Ren David H, Yamamoto Kazuaki, Ladage Patrick M, Molai Michael, Li Ling, Petroll W Matthew, Jester James V, Cavanagh H Dwight
Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9057, USA.
Ophthalmology. 2002 Jan;109(1):27-39; discussion 39-40. doi: 10.1016/s0161-6420(01)00867-3.
To determine effects of lens type and oxygen transmissibility on human corneal epithelium during extended wear (EW).
Prospective, randomized, double-masked, single-center, parallel treatment groups, 1-year clinical trial.
One hundred seventy-eight patients completed the study: (1) high-O(2) soft lens (6-night [N] EW) (n = 27); (2) hyper-O(2) soft lens (6N-EW, n = 33) or (30N-EW, n = 66); and (3) hyper-O(2) rigid gas-permeable lens (RGP) (30N-EW, n = 52).
Irrigation chamber to collect exfoliated corneal surface cells, confocal microscopy, and tear collection at baseline, 1, 3, 6, 9, 12 months of EW.
(1) Pseudomonas aeruginosa (PA) binding to exfoliated corneal surface cells; (2) central epithelial thickness; (3) superficial epithelial cell area; (4) epithelial surface cell exfoliation; and (5) tear lactate dehydrogenase.
Quantitative evidence demonstrated increased binding of PA to human exfoliated corneal epithelial cells during the first 3 months of soft lens EW; the control high-O(2) test lens showed significantly higher bacterial binding (P < 0.05). Binding activity gradually decreased thereafter and returned to baseline after 9 and 12 months. The corneal epithelium demonstrated enlargement of surface cell size, thinning of central epithelium, and a significant decrease in surface cell shedding (P < 0.05). Remarkably, there was subsequent partial adaptive recovery in cell shedding and epithelial thickness but not surface cell size. There was no significant difference between 6N and 30N continuous wear of the hyper-O(2) soft lens for all outcome measures. Importantly, hyper-O(2) RGP lens wear did not show significantly increased PA binding during 1 year.
This study establishes three important new findings: (1) hyper-O(2) soft lens EW produces significantly less PA binding than the lower O(2) soft lens with no significant difference in PA binding with 6N versus 30N EW of the hyper-O(2) soft lens; (2) there is a remarkable adaptive recovery after 6 months with all soft lens wear with gradual return to prelens PA binding levels and partial recovery of other outcome measures for all test lenses EW except surface cell size; (3) 30N EW of the hyper-O(2) RGP lens produced no significant increases in PA binding over 1 year. Taken together, these results suggest that introduction of new hyper-O(2) transmissible lens materials into clinical use may offer safer EW, and future epidemiologic studies of ulcerative infectious keratitis should consider both lens type and time in lens EW in any incidence/risk analysis.
确定在长时间佩戴（EW）期间镜片类型和透氧性对人角膜上皮的影响。
前瞻性、随机、双盲、单中心、平行治疗组，为期1年的临床试验。
178名患者完成了该研究：（1）高氧软镜（6晚[N]EW）（n = 27）；（2）高氧软镜（6N - EW，n = 33）或（30N - EW，n = 66）；以及（3）高氧硬性透气性镜片（RGP）（30N - EW，n = 52）。
在EW的基线、1、3、6、9、12个月时，使用冲洗室收集角膜表面脱落细胞、共聚焦显微镜检查和泪液收集。
（1）铜绿假单胞菌（PA）与角膜表面脱落细胞的结合；（2）中央上皮厚度；（3）浅表上皮细胞面积；（4）上皮表面细胞脱落；以及（5）泪液乳酸脱氢酶。
定量证据表明，在软镜EW的前3个月期间，PA与人角膜上皮脱落细胞的结合增加；对照高氧测试镜片显示出显著更高的细菌结合（P < 0.05）。此后结合活性逐渐降低，并在9个月和12个月后恢复到基线水平。角膜上皮表现出表面细胞大小增大、中央上皮变薄以及表面细胞脱落显著减少（P < 0.05）。值得注意的是，随后细胞脱落和上皮厚度有部分适应性恢复，但表面细胞大小没有恢复。对于所有观察指标，高氧软镜6N和30N连续佩戴之间没有显著差异。重要的是，高氧RGP镜片佩戴1年期间PA结合没有显著增加。
本研究得出三个重要的新发现：（1）高氧软镜EW产生的PA结合明显少于低氧软镜，高氧软镜6N与30N EW的PA结合无显著差异；（2）所有软镜佩戴6个月后有显著的适应性恢复，逐渐恢复到镜片佩戴前的PA结合水平，除表面细胞大小外，所有测试镜片EW的其他观察指标有部分恢复；（3）高氧RGP镜片30N EW在1年期间PA结合没有显著增加。综上所述，这些结果表明，将新的高氧可透性镜片材料引入临床使用可能提供更安全的EW，并且未来关于溃疡性感染性角膜炎的流行病学研究在任何发病率/风险分析中都应考虑镜片类型和镜片EW时间。
