OBJECTIVE:To evaluate the toxicity of retinoic acid in silicone oil to the retinal tissue. METHOD:Twelve New Zealand white rabbits(24 eyes)were divided into three grorps at random. Three days after gas-compression vitrectomy,24 eyes were unedrgone gas/silicone oil exchange. The silicone oil 0.5 ml was injected intravitreally in 4 eyes as controls ,and 5mu;g/ml retinoic acid silicone oil 0.5ml in 10 eyes and 10 mu;g/ml retinoic acid silicone oil 0.5 ml in 10 eyes respectively as 2 study groups. After intravitrea[ injections, all the eyes were examined by ophthalmoscopy on the 1st, 3rd, 7th, 14th, 21st and 28th day. The retinas of the enucleated eyes on the 28th day were then examined by light microscopy and transmission electrone microscopy. RESULT: No evidence of toxicity was found in retinas after intravitreal injections of silicone oil with 5 mu;g/ml or 10 mu;g/ml retinoic acid. CONCLUSION :There was no toxic effect on the retinas by using 5 mu;g/ml or 10 mu;g/ml retinoic acid in intravitreal silicone oil tamponade operation. （Chin J Ocul Fundus Dis,1997,13: 81-82）
Objective To probe the clinical feature and complications of extraction of silicon oil after operation of simple rhegmatogenous retinal detachment in child patients. Methods The clinical materials of 22 patients (22 eyes) of child patients (5~14 years old) and 11 cases (11 eyes) of adult patients with simple rhegmatogenous retinal detachment undergone surgical treatment and subsequent retraction of silicon oil tampon, were reviewed and analyzed retrospectively. The reasons of extraction silicon tampon, ocular complications of intrao cular silicon tamponade and the changes of visual acuity pre- and post-extraction of silicon tamponade in above 2 groups were explored. Results The main reason for the extraction and complications of silicon oil tamponade were similar in both groups. The rate of occurrence of the complications in either group rose as time went on . There was no significant difference in change of visual acuity between two groups after the extraction of silicon oil tampon. Conclusion The responses to silicon oil after the operation for simple rhegmatogenous retinal detachment is quite similar in either children or adult patients,and there is no obvious difference between child and adult patients in the results of silicon oil extraction. (Chin J Ocul Fundus Dis，2000，16：139-212)
Objective To verify the changes of optics and refraction of the eyes after retinal detachment surgery with the tamponade of silicone oil in vitreous cavity. Methods The optical calculation was taken as the following by using the parameter of Gullstrand model eye:（1）The refraction of silicone filled eye in non-accommodative status;（2）The refraction of silicone filled eye in non-accommodative status;（3）The aniseikonia analysis when one eye filled with the silicone oil;（4）The IOL power re-calculation． Results （1） Compa red with the normal eye,the eye filled with silicone oil is moved toward high hyperopia of +9．19 D;（2）When corrected,the accommodation amplitude reduced 1.42 D induced by filling silicone oil. Conclusion When eye filled with silicone oil,the change of refractive power tends to be highly hyperopic,the amplitude of accommodation decreased,and the regular IOL power calculation formula is no longer available. (Chin J Ocul Fundus Dis，2000，16：139-212)
ObjectiveTo compare the effects of intravitreal tamponade of C3F8 with silicon oil on postoperative vitreous hemorrhage and visual prognosis after vitrectomy for proliferative diabetic retinopathy (PDR). MethodsThe clinical data of 121 patients (127 eyes) who underwent primary vitrectomy due to PDR were analyzed retrospectively. All the patients were divided into two groups according to different intravitreal tamponade, including C3F8 tamponade group (53 patients with 56 eyes) and silicone oil tamponade group (68 patients with 71 eyes). There was no difference of gender (χ2=0.956), age (t=1.122), duratiion of diabetes (t=0.627), fasting blood glucose (t=1.049), systolic pressure (t=1.056), diastolic pressure (t=0.517), history of hypertension (χ2=0.356), nephropathy (χ2=1.242), preoperative laser photocoagulation (χ2=1.225) and All the patients underwent three port pars plana vitrectomy. The mean follow-up was 2 years ranging from 6 months to 4 years. And then the incidence and onset time of postoperative vitreous hemorrhage and postoperative BCVA of the two groups were compared. ResultsPostoperative vitreous hemorrhage occurred in 14 of 56 eyes (25.00%) in C3F8 tamponade group. The average onset time of postoperative vitreous hemorrhage were (64.64±59.09) days ranging from 7-225 days and mostly were within 30-60 days (35.71%, 5/14). Postoperative vitreous hemorrhage also occurred in 7 of 71 eyes (9.89%) of silicone oil tamponade group after silicone oil removal with an average onset time of (25.29±20.46) days ranging from 3-65 days and were mostly within 15-30 days (42.86%, 3/7). There was a significant difference in the incidence of postoperative vitreous hemorrhage between the two groups (χ2=5.200, P<0.05). BCVA of the two groups was improved significantly after operation (Z=2.472, 3.114; P<0.05). Postoperative BCVA of silicone oil tamponade group was poorer than C3F8 tamponade group (Z=1.968, P<0.05). ConclusionBoth C3F8 and silicone oil tamponade can improve the visual acuity after vitrectomy for PDR. Compared with C3F8, silicone oil tamponade had lower incidence and late onset of postoperative vitreous hemorrhage after vitrectomy for PDR.
