Transient High Intraocular Pressure Research Articles

Risk Factors of Urrets-Zavalia Syndrome after Penetrating Keratoplasty.

Objective: The objective of this study was to analyze the clinical features and risk factors of Urrets-Zavalia syndrome (UZS) after penetrating keratoplasty (PKP). Methods: The medical records of 152 patients who underwent PKP at the Department of Ophthalmology, Tongji Hospital, between January 2014 and December 2016 were retrospectively reviewed. UZS was diagnosed based on pre- and post-operative pupillary findings. The relationships among the primary disease, postoperative intraocular pressure (IOP), and the incidence of UZS were statistically analyzed. The pupillary changes during the follow-up period were studied. Results: Among the 152 included patients, 23 were diagnosed with UZS, with an incidence of 15.13%. The primary diseases of the UZS patients were keratoconus (eight cases, 34.78%), viral keratitis (six cases, 26.08%), leukoma (four cases, 17.39%), fungal corneal ulcer (two cases, 8.70%), corneal endothelial decompensation (two cases, 8.70%), and corneal degeneration (one case, 4.35%). The incidence of UZS in keratoconus patients was higher than that in patients with fungal corneal ulcer (42.11% versus 6.25%, p = 0.003); In addition, the transient postoperative high IOP was not significantly related to the incidence of UZS in keratoconus patients in our study (p = 0.319). Twenty-one patients with UZS were followed up for >6 months, seven of whom (33.33%) recovered spontaneously (within the range of 48 days to 1.5 years). Conclusion: In our study, the incidence of UZS after PKP was 15.13%, and 33.33% of these patients recovered spontaneously. UZS may be more likely to occur in patients with keratoconus. Postoperative transient high IOP may increase the incidence of UZS after PKP for keratoconus.

Macular buckling for highly myopic traction maculopathy

Objective: To observe the efficacy of macular buckling in the treatment of highly myopic traction maculopathy. Methods: Retrospective case series study. The patients with high myopia who underwent macular buckling at the Zhongshan Ophthalmic Center of Sun Yat-sen University from June 2014 to June 2019 were enrolled, including 136 males and 212 females. The age was (56.68±11.59) years old. The outcomes measured included retinal reattachment rate, foveoschisis recovery rate, macular hole closure rate, postoperative best corrected visual acuity (BCVA), axial length (AL), and complications. The measurements were recorded preoperatively and at 1 month, 6 months, 1 year, 2 years, and 3 years postoperatively. The data was statistically analyzed using paired t test. Results: A total of 378 eyes were included, including 216 eyes with foveoschisis and macular detachment and 162 eyes with macular holes and macular detachment. Among them, 296 eyes underwent macular buckling, and the other 82 eyes underwent macular buckling combined with pars plana vitrectomy. During the follow-up period, 373 eyes (98.68%) achieved retinal reattachment; in patients with foveoschisis, 204 eyes (94.44%) were recovered; in patients with macular holes, 89 eyes (54.09%) achieved closure. All the postoperative results of BCVA were better than the preoperative value (1.459±0.841). BCVA continued to increase from postoperative month 1, remained stable at 1 year, and reached 0.908±0.606 at 3 years (t=6.896, P<0.01). All the postoperative results of AL were shorter than the preoperative value. The AL shortened by (4.423±1.740)mm at one month (t=33.144, P<0.01), increased gradually thereafter, remained stable at 1 year, and shortened by (2.101±1.643) mm at three years (t=6.392, P<0.01). The common complications included transient high intraocular pressure in 98 eyes (25.92%), epiretinal hemorrhage in 67 eyes (17.72%), and vitreous hemorrhage in 9 eyes (2.38%), which all resolved spontaneously within 1 month. In the early postoperative period, all patients had a certain degree of eye movement limitation, and 39 eyes (10.31%) had diplopia which resolved within 6 months without treatment. The strabismus surgery was arranged to treat esotropia in 6 eyes (1.58%). The macular buckle was removed from 1 eye (0.26%) because of the inability to tolerate diplopia. There were 8 eyes (2.11%) requiring a second operation to adjust the position of the buckle. The macular buckle was also removed from 4 eyes (1.05%) due to the implant rejection. Conclusion: Macular buckling can effectively shorten the AL, resolve posterior scleral staphyloma, and improve vision in the treatment of highly myopic traction maculopathy. (Chin J Ophthalmol, 2021, 57: 433-439).

