Vitrectomy Group Research Articles

Traumaassoziierte rhegmatogene Netzhautablösung im Kindesalter

Rhegmatogenous retinal detachments (RRD) in children and adolescents are uncommon and present about 3-5 % of all retinal detachments. Etiology, pathogenesis and therapy differ significantly from adults. The current study addresses juvenile RRD after trauma to contribute to the limited knowledge about this condition. The current study includes 27 eyes of 25 patients aged up to 18 years that were operated on between 2000 and 2012. They presented 42.4 % of all RRD of that age group. We analyzed the following parameters: demographic data, retinal detachment characteristics, surgical techniques and outcomes. Mean age was 15,3 years and 77 % were boys. Retinal detachment occurred between 3 days and 11 years after trauma (median: 3,5 months). Two thirds of RRDs were classified as acute, the remainder showed symptoms of chronicity, e.g. pigment demarcation and subretinal strands or PVR. The macula was detached in 81,5 %. Retinal dialysis was the most common type of break (44,8), followed by giant retinal tears (18,5 %). In 3 out of 5 eyes with severe PVR due to self-aggressive behavior a causative retinal defect was not identified. Episcleral buckling surgery was the preferred method in any case that deemed manageable with a segmental sponge or encircling band (14 eyes). Primary vitrectomy was performed in more complex retinal detachments (13 eyes), and most of them had silicone oil tamponade. Primary reattachment was achieved in 83 % in the buckling group and 80 % in the vitrectomy group (3 eyes with self-harm excluded). Finally, all eyes had attached retinas. Postoperatively, visual acuity improved or remained stable in successfully treated eyes. Late complications in the vitrectomy group were cataract development in half of the phakic eyes. Retinal dialysis and giant retinal tears are the most frequent retinal lesions in posttraumatic RRD. Delayed diagnosis is a common problem, as most of the cases preset with macula-off detachments and clinical signs of chronic RRD. A conventional approach to traumatic RRD using scleral buckling techniques is recommended whenever possible. Differently from adults, strong vitreoretinal adhesions are present and the vitreous is rarely detached which makes a complete vitrectomy challenging. Furthermore there is a significant risk of postoperative cataract despite of the young age. However, cases with giant retinal tear and complex detachments due to PVR require vitrectomy maneuvers, usually with the use of silicone oil. A special subgroup presents PVR-detachments due to chronic auto-aggressive behavior of disabled young patients. Despite of extreme vitreoretinal maneuvers used, those eyes might be inoperable or late failures due to chronic aggressive PVR. On the whole, delayed diagnosis and advanced RRD limit final vision. However, after successful surgery, approximately half of the eyes improve, many retain vision. As preserving vision in young patients is of great impact for their whole lifespan, any attempt should be made to achieve a stable retinal situation.

PARS PLANA VITRECTOMY IN THE MANAGEMENT OF PATIENTS DIAGNOSED WITH ENDOPHTHALMITIS FOLLOWING INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR INJECTION

To evaluate the possible benefit of pars plana vitrectomy in the treatment of patients with endophthalmitis following antivascular endothelial growth factor (VEGF) injection. The authors retrospectively reviewed the medical records of all patients in their practice with a diagnosis of endophthalmitis from January 1, 2007, through December 31, 2011. Only those with a clinical presentation consistent with endophthalmitis after intravitreal anti-VEGF injection were included. Clinical data that were collected and recorded included visual acuities and the method of initial and subsequent treatment of endophthalmitis following anti-VEGF injection: tap and injection of intravitreal antibiotics (TAP) and tap and inject with subsequent pars plana vitrectomy (VIT). The authors identified 23 patients meeting criteria. Nineteen patients had received bevacizumab and four patients had received ranibizumab. The median time from last injection to presentation was 4 days (range, 1-18 days) with a median follow-up of 15 months (range, 5-48 months) after being diagnosed of endophthalmitis. Nine patients had positive cultures. The median baseline visual acuity (preendophthalmitis) was 20/70 (range, 20/25 to counting fingers at 2 ft) with a median presenting visual acuity of counting fingers at 1 ft (range, 20/50 to light perception vision). Overall, 90% (9/10) of the patients in TAP only group regained visual acuity within 1 line or better of baseline versus 46% (6 of 13) in the TAP and VIT group. Only one of the patients treated with TAP alone suffered more than one line of visual acuity loss. Patients diagnosed with endophthalmitis after anti-VEGF intravitreal injection who underwent TAP regained baseline visual acuity more often than those who underwent TAP and VIT. This study did not support a benefit for VIT in all patients, rather only in those cases who warranted it because of worsening clinical course. The study suggests that TAP is a viable primary intervention for endophthalmitis after anti-VEGF injection.

