Frucht-Pery J, Golan G, Hemo I, Zauberman H, Shapiro M
Department of Ophthalmology, Hadassah University Hospital, Jerusalem, Israel.
Graefes Arch Clin Exp Ophthalmol. 1995 Aug;233(8):532-4. doi: 10.1007/BF00183436.
The treatment of Pseudomonas keratitis has many limitations, and further investigation to identify more effective approaches is required. We therefore studied the possible contribution of the debridement effect of 193-nm excimer laser on Pseudomonas keratitis in rabbit eyes.
Pseudomonas keratitis was induced in 30 rabbit eyes by inflicting controlled central corneal scratches and applying a drop of Pseudomonas aeruginosa suspension. After 24 h, one cornea of each animal was photo-ablated (excimer laser: fluency 90 mJ/cm2, 10 Hz, 213 pulses), yielding 50 microns of tissue ablation, while the follow cornea served as control. Five groups of six animals each were formed and received: a subconjunctival injection of gentamicin 20 mg (group 1), topical 14 mg/ml gentamicin hourly (group 2) or every 2.5 h (group 3), or NaCl 0.9% hourly (group 4) for 8 h. In group 5, animals were sacrificed without additional treatment. After 9 h corneas were excised, homogenized, serially diluted, and plated on agar blood plates. The numbers of colony-forming units (CFU) per cornea were statistically evaluated (Mann-Whitney test).
In control eyes, a greater decrease of CFU was observed in group 2 than in group 3 (P = 0.03). In laser-ablated eyes, there was no difference in CFU between groups 2 and 3. Comparison of the excimer-treated and control eyes revealed a greater number of bacteria (CFU) in controls only in group 3 (P = 0.02).
Our study suggests that controlled debridement of cornea with excimer laser may improve the effect of topical antibiotics.
铜绿假单胞菌性角膜炎的治疗存在诸多局限，需要进一步研究以确定更有效的治疗方法。因此，我们研究了193纳米准分子激光的清创作用对兔眼铜绿假单胞菌性角膜炎可能产生的影响。
通过在30只兔眼的中央角膜进行可控划痕并滴加一滴铜绿假单胞菌悬液来诱导铜绿假单胞菌性角膜炎。24小时后，对每只动物的一只角膜进行光消融（准分子激光：能量密度90 mJ/cm²，频率10 Hz，213脉冲），造成50微米的组织消融，而另一只角膜作为对照。将动物分为五组，每组六只，分别接受：结膜下注射20毫克庆大霉素（第1组）、每小时局部应用14毫克/毫升庆大霉素（第2组）或每2.5小时局部应用一次（第3组），或每小时应用0.9%氯化钠溶液（第4组），持续8小时。第5组动物不进行额外治疗即处死。9小时后切除角膜，匀浆，连续稀释，接种于血琼脂平板上。对每只角膜的菌落形成单位（CFU）数量进行统计学评估（曼-惠特尼检验）。
在对照眼中，第2组的CFU下降幅度大于第3组（P = 0.03）。在激光消融眼中，第2组和第3组的CFU没有差异。准分子激光治疗组与对照组相比，仅在第3组中对照组的细菌（CFU）数量更多（P = 0.02）。
我们的研究表明，用准分子激光对角膜进行可控清创可能会提高局部抗生素的治疗效果。