Vitrectomy combined with posterior scleral reinforcement for high myopic macular retinoschisis

Objective To investigate the clinical efficacy of vitrectomy combined with internal limiting membrane peeling and posterior scleral reinforcement for the treatment of high myopic macular retionschisis. Methods The data of 37 eyes of 37 patients with high myopia and macular splitting who were treated in our hospital from Mar. 2014 to Feb. 2017 were analyzed retrospectively. All patients were treated with posterior scleral reinforcement combined with vitrectomy, internal limiting membrane peeling and intravitreal injection of air. Among them partial cataract patients were treated with phacoemulsification and intraocular lens implantation. The follow-up time was 12 months. Results After operation, the retinoschisis was completely closed in 37 eyes. The thickness of central macular retina at 3 months after operation was significantly lower than that before operation (P<0.05). The best corrected visual acuity at 6 months postoperatively was significantly higher than preoperatively(P<0.05), and the visual acuity at 12 months after operation was higher than that at 6 months after operation (P<0.05). The axial length at 6 months after operation was significantly shorter than that preoperatively(P<0.05), and the axial length at 12 months after operation was shorter than that at 6 months after operation (P<0.01). Transient high intraocular pressure occurred in 2 eyes. No secondary surgery treated or other complication occurred. Conclusion The clinical efficacy of posterior scleral reinforcement combined with vitrectomy and internal limiting membrane peeling for the treatment of high myopic macular retionschisis is good. Key words: Reinforcement, posterior sclera; Retinopathy; Myopia, high; Splitting, macula

KR-31378, a Potassium-Channel Opener, Induces the Protection of Retinal Ganglion Cells in Rat Retinal Ischemic Models

KR-31378 is a newly developed KATP-channel opener. To investigate the ability of KR-31378 to protect retinal ganglion cells (RGC), experiments were conducted using two retinal ischemia models. Retinal ischemia was induced by transient high intraocular pressure (IOP) for acute ischemia and by three episcleral vein occlusion for chronic retinal ischemia. KR-31378 was injected intraperitoneally and administered orally in the acute and chronic ischemia models, respectively. Under the condition of chronic ischemia, RGC density in the KR-31378–treated group was statistically higher than that in the non-treated group, and IOP was reduced. In the acute retinal ischemia model, 90% of RGC were degenerated after one week in non-treated retina, but, RGC in KR-31378–treated retina were protected from ischemic damage in a dose-dependent manner and showed inhibited glial fibrillary acidic protein (GFAP) expression. Furthermore, the KR-31378 protective effect was inhibited by glibenclamide treatment in acute ischemia. These findings indicate that systemic KR-31378 treatment may protect against ischemic injury–induced ganglion cell loss in glaucoma.

Intravitreal injection of conbercept during vitrectomy surgery to treat severe proliferative diabetic retinopathy