PURPOSE:To evaluate the ability Of retinoic acid(RA) in silicon oil(SiO)to inhibit the proliferation of injected intraocular fibroblast cells. METHODS:Thirty New Zealand white rabbits (58 eyes)were divided into three groups. In control group ,only SiO(10 eyes)or BSS(10 eyes)were injected intravitreally and 5mu;g/ml (18 eyes)or 10mu;g/ml (20 eyes)RA in SiO were injected into other lwo groups respectively. Three days after gas-compression vitrectomy, 2 times;105 fibroblasts and Sio(0.5ml)or BSS(0.5ml)were injected in all eyes sequentially.The morbidity of tractional retinal detachment (TRD) were observed by ophthalmoscope until 4 weeks. RESULTS:After 4 weeks,in control ,5mu;g/ml RA in SiO and 10mu;g/ml RA in SiO group,80. 00%,44.44%,and 30.00% eyes developed TRD respectively. Significant statistical differences were found between the control group and the two treated groups (P＜0.05). CONCLUSIONS:5mu;g/ml or 10mu;g/ml RA in SiO can inhibit the occurrence of TRD effectively. （Chin J Ocul Fundus Dis,1997,13:174-176）
Objective To investigate the main causes and risk factors of recurrent retinal detachment (RRD) after silicone oil removal (SOR) in eyes with complex retinal detachment. Methods It was a retrospective case series study. A total of 458 eyes of 455 consecutive patients who underwent pars plana vitrectomy with silicone oil tamponade were recruited in this study. All patients underwent vitrectomy operation. Additionally, they were given heavy water, membrane peeling, retinotomy or partial cutting, intraocular laser photocoagulation or frozen, gas-liquid exchange or direct oil exchange operation accordingly. Ninety-eight eyes with multiple holes, old retinal detachment, hyperplasia and serious traction lesions underwent scleral buckling surgery simultaneously. Intravitreal silicone oil was padded at the end of operation. Cutting, stripping or resection and 360° preventive laser photocoagulation were applied while the epiretinal membrane was found and need treatment during SOR. Holes or suspicious hiatus underwent intraocular laser photocoagulation or cryotherapy during the operation. One week after SOR and during follow-up, the visual acuity, intraocular pressure (IOP), slit lamp microscope, and ophthalmoscope examination were examined with the same technique and methods as preoperation. The eyes were divide into two groups based on the attachment status of retina after SOR, which were reattached group (419 eyes) and redetached group (39 eyes) respectively. The following data were recorded: the age of patients, ocular axial length, logarithm of minimum angle of resolution (logMAR) best corrected visual acuity (BCVA) and IOP before vitrectomy operation and before and after SOR, the number of retinal breaks, the duration of silicone oil filling, the duration of followup, and the related factors during vitrectomy operation and SOR. The relation of age, sex, high myopia, the size and location of holes, aphakic eye, proliferative vitreoretinopathy (PVR) C3 level and above, previous history of failed retinal detachment operation, 360° preventive laser photocoagulation, assistant scleral buckling surgery, SOR via corneal puncture to RRD after SOR were analyzed. Odds ratio (OR) and its 95% confidence interval (CI) were calculated for the age ＜40 years old and gender. High myopia, assistant scleral buckling surgery and SOR via corneal puncture were further analyzed by multiple regression equation. Results After SOR operation, the total average logMAR BCVA was 0.86±0.63. The average logMAR BCVA was 0.82±0.59 and 0.99±0.70 respectively for the reattached and redetached groups, which was not statistically different (F=1.559,P＞0.05). The number of high myopia eyes in the reattached and redetached groups were 116 and 22 eyes, respectively, accounted for 27.7% and 56.4%, and the difference was statistically significant (χ2=13.984,P＜0.01). Three eyes underwent vitrectomy with scleral buckling occured RRD, accounting for 3.1%; while 36 eyes underwent vitrectomy without scleral buckling occured RRD, accounting for 10.0%. The incidence of RRD between them was statistically significant (χ2=4.761,P＜0.05). The incidence of RRD was not retated to the PVR levels before the operation, previous history of failed retinal detachment operation, aphakic eye and preventive laser photocoagulation (OR=1.626, 1.699, 1.986, 0.709; 95%CI:0.836-3.162, 0.832-3.658, 0.921-4.279, 0.268-1.875; P＞0.05) . RRD had a close relation with high myopia and assistant scleral buckling surgery (OR=3.380, 0.284; 95%CI:1.733 -6.595, 0.086-0.944; P＜0.05). The raise of risk derived from SOR via corneal puncture had no statistical significance (OR=2.119; 95%CI: 1.043-4.306; P＞0.05). The incidence of RRD after SOR was 8.5%; of which, 35.9% originated from new breaks and 69.2% were related to new breaks, in contrast, only 5.1% originated from PVR but 51.3% were related to PVR. ConclusionsHigh myopia is an independent prognostic risk factor of RRD after SOR. Combined scleral buckling surgery is a protective factor of RRD after SOR. To the well reattached eyes before SOR, the new breaks seems to be the main cause of RRD, wheras PVR was probably a secondary phenomenon.