myopia by the combination of the fundus examination, optic coherence tomography and multifocal electroretinogram （mERG）. To analyze the relationships among macular function, ocular axis length, refraction and corrected visual acuity. Methods Case series including 36 eyes of 31 consecutive pathologic myopia cases, which were chosen from Tongren Eye Center from February to April 2006 and divided into two groups according to ocular axis length：group A, composed of 12 eyes from 10 cases （axis length ≥30. 00 mm） and group B, composed of 24 eyes from 21 cases （ 〈 30. 00 mm）. Manifest refraction, A and B scan, fundus examination, OCT scan for the macular area, the measurement of the thickness of the retinal neuroepithelial layer and mERG were carried out for each eyes. The results were further analyzed by comparing the ocular axis length, diopter of myopia, corrected visual acuity, results of the OCT study and mERG. Relationships among the macular function, ocular axis length, refraction and corrected visual acuity were also analyzed. Results The mean ocular axis length, diopter of myopia, corrected visual acuity of group A were （31.77 ± 1.27 ） mm, （ -22.92 ± 7. 10）D and（0. 31 ± 0. 25 ）, respectively. The mean ocular axis length, diopter of myopia, corrected visual acuity of group B were（28.64 ± 1.17） mm, （ - 14. 03 ±5.37）D,（0.55 ±0.35）, respectively. Statistically significant difference was shown between these two groups （ t = - 2.28, P 〈 0.05 ）. The thickness of neural retina of area 1 to 5 in group A was smaller than that of group B, and significant differences exists between these two groups（ P = 0. 016,0. 032,0. 048,0. 009,0. 002 ）. There were statistical differences in amplitude densities of P1 waves in central macular, super-temporal quadrants, super-nasal quadrants and infer-nasal quadrants between these two groups（ t = 3.63,2.71,2.21,2.32,2.64 ,P 〈 0.05）. Amplitude densities of P1 waves showed negative correlation to ocular axis length （ r = - 0. 498, P 〈 0. 01 ） and positive correlation to corrected visual acuity （r=-0. 468 ,P 〈 0. 01 ）. Ocular axis length showed positive correlation to diopter of myopia （ r = 0. 800, P 〈 0.01 ） and negative correlation to corrected visual acuity （ r = - 0. 605, P 〈 0.01 ）. Diopter of myopia was negatively correlated to corrected visual acuity （ r = - 0. 616, P 〈 0. 01 ）. Conclusions Visual function loss in pathologic myopia is correlated with the increase of diopter of myopia, decrease of corrected visual acuity, increased macular disease and decreased macular function and extensive elongation of ocular axis in pathologic myopia. A combination of fundus examination, OCT scan and mERG may contribute to the earlier detection and monitoring of progression of the macular abnormality. （ Chin J Ophthalmol,2008,44 ： 794-799 ）