Objective To observe and analysis the clinical effects and postoperative complications of intravitreal injection of conbercept during vitrectomy surgery (VRS) in severe proliferative diabetic retinopathy (PDR) treatment. Methods This is a prospective non-randomized controlled clinical study.A total of fifty-seven patients (sixty eyes) with severe PDR were enrolled in Tianjin Eye Hospital from June 2015 to March 2016, and the patients were divided into conbercept injection group and control group according to the patients' surgical method intention selection.The patients in conbercept injection group received an intravitreal injection of 0.05 ml conbercept solution during the surgery.The patients in control group only received VRS.The operations of the two groups were completed by the same doctor, and the follow-up time was 6 to 10 months after the surgery.The incidence of postoperative complications including a transient high intraocular pressure, early and late incidence of vitreous hemorrhage(VH), epiretinal membrane and traction retinal detachment(TRD), neovascular glaucoma(NVG), the central retinal thickness(CRT) and the best corrected visual acuity(BCVA)(LogMAR visual acuity) were comparatively analyzed. Results The incidence of early VH was 6.7%(2/30) in conbercept injection group, which was significantly lower than 26.7%(8/30) in control group (χ2=4.32, P=0.04). The incidences of late VH were 3.3%(1/30) and 10.0%(3/30) in conbercept injection group and control group, and the differences had no statistically significant difference (χ2=1.07, P>0.05). The incidences of a transient high intraocular pressure, TRD and NVG between the two groups had no statistically significant difference (χ2=0.69, 0.22, 2.07; all at P>0.05). The change of CRT from one week to one month after the operation in conbercept injection group was more remarkable than that in the control group, and the difference was statistically significant (t=-3.23, P<0.05). The mean LogMAR BCVA in two groups at 1 month and 6 months after operation were both improved in different degrees compared with the preoperative vision.The difference of mean LogMAR BCVA at 6 months was statistically significant (P<0.05). Conclusions The intravitreal injection of conbercept during VRS in severe PDR patients can effectively prevent postoperative early VH, decrease CRT and improve visual acuity. Key words: Diabetic retinopathy/surgery; Microincision vitrectomy surgery; Conbercept

Surgical treatment for persistent pupillary membranes

To explore surgical treatment for persistent pupillary membrane (PPM) and its effect. Methods: The medical records and postoperative follow-up data for 12 consecutive patients (16 eyes), who were submitted to PPM resection in Xiangya Hospital, Central South University from March 2011 to August 2016, were retrospectively reviewed. Results: Among 12 consecutive patients (16 eyes), 8 patients (12 eyes) with PPM and clear lens were submitted to simply PPM resection, and 4 patients (4 eyes) with PPM and cataract were submitted to PPM resection combined with cataract surgery. In the patients who received the combined operation, phacoaspiration with or without intraocular lens implantation was performed in 3 eyes or in 1 eye. In the early stage after surgery, 1 eye was complicated with a transient high intraocular pressure. In the patients who were submitted to PPM resection, the final follow-up visual acuity in 7 patients (11 eyes) were improved except 1 patient (1 eye). After the PPM resection combined with cataract surgery, the follow-up visual acuity was improved in 2 patients (2 eyes) but not in the other 2 patients (2 eyes). Conclusion: The surgical treatment is effect on congenital pupil residual membrane. Serious membrane pupil residual membrane should be surgically treated at early stage, and amblyopia treatment after the surgery is important.

Comparison of intra- and postoperative complications of phaco between sequential and combined procedures of 23-gauge vitrectomy and phaco

PurposeTo evaluate the intra- and postoperative complications of phacoemulsification in sequential and combined procedures of 23-gauge vitrectomy and cataract surgery. MethodsThe medical records of 376 patients who underwent phacoemulsification in a vitrectomized eye (sequential group) and 458 patients who underwent combined vitrectomy and phacoemulsification (combined group) were retrospectively reviewed. Main outcome measures were intra- and postoperative complications of phacoemulsification surgery. Surgical indications were a progressed cataract with various retinal conditions. ResultsThe most common intraoperative complication during phacoemulsification was posterior capsule rupture in both groups. The rate of this complication was higher in the sequential group (18 eyes, 4.8%) than in the combined group (7 eyes, 1.5%) (p=0.006). The most common early postoperative complication was transient high intraocular pressure (68 eyes, 14.8%) and late postoperative complication was pupillary in the synechia combined group (82 eyes, 17.9%). The most common early postoperative complication was transient high intraocular pressure (29 eyes, 7.7%) and late postoperative complication was posterior capsule opacification (27 eyes, 7.2%) in the sequential group. Fibrinous exudation occurred more in the combined group (57 eyes, 12.4%) than in the sequential group (19 eyes, 5.1%) (p=0.000). ConclusionBoth sequential and combined cataract surgeries seemed to be safe. Combined surgery could be preferred in harder cataracts and zonular dehiscence.

