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)
Objective To evaluate the visual results,surgical tec hnique and safety of secondary intraocular lens (IOL) implantation in aphakic eyes following vitrectomy and lensectomy for complicated ocular trauma or retinal detachment． Methods The clinical records of 3 2 cases (32 eyes),received these surgeries during November 1996 and December 1999,were reviewed retrospectively.During the secondary operation，intraocular infu sion through the pars plana was performend and the type of IOL was chosen based on the integrity of lens capsule. Results The study included 30 eyes suffering from trauma (foreign bodies in 15 eyes,penetrating injury with traumatic endophthalmitis and with vitreous hemorrhage in 6 eyes respectively, blunt trauma with lens dislocation in 3 eyes),and 2 eyes with primary retinal detachment.Those eyes all received vitrectomy,lensectomy,and/or remova l of foreign bodies and corneal suture.The interval of two operations ranged from 1 to 16 months with an average of 6.8plusmn;3.7 months.Posterior chamber IOL was implanted in the ciliary sulcus in 25 eyes with a whole or 2/3 of lens capsule,trans scleral suture fixation of IOL in 5 eyes,anterior chamber IOL and IOL with artificialiris in one eye respectively.Silicone oil was removed in 5 eyes duri ng the secondary operation.Post-operative visual improvement was achieved in 29 eyes.Main complications were corneal edema and low intraocular pressure after operation. Conclusion Intraocular infusion and proper IOL implantation during the secondary operation following vitrectomy can provide selected aphakic eyes with better visual recovery. (Chin J Ocul Fundus Dis, 2001,17:96-98)
Objective To further investigate pathologic mechanism of retinal phototrauma. Methods Twenty Wistar rats were divided into control and experimental groups.Their eyes were extracted in 12，24 and 36 hours after light exposure.HE stained retina samples were examined and TDT-mediated dUTP nick end labelling(TUNEL)method was employed to distinguish apoptotic cells. Results After 12-hour light exposure,slight vesiculation was observed in the rod outer segment of the retinas.After 24-hour light exposure,the outer nuclear layer showed predominant fractured and condensed nuclei and fragmented DNA.After 36-hour light exposure,the rod outer and inner segments were lysed and most of the nuclei in the outer nuclear layer were disappeared. Conclusions Apoptosis of photoreceptor cell is one of the important mechanisms which cause experimental retinal photoinjury of rats. (Chin J Ocul Fundus Dis, 1999, 15: 167-169)
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)
Objective To find out about the characteristics and prognosis of retinal detachment due to ocular contusion.Methods The clinical data of 36 patients(36 eyes)with retinal detachment due to ocular contusion were retrospectively analyzed.Results There were 3 eyes(8．3％)with huge retinal hole(≥90°)，4 eyes(11．1％)oral tear of ora serrata retinae，4 eyes(11．1％)with macular hole，3 eyes(8.3％)with tractive retinal detachment，and 22 eyes(61．2％)with retinal hole(lt;90°)at other positions(including temporal peripheral hole in 9，nasal peripheral hole in 5，and posterior polar hole in 8).Proliferative vitreoretinopathy(PVR)was found in a11 patients withConclusions Retinal detachment due to ocular contusion often go with PVR．The interval from contusion to retinal detachment varies from days to months.Visual prognosis can be good when retinal detachment is diagnosed and treated in time． (Chin J Ocul Fundus Dis，2004，20：1-66)
Objective To investigate the degenerative changes in the inner rat retina after photic injury.Methods After 24 hour-dark adaptation, sixty Lewis rats were exposed in a ventilated green plexiglass chamber that transmitted continuous green light between 480-520 nm with an intensity of 900～1 000 lx. After 24 hour exposure, the rats stayed in darkness and were sacrificed after 1 day, 3,7 or 14 days. The neurons in the inner retina were marked by immunohisto chemical technique and observed by light and electronic microscope.Results The apoptotic photoreceptor cells were noted after photic injury. The degeneration and decreasing number of rod bipolar cells were found after 3 days; the edema of horizontal cells occurred after 1 day but ameliorated gradually; decreasing number of amacrine cells was found after 1 day; sustained edema of ganglion cells and prolifeeration of the Müller cells were found after photic injury. Pyknotic and edematous neruronal degenerations of inner retina were found in ultrastructural study.Conclusion The neurons in the inner retina as well as Müller cells are involved in the degeneration after photic injury. Different neurons manifest different patterns of degeneration.(Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To explore the therapeutic value and effects of relaxing retinotomy for perforating traction retinal detachment(PTRD). Method A retrospective survey was done in 21 patinets (21 eyes) with PTRD who underwent vitrectomy combined with relaxing retinotomy in our hospital from 1998 to 2001.Results The retinae were completely reattached in all 21 cases. The visual acuity of 12 patients (57%) was counting finger, and the best visual acuity was 0.05. Among the 18 patients who were followed up for 6 to 25 months, 14(77.8%) remained retinal reattachment. Conclusions Relaxing retinotomy is effective for anatomic reattachment of PTRD, especially to the patients with retinal incarceration and severe proliferative vitreoretinopathy. (Chin J Ocul Fundus Dis，2003，19：5-7)
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)
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)