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 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)
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 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 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)
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 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 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 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)
ObjectiveTo investigate the effect of blue light on Ca2+-protein kinase C (PKC) signaling pathway in human retinal pigment epithelial (RPE) cells in vitro. MethodsPrimary human RPE cells were cultured in vitro and characterized. The experiments were carried out using the 4th generation of human RPE cells. The PKC protein level was measured by Western blot to determine the most appropriate concentration of phorbol ester (PMA) and calcium phosphate binding protein (calphostin C) on PKC expression. Non-radioactive isotope method was used to determine the effect of blue light on PKC expression of cultured cells. Blue-light damage model of human RPE cells was established by 6 hour irradiation of medical blue-light lamp [20 W, 450-500 nm wavelength, (2000±500) Lux], and 24 hours prolongation of post-exposure culture. The human RPE cells were randomly divided into 5 groups. Group A did not receive light irradiation, group B only received blue light irradiation, group C was blue light irradiation and 0.1 mmol/L nifedipine treatment, group D was blue light irradiation and 100.0 nmol/L calphostin C treatment, group E was blue light irradiation and 100.0 nmol/L PMA treatment. Intracellular Ca2+ concentration was measured by acetoxymethyl ester (Fluo 3-AM) labelling and confocal microscope imaging. ResultsThe PKC protein expression in 100.0 nmol/L or 200.0 nmol/L PMA-treated groups was higher than 0.1, 1.0, 10.0, and 50.0 nmol/L PMA-treated groups, the difference was statistically significant (F=217.537, P<0.05), but there was no statistically difference between 100.0 nmol/L and 200.0 nmol/L PMA-treated groups (P=0.072). The PKC protein expression in 100.0 nmol/L or 200.0 nmol/L calphostin C-treated groups was lower than 5.0, 25.0, 50.0, and 75.0 nmol/L calphostin C-treated groups, the difference was statistically significant (F=164.543, P<0.05), but there was no statistically difference between 100.0 nmol/L and 200.0 nmol/L calphostin C-treated groups (P=0.385). PKC level in blue light group was higher than non-light group, the difference was statistically significant (t=-9.869, P<0.05). The Ca2+ fluorescence intensity values in group B, C, D and E was higher than group A, the difference was statistically significant (F=26 764.92,P<0.05). The Ca2+ fluorescence intensity values in group E was higher than group B, C and D (P<0.05), and that in group B was higher than group C and D (P<0.05). ConclusionsThe PKC activity and intracellular Ca2+ concentration in human RPE cells increase after blue-light irradiation. Both calcium channel inhibitor nifedipine and PKC inhibitor calphostin C can reduce intracellular Ca2+ concentration in human RPE cells. PMA can induce intracellular Ca2+ concentration in human RPE cells after blue light irradiation.