The surgical management for proliferative diabetic retinopathy with cataract

Objective To investigate the curative efficacy of vitrectomy and lensectomy preserving anterior lens capsule combined with extra-panretinal photocoagulation(E-PRP) for proliferative diabetic retinopathy(PDR) with cataract. Methods Total of 70 eyes of 67 patients who were suffered from PDR with cataract received treatment in our hospital from January 2010 to June 2013.All eyes were treated by vitrectomy and lensectomy preserving anterior lens capsule combined with E-PRP. Silicone oil tamponade was done in all eyes.The followed up time was 12-25 months. The intraocular pressure, visual acuity, eye anterior and posterior segment conditions were observed. Results Postoperatively the visual acuity improved in 58 eyes(82.86%)and unchanged in 12 eyes(17.14%). Two eyes (2.86%)were found iris neovascuiarization (INV)and progressed to neovascular glaucoma, INV in 4 eyes gradually subsided.The postoperative complication incidence of transient high intraocular pressure, posterior synechia and 3 grade turbidity of anterior lens capsule was 21.43%(15 eyes ) , 5.71%( 4 eyes ) and 8.57%( 6 eyes ) . The rate of retinal reattachment was 100%. Five eyes suffered from recurrent retinal detachment after silicone oil removal.Epiretinal membranes formated in 8 eyes.Severe macular edema occurred in 2 eyes.Two eyes suffered from optic atrophy.Finally, 59 eyes(84.29%)received secondary intraocular lens implantation. Conclusion Vitrectomy and lensectomy preserving anterior lens capsule combined with E-PRP is safe and effective for PDR with cataract.It can keep the normal physiological barrier between the anterior chamber and the posterior chamber, decrease the complications before and after the operation, and the visual acuity get good recovery. Key words: Vitrectomy; Lensectomy; Anterior lens capsule; Extra-panretinal photocoagulation; Diabetic retinopathy, proliferative

The clinical efficacy of secondary implantation of iris-fixated intraocular lens for traumatic aphakia

Objective To evaluate the clinical efficacy of secondary implantation of iris-fixated intraocular lens for traumatic aphakia. Methods Postoperative outcomes of secondary implantation of iris-supported Artisan IOL in 18 unilateral aphakic patients with penetrating eye injuries or contusion were analysed retrospectively. The uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalents (SE), and endothelial cell density (ECD) were compared before and after the surgery. Results Mean postoperative follow-up time was (11.42±4.51) months. The UCVA was improved in all patients. The mean endothelial cell loss rate was 3.7% in the first 3 postoperative months. 18 eyes achieved the desired anatomic results. No intraoperative complication occurred. Transient high intraocular pressure occurred in 3 cases, 2 cases with iris depigmentation. And no retinal or choroidal detachment, macular edema, hyphema or vitreous haemorrhage was observed. Conclusion Secondary implantation of iris-fixated IOL is an effective and safe procedure for traumatic aphakia, which has good visual rehabilitation and low occurrence of complication. Key words: Aphakia, traumatic; IOL, iris-fixated; Implantation, secondary

Long-term changes of corneal endothelial cells following Artisan phakic intraocular lens implantation

