| Objective To evalute the effecct of the derease of IOP by contract transscleral krypton laser cyclophotocoagula- tion . To find a energy levels of contract transscleral cyclopho- tocoagulation by krypton laser. To study the possibility of cyclophotocoagulation used to cure primary open angle glaucoma as the first method.Methods contract transscleral cyclophotocoagulation by krypton laser of green and yellow (wavelength-green:520nm and yellow:568.2nm) were performed in 32 eyes of 32 pigmented rabbits. 32 rabbits were choiced by the double blind to get rid of those IOP were too high or too low. One eye of each rabbit was chosen at random underwent contract transsclera cyclophotocoagulation; the other one was the control。32 rabbits were divided into four groups eqully at random.20 of them were examined in IOP,aqueous outflow facility (C value),aqueous flow rate (F value) and electroretinogram.12 of them were used in histopatholgy. Each group underwent different energy: A:500mv,0.7s; B:750mv,0.7s; C:700mv,0.5s; D:900mv,0.5s。The krypton laser was delivered via a fiberoptic probe with compression of the sclera by the probe. The applications were located 0.5 mm from the limbus. spot diameter was 500um. The distance of two adjacent applications were 500um.There were about 20-24 burns on each eye.Examination were performed at before photocoagulation and 1,3,7,15,30 days after photocoagulation to observe cornea,anterior chamber,aqueous flare,keratic precipitate ,pupil,lens,vitreous body by slit-lamp biomicroscope.To examine retina by directed opthalmoscope.To do tonometry with pair readings of 2 weights use schiotz tonometer.Tonographic aqueous outflow facility and aqueous flow. In general anaesthesia by intravenous Ethyl carbamate ,to do tonometry use schiotz tonomeyter .First use weight of 10g or 15g ,then use weight of 5g or 7.5g after 5 minutes, and continu 5 minutes to obtain a data. To obtain aqueous outlow facility by using the table of Gaofeng Xu.To do electroretinogram on the time before photocoagu- lation and 1,3,7,30 days after photocoagulation under surface anaesthesiaOphthalmectomy were done under anaesthesia by intravenous Ethyl carbamate. The lesions were studied histopathologic examination on 3,7,15, 30days after treatment.All the data obtained in the present study were analyzed statistically by T-test and analysis of variance of SAS6.12 softwear。Result 1 Four group of animals were examined at 1,3,7,15,30 days after photocoagulation and observed conjunctival congestion. The applications 0.5 mm from the limbus were observed. trasparent Cornea ,No obvious KP and aqueous flare were observwd. One eye was observed atonic pupil .No obvious chang on retina compaired with before sugery. No eye ball atrophy and phthisis bulbi.2 Aqueous Humor Dynamics in rabbits2.1 The intraocular pressure. The IOP were decreased on the 1 day after photocoagulation in Group A and group B. The IOP were decreased on the 7 day after photocoagulation in Group C. And Group D had no chang were observed.2.2 Aqueous outflow facility.The aqueous outflow facility of Group A were decreased on the 1,3 day after photocoagula- tion. The aqueous outflow facility of Group B were decreased on the 1,3 ,7day after photocoagulation. The aqueous outflow facility of Group C and D had no change after photocoagulation.2.3 Aqueous flow. The aqueous flow of Group A and Group B decreased obviously just on the 1st day after photocoagulation. The aqueous flow of Group D decreased on the 7 day after photocoagulation. And the aqueous flow of Group C decreased just on the 15 day after photocoagulation.3 Electroretinogram examination. The amplitude and park lentence of ERG did not change obviously betwin before and after photocoagulation.4 Histopathological findings Light microscopy and Transmisson elctron microscope revealed Nonpigmented epithelia cells turn flat even atrophied; pigmented epithelia cells arranged disorder,the pigment vesicle is lost or piled up, interstitiu...
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