Szentmáry Nóra, Seitz Berthold, Langenbucher Achim, Schlötzer-Schrehardt Ursula, Hofmann-Rummelt Carmen, Naumann Gottfried O H
1st Department of Ophthalmology, Semmelweis University, Budapest, Hungary.
Cornea. 2006 Apr;25(3):257-63. doi: 10.1097/01.ico.0000176603.87376.d8.
The histologic changes after phototherapeutic keratectomy (PTK) in corneas with granular and macular dystrophy were studied.
We studied 3 corneas of 2 patients (1 granular, 2 macular dystrophy), who underwent penetrating keratoplasty (PK) at 0.8, 2.16, and 3.25 years after PTK; and 11 corneas (controls) from 10 PK patients (5 granular, 6 macular dystrophy) by light microscopy and by transmission electron microscopy. PTK was performed by using the Asclepion-Meditec MEL 60 excimer laser.
After PTK the epithelium (15-40 versus 5-100 microm), and the upper stromal collagen lamella thickness (50-75 versus 50-100 microm) were less irregular than for the controls. In 1 eye (macular dystrophy) 10 months after PTK an acid mucopolysaccharide-positive band was detected in the subepithelial stroma, which could be removed by hyaluronic acid digestion. This fact suggests that it was "haze" formed after PTK, rather than a subepithelial recurrence of the dystrophy. All PTK corneas had deposits in the mid- and posterior stroma. Concerning controls, deposits were detected under the epithelium in all corneas. Electron microscopy of the study corneas revealed a mostly continuous basal lamina, occasionally forming projections into the subepithelial stroma, and large numbers of well-developed hemidesmosomes (5.2 +/- 0.8 per microm membrane length) present at greater density than in the controls (3.5 +/- 0.8).
In stromal dystrophies, PTK was effective in removing large subepithelial stromal plaques. There were no subepithelial recurrences, and hemidesmosome density was increased.
研究光治疗性角膜切削术（PTK）后颗粒状和斑状角膜营养不良角膜的组织学变化。
我们研究了2例患者的3只角膜（1只颗粒状、2只斑状角膜营养不良），这些患者在PTK术后0.8、2.16和3.25年接受了穿透性角膜移植术（PK）；并通过光学显微镜和透射电子显微镜研究了10例PK患者（5只颗粒状、6只斑状角膜营养不良）的11只角膜（对照）。PTK使用Asclepion-Meditec MEL 60准分子激光进行。
PTK术后，上皮层（15 - 40微米对5 - 100微米）和浅层基质胶原板层厚度（50 - 75微米对50 - 100微米）比对照更规则。在PTK术后10个月的1只眼中（斑状角膜营养不良），在角膜上皮下基质中检测到一条酸性粘多糖阳性带，可通过透明质酸消化去除。这一事实表明它是PTK术后形成的“雾状混浊”，而非角膜营养不良的上皮下复发。所有PTK角膜在基质中部和后部均有沉积物。关于对照，所有角膜在角膜上皮下均检测到沉积物。研究角膜的电子显微镜检查显示，基底膜大多连续，偶尔向角膜上皮下基质形成突起，且大量发育良好的半桥粒（每微米膜长度5.2±0.8个）的密度高于对照（3.5±0.8个）。
在基质性角膜营养不良中，PTK有效地去除了大的角膜上皮下基质斑块。没有上皮下复发，且半桥粒密度增加。
