Hyperglycemic Effects of a Periocular Dexamethasone Injection in Diabetic Patients after Vitreoretinal Surgery

Objective To examine the hyperglycemic effects of periocular dexamethasone injection in type 2 diabetic patients after vitreoretinal surgery （VRS）. Methods This was a retrospective non-randomized controlled trial. Twenty consecutive hospitalized patients with type 2 diabetes and ocular inflammatory reaction after VRS were enrolled in this study. Ten patients received 2.5 mg dexamethasone and 10 patients received 5 mg dexamethasone. Fourteen consecutive type 2 diabetic patients without ocular inflammatory reaction after VRS were used as control group. We measured fasting blood glucose （FBG） and at 2 h after each meal （post prandial glucose, PBG; 09：00, 13：00, and 19：00 h） after periocular dexamethasone injection. Differences among three groups were determined by q tests. Results The PBG levels in both dexamethasone-treated groups started to increase within 5 h after injection （i.e., PBG at 13：00 h）, and were significantly increased at 29：00 h after injection （P〈0.05）. BG levels were almost 2-fold higher than at baseline and compared with the control group. The BG values declined gradually by 24 h to 48 h after injection. There were no differences in BG levels between the two dexamethasone-treated groups （P〉0.05）, except for PBG at 19：00 h on day 2 after injection （P〈0.05）. Conclusion Periocular dexamethasone injection can cause transient hyperglycemia in diabetic patients after VRS. BG monitoring should be performed following such injection.

Primary 23-gauge vitreoretinal surgery for rhegmatogenous retinal detachment

AIM: To report the effectiveness and safety of primary 23-Gauge (G) vitreoretinal surgery for rhegmatogenous retinal detachment (RRD). · METHODS: In this retrospective study, 49 eyes of 49 consecutive patients who underwent primary 23-G transconjunctival sutureless vitrectomy (TSV) for RRD between January 2007 and July 2009 at our institution were evaluated. · RESULTS: Mean follow-up time was 8.9±7.7 months (1-28 months). Retinal reattachment was achieved with a single operation in 47(95.9%) of 49 eyes. In two eyes (4.1%), retinal redetachment due to new breaks was successfully treated with reoperation using the 23-G TSV system. Mean logMAR visual acuity was 2.01±0.47 preoperatively and 1.3±0.5 postoperatively (P <0.001, Paired t -test). Mean preoperative intraocular pressure (IOP) was 14.1±2.8mmHg. Mean postoperative IOP was 12.3±3.6mmHg at 1 day, 13.1±2.1mmHg at 1 week, 14.3±2.2mmHg at 1 month. Iatrogenic peripheral retinal break was observed in 1 eye(2.0%) intraoperatively. No sutures were required to close the scleral or conjunctival openings, and no eyes required convertion of surgery to 20-G vitrectomy. · CONCLUSION: Primary 23-G TSV system was observed to be effective and safe in the treatment of RRD.

Combining robot-assisted surgical system and 3D visualization system for teaching minimally invasive vitreoretinal surgery

AIM:To investigate the feasibility of teaching minimally invasive vitreoretinal surgery with a robot-assisted surgical system and a three-dimensional(3D) visualization system.METHODS:Enucleated porcine eyes were established as an animal model for removing foreign bodies.Forty medical students were recruited to remove foreign bodies to compare the traditional microscope and the 3D system.One junior resident performed the surgical task with manual and robot-assisted operations on 20 porcine eyes for each group.One senior surgeon evaluated the retinal invasion by a graded injury degree.The learning curve for minimally invasive vitreoretinal surgery was described.RESULTS:Compared with the robot-assisted group,the injury degree was higher in the manual group.For the first ten surgeries,the manual and robot-assisted groups had injuries of 2.60±1.35(4 to 0) and 1.80±1.62(4 to 0),respectively.For the last ten surgeries,the injury degrees were 1.90±1.20(3 to 0) and 0.80±0.42(1 to 0).Considering the manual and robot-assisted groups together,95%,75% and 60% of the students considered surgical manipulation with the 3D visualization system to be more comfortable,easier and clearer,respectively.CONCLUSION:The robot-assisted surgical system and 3D visualization system may have value in teaching minimally invasive vitreoretinal surgery.