Background Artisan phakic intraocular lens (pIOL) implantation was demonstrated to be safe and effective for the correction of high myopia in short-term.However, long-term corneal endothelium status after operation should be concerned. Objective This study was to investigate the long-term changes of corneal endothelial cell density (ECD) and morphology following Artisan pIOL implantation for the correction of high myopia. Methods Fifty-one eyes of 27 patients who received Artisan PIOL implantation for high myopia from January 2005 to December 2008 were retrospectively analyzed.The central corneal ECDs were detected by corneal endothelial cell counter before surgery and 6 months and 1 year, 2, 3, 4, 5, 6 years after surgery, and the coefficient of variation (CV) and standard deviation (SD) of cellular area were evaluated.ECD loss rate with time lapse was calculated ([preoperative ECD-postoperative ECD]/preoperative ECD×100%). Results Six years after surgery, there were 34 eyes with BCVA≥1.0, 14 eyes with BCVA higher than preoperative and 8 eyes with BCVA lower than preoperative.The mean intraocular pressure was (14.23±2.14)mmHg 6 years postoperative.The preoperative mean ECD was (3 184.05±233.55)/mm2, and the ECD was gradually reduced over time with the cell loss 2.34% in 6 months, 5.32% in 1 year, 6.32% in 2 years, 8.06% in 3 years, 12.59% in 4 years, 15.63% in 5 years and 19.49% in 6 years after operation.Before surgery, The mean CV of cellular area was 37.17±7.12, and the SD of cellular area was 118.77±21.39, and those 6 years after surgery were 32.24±4.62 and 125.60±18.49, respectively.The mean CV and SD of cellular area were significantly different among different time points (P=0.000, 0.036). Eight eyes with localized iris depigmentation, 6 eyes with IOL dyssymmetry, 3 eyes with transient high intraocular pressure and 2 eyes with Macular hemorrhage were obtained after surgery. Conclusions Corneal endothelial cells appear obvious changes in both number and morphology after Artisan pIOL implantation in high myopia.ECD is gradually reduced with time lapse, and the shape of the cells occur remodeling during 6-year fellow-up duration.Overall, endothelial specular microscopy is mandatory before and after surgery for a long term. Key words: Phakic; Intraocular lens; Cornea endothelial cell; High myopia

Influence of transient intraocular pressure elevation during laser in situ keratomileusis on rabbit retina thickness.

To utilize tissue micro measurement to study the effect of transient high intraocular pressure (IOP) induced by different durations of suction during laser in situ keratomileusis (LASIK) on rabbit retina thickness. Sixty healthy New Zealand white rabbits were randomly divided into a control group, and 3 negative-pressure suction groups (20s group, 45s group, and 3min group) and each group was comprised of 15 rabbits (30 eyes); the latter 3 groups were the transient high IOP models. The retinal tissue around the papilledema was separated. Hematoxylin and eosin (HE) staining was carried out to generate slices for light microscopy. The changes in the retina thickness values of each layer were measured for all animals in each group at different postoperative recovery periods and compared with the values recorded for the animals in the control group. The thickness of the retinal tissue showed a normal distribution. The ANOVA was performed by using SPSS13.0 statistic software. In the comparison between the 20s and 45s negative-pressure suction groups and the control group, no significant differences were observed, except at 14d. Significant difference was observed between the 3min negative-pressure suction group and the control group, and the retina thickness value of each layer reached a peak at 14d after repair. Conventional negative suction during LASIK may not lead to significant changes in retinal tissue thickness; however, if the suction duration is increased to 3min, it will cause significant changes in retinal tissue thickness.

The minimal scleral buckling surgery for rhegmatogenous retinal detachment

Objective To analyse the clinical efficacy of the minimal scleral buckling surgery for rhegmatogenous retinal detachments(RRDs). Methods This retrospective study was performed on 165 eyes of 162 patients of rhegmatogenous retinal detachments (RRDs). All cases received the minimal scleral buckling surgery , which did not been perform subretinal fluid drainage and sclera buckling limited only to the area of retinal tears. Results In this research, Of the 165 eyes, retina in 156 eyes (94.55%) reattached after the surgery and the subretinal fluid in 154 eyes was completely absorbed within 1 week post operation. There were 4 eyes with superior globular retinal detachment reattached after pneumatic retinopexy, 4 eyes with complicated retinal detachment were performed pars plana vitrectomy, another 1 patient gave up therapy. The results showed that complications of this surgery were rare. Some cases (20 eyes, 12.12%) experienced transient high intraocular pressure and returned to normal after medical treatment in 3 to 5 days. There were no intraocular hemorrhage, infection or iatrogenic retinal incarceration. In 3 to 6 months post operation, the refractive state had no difference compared with preoperation. Conclusion the exocular minimal surgery is a kind of segmental buckling and nondrainage surgery. The complication is rare and reoperation rate is low, it is a reasonable surgery for retinal detachment. This surgery is primary suitable for globular rhegmatogenous retina detachment and those retinal detachment with PVR less then level C1. Key words: Retinal detachment, rhegmatogenous; Scleral buckling surgery, minimal

