Liu Z, Pflugfelder S C
Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, People's Republic of China.
Ophthalmology. 1999 May;106(5):939-43. doi: 10.1016/S0161-6420(99)00513-8.
To evaluate corneal surface regularity and the effect of artificial tears on the regularity of the corneal surface in dry eye.
A prospective, clinic-based, case-control study.
A total of 64 eyes of 33 normal subjects and 42 eyes of 22 patients with aqueous tear deficiency were evaluated.
Indices of the TMS-1 corneal topography instrument (Tomey Technology, Cambridge, MA) were used to evaluate corneal surface regularity and potential visual acuity (PVA) in patients with aqueous tear deficiency dry eye before and after the instillation of artificial tears and in normal subjects. The TMS-1 topographic maps were classified into round, oval, symmetric bow-tie, asymmetric bow-tie, and irregular patterns.
The surface regularity index (SRI), surface asymmetry index (SAI), PVA index, and topographic pattern of the TMS-1 were compared between normal and dry eyes and in dry eyes before and after the instillation of artificial tears.
The SRI and SAI were significantly elevated and the PVA was significantly reduced in dry eye patients compared with normal subjects: 0.31+/-0.22, 0.30+/-0.16, and 20/17.89+/-20/3.04, respectively, in normal subjects and 1.28+/-0.73, 1.05+/-1.17, and 20/33.45+/-20/13.99, respectively, in patients with dry eye (P<0.001 for all indices). The average amount of astigmatism was also increased in dry eyes (2.10+/-1.96 prism diopters) compared with normal eyes (1.13+/-0.53 prism diopters, P = 0.02). In dry eyes, the SRI and SAI were positively correlated with corneal fluorescein staining scores (P = 0.005 for SRI and P = 0.016 for SAI). The mean PVA was not significantly different from the mean actual corrected visual acuity. The dry eyes had a significantly lower percentage of symmetric bow-tie patterns and a greater percentage of irregular patterns on topographic maps than normal eyes. After the instillation of artificial tears, the SRI, SAI, and mean astigmatism all decreased significantly (P<0.001 for SRI, P<0.002 for SAI, P = 0.04 for astigmatism) and the PVA improved (P<0.001) in dry eyes. An irregular topographic pattern was observed in 45.24% of dry eyes, and this decreased to 30.95% after the instillation of artificial tears (P<0.005).
Patients with aqueous deficiency have an irregular corneal surface that may contribute to their visual difficulties. The SRI and SAI could be used as objective diagnostic indices for dry eye as well as for evaluating the severity of this disease and the effect of artificial tears. Artificial tears have the secondary benefit of smoothing the corneal surface in dry eye.
评估角膜表面规则性以及人工泪液对干眼患者角膜表面规则性的影响。
一项前瞻性、基于临床的病例对照研究。
共评估了33名正常受试者的64只眼和22名水样泪液缺乏患者的42只眼。
使用TMS-1角膜地形图仪（多美技术公司，马萨诸塞州剑桥）的指标，评估水样泪液缺乏型干眼患者滴入人工泪液前后以及正常受试者的角膜表面规则性和潜在视力（PVA）。TMS-1地形图分为圆形、椭圆形、对称领结形、不对称领结形和不规则形。
比较正常眼和干眼之间以及干眼患者滴入人工泪液前后的TMS-1表面规则性指数（SRI）、表面不对称指数（SAI）、PVA指数和地形图类型。
与正常受试者相比，干眼患者的SRI和SAI显著升高，PVA显著降低：正常受试者的SRI、SAI和PVA分别为0.31±0.22、0.30±0.16和20/17.89±20/3.04，干眼患者分别为1.28±0.73、1.05±1.17和20/33.45±20/13.99（所有指标P<0.001）。干眼患者的平均散光量也比正常眼增加（2.10±1.96棱镜度）（正常眼为1.13±0.53棱镜度，P = 0.02）。在干眼患者中，SRI和SAI与角膜荧光素染色评分呈正相关（SRI的P = 0.005，SAI的P = 0.016）。平均PVA与平均实际矫正视力无显著差异。干眼患者地形图上对称领结形的比例显著低于正常眼，不规则形的比例高于正常眼。滴入人工泪液后，干眼患者的SRI、SAI和平均散光量均显著降低（SRI的P<0.001，SAI的P<0.002，散光的P = 0.04），PVA改善（P<0.001）。45.24%的干眼患者观察到不规则地形图类型，滴入人工泪液后降至30.95%（P<0.005）。
水样泪液缺乏患者的角膜表面不规则，这可能导致他们出现视力问题。SRI和SAI可作为干眼的客观诊断指标，也可用于评估该疾病的严重程度和人工泪液的效果。人工泪液对干眼患者具有使角膜表面变光滑的额外益处。