Strategy for the Management of Uncomplicated Retinal Detachments: The European Vitreo-Retinal Society Retinal Detachment Study Report 1

To study success and failure in the treatment of uncomplicated rhegmatogenous retinal detachments (RRDs).Nonrandomized, multicenter retrospective study.One hundred seventy-six surgeons from 48 countries spanning 5 continents provided information on the primary procedures for 7678 cases of RRDs including 4179 patients with uncomplicated RRDs.Reported data included specific clinical findings, the method of repair, and the outcome after intervention.Final failure of retinal detachment repair (level 1 failure rate), remaining silicone oil at the study's conclusion (level 2 failure rate), and need for additional procedures to repair the detachment (level 3 failure rate).Four thousand one hundred seventy-nine uncomplicated cases of RRD were included. Combining phakic, pseudophakic, and aphakic groups, those treated with scleral buckle alone (n = 1341) had a significantly lower final failure rate than those treated with vitrectomy, with or without a supplemental buckle (n = 2723; P = 0.04). In phakic patients, final failure rate was lower in the scleral buckle group compared with those who had vitrectomy, with or without a supplemental buckle (P = 0.028). In pseudophakic patients, the failure rate of the initial procedure was lower in the vitrectomy group compared with the scleral buckle group (P = 3×10(-8)). There was no statistically significant difference in failure rate between segmental (n = 721) and encircling (n = 351) buckles (P = 0.5). Those who underwent vitrectomy with a supplemental scleral buckle (n = 488) had an increased failure rate compared with those who underwent vitrectomy alone (n = 2235; P = 0.048). Pneumatic retinopexy was found to be comparable with scleral buckle when a retinal hole was present (P = 0.65), but not in cases with a flap tear (P = 0.034).In the treatment of uncomplicated phakic retinal detachments, repair using scleral buckle may be a good option. There was no significant difference between segmental versus 360-degree buckle. For pseudophakic uncomplicated retinal detachments, the surgeon should balance the risks and benefits of vitrectomy versus scleral buckle and keep in mind that the single-surgery reattachment rate may be higher with vitrectomy. However, if a vitrectomy is to be performed, these data suggest that a supplemental buckle is not helpful.The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Scleral buckling versus vitrectomy for macula-off rhegmatogenous retinal detachment as accessed with spectral-domain optical coherence tomography: a retrospective observational case series.

BackgroundScleral buckling surgery and pars plana vitrectomy are competing methods in the treatment of retinal detachment. The recent development of spectral-domain optical coherence tomography (SD-OCT) has dramatically improved the visualization of the photoreceptor layer relative to conventional OCT, and offers new opportunities to investigate the discordances between anatomic and functional outcomes after retinal detachment surgery. Hence, the study aim was to use SD-OCT to compare the postoperative macular recovery between scleral buckling and vitrectomy for macular-off rhegmatogenous retinal detachment.MethodsIn this retrospective observational case series, we observed 32 patients who underwent scleral buckling surgery (group 1) and 26 patients who underwent pars plana vitrectomy (group 2) as the primary surgery for macula-off rhegmatogenous retinal detachment. OCT was used to examine microstructural changes in the macular area.ResultsThe mean visual acuity improvement was 0.4 ± 0.8 logMAR in group 1 and 0.7 ± 0.9 logMAR in group 2. As detected by SD-OCT, subretinal fluid was present in 26 of the group 1 eyes (81.3%) and 5 of the group 2 eyes (19.2%) at 8 weeks postoperatively.This difference was statistically significant (Fisher’s exact test, P < 0.05). Moreover, detection by SD-OCT revealed epiretinal membranes in 5 of the group 1 eyes (15.6%) and 11 of the group 2 eyes (42.3%), a difference that was statistically significant (Fisher’s exact test, P < 0.05).ConclusionsMacular recovery and the mean visual acuity differed between the 2 groups of patients. With the help of SD-OCT, we observed that subretinal fluids could persist for a relatively longer period after scleral buckling. Based on our results, we conclude that primary vitrectomy surgery is a better choice for macular recovery of the macula-off rhegmatogenous retinal detachment.

VITRECTOMY AND PANRETINAL PHOTOCOAGULATION REDUCES THE OCCURRENCE OF NEOVASCULAR GLAUCOMA IN CENTRAL RETINAL VEIN OCCLUSION WITH VITREOUS HEMORRHAGE

The purpose of this study was to evaluate the best-corrected visual acuity and occurrence of neovascular glaucoma with vitrectomy (VT) and panretinal photocoagulation or without VT in central retinal vein occlusion (CRVO) associated with vitreous hemorrhage (VH). The charts from patients diagnosed as having CRVO with VH at Chang Gung Memorial Hospital (Taiwan) were reviewed. They were grouped based on whether they also underwent VT. The main outcome measurements were the best-corrected visual acuity and incidence of neovascular glaucoma. There were 83 eyes that had CRVO with VH from 83 patients (VT group, 56 eyes; non-VT group, 27 eyes). There was no significant difference between the VT and non-VT groups in terms of age, gender, diabetes, hypertension, lens status, and follow-up period. The non-VT group had a better best-corrected visual acuity (P = 0.018) and less VH (P = 0.025) than the VT group at baseline; however, the VT group had a better best-corrected visual acuity at the end of the follow-up than the non-VT group (P < 0.001). Most importantly, there was a higher neovascular glaucoma development (37%) in the non-VT group compared with that (14.3%) in the VT group (P = 0.025). The visual outcomes of CRVO with VH are unfavorable whether VT was performed. However, VT and panretinal photocoagulation improved visual acuity and reduced the incidence of neovascular glaucoma in CRVO with VH.