Long-term outcomes of Ahmed glaucoma valve implantation for treating refractory glaucoma

To explore the efficacies and complications of Ahmed glaucoma valve implantation for treating refractory glaucoma. A retrospective study of case series was conducted for 24 patients (26 eyes) with refractory glaucoma from February 2001 to July 2008 at our hospital. Ahmed glaucoma valve implantation was performed. Pre- and post-operative best spectacle-corrected visual acuity (BSCVA), intraocular pressure (IOP), number of medications and complications were recorded and analyzed. The follow-up period was 58-159 months. The post-operative values of IOP were 13.02+/-6.79, 11.43+/-5.24 and 18.56+/-6.43 mmHg at 1 day, 1 month and the last follow-up respectively. There were significant difference when compared with pre-operative IOP (37.59+/-10.76 mmHg, P < 0.01). And 65.38% of eyes maintained or gained ≥ 1 line of BSCVA. But there was no significant difference with pre-operative BSCVA (P = 0.110). Twenty eyes required anti-glaucoma drugs after glaucoma valve implantation and the average number of medication was 1.72+/-0.98. There was significant difference with the pre-operative medication number 2.7 ± 0.7 (P = 0.001). The surgical success rate was 73.1%. And the causes of failure were endophthalmitis, corneal endothelial decompensation, persistent conjunctival wound non-healing, glaucoma valve exposure and loss of light perception.Early postoperative complications were ocular hypotony, shallow anterior chamber, hyphema, transient high IOP and tube occlusion. And long-term complications included encapsulated cyst formation, tube exposure, corneal endothelial decompensation and endophthalmitis. Ahmed glaucoma valve implantation is efficacious for refractory glaucoma.However, clinicians should pay attention to the prevention and treatment of complications.

Outcomes of Outpatient Fluid-Gas Exchange for Open Macular Hole After Vitrectomy

To report the efficacy and safety of outpatient fluid-gas exchange for open macular hole after primary vitrectomy. Retrospective interventional case series. setting: Institutional. patients: Thirty-six patients with primary failed closure or reopened holes after primary vitrectomy. intervention: Fluid-gas excahnge with 15% perfluoropropane (C3F8) or 20% sulfur hexafluoride (SF6) was performed to reclose the hole under topical anesthesia. main outcome measures: The hole closure rate and type, pre- and postexchange best-corrected visual acuity (BCVA), and complication rates were assessed. Thirty-two eyes (89%) achieved anatomic success from 1-3 weeks after the fluid-gas exchange. Twenty-two eyes (61%) achieved type 1 closure, 10 eyes (28%) achieved type 2 closure, and 4 eyes (11%) did not achieve closure. The BCVA for type 1 closure improved significantly from logarithm of the minimal angle of resolution (logMAR) 1.66 ± 0.41 to 0.84 ± 0.41, with a P value <.001. The BCVA for type 2 closure improved from logMAR 1.77 ± 0.41 to 1.52 ± 0.41, with a P value of .05. All patients with an unclosed hole after fluid-gas exchange had a stage IV macular hole before the primary vitrectomy and a hole size larger than 1000 μm. The complication related to fluid-gas exchange procedure was transient high intraocular pressure, which responded well to topical antiglaucoma medications. There were 2 retinal detachment cases following the exchange; surgery to reattach the retina was performed, with visual acuity recovery. Outpatient fluid-gas exchange is an effective treatment option for eyes with open holes following vitrectomy.

