Objective To investigate the causes of failure of the primary vitrectomy,sum up the experience for secondary vitreous surgery and improve the success rate of primary vitrectomy for complicated retinal detachment． Methods The records of a consecutive series of 60 patients(65 eyes)that underwent secondary vitreous surgery between 1997 to 1998 were retrospectively reviewed.The age of patient ranged from 9 to 63 years(mean 36),and the followup period ranged from 3 to 18 months(mean 10.5 months). Results The main causes of failure of the primary vitrectomy were postoperative recurrence of proliferative vitreoretinopathy(PVR),unwell closed retinal breaks,and intra-and postoperative complications.In 46 of 65 eyes the retina was reattached after secondary vitreous surgery(70．1%)．Postoperatively,31 eyes (47.7%) had a visual acuity(VA)improved,16 eyes(24.6%)had a VA unchanged,and 18eyes(27.7%)had a VA reduced．Fifteen eyes(23.1%)had a VA of ge;0.05 and the best VA was 0.4．Thirty-nine eyes were followed-up from 3 to 18 months(mean 10.5)．In 35 of 39 eyes,the retina was reattached(89.7%),26 eyes(40%)had a VA of ge;0.05,and 7 eyes(10.7%)were hypotonic. Conclusions The keys to the success of secondary vitreous surgery are to restore the mobility for retina by eliminating the PVR completely,and avoid intraoperative complicattions by choosing the appropriate closure procedure for retinal breaks and the suitable intraocular tamponades. (Chin J Ocul Fundus Dis,20000,16:24-26)
Objective To observe the changes of the multifocal electr oretinograph (mf-ERG) in commotio retinae. Methods The affected eyes (traumatic group) and the fellow eyes (control group) of 31 patients with unilateral commotio retinae were examined by RETI scan 3.15 system. The responses of 61 retinal regions were recorded, and the average amplitude densities of the N1 (the first negative) wave and P1 (the first positive) wave in different regions of retinal were analyzed. Results The average amplitude densities of 1-4 rings in N1wave and 1-5 rings in P1wave were much lower in traumatic group than those in the control. Conclusions The average amplitude densities of N1wave and P1wave of mf-ERG in retin al affected regions decreases markedly in eyes with commotio retina; mf-ERG may provide the quantificational and orientational detection for the visual ability of the eyes with commotio retinae.(Chin J Ocul Fundus Dis，2004，20：226-228)
Objective To investigate the therapeutic effects of subconjunctival verapamil on outcome in an experimental model of traumatic proliferative vitreoretinopathy. Methods An experimental model of traumatic proliferative vitreoretinopathy was induced in pigme nt rabbits,which then were selected randomly to receive either subconjunctival verapamil injection treatment or a placebo injection(control)daily for 3 weeks.Animals were examined by indirect ophthalmoscopy at weekly intervals for 5 weeks. Eyes were enucleated for light microscopy 5 weeks later. Results Fifty-six percent(18 of 32)of the rabbits receiving subconjunctival verapamil injection had developed tractional retinal detachment,whereas eighty-one percent(26 of 32)of control animals had developed tractional retinal detachment(chi;2=4.655,P=0.031).The results of clinical examination and light microscopy didn't show evidence of toxicity between the verapamil treated animals and control animals. Conclusion Subconjunctival verapamil decreased the incidence of tractional retinal detachment due to traumatic proliferative vetreoretinopathy in this rabbit model.Verapamil at the dose used in this model has no evident toxicity on rabbit eyes.Further studies are needed to determine the doseresponse and efficacy of the drug. (Chin J Ocul Fundus Dis,1999,15:69-71)