Intravitreal Avastin as an adjunct in patients with proliferative diabetic retinopathy undergoing pars plana vitrectomy

Intravitreal Bevacizumab (Avastin, Genentech Inc., San Francisco, CA) (IVB) has been shown to cause regression of neovessels in proliferative diabetic retinopathy due to its anti-angiogenic effects. This study was performed to investigate the role of Avastin as an adjunct to the management of patients with proliferative diabetic retinopathy undergoing pars plana vitrectomy. Fifty four eyes of 54 patients with proliferative diabetic retinopathy scheduled for surgery were included in the study. They were randomized to vitrectomy with preoperative IVB (group one) or standard vitrectomy (group 2). Group one underwent a single intravitreal injection of bevacizumab 1.25 mg /0.05ml one week prior to vitrectomy. Main outcome measures were best corrected visual acuity (BCVA) after surgery, post-operative complications. Mean age of the patients was 52.07±5.54 years (range 39-67). At 6 months, 20 patients in group one had BCVA better than baseline as compared to 12 patients in group 2. In group one, only one patient had early post-operative vitreous hemorrhage, whereas 11 patients in group two had early vitreous hemorrhage. Preoperative IVB is helpful in improving BCVA post operatively, reducing the time of surgery, decreasing the incidence of intraoperative and postoperative bleeding and reducing the frequency of rubeosis and hyphaema.

Influence of intravitreal avastin on the expression of cell factors in retinal proliferative membrane in proliferative diabetic retinopathy eye

Background A main cause of visual impairment in proliferative diabetic retinopathy (PDR) is vitreous hemorrhage and retinal detachment due to contraction of fibrovascular membrane.To explore the pathogenic mechanism of fibrovascular membrane is a new target for the prevention and management of PDR.Objective This study was to determine the change in expression of vascular endothelial growth factor (VEGF),connective tissue growth factor(CTGF) and pigment epithelium derived factor(PEDF) in the proliferative membranes of patients with PDR after intravitreal injection of avastin,an anti-VEGF agent.Methods This study was approved by the Medical Ethic Committee of Tianjin Medical College,and written informed consent was obtained from each patient before enrollment.A prospective randomized-controlled study was designed.Twenty-six eyes of 24 patients with PDR scheduled for surgery were enrolled from January to June,2008 in Tianjin Medical College Eye Hospital.The patients were randomized into the simple vitrectomy group and avastin injection combined with vitrectomy group,with matched gender,age and disease duration.1.25 mg (0.05 ml) of avastin was intravitreally injected prior to surgery,and vitrectomy was performed 10 days after injection in the avastin injection combined with vitrectomy group,and only vitrectomy was given in the simple vitrectomy group.Preretinal membrane was collected during the surgery.Expression of VEGF,CTGF and PEDF in the preretinal membranes was assayed by immunochemistry.Results VEGF,CTGF and PEDF were expressed in the cytoplasm.The rate of VEGF expression in the preretinal membranes was 30.77％ in the avastin injection combined with vitrectomy group,showing a significant reduction in comparison with the simple vitrectomy group(100.00％)(U =4.000,P＜0.01).The rate of expression CTGF was remarkable elevated in the avastin injection combined with vitrectomy group compared with the simple vitrectomy group (92.31％ vs.62.54％)(U=7.500,P=0.048).However,no significant difference was found in the expression rate of PEDF between the two groups(100.00％ vs.92.31％) (U =65.500,P =0.299).Conclusions The results suggest that intravitreal injection of anti-VEGF drugs resulted in the decrease of VEGF expression and increased CTGF expression in proliferative membranes from patients with PDR. Key words: Anti-vascular endothelial growth factor/avastin; Diabetic retinopathy; Retinal proliferative membrane; Vascular endothelial growth factor; Connective tissue growth factor; Pigment epithelium derived factor

Comparison of the 20-Gauge Conventional Vitrectomy Technique with the 23-Gauge Releasable Suture Vitrectomy Technique

PurposeTo compare the efficacy of the transconjunctival releasable suture technique for pars plana vitrectomy using 23-gauge (23G) instruments versus the conventional 20-gauge (20G) technique.MethodsA retrospective and interventional case series was consecutively performed for 199 eyes of the 192 patients that were a part of this study. Clinical data were reviewed retrospectively regarding the operation time, preoperative and postoperative intraocular pressure, visual acuity and astigmatism for 54 consecutive patients who received a 23G releasable suture vitrectomy and for 98 consecutive patients who received a 20G conventional vitrectomy during the period between April 2007 and September 2010.ResultsMean operation time based on the operation record was 88.5 ± 20.1 minutes in the 23G releasable suture vitrectomy group and 102.1 ± 23.1 minutes in the 20G conventional vitrectomy group, respectively (p = 0.01). The last best-corrected visual acuity (BCVA) was significantly better than the preoperative BCVA in both patient groups (p = 0.01, p = 0.01). The 23G releasable suture group showed less surgically induced astigmatism than the 20G conventional vitrectomy group. Vitreous bleeding was observed to be in 6 eyes (5.9%) in the 23G group, and in 8 eyes (8.2%) in the 20G group. In addition, ocular hypertension was noted to be in 3 eyes (3.0%) in the 23G group, and 6 eyes (6.1%) in the 20G group. No serious complications such as postoperative hypotony or endophthalmitis were observed in either group.ConclusionsThe 23G releasable suture technique is as effective as the 20G conventional technique and offers several advantages.