Clinical observation of ICL implantation in high myopia

Objective To observe the efficacy and complication of implantable contact lens (ICL) implantation in treatment of high myopia.Methods 89 cases(114 eyes) diagnosed as high myopia were treated with ICL implantatioin.Uncorrected visual acuity,best corrected visual acuity,refraction,anterior chamber depth,ocular axial length,corneal endothelial cell density and intraocular pressure were observed.Results After 12 months of observation,the uncorrected visual acuity,best corrected visual acuity and refraction were significantly better than the preoperative one (P ＜ 0.05).While at the aspect of anterior chamber depth,ocular axial length and corneal endothelial cell density,there was no significant change (P ＞0.05).Except for one case of transient high intraocular pressure,the patients had no complications of cataract,glaucoma or pigment dispersion.Conclusion ICL implantation used in treatment in high myopia shows characteristics of predictability,security,stability,reversible and significant effect. Key words: ICL; Implantation; Myopia, high

Microarray-based gene expression profiles in rabbit retina due to negative pressure suction

We investigated a possible molecular pathogenesis involving retinal ganglion cell apoptosis following transient high intraocular pressure. Changes in the gene expression profiles of the retina were detected via gene chip methodology. Twelve New Zealand white rabbits were randomly assigned to control and 3-min negative pressure suction groups. The control group was treated only with a laser, and the experimental group was also treated with suction for 3 min, using a negative pressure generator. Total RNA was then extracted from the retinal tissue at different recovery stages to analyze gene expression profiles using the Agilent rabbit one-way gene chip. The groups were then compared. Immediately after negative pressure suction induction, 704 genes were differentially expressed. Among these, 485 genes were upregulated, and 219 were downregulated. Expression of the genes encoding CRYAA, CRYAB, and TLR3 genes, which are involved in apoptosis, was elevated. The KRT18 gene, which is involved in apoptosis, had reduced expression. Seven days after negative pressure suction, 482 genes were differentially expressed. Among these, 178 genes were upregulated, and 304 were downregulated. Expression of the genes encoding CRYAB, IL1-BETA and IL1R1, which are involved in apoptosis, was upregulated. Ten days after negative pressure suction, 402 genes were differentially expressed. Of these, 213 genes were upregulated, and 189 were downregulated. Apoptosis genes CRYAB, CRYBA3, CRYBB2, IL1- BETA, and IL1R1 showed higher expression levels. We concluded that negative pressure suction for long periods of time (for example, 3 min) results in changes in gene expression. Genes with higher fold changes help protect retinal ganglion cells from apoptosis. We suggest that promoting the expression of these genes should be considered as a new means for treating ischemic-hypoxic retinopathy.

Safety of Vitrectomy for Floaters

To assess the risks of vitrectomy for the removal of primary and secondary vitreous opacities. Retrospective, nonrandomized, interventional case series. We reviewed the results of 116 consecutive cases of vitrectomy for vitreous floaters. Eighty-six cases were primary and 30 cases were secondary floaters. Main outcome measures were the incidence of iatrogenic retinal breaks and postoperative rhegmatogenous retinal detachments. We found iatrogenic retinal breaks in 16.4% of operations. There was no statistically significant difference in risk between cases of primary and secondary floaters. Intraoperative posterior vitreous detachment induction was found to increase significantly the risk of breaks. Retinal detachment occurred in 3 cases (2.5%), all after operations for primary floaters. One case of complicated retinal detachment ended with a low visual acuity of hand movements. Cataract occurred in 50% of phakic cases. Transient postoperative hypotony was found after 5.2% of our operations, and transient postoperative high intraocular pressure was encountered in 7.8%. An intraoperative choroidal hemorrhage occurred in 1 case, which resolved spontaneously. The mean visual acuity improved from 0.20 to 0.13 logarithm of the minimal angle of resolution units. The risk profile of vitrectomy for floaters is comparable with that of vitrectomy for other elective indications. Retinal breaks are a common finding during surgery and treatment of these breaks is crucial for the prevention of postoperative retinal detachment. Patients considering surgery for floaters should be informed specifically about the risks involved.