PURPOSE:To evaluate the activitv of protein kinase C(PKC) in response to retinal photochemical insult in rat. Furthermore, to investigate the effect of dexamethasone(DXM ) on PKC activity. METHODS :The experiments were performed on 48 SI') rats whieh were separated into two groups,control and treated groups,and the latter received daily intraperitoneal injections of DXM (1 mg/kg)for 5 consecutive days,starting 3 days before light exposure. The animals were continually exposed to green fluorescent light (510nm~560nm) with an illuminance level of (1 900plusmn;106.9)lx for 24 hrs.The retinal enzyme activity of PKC was tested at 6 hrs,1 day,3 days,7 days,and 14 days after light exposure respectively. RESULTS:In animal models,PKC activity showed a transient increase in both groups at 6 hrs after light exposure and then decrease persistently there alter. The activity of PKC was unresponsive to DXM intervention. CONCLUSIONS :These results suggested that the persistent lower PKC activity might result in disturbance of retinal function in rat retinal photochemical injury. （Chin J Ocul Fundus Dis,1997,13: 78-80）
Objective To investigate the effect of retinectomy 360° for severe ocular rupture and evaluate the related factors associated w ith prognosis. Methods We retrospectively analyzed 28 consecutive patients (28 eyes), 18 men and 10 women, with severe ocular rupture admitted to the Chinese PLA General Hospital between January 1999 and October 2002. The patient′s ages ragned from 16 to 58 years, mean 29 years. According to the internation standardized classification of ocular trauma, the injuries located in zone I in 5 eyes, zone I-II in 8 eyes，zone II in 3 eyes, zone II-IIIⅢ in 5 eyes, zone III in 7 eyes, zone II in 3 eyes, zone II-III in 5 eyes and zone III in 7 eyes. The presenting visual acuity was in grade 4 (0.02 to light perception) in 19 eyes, and grade 5 in 9 eyes. In 28 patients, 13 had the total absence of iris and lens, 10 had iris deletion more than 1/2, and 15 had lens opacity or rupture. Ultrasound biomicroscopy and B-scan revealed ciliochoroidal detachment in 17 eyes. The B-scan revealed vitreous hemorrhage and retinal detachment in all paitents. The intraocular pressure was from 5 to 11 mm Hg in all patients. The therappeutic operative procedures which were performed by one surgeon in all of the affected eyes included standard 3-port pars plana vitrectomy with scleral encircling buckle, endophotocoagulation and tamponading with silicone oil in all patients; lensectomy in 15 eyes; 360° retinotomy and retinectomy at anterior equator in 16 patients, and posterior equator in 12 eyes.Results During the operation, all patients were confirmed with vitreous hemorrhage and retinal detachment, including hemorrhagic ciliary body detachment in 9 eyes, suprachoroidal hemorrha ge in 12 eyes, retinal twisting like morning glory in 11 eyes, and retinal incarceration in 17 eyes. Postoperative follow-up In 26 eyes who were followed up postoperatively from 6 months to 46 months, retinal reattachment was found in 20 patients (76.9%) in whom the retina of 3 was reattached after revitrectomy and the silicone oil of 8 was removed at the fourth month after operation. In 20 eyes with reattached retina, 14 (70.0%) had corrected visual acuity of 0.02 or more, including 7 (35.0%) had 0.05 or more, 3 had 0.1 or mor e, and 1 had the best visual acuity of 0.3.Conclusion Retine ctomy may improve the prognosis of severe ocular rupture and save the visual fun ction of some patients.(Chin J Ocul Fundus Dis，2003，19：333-404)
Open-globe injuries (OGI) result in complicated and diverse conditions with different mechanisms and anatomical locations, which lead to completely different outcomes based on when to perform pars plana vitrectomy (PPV) after trauma. The PPV operation time points are generally divided into early (0 - 3 days), delayed (4 - 14 days), and late (> 2 weeks). There are still some controversies about the PPV time points after OGI. Injuries with intraocular foreign bodies or high risk of infection usually need early surgery to reduce the occurrence of endophthalmitis. However corneal edema and vitreous hemorrhage can increase the difficulties for early diagnosis and surgery. If there is choroidal hemorrhage or severe trauma in the back part of the eye, delayed intervention can allow the blood clots to be liquefied and removed easily. But there is higher incidence of postoperative complications. Late surgery can reduce the difficulty of PPV, but the increased incidence of proliferative vitreoretinopathy may lead to severe retinal traction, tears and postoperative scar formation.