Pars plana vitrectomy for disturbing primary vitreous floaters: clinical outcome and patient satisfaction

Primary vitreous floaters can be highly bothersome in some patients. In the case of persistently bothersome floaters, pars plana vitrectomy may be the most effective treatment. The aim of this study is to evaluate the incidence of complications, and patient satisfaction, after pars plana vitrectomy for disabling primary vitreous opacities. We included a total of 110 eyes that underwent pars plana vitrectomy between February 1998 and August 2010. Fifty-seven eyes (51.8%) underwent 20-gauge vitrectomy, whereas 53 eyes (48.2%) underwent 23-gauge vitrectomy. In a retrospective manner, we assessed intraoperative and postoperative complications. There was a considerable range of time between surgery and questionnaire (range: 4-136 months). Patient satisfaction was assessed by a questionnaire based on a modified NEI VFQ-25 questionnaire. A retinal detachment occurred in 10.9% of cases, and the incidence did not differ significantly between the 20-gauge and 23-gauge vitrectomy groups. In 4.5% of the eyes, a retinal detachment developed within the first 3 months, and 6.4% occurred later in the postoperative period. Cystoid macular edema occurred in 5.5%, and an epiretinal membrane was seen postoperatively in 3.6% of cases. Development of glaucoma requiring glaucoma surgery, a macular hole, and postoperative scotoma, each occurred in 0.9% of cases. No cases of endophthalmitis occurred. Eighty-five percent of patients were satisfied or very satisfied with the results of the vitrectomy. Eighty-four percent of all patients were completely cured from their troublesome vitreous floaters, and an additional 9.3% of patients were less troubled by vitreous floaters. Ten patients (9.3%) were dissatisfied, and six of these patients (5.6%) had a serious complication that resulted in permanent visual loss. Pars plana vitrectomy is an effective approach to treat primary vitreous floaters, resulting in a high rate of patient satisfaction. Postoperative complications may be more frequent than previously reported, so patients should be well-informed about the complication rate before reaching informed consent about this surgical intervention. Additional preventive measures should be considered to reduce this complication rate.

The clinical study of early post-cataract surgery capsular block syndrome

Objective To discuss the causes,prevention and treatment of persistent high intraocular pressure caused by early capsular block syndrome (CBS) after phacoemulsification and intraocular lens (IOL) implantation.Methods 54 patients who developed early postoperative CBS were included in this study.22 cases received anterior vitrectomy and anterior chamber gas injection,19 cases received YAG laser anterior or posterior capsulotomy,13 cases only received medication to drop intraocular pressure.Statistical data was analysed by SPSS 13.0 software package to compare the efficacy of treatment.Results The corrected visual acuity improved after one week of treatment,there was no significant difference between the three groups (P =0.594).The high intraocular pressure relieved,there was significant difference (P =0.048).After three months of follow-up,there was no significant difference between the three groups of corrected visual acuity (P =0.240),but there was significant difference of IOP (P =0.030).Furthermore,there was no significant difference of IOP between the vitrectomy group and laser group (P =0.725),but the IOP of the vitrectomy group and laser group was significantly better than that of medication group (P =0.004,P =0.033).Conclusion The early postoperative CBS can be prevented by expansion of capsulorhexis diameter,selecting appropriate intraocular lens,and improving surgical skills to complete removal of the viscoelastic material.When the medication fails,early operation of anterior vitrectomy and anterior chamber gas injection can effectively reduce intraocular pressure and improve corrected visual acuity,which may achieve the same effect of laser treatment. Key words: Post-cataract surgery; Capsular block syndrome; High intraocular pressure ; Anterior vitrectomy ; YAG laser

Acute retinal necrosis: factors associated with anatomic and visual outcomes

To examine the factors associated with anatomic and visual outcomes in Japanese patients with acute retinal necrosis (ARN). One hundred four patients with ARN who were followed for more than 1 year at nine referral centers were reviewed. Retinal involvement at initial presentation was classified into four groups: zone 1 (posterior pole, n = 22), zone 2 (midperiphery, n = 54), zone 3 (periphery, n = 25), and unknown (n = 3). Forty-eight eyes underwent prophylactic vitrectomy before development of retinal detachment (vitrectomy group); 56 eyes were treated conventionally without prophylactic vitrectomy (observation group). The retina was attached in 28 of 48 eyes (58.3 %) in the vitrectomy group and 42 of 56 eyes (75.0 %) in the observation group at the final visit (P = 0.071). At 1 year, 56 eyes (53.8 %) had a best-corrected visual acuity (BCVA) of 20/200 or worse. Multivariate logistic regression analyses identified zone 1 disease (odds ratio = 4.983) and optic nerve involvement (odds ratio = 5.084) as significantly associated with BCVA of 20/200 or worse. Among the zone 3 eyes, significantly (P = 0.012) more eyes in the observation group than in the vitrectomy group had an attached retina. Prophylactic vitrectomy did not improve the final BCVA in any eyes. Zone 3 eyes had better outcomes without prophylactic vitrectomy.