Clinical observations of vitreoretinal surgery for four different phenotypes of X-linked congenital retinoschisis

AIM： To evaluate the outcomes of vitreoretinal surgery for four different phenotypes of X-linked retinoschisis （XLRS）. METHODS： This study included thirty-one eyes of 25 patients who developed XLRS with severe complications. Among the 31 eyes, there were 7 eyes with vitreous hemorrhage, 8 eyes with retinal detachment and vitreous hemorrhage, and 16 eyes with rhegmatogenous retinal detachment. All of the patients underwent standard three-port pars plana vitrectomy. All of the eyes were divided into 4 groups before surgery according to a modified classification scheme, with the first three groups as follows： group A, with foveal cystic schisis; group B with macular lamellar schisis; and group C with foveolamellar changes. Peripheral schisis was not present in these 3 groups; however, group D was a complex group with both macular and peripheral changes. One year after surgery, we analyzed the best corrected visual acuity and postoperative anatomical and functional outcomes of these 4 groups. RESULTS： There were 7 eyes in group A （22.6%）, 1 eye in group B （3.2%）, 15 eyes in group C （48.4%） and 8 eyes in group D （25.8%）. Postoperative anatomical and functional outcomes were satisfactory at the last visit, while the mean visual acuity was increased to 0.27±0.11, with a significant difference （t=-1.049, P=0.000） compared with the results before surgery （0.1±0.08）. Visual acuity was improved in 23 eyes （74.2%）. Complications were found in three eyes： two eyes with proliferative vitreoretinopathy and traction retinal detachment 10 and 12mo after surgery, respectively; and one eye with vitreous hemorrhage 15mo after surgery. These eyes were in groups C and D. The retinas remained attached in these 3 eyes after reoperation. CONCLUSION： We should pay greater attention to XLRS with foveolamellar changes because it is the most changeable phenotype. Once complications occur, vitreoretinal surgery can significantly improve visual acuity and restore the anatomic structure of the retina.

Corneal epithelial defects following vitreoretinal surgery:incidence and outcomes from the DISCOVER study

AIM:To investigate the incidence,risk factors,clinical course,and outcomes of corneal epithelial defects(CED)following vitreoretinal surgery in a prospective study setting.METHODS:This was a post-hoc analysis of all participants in DISCOVER intraoperative optical coherence tomography study.Subjects with CED 1 d after surgery without intraoperative corneal debridement was defined as the postoperative CED group.Subjects who underwent intraoperative debridement were defined as intraoperative debridement group.Eyes were matched 2:1 with controls(eyes without postoperative CED)for comparative assessment.The primary outcomes were the incidence of CED on postoperative day one and the incidence of required intraoperative debridement.Secondary outcomes included time to defect closure,delayed healing(>2 wk),visual acuity(VA)and presence of scarring at one year and cornea consult.RESULTS:This study included 856 eyes that underwent vitreoretinal surgery.Intraoperative corneal debridement was performed to 61(7.1%)subjects and postoperative CED developed spontaneously in 94(11.0%)subjects.Significant factors associated with postoperative CED included prolonged surgical duration(P=0.003),diabetes mellitus(P=0.04),postoperative ocular hypotension(P<0.001).Prolonged surgical duration was associated with intraoperative debridement.Delayed defect closure time(>2 wk)was associated with corneal scar formation at the end of the 1 y in all epithelial defect subjects(P<0.001).The overall rate of corneal scarring for all eyes undergoing vitrectomy was 1.8%.CONCLUSION:Prolonged duration of surgery is the strongest factor associated with both intraoperative debridement and spontaneous postoperative CED.Delayed defect closure is associated with a greater risk of corneal scarring at one year.The overall rate of corneal scarring following vitrectomy is low at<2%.