Objective To observe the effect of blue light on apoptosis of cultured human retinal pigment epithelial (RPE) cells in vitro. Methods Human RPE cells were exposed to blue light, and the cells were divided into 3 groups: group A, with various intensity of illumination; group B: with same intensity but different time of illumination; group C: with same intensity and time of illumination but different finish time of the culture. The apoptosis of RPE cells was observed by TdT-dUTP terminal nick-end labeling (TUNEL) and annexin V-fluoresein isothiocyanate (FITC)/propidium iodide (PI) flow cytometry, and transmission electron microscopy. Results The positive cells stained by TUNEL shrinked and turned round, whose nuclei concentrated and congregated like the crescent or hat. Cracked nuclei and membrane bleb were found. Swollen mitochondrial, disappeared inner limiting membrane of mitochondria, and dilation of the rough endoplasmic reticulum with metabolite were observed by transmission electronmicroscopy. In group A, mild damage of RPE cells was found when the threshold value of the intensity of illumination was less than（500±100）lx, and the apoptosis and necrosis of RPE cells aggravated as the intensity of illumination increased; in group B, as the time of illumination extended, the number of apoptotic RPE cells didn′t increase while the necrosis increased; in group C, 6 and 12 hours after illumination, apoptosis of cells was the main injury, while apoptosis with necrosis was found and necrotic cells increased as the time of illumination was prolonged. Conclusions Illumination with blue light may cause damages of human RPE cells in vitro, with the modalities of apoptosis, apoptotic necrosis and necrosis. The extent of injury is dependent on intensity and duration of the illumination. (Chin J Ocul Fundus Dis, 2005, 21: 384-387)
ObjectiveTo observe the early ultrastructural changes of the optic nerves after the brain impact injury.MethodsEighteen 15-week-old Wistar rats were used in the air-pressure brain impact injury examination. All of the rats underwent the procedures of right-parietal-bone fenestration after abdominal cavity anesthesia with 1% sodium pentolbarbital (45 mg/kg), and then they were divided randomly into 3 groups, i.e., mild injury group (8 rats) underwent with 7 kg of air pressure in distance of 11 cm; severe injury group (8 rats) with 7 kg of airpressure in distance of 8 cm; and control group (2 rats) underwent with the parietalbone fenestration but without impact injury.The ultrastructural changes of the optic nerves were observed 1, 6, 24, and 72 hours after the injury by electron microscopy.ResultsThe difference of ultrastructural changes of optic nerve was not obvious in wild injury group and the control group, and the lanthanum nitrate was only found in the blood vessels in optic nerve. The lanthanum nitrate entered the nerve stroma 1 hour after severe and increased as time goes on. Simultaneously, displayed dilatation of endoplasmic reticulum, cavitation and tumefaction of mitochondrion, vacuolation of nerve stroma, and vacuolation of some axis-cylinder were seen in the glial cells.ConclusionThe brain impact injury may cause ultrastructural changes of the optic nerve and increase of permeability of blood vessels. (Chin J Ocul Fundus Dis, 2005,21:41-43)
Objective To observe the clinical characteristics of severe ocular detonator explosive injuries and to evaluate the therapeutic effects of vitrectomy on it. Methods Clinical data of 37 consecutive patients (65 eyes) with severe ocular detonator explosive injuries were retrospectively analyzed. The patients included 36 males and 1 female with the average age of 28.6 years. The biocular injuriy was in 31 cases (83.8 %), and one-eyed injury was in 6 cases (16.2%). A total of 48 eyes had severe explosive injury. The visual acuity was no light perception in 9 eyes in which 3 eyeballs were obviously atrophic, light perception in 28 eyes, hand moving in 4 eyes, and counting finger/33 cm in 7 eyes. Vitrectomy was performed on 46 eyes, in which 41 had severe ocular explosive injury. There were no vitreous surgery indications in 13 eyes of 19 eyes didnprime;t undergo surgery; the other 6 eyes didnprime;t undergo surgery due to the atrophic eyeballs or economic reasons. The treating time after trauma was within 1 week in 7 patients (18.9%), 1 week to 1 month in 13 (35.2%), and more than 1 month in 17 (45.9%). The follow-up duration lasted 6 months to 2 years after operation with the average of 8.6 months. Results In 65 eyes, the occupation ratio of conjunctival foreign bodies was 66.2%; corneal foreign bodies was 46.2%; vitreous hemorrhage was 70.8%; intraocular foreign bodies (IOFB) was 69.2%; retinal shocking injury or optic nerve blasting injury was 56.9%. The visual acuity improved in 33 eyes, remained unchanged in 25 eyes, and decreased in 7 eyes. In 46 eyes which had undergone vitrectomy, IOFB injuries was in 35 eyes (76.1%); the visual acuity increased in 26 eyes (59.5%), remained unchanged in 13 eyes (28.3%), and didnprime;t cure in 7 eyes (15.2%) in which 2 eyes underwent ocular enucleation and 5 eyes were atrophic. The increasing rate of visual acuity in the patients who accepted the treatment more than 1 month after injury was low. The occupation ratio of monocular blindness was 51.4% and biocular blind was 8.1%. Conclusions Most of severe ocular explosive injuries by detonator are with IOFB. causes of the high blinding rate are late treatment and serious injury. Strengthening the diagnosis and treatment of retinal shock and optic nerve blast, and performing vitrectomy as soon as possible can improve prognositc visual function of injured eyes.
Objective To observe the changes of electroretino gram(ERG) in temporary traumatic ocular hypotension and to detect the possiblem echanism. Method The rabbit model with ocular hypotenstion was made. At the 2nd, 4th, 8th, 16th week after trauma, the ocular tension and ERG was examined. Result Amplitude of b wave in treated group was 2.5 times as high as that in the control at the 2nd week after trauma, and then decrease to 1.5 times as high as that in the control at the 16th week. Conclution Higher amplitude of b-wave of ERG in rabbit with ocular hypotension may be related to blood circulation congestion, which might lead to accumulation of the metabolic toxin. (Chin J Ocul Fundus Dis，2004，20：189-191)