EARLY POSTOPERATIVE INTRAOCULAR PRESSURE STABILITY AFTER COMBINED 23-GAUGE SUTURELESS VITRECTOMY AND CATARACT SURGERY IN PATIENTS WITH PROLIFERATIVE DIABETIC RETINOPATHY

To compare rates of early postoperative hypotony and intraocular pressure (IOP) elevation between 23-gauge sutureless vitrectomies with and without phacoemulsification and intraocular lens implantation in patients with proliferative diabetic retinopathy. This study reviewed the medical records of 302 eyes of patients who underwent primary 23-gauge sutureless vitrectomy for the complications of proliferative diabetic retinopathy. A case series of 207 eyes that underwent combined vitrectomy and cataract surgery (combined group) was compared with that of 95 eyes that underwent vitrectomy only (vitrectomy group): The eyes that remained phakic after the vitrectomy were excluded from this study. The main outcome measures were postoperative hypotony (IOP < 6 mmHg or IOP < 10 mmHg with choroidal detachment) and IOP elevation (>30 mmHg). Postoperative hypotony was identified in 4 (1.9%) of 207 eyes in combined group, but in 7 (7.4%) of 95 eyes in vitrectomy group (P = 0.048). Rate of IOP elevation was very low and not different between the two groups. The multivariate analysis showed that vitrectomy without cataract surgery was associated with the postoperative hypotony (odds ratio = 4.6, P = 0.045). The incidence of early postoperative hypotony was lower in combined sutureless vitrectomy and cataract surgery than in sutureless vitrectomy alone and that of IOP elevation was very low in both groups. The maintenance of a stable IOP with a low risk of IOP fluctuation may be an additional advantage of sutureless diabetic vitrectomy combined with cataract surgery.

Efficacy and necessity of prophylactic vitrectomy for acute retinal necrosis syndrome.

To compare the efficacy of prophylactic vitrectomy for acute retinal necrosis syndrome(ARN) with routine treatment in Chinese patients, thereby investigate the necessity of prophylactic vitrectomy for ARN. Thirty patients (37 eyes) were retrospectively included in this study. The eyes were divided into 2 groups by treatment, including routine treatment, which consisted of antiviral medication and vitrectomy after retinal detachment (RD) (n=21), and prophylactic vitrectomy, which consisted of antiviral medication and vitrectomy for the prevention of RD performed during the active inflammatory phase (n=16). The extent of necrosis was determined by fundus photographs at the time of presentation (for eyes with mild vitreous opacity) or the drawings in the operation records. Necrosis of the 37 eyes was divided into 3 grades, including peripheral, middle-peripheral and extensive. The follow-up period ranged from 8 to 57 months. Differences in visual acuity and necrosis between groups were identified using independent samples t-test. Necrosis was more extensive in the routine treatment group than in the prophylactic vitrectomy group (P<0.05). In the routine treatment group, conservative treatment improved necrosis and prevented RD in 6 eyes (29%). Seven eyes (33%) obtained anatomical success, but retinal redetachment occurred in 8 eyes (57%). There were also 5 eyes (24%) developed ocular hypotony or atrophy. Ten eyes (48%) achieved equal or increased visual acuity. In the prophylactic vitrectomy group, RD occurred in 2 eyes (13%). Twelve eyes (75%) were completely anatomically successful, and 10 eyes underwent silicone oil removal. Only one eye (6%) became ocular hypotony. Fourteen eyes (88%) achieved equal or increased visual acuity. The prophylactic vitrectomy group achieved better vision trends than the routine treatment group (P<0.05). Eyes with peripheral necrosis had better visual outcomes than those with mid-peripheral (P<0.05) or extensive (P<0.05) necrosis. However, there was no significant difference between eyes with mid-peripheral and extensive necrosis (P=0.3008) Prophylactic vitrectomy can prevent RD and improve the prognosis of ARN, making it an option for cases with rapidly progressing necrosis despite antiviral treatment and cases with moderate to extensive necrosis and severe vitreous opacity.

Comparison of 23G and 20G vitrectomy for treatment of proliferative diabetic retinopathy

