GDxVCC系统检测视网膜神经纤维层在青光眼早期诊断中的价值

Retinal nerve fiber layer examined by GDxVCC in early diagnosis of glaucoma

目的比较正常人和不同程度青光眼患者GDxVCC系统检测RNFL参数的不同，评价GDx各参数的敏感性、特异性，探讨GDxVCC系统检测视网膜神经纤维层在青光眼早期诊断中的价值。方法对35例（35只眼）原发性开角型青光眼、33例（33只眼）慢性闭角型青光眼、27例（27只眼）急性闭角型青光眼以及年龄相匹配的36人（36只眼）正常人进行GDxVCC系统和静态视野检查。GDxVCC系统检查，视盘周围视网膜神经纤维层（retinalnervefiberlayer，RNFL）任一参数与系统内所附中国正常人数据库对比概率〈5％或NFI〉30或视网膜神经纤维标准偏差图上连续有10个超级像素概率〈5％定义为具有青光眼性视网膜神经纤维层结构损害，并判断为青光眼。结果22只正常眼被判断为非青光眼（61．1％），82只青光眼被判断为青光眼（86．3％），RNFL参数椭圆平均值、上方平均值、下方平均值、TSNIT标准偏差、神经纤维指数，标准偏差图诊断青光眼的敏感性分别为48．4％、56．8％、48．4％、50．5％、62．1％，特异性分别为97．2％、100％、97．2％、94．4％、97．2％、61．1％。GDxVCC系统诊断早期、中期、晚期青光眼的敏感性分别为77．36％、95．83％、100％。结论GDxVCC系统诊断早期青光眼的敏感性和特异性均高，而且RNFL参数中神经纤维指数的敏感性最高。

Objective To evaluate the usefulness of the scanning laser polarimeter with variable corneal compensation （GDxVCC） for glaucoma detection in a Chinese population, and to investigate the retinal nerve fiber layer （RNFL） thickness difference between normal subjects and glaucoma patients. Methods Thirty-six eyes of 36 normal subjects, 33 eyes of 33 primary chronic angle-closure glaucoma patients, 27 eyes of 27 primary acute angle-closure glaucoma and 35 eyes of 35 primary open-angle glaucoma patients were studied. The glaucoma patients were age-matched with the normal. The thickness of retinal nerve fiber layer was measured with GDxVCC. An eye was diagnosed as glaucoma, if one of the parameters showed P 〈0.05 on the results of the examination reports including four TSNIT parameters （the average of TSNIT, superior, inferi- or, and TSNIT Std. Dev.）, nerve fiber indicator （NFI）〉30, and at least 10 consecutive defects of superpels showed in deviation map （P 〈0.05）. Results Of 22 normal eyes （61.1%） were diagnosed as non-glaucoma and 82 glaucomatous eyes （86.3%） were diagnosed as glaucoma by GDxVCC. Sensitivity of the average of TSNIT, superior, inferior, TSNIT Std. Dev., NFI and the deviation map were 48.4%, 56.8%, 48.4%, 50.5%, 62.1% respectively and specificity were 97.2%, 100%, 97.2%, 94.4%, 97.2% and 61.1% respectively. Sensitivity of detection early, moderate and progression glaucoma by GDxVCC were 77.36%, 95.83%, 100% respectively. Conclusions GDxVCC is a valuable technology to detect retinal nerve fiber layer defect in early glaucoma. It is shown that ttie NFI has highest sensitivity.