Clinical application of irrigation in therapeutic keratoplasty for suppurative keratitis with severe hypopyon

To investigate the safety and clinical efficacy of anterior chamber irrigation combined with corneal transplantation in the treatment of corneal ulcer with severe hypopyon. Non-randomized retrospective case series. Twenty patients (20 eyes) suffered from corneal ulcer with severe hypopyon were enrolled in Shandong Eye Hospital from January 2008 to June 2009, and 13 patients with significant corneal endothelial plaque, which hard to determine the lesion edge under microscope. Twenty patients received anterior chamber irrigation combined with penetrating or lamellar keratoplasty treatment; the donors were preserved in the medium-term preservation solution or freeze-dry preservation of glycerine. Intraoperative and postoperative complications, visual acuity, immune rejection were collected as outcome measures. Twenty cases received anterior chamber irrigation combined with corneal transplantation successfully, eleven of which received penetrating keratoplasty (PK) and 9 received lamellar keratoplasty (LK). Ten cases that underwent PK using donors preserved in medium-term solution, and the remaining using donors cryopreserved at -20 degrees C. Intraoperative complications include bleeding iris (11 cases), postoperative complications including iris adhesions (8 cases), transient high intraocular pressure (4 cases), anterior chamber hemorrhage (5 cases), and were cured after drug treatment. One case suffered recurrence of fungal keratitis and received repeat PK. Four cases occurred endothelial immune rejection, 3 cases were controlled and 1 case occurred graft failure after anti-rejection treatment. In the final follow-up in December 2009, 17 grafts were clear and 3 grafts were edema. In the treatment of severe corneal ulcer with hypopyon, anterior chamber irrigation combined with penetrating or lamellar keratoplasty is an effective and a safety method.

KR-31378, a Potassium-Channel Opener, Induces the Protection of Retinal Ganglion Cells in Rat Retinal Ischemic Models

KR-31378 is a newly developed K(ATP)-channel opener. To investigate the ability of KR-31378 to protect retinal ganglion cells (RGC), experiments were conducted using two retinal ischemia models. Retinal ischemia was induced by transient high intraocular pressure (IOP) for acute ischemia and by three episcleral vein occlusion for chronic retinal ischemia. KR-31378 was injected intraperitoneally and administered orally in the acute and chronic ischemia models, respectively. Under the condition of chronic ischemia, RGC density in the KR-31378-treated group was statistically higher than that in the non-treated group, and IOP was reduced. In the acute retinal ischemia model, 90% of RGC were degenerated after one week in non-treated retina, but, RGC in KR-31378-treated retina were protected from ischemic damage in a dose-dependent manner and showed inhibited glial fibrillary acidic protein (GFAP) expression. Furthermore, the KR-31378 protective effect was inhibited by glibenclamide treatment in acute ischemia. These findings indicate that systemic KR-31378 treatment may protect against ischemic injury-induced ganglion cell loss in glaucoma.

Research on Influences of Transient High IOP during LASIK on Retinal Functions and Ultrastructure

Objectives. To study the influences of transient high intraocular pressure(IOP) during LASIK on retinal functions and ultrastructure. Methods. Thirty-two New Zealand white rabbits were randomly divided into normal control, experimental control, negative suction 20 s and negative suction 3 min groups. The experimental control group was treated only by laser. Rabbit eyes received suction for different periods of time (20 s, 3 min) by negative pressure generator in different groups. The changes of neuro-optic and retinal ultrastructure were observed under electron and light microscopes; retinal neurofunctional changes were observed with flash-visual evoked potential (F-VEP) and flash-electroreinogram (F-ERG). Results. There was no obvious change in optic nerve, retina, ERG a-wave and b-wave in normal control and experimental control groups. There were slight changes in tissues of optic nerve and retina at various times of suction 20 s compared with control group, and a sharp change in suction 3 min group within 14d after operation, but these changes recovered at 28d . Amplitude of ERG b-wave observed at different time will decrease with suction periods prolonged. It can recover to normal level with the prolonged recovery periods. Amplitude and incubation period of ERG a-wave and VEP-P did not change significantly after different duration of suction. Conclusions. The transient high IOP during LASIK might have influence on retinal function and ultrastructure, but these changes were reversible.