A novel temporary keratoprosthesis technique for vitreoretinal surgery

AIM:To investigate the safety of vitreoretinal surgery when using a soft contact lens as a temporary keratoprosthesis(TKP)in patients with severe corneal opacifications.METHODS:Three patients with simultaneous corneal and vitreoretinal pathology were treated with a soft contact lens that was used as a TKP to facilitate vitreoretinal surgery.The soft contact lens was fixated with sutures onto the globe so that no leakage was possible.RESULTS:Vitreoretinal surgery with excellent fundus view was possible in all cases.The soft contact lens allowed safe central and peripheral vitrectomy.Surgery was successful in all cases.CONCLUSION:A soft contact lens properly fixated on the globe can successfully replace a TKP.This surgical procedure has several advantages like one size fits all,low costs,and easy access to the material.

Vitreoretinal surgery combined with C-arm fluoroscopic-guided removal of intraorbital foreign body following ocular perforating injury

Perforating ocular trauma with retained intraorbital foreign body （IOrFB） is a severe injury with a poor prognosis. The injury involves the posterior segment of the eye, and foreign bodies are mostly lodged posterior to the globe. Vitreoretinal surgery and IOrFB removal are always performed separately in patients with ocular perforating injury and IOrFBs. Obviously, separate procedures increase the cost and patient discomfort, lntraoperative fluoroscopy,

Pars plana vitrectomy for retinal detachment using perfluoro-n-octane as intraoperative tamponade:a multicenter,randomized,non-inferiority trial

AIM:To evaluate the efficacy and safety of perfluoro-n-octane(PFO)for ophthalmic surgery versus F-Octane as an intraoperative tamponade in pars plana vitrectomy(PPV)in management of retinal detachment.METHODS:This multicenter,prospective,randomized,double-masked,parallel-controlled,non-inferiority trial was conducted in three ophthalmology clinical centers in China.Patients with retinal detachment,who were eligible for PPV were consecutively enrolled.Participants were assigned to PFO for ophthalmic surgery or F-Octane for intraocular tamponade in a 1:1 ratio.Best-corrected visual acuity(BCVA),intraocular pressure(IOP)measurement,and dilated fundus examination were performed preoperatively and at 1,7±1,28±3d postoperatively.The primary outcome was complete retinal reattachment rate at postoperative day one.The non-inferiority margin was set at 9.8%.The secondary outcomes included intraoperative retinal reattachment rate,and mean changes in IOP and BCVA from baseline to 1,7±1,28±3d postoperatively,respectively.Safety analyses were presented for all randomly assigned participates in this study.RESULTS:Totally 124 eligible patients completed the study between Mar.14,2016 and Jun.7,2017.Sixty of them were randomly assigned to the PFO for ophthalmic surgery group,and 64 were assigned to the F-Octane group.Baseline characteristics were comparable between the two groups.Both groups achieved 100%retinal reattachment at postoperative day one(difference 0,95%CI:-6.21%to 5.75%,P=1).The pre-defined noninferiority criterion was met.No significant difference was observed in intraoperative retinal reattachment rate(difference 1.77%,P=0.61),mean changes in IOP(difference 0.36,-0.09,2.22 mm Hg at 1,7±1,28±3d postoperatively,with all P>0.05)and BCVA(difference 0.04,-0.02,0.06 logMAR at 1,7±1,28±3d postoperatively,all P>0.05)between the two groups.No apparent adverse events related to the utilization of PFO were reported.CONCLUSION:In patients with retinal detachment undergoing PPV,PFO for ophthalmic surgery is non-inferior to F-Octane as an intraocular tamponade,and both are safe and well-tolerated.

