| After phacoemulsification of the lens,intraocular lens implantation for treatment of cataract has the characteristics of small incision,rapid healing,rapid visual recovery and optimistic prognosis.It is the first choice for medical treatment,and has been widely used in human medicine.In the present experiment,a canine cataract model was established by using the oxidative damage protocol,followed by fragmentation the lens with phacoemulsification method.The clinical effects of rigid J-IOL implantation and folding IOL implantation were compared by observation of the Diff-Quik staining of aqueous,postoperative corneal tissue sections and measurement of intraocular pressure,peripheral blood parameters and gene expressions of IL-6,TNF-a and TGF-?1 in iris and ciliary body.The test report is as follows:Thirty-six healthy Beagle dogs,aged 8 months to 1.5 years,weighing 4 to 8 kg,were selected for the study.Twelve dogs were used as oxidative injury cataract models and were divided into control group(group A)and test group(group B)with 6 dogs each.In test group,0.2mL of the mold solution contained in a 1mL syringe,was infected into the lens cortex at the first day.The insertion point was between 9 to 12 o'clock directions along the limbus,caution should be taken to avoid the iris.The needle point advanced through the anterior lens capsule and move forward 2?3 mm within the lens cortex.After injection of the mold solution,the needle should be kept in place for 3 min before withdrawal.Then the sterile cotton swab was pressed on the needle point for 1 min.The dogs in group A were subjected to the same treatment as in group B,but the mold solution was replaced by saline.The injections of the saline of mold solution were repeated three times on the 3 rd and 6th day.From day 1 to day 3?the twelve dogs were treated with both diclofenac sodium dyedrops and norfloxacin eyedrops,three times a day.At day 7,14 and 21,the slit lamp was used to observe and evaluate the transparency of the lens.The blood routine examination and intraocular pressure measurement were performed at the same time points.At day 14 and 28,the eyeballs were collected for observation.The aqueous humor was stained by Diff-Quik.The lens was observed for histopathological changes.As a result,at day 7,the depth of the anterior chamber of dogs in both groups became shallow under the slit lamp.The corneal transparency was normal.No obvious color abnormality of the lens was found.Compared with group A,there were black spots on the anterior capsular of the dogs in group B.On day 14,21 and 28,no significant change was found in the lens of group A compared with the 7th day.In group B,there were white patches at the center of the lens,and radial wedge turbidity and gradual fusion in the cortical area.Histological observation showed that on day 14,the injury of the capsular membrane and the cortical rupture were observed in both groups at injection points.On day 28,the cortical area was still damaged,whereas the anterior capsule was healed at the needle point in group A.In group B,the lens epithelial cells(LECs)were disordered irregularly and loosely in morphology with pale cytoplasm.A large number of vacuoles were found in the lens cortex.In both groups,the WBC in peripheral blood was normal,and no WBC in aqueous humor.The intraocular pressures of both groups were lower than normal at day 7,and then returned to normal values at day 14,21 and 28.Twenty-four canine oxidatively injurious cataract model were made and randomly divided into two groups(group C and group D)the 12 dogs in each group.In group C,the lens of the dogs were broken up by phacoemulsification,followed by implantation of hard artificial lens.The lens of dogs in group D were broken up by phacoemulsification,which was the same as group C,but followed by implantation of folded IOLs.The position of the intraocular lens and the ocular surface were observed by slit lamps on the day 7,14,21,28,35.Routine blood tests,intraocular pressure measurements and visual assessment were performed at the same time points.Eyeballs were collected on the day 14 and 35.The observation of Diff-Quik staining of aqueous and the histopathology of cornea,as well as the gene expression analysis of IL-6,TNF-?,and TGF-?1 in the iris and ciliary body were performed.The results were as follows:(1)Slit lamp observation:On the 7th and 14th day,dogs of both groups presented edematous at the corneal incision,and other parts were transparent.The pupil shape was regular and round.No floc was found in the anterior chamber.The IOL color was transparent;on the 21st,28th and 35th day,the corneal incision edema gradually disappeared.The entire cornea was transparent.The pupil shape was regular.There was no flocculent and transparent abnormality in the anterior chamber.IOL displacement occured in both experimental dogs.Reduced pigmentation of iris and IOL adhesion were observed at the incision site.(2)Intraocular pressure,leucocyte counts in peripheral blood,and aqueous humor:In both groups,intraocular pressure and peripheral blood leukocyte counts(WBC)were within the normal range at all time points(P>0.05).No WBC was seen in the aqueous humor in both groups at day 14 and 35.(3)Corneal tissue section:On the 14th day,the wounds were covered by the corneal epithelial cells in both groups.The fibers at the border of the corneal incision were disordered.The inflammatory cell infiltration at the incision site and neovascularization in the stroma were observed in both groups.On the 35th day,the corneal epithelial cells of the two groups were completely covered and the surface was smooth.The thickness of the cornea was within the normal range.There was still a small amount of inflammatory cells at the edge of the wound,Only the fibers at the edge of the wound were slightly disordered.(4)Gene expressions of IL-6,TNF-a and TGF-P of the iris and ciliary body:No significant changes(P>0.05)were measured in the expressions of TNF-?,IL-6 and TNF-a of the iris and ciliary tissues of both groups.(5)Postoperative visual assessment:On the 35th day,dogs of both groups were able to pass through the Y-type maze quickly,indicating the recovery of the vision.In summary,the canine oxidative injury cataract model could be successfully made using self-made oxidizing solution.After oxidatively breaking the damaged lens and implanting the intraocular lens,both the rigid J-IOL and the folded flat IOL could rapidly improve the postoperative vision of the dogs.Implanted two kinds of IOL,a few experimental dogs appeared IOL shift.In comparison,the folded IOL could be transposed into the anterior chamber,whereas the rigid J-IOL only displaced within the capsular bag with relative better stability. |
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