Corneal Epithelium Pathological Changes Of Wear Long-Term Soft Contact Lens

ObjectiveComparison the patient's pathological change of wear long-term corneal soft contact lens and never wear soft contact lens, both within the unit area of corneal epithelial tissue cells, epithelial thickness, cell morphology and PCNA. To investigate the effects of wear long-term soft contact lens on corneal, so as to provide effective treatment method for clinical.Methods1.Select patients:Choose 33 cases wear soft contact lens longer than three years patients as experiment group and never wear soft contact lenses patients 33 cases as control group.2. Test group:(1) Experimental groups1 Experimental group A of wear soft contact lens longer than three years 60 eyes of 30 patients, including male 13 cases of 26 eyes and female 17 cases with 34 eyes, age 18-41 years, mean 27.38±5.66 years,.2) Experimental group B of wear soft contact lens longer than three years 6 eyes of 3 patients including male 1 case with 2 eyes and female 2 cases with 4 eyes.(2) Control groups1) Control group A never wear contact lens 60 eyes of 30 patients, were male 15 cases of 30 eyes and female 15 cases with 30 eyes, aged 18-40 years, mean 26.87±6.73 years.2) Control group B never wear soft contact lens 6 eyes of 3 patients. including male 2 cases with 4 eyes and female 1 case with 2 eyes no significant differences between the two groups.3. Production of specimen:In the excimer Flap-free Epi-LASIK surgery, the use of Epi-K knife to remove the flap on the glass 4. Detection (group A patients):(1) Thickness:The corneal flap started, flat on the glass, using the ultrasonic method measuring its thickness.(2) basal cell count:1) after HE staining, fixation, dehydration, transparent, the observed changes in the number of basal cells under microscope.2) Fresh corneal flap by Wright's stain, to observe the changes in the number of basal cells under microscope.5. Pathological (group B patients):1)Take corneal flap, after fixation, dehydration, transparent, embedded, sliced. HE staining, fixed, dehydrated, transparent under the pathological microscope to observe the corneal flap's and cell morphology change.2)The corneal flap after Immunohistochemistry technique to measure Proliferating Cell Nuclear Antigen(PCNA). Results1. In vitro by ultrasound measurement of corneal flap thickness, long-wear soft contact lens corneal epithelium, corneal thickness was 55.33±4.56μm; control group, the thickness of corneal epithelium 57.19±3.82μm, a significant difference between the two, there were statistically significant (p<0.05).2. Under microscope corneal flap in vitro observation of corneal epithelium basal cells and found that long-term soft contact lens wearing cornea group, reduce the number of basal epithelial cells, to 3872.57±153.16 cells/mm2; control group, the number of basal epithelial cells cells 3989.18±289.58/mm2, significant differences between the two, there were statistically significant (p <0.01).3. Morphological changes by comparison, those who wear long-term soft contact lens thick basement membrane, relatively rough, cells loosely arranged and less structured morphology.4. Positive cells of PCNA can be found in the long-wear soft contact lens corneal epithelium basal cells5. With Epi-K to remove the epithelial flap basal cell integrity, the interface is smooth, there is no stromal cell.Conclusion1. Long-term wear soft contact lens can cause corneal epithelial damage, so that the thickness of corneal epithelial thinning; density of corneal epithelium basal cells decreased; make corneal epithelial changes in the organizational structure of pathology, the connection between cells and basement membrane destruction, the shape of corneal epithelium basal cells changed, Positive cells of PCNA existing.2. Epi-K epithelial knife detach a complete corneal flap, there is neither residual epithelial cells, it will not damage before the elastic layer, but will not damage the substrate layer, can be retained to prepare a smooth surface for excimer laser ablation. Confirmed the Epi-K epithelial surface of the cutting knife in excimer laser surgery has its own unique advantages.