ABSTRACT
Photorefractive keratectomy for the correction of myopia was performed in 32 eyes of 16 green monkeys. The corneas healed satisfactorily, with normal formation of basal lamina and hemidesmosomal attachments visible in 14-week histologic specimens. No recurrent erosions were observed clinically. After a transient period of faint haze, all corneas were clear at 17 weeks and remained clear through the 1-year follow-up. In terms of accuracy, all corneas demonstrated a significant flattening compared with preoperative values, but no significant difference was seen between the groups with different intended corrections (1.5 and 3 diopters). The changes in corneal shape stabilized by 17 weeks, as measured by keratometry. The clinical results suggest that mechanical removal of the epithelium is preferable to laser ablation of the epithelium. Overall, the results demonstrate that excimer laser ablation of the corneal stroma can produce a stable diptric change in the primate cornea with good healing and long-term corneal clarity.
Subject(s)
Cornea/surgery , Laser Therapy , Myopia/surgery , Animals , Chlorocebus aethiops , Cornea/pathology , Epithelium/surgery , Follow-Up Studies , Random Allocation , Refraction, Ocular , Wound HealingABSTRACT
The excimer laser offers entirely new corneal surgery procedures. In this paper, we describe conditions for one such procedure, photorefractive keratectomy, the direct reshaping of the cornea's central optical zone using tissue ablation with far ultraviolet radiation. We present equations for the required tissue ablation to achieve required refractive corrections. Conditions for beam uniformity are presented and a method of achieving better beam uniformity using beam integration by rotation is demonstrated. The healing of rabbit corneas after area ablation was observed. Five days after treatment, the surface quality of deep cuts was very irregular; the shallow cuts produced more regular results, as predicted by our calculations of beam characteristics.
Subject(s)
Cornea/surgery , Laser Therapy/methods , Refractive Surgical Procedures , Animals , Cornea/physiology , Cornea/ultrastructure , Microscopy, Electron , Models, Theoretical , Rabbits , Wound HealingSubject(s)
Creatine Kinase/metabolism , Mitosis , Actins/physiology , Animals , Cell Line , Creatine/analogs & derivatives , Creatine/pharmacology , Creatine Kinase/antagonists & inhibitors , Creatine Kinase/immunology , Cytoskeleton/physiology , Fluorescent Antibody Technique , Microtubules/physiologyABSTRACT
Using an antibody specific for creatine phosphokinase (CPK), we have discovered an association between that enzyme and the cytoskeleton. Immunofluorescence observations show that CPK is associated with intermediate filaments in PTK cells and BALB/3T3 cells. The CPK distribution also follows intermediate filaments when cells are treated with colchicine.