Objective To compare the outcomes of 23G and 20G vitrectomy in treatment of proliferative diabetic retinopathy (PDR).Methods This was a prospective randomized study.One hundred twenty six patients (142 eyes) suffering from PDR with symptoms requiring vitrectomy were randomly divided into 20G vitrectomy group (66 patients,74 eyes) and 23G vitrectomy group (60 patients,68 eyes).Visual acuity,intraocular pressures,indirect ophthalmoscopy,B-scan ultrasound,tear film break up time (BUT),Schirmer I test (S I T),astigmatic power and the astigmatic axial at 6 mm area of anterior and posterior corneal surface were observed and measured before surgery.The follow-up period was 15.0 and 12.5 months separately in 20G and 23G groups.Intraoperative complications,operation time,postoperative visual acuity,intraocular pressure,postoperative complications,re-operation,and postoperative ocular conditions including changes of astigmatic power and the astigmatic axial measurements were analyzed.Results At last follow-up,there was 49 eyes (66.2％) and 47 eyes (69.1％) with visual acuity ≥0.05 in 20G and 23G groups.Comparing visual acuity ≥0.05,there was no statistical difference between the groups (x2=0.14,P＞0.05).The eyes suffering from iatrogenic injuries were 18 (24.3％) and seven (10.3％).There was obvious difference in iatrogenic injury between the two groups (x2=4.81,P＜0.05).The mean surgical times were (69.0±8.2) and (51.0±6.3) minutes in 20G and 23G group,which was significantly different (t=3.65,P＜0.05).The postoperative third day,hypotony was detected in three (4.1％) and 11 eyes (14.7％) in 20G and 23G group,which was a significantly different (x2=5.85,P＜0.05).Postoperatively high intraocular pressures were not significantly different between the two groups (x2=2.54,P＞0.05).There were 24 (32.4％) and 14 eyes (20.6％) in 20G and 23G group.There were significant differences in BUT,S I T,astigmatic power and the astigmatic axial measurements compared with those preoperatively at the first month after operation (t=3.35,4.12,-3.12,-3.22; P＜0.05),but no significant differences in them at the third and sixth month after operation (third month:t =0.45,0.98,-2.12,-1.02; P＞0.05,and the sixth month:t=0.95,1.48,-1.02,-2.11; P＞0.05).In 23G group,there were no significant differences in BUT,S I T,astigmatic power and the astigmatic axial measurements compared with those preoperatively at the first,third and sixth month after operation (first month:t=l.21,1.46,-2.32,-1.61; P＞0.05,third month:t=1.45,2.21,-2.19,-1.89; P＞0.05,and sixth month:t=1.92,1.25,-1.76,-2.35; P＞0.05).Conclusion 23G vitrectomy is a safe and effective treatment for PDR with shorter surgery time,fewer surgical complications and postoperative ocular surface changes. Key words: Diabetic retinopathy/surgery; Vitrectomy; Comparative study

Comparison of 23G and 20G vitrectomy for treatment of infectious endophthalmitis

Objective To compare the outcomes and safety of 23G and 20G vitrectomy for treatment of infectious endophthalmitis.Methods This was a retrospective case study.Sixty-seven eyes of 67 eyes suffering from infectious endophthalmitis with a history of trauma or intraocular operation history were enrolled in this study.They were diagnosed by the examinations of best corrected visual acuity,intraocular pressures,slit lamp microscope,indirect ophthalmoscopy,B-scan ultrasound and CT.There were 49 males (49 eyes) and 18 females (18 eyes).The patients aged from 18 to 72 years with a mean age of (43±13)years.There were 60 patients (60 eyes) with a history of trauma,7 patients (7 eyes) with intraocular operation history.The patients were enrolled into 20G vitrectomy group (35 patients,35 eyes) before December,2009 and 23G vitrectomy group (32 patients,32 eyes) after January,2010 when 23G vitrectomy system was imported in this hospital.Vitreous purulence was taken in all patients at the beginning of the surgery for bacteria and fungal culture and drug sensitivity test. A standard vitrectomy with artificial posterior vitreous detachment followed by internal limiting membrane peeling,and (or) intraocular laser photocoagulation,cryocoagulation,fluid-air exchange with intraocular silicone oil or gas tamponade were performed in all eases.Broad-spectrum antibiotics and glucocorticoids were used systematically for one week after surgery,but glucocorticoids were not used for fungal infections.The follow-up was ranged from two to nine months with a mean of (7 ± 1) months.The surgical time,inflammation situation,visual acuity,intraocular pressure, retinal reattachment rare,iatrogenic retinal hole rate, bulbar conjunctiva scar formation rate,reoperation rate and eye retention situation before and after surgery were comparatively analyzed.Results The mean surgical times were (126 ± 12) and (89 ± 12) minutes in 20G and 23G group,which was significantly different (t=3.125,P＜0.05).The major surgery complications were ora serrata dialysis and other iatrogenic retinal breaks,and were occurred in 34 eyes,including 30 eyes (85.71％) in 20G group and 4 eyes (12.50％) in 23G group (x2 =35.85,P＜0.05).These 4 eyes in 23G group received foreign body removal surgery previously.The inflammation was controlled in 65 eyes (97.01％) including 34 eyes (97.14％) and 31 eyes (96.88％) in 20G and 23G group respectively,which was not significantly different (x2=0.004,P＞0.05).At last follow-up,There was no statistical difference of visual acuity between the two groups (t=3.12,P＞0.05).Fourteen eyes underwent silicone oil tamponade including 13eyes (37.14％) and 1 eye (3.13％) in 20G and 23G group respectively,which was significantly different (x2=11.703,P＜0.05).Nine eyes underwent reoperation (13.43％),including 8 eyes (22.86％) and 1eye (3.13％) in 20G and 23G group respectively,which was significantly different (x2=5.597,P＜0.05).The 8 re-operated eyes in 20G group included 1 eye of recurrent endophthalmitis and 7 eyes with retinal detachment,the 1 re-operated eye in 23G group was of recurrent endophthalmitis.There was significantly different (x2=7.147,P＜0.05) for the rate of retinal detachment between the 2 groups.There were 40eyes with bulbar conjunctiva scar including 35 eyes (100.00％) and five eyes (15.63％) in 20G and 23G group.Conclusion 23G vitrectomy is an effective treatment for infectious endophthalmitis with shorter surgery time,lower reoperation rate,lower retinal reattachment rate and fewer bulbar conjunctiva scar. Key words: Endophthalmitis/surgery; Vitrectomy; Comparative study