Characteristics of macular microvasculature before and after idiopathic macular hole surgery

AIM:To evaluate the macular microvasculature before and after surgery for idiopathic macular hole(MH)and the association of preoperative vascular parameters with postoperative recovery of visual acuity and configuration.METHODS:Twenty eyes from 20 patients with idiopathic MH were enrolled.Optical coherence tomography angiography(OCTA)images were obtained before,2 wk,1,and 3 mo after vitrectomy with internal limiting membrane peeling.Preoperative foveal avascular zone(FAZ)area and perimeter and regional vessel density(VD)in both layers were compared according to the 3-month best-corrected visual acuity(BCVA).RESULTS:The BCVA improved from 0.98±0.59(log MAR,Snellen 20/200)preoperatively to 0.30±0.25(Snellen 20/40)at 3 mo postoperatively.The preoperative deep VD was smaller and the FAZ perimeter was larger in the 3-month BCVA<20/32 group(all P<0.05).A significant reduction was observed in FAZ parameters and all VDs 2 wk postoperatively.Except for deep perifoveal VD,all VDs recovered only to their preoperative values.The postoperative FAZ parameters were lower during follow-up.Decreases in preoperative deep VDs were correlated with worse postoperative BCVA(Pearson’s r=-0.667 and-0.619,respectively).A larger FAZ perimeter(Spearman’s r=-0.524)and a lower deep perifoveal VD preoperatively(Pearson’s r=0.486)were associated with lower healing stage.CONCLUSION:The status of the deep vasculature may be an indicator of visual acuity in patients with a closed MH.Except for the deep perifoveal region,VD recovers only to preoperative levels.

Vitreoretinal surgical training-assessment of simulation,models,and rubrics-a narrative review

Background and Objective:Vitreoretinal surgery requires fine micro-surgical training and handling of delicate tissue.To aid in the training of residents and fellows,unique educational modalities exist to help facilitate the development of these microsurgical skills.From virtual simulators to artificial eye models,simulation of the posterior segment has gained an increased focus in vitreoretinal surgical training programs.Development of surgical curricula for vitreoretinal training and attainment of surgical milestones has been a key component in integrating these educational training modalities.We will explore various simulators,eye models,and potential rubrics and discuss unique ways each may help and complement one another to train future vitreoretinal surgeons.Methods:We conducted a systematic PubMed search of various review studies(from publications in English ranging from January 1978 to December 2020)discussing surgical simulators,eye models,and surgical rubrics for vitreoretinal surgery and their potential impacts upon training.Key Contents and Findings:Our review assesses the benefits and applicability of various simulators,eye models,and surgical rubrics upon training.Conclusions:Utilization of vitreoretinal surgical training tools may aid in complementing the hands-on surgical training experience for vitreoretinal surgical fellows.By using simulators and rubrics,we may better be able to standardize training for reaching vitreoretinal surgical milestones and providing adequate feedback to improve surgical competency and ultimately patient outcomes.

Anatomical and functional outcomes after Densiron 68 heavy silicone oil tamponade for complicated retinal detachment in Chinese eyes

AIM:To evaluate the safety and efficacy of Densiron 68 heavy silicone oil (HSO) tamponade for complicated retinal detachment(RD)in Chinese eyes.METHODS:Twenty-one eyes of 21 patients with complicated RD were included in this retrospective study.All patients underwent pars plana vitrectomy with an internal tamponade using Densiron 68 HSO.Anatomical and functional results and complications were evaluated,including retinal status,visual acuity(VA),intraocular pressure(IOP),intraocular inflammation,lens opacity,and HSO emulsification.RESULTS:Allthepatients were followed up for 3mo to1y(5.8±1.16mo).Retinal reattachment was achieved in 19of 21 patients(90.5%).VA improved in 18 of 21 patients(85.7%),from 1.93 logMAR(±0.48)to 1.52 logMAR(±0.45)(P=0.001).Postoperative complications included early dispersion of HSO in 7 eyes(38.8%),cataract in 10 of 18phakic eyes(55.5%),moderate postoperative inflammation reaction in 10 eyes(47.6%),and elevated IOP in 5 eyes(23.8%),all of which were controlled by medication or by surgery.CONCLUSION:Highanatomical and functional success rates can be achieved with primary vitrectomy for complicated RD by using Densiron 68 HSO;however,it should not be ignored that Densiron 68 HSO can cause some complications in the eye.