Long-term Outcomes of Vitrectomy for Progressive X-Linked Retinoschisis

To evaluate the long-term outcomes of vitrectomy for progressive X-linked retinoschisis. Prospective, nonrandomized, consecutive, interventional case series. Twenty-eight eyes of 22 patients who were diagnosed with progressive X-linked retinoschisis were divided into 2 groups: a nonsurgical group (n = 11) and a vitrectomy group (n = 17). The main outcome measures included best-corrected visual acuity, the area of the macular schisis cavity measured by optical coherence tomography, the retinal anatomic status, and complications. The mean follow-up period was 34.7 months (range, 10 to 68 months). The mean best-corrected visual acuity increased from 20/125 at baseline to 20/55 at the final follow-up in the vitrectomy group (P = .001), but decreased from 20/100 at baseline to 20/400 at the final follow-up in the nonsurgical group (P = .000). In the vitrectomy group, the macular schisis cavity resolved in all 17 eyes; the mean area of the macular schisis cavity decreased from 0.85 mm(2) at baseline to 0.23 mm(2) at the final follow-up (P = .000), and the retinas of 16 eyes (94%) were attached after surgery. In the nonsurgical group, retinal schisis progressively extended in 9 eyes (82%); the mean area of the macular schisis cavity increased from 0.82 mm(2) at baseline to 1.21 mm(2) at the final follow-up (P = .000); in 8 eyes (72%), retinal detachment developed, and 2 eyes (18%) experienced vitreous hemorrhage, which terminated the observations. Vitrectomy may be an effective and essential treatment for patients with progressive X-linked retinoschisis to prevent a deterioration of vision before severe complications developed in their eyes.

The clinical observation of combined surgery for proliferative diabetic retinopathy.

Objective To compare the effect of vitrectomy combined with pars plana lensectomy or phacoemulsification,intraocular lens implantation(combined vitrectomy),and pars plana vitrectomy alone on retinal disorders resulting from diabetic retinopathy.Methods The clinical data,vision,and complications of 32 patients(40 eyes)who underwent combined vitrectomy and 28 patients(33 eyes)who underwent vitrectomy alone retrospectively were analyzed.Results Final visual acuity were all improved in the two groups,which was achieved in 31 eyes in group of combined vitrectomy(77.50％),in 22 eyes in group of vitrectomy alone(66.67％).There were significant difference between them(x2 =4.74,P ＜0.05).Five eyes with preoperative iris neovascularization was completely fade away within 1-2 months in combined vitrectomy group,while only 1 eye in vitrectomy alone group.Nine eyes were found postoperative fibrin formation in combined vitrectomy group and only 1 eye in vitrectomy alone group.Seven eyes occurred posterior synechia in combined vitrectomy group and 1 eye in vitrectomy alone group.Conclusion Combined phacoemulsification,intraocular lens implantation with vitrectomy(combined vitrectomy)is safe and effective in treating patients with proliferative diabetic retinopathy.It could avoided second operation for postvitrectomy cataract,and help earlier visual rehabilitation,but it may increase the incidence of fibrin formation and posterior synechia of the iris. Key words: Diabetic retinopathy; Vitrectomy; Phacoemulsification

Influence of vitrectomy for corneal thickness in diaebetic retinopathy eyes with Pentacam

Background The research of corneal thickness after pars plana vitrectomy in DM patient plays an important role not only theoretically but clinically. Objective Present study was to evaluate the change in corneal thickness after pars plana vitrectomy. Methods A prospective coherent study was designed.Seventy-five eyes of 70 consecutive diabetic retinopathy(DR) patients were collected in Tianjin Medical University Eye Center.Pentacam was used to assess the central and periphery corneal thickness by the same investigator preoperatively and 7 days,1 and 3 months postoperatively,respectively.The thickness values from five corneal zone were obtained,including cornea vertex,the thinnest point of the cornea,periphery cornea near the scleral incision of 4 mm away to vertex of cornea on vertical and 240°,120°,60° meridian ( right eye) or 300°,120°,60° meidian ( left eye ).These results were compared and analyzed with ANOVA of repeated measurement data.Subgroup analysis was performed to evaluate the influence of different corneal positions,the use of conventional 20g or 23g transconjunctival sutureless vitrectomy(TSV) groups,surgery duration,gas or fluid endotamponde on corneal thickness.This study was approved by Ethic Committee of this hospital.Written informed consent was obtained from the subjects before any relative medical procedure. Results The mean corneal thickness was ( 639.9 ± 103.1 ),( 689.5 ± 119.3 ),( 666.5 ±113.7),( 650.8 ± 108.6 ) μm before operation,postperative 7 days,1 and 3 months respectively.As covariates appearing in the model,the corneal thickness change rates were revised as the parameters as following: diabeitc duration =13.0 and age =57.2.The revised corneal thickness was significant different among various time points( F=210.928,P=0.000) and different corneal zones(F=24.843,P=0.000) with the size order in turn P4＞P3＞P1＞P2＞P5.The corneal thickness change rates were less in 23g TSV group compared with conventional 20-g group (F =53.843,P =0.000) and BSS tamponade group compared with gas tamponade group ( F =5.288,P =0.022).But no significant difference was found in the revised corneal thickness among surgery duration ＜ 1 hour group,1-2 hour group and ＞2 hour group( F=1.233,P =0.293). Conclusions Vitrectomy is a safe procedure on the ground of cornea,but TSV and fluid endotamponade appear to be more beneficial to the protection of cornea.Pentacam could offer the reliable data in not only central cornea but also periphery cornea. Key words: Corneal thickness/center, periphery; Transconjunctival sutureless vitrectomy; Diabetic retinopathy

Comparison of Efficacy and Safety between Transconjunctival 23-Gauge and Conventional 20-Gauge Vitrectomy Systems in Macular Surgery

PurposeTo compare the efficacy and safety of 23-gauge transconjunctival vitrectomy with the conventional 20-gauge method in idiopathic epiretinal membrane and macular hole surgery.MethodsSixty-one consecutive patients undergoing vitrectomy for idiopathic epiretinal membrane and macular hole were recruited to either 20- or 23-gauge vitrectomy groups and prospectively evaluated. Surgical success rates, operating time, surgery-related complications, long-term visual outcomes, and postoperative ocular surface problems are compared in the two groups.ResultsThere were 31 eyes in the 20-gauge group and 33 eyes in the 23-gauge group. The macular hole closure rate after the first surgery was 83% and 90.9% in the 20-gauge and 23-gauge groups, respectively, with no significant difference between groups (p = 0.59). The success rate for idiopathic epiretinal membranes cases was 100% in both groups. There was no statistically significant difference between overall surgical times (p = 0.90). None of the patients in either group experienced postoperative complications of severe postoperative hypotony, vitreous hemorrhage or endophthalmitis, except one eye in the 20-gauge group, which was found to have retinal detachment. In both groups, statistically significant improvement in visual acuity was achieved 1-month postoperatively (p = 0.002) and thereafter at all postoperative visits (p < 0.05). The mean ocular surface scores were significantly lower in the 23-gauge group at all postoperative visits compared with the 20-gauge group scores (p = 0.001).ConclusionsTransconjunctival 23-gauge vitrectomy appears to be as effective and safe as conventional 20-gauge vitrectomy in idiopathic epiretinal membrane and macular hole surgeries.

A pharmacokinetic study of vancomycin injected into the vitreous of rabbit eyes with endophthalmitis in different pathological conditions

Objective To observe the concentration of vancomycin and the changes of pharmacokinetic parameters in rabbit vitreous with endophthalmitis in different pathological conditions.Methods Eighty-one adult healthy rabbits were randomly divided into endophthalmitis with lens group (group A),aphakic endophthalmitis group (group B),aphakic endophthalmitis and vitrectomy group (group C),27 rabbits in each group.The right eyes of all rabbits received intravitreal injection of 1 ml (10 mg/ml) vancomycin.Three rabbits from each group were sacrificed at 0.5,2.0,4.0,6.0,12.0,24.0,48.0,72.0,84.0 hours after the injection.The eyes were harvested to collect the vitreous.The vitreous concentrations of vancomycin in all the groups were detected by high performance liquid chromatography (HPLC-UV).The pharmacokinetic parameters including the area under the curve (AUC) of the concentration-time graph,clearance rate (CL),half-life period (t1/2) and peak concentration (Cmax) were calculated by 3p 97 pharmacokinetic software.Results The concentrations of vancomycin in the group A were always higher than the therapeutic drug levels after injection.In the group B and C,the concentrations of vancomycin remained significantly high at 0.5,2.0,4.0,6.0 and 12.0 hours after injection,decreased quickly at 24 and 48 hours after injection,below the minimal inhibitory concentrations at 72 hours after injection.The differences were statistically significant among group A,B and C (t =4.968,5.232; P＜0.05),but not statistically significant between group B and C (t=1.279,P＞0.05).The AUC were 15 790.61,7643.94,7443.44 μg/(ml · h),CL were 0.063,0.131,0.134 ml/h,t1/2 were 13.49,7.15,6.93 hours and Cmax were 711.56,648.45,667.74 μg/ml in the group A,B and C,respectively.In the group A,the CL was lower (t=2.963,3.097 ; P＜0.05 ) and t1/2 was longer (t=3.315,3.481 ; P＜0.01 ) than those in the group B and C,but there was no significant difference on Cmax (t =1.687,1.214;P＞0.05).Conclusion The pharmacokinetic parameters of vancomycin in rabbit vitreous with endophthalmitis varied between different pathological conditions. Key words: Endophthalmitis/ drug therapy; Vancomycin/administration & dosage; Pharmacokinetics; Disease models, animal