Comparison of outcomes of idiopathic macular holes treated by vitrectomy with air or silicone oil tamponade based on the hole size

AIM:To compare the efficacy of vitrectomy combined with air or silicone oil in the treatment of idiopathic macular hole(IMH).METHODS:According to the results of high-definition optical coherence tomography(HD-OCT),75 cases(75 eyes)of IMH in stage II-IV(Gass stage)in the General Hospital of Chinese PLA from January 2017 to December 2019 were collected for this retrospective study.The best corrected visual acuity(BCVA)and minimum diameter of IMH(MMHD)were measured.Eyes underwent vitrectomy combined with internal limiting membrane peeling operation,and were divided into disinfection air group(30 eyes)and silicone oil group(45 eyes)according to the intraocular tamponade.For MMHD≤400μm(MMHD1),there were 23 eyes in air group and 16 eyes in silicone oil group.For MMHD2>400μm(MMHD2),there were 7 eyes in air group and 29 eyes in silicone oil group.One month after surgery,the closure rates of IMH and BCVA were compared and analyzed.According to HD-OCT,the closure shape was graded with A(bridge closure)and B(good closure).RESULTS:The closure rates of air group and silicone oil group were 86.67%and 95.56%respectively with no significant difference(P>0.05);For MMHD1,those of air group and silicone oil group were 95.65%and 100%respectively with no significant difference(P>0.05);For MMHD2,those of air group and silicone oil group were 57.14%and 93.10%respectively,and those of the silicone oil group were higher than the air group(P<0.05).There was no significant difference in the closure shape grade between MMHD1 air group and silicone oil group(P>0.05).The proportion of Grade B in MMHD2 silicone oil group was higher than that in the air group(P<0.05).BCVA of each group after operation was better than that before operation,and there was no significant difference between air group and silicone oil group.While among them,MMHD1 air group was better than silicone oil group(P<0.05),and there was no significant difference between MMHD2 air group and silicone oil group(P>0.05).CONCLUSION:For smaller IMH(≤400μm),the efficacy of vitrectomy combined with air should be considered better than silicone oil;for larger IMH(>400μm),the efficacy of silicone oil may be better than air.

Surgical Treatment for Complications of Congenital Retinoschisis

This study examined the clinical features of complications of congenital retinoschisis and the clinical efficacy of vitreoretinal surgery in the treatment of these complications.The clinical efficacy of surgical treatments was retrospectively analyzed in 10 patients with congenital retinoschisis（10 eyes） complicated with rhegmatogenous retinal detachment（n=5）,vitreous hemorrhage（n=2） and macula-involving schisis（n=1）.All the patients suffered foveal and peripheral schisis.They were treated with scleral buckling（n=1） or vitrectomy（n=9）.After the surgical treatment,the retina was reattached in patients with rhegmatogenous retinal detachment;the refractive media became transparent in those with vitreous hemorrhage;the visual acuity in 80% of patients was improved;no remarkable progression of schisis was found;no severe operative complications occurred.It was concluded that vitreoretinal surgery in the treatment of complications of congenital retinoschisis is safe and effective,and helps improve and maintain the visual function.

A simple new technique for the induction of residual posterior vitreous cortex removal and membrane peeling

AIM:To describe a quick,cost-effective alternative to using a scraper to remove the residual posterior vitreous cortex and create an inner limiting membrane(ILM)flap during vitrectomy.METHODS:The surgical technique and a retrospective interventional single-center series of cases were described.A hook was made on the tip of a conventional syringe needle(outer diameter,0.6 mm;23 gauge)by bending the needle against a plate.We used this hook to remove the residual posterior vitreous cortex and create an ILM flap during vitrectomy.The efficacy and safety of using this instrument in ophthalmological procedures for a variety of vitreoretinal disorders were evaluated.RESULTS:The hook was effective for removing focal or diffuse residual posterior vitreous cortex in eyes with rhegmatogenous retinal detachment,proliferative diabetic retinopathy,and pathological myopia.It was also successfully used to make a free edge of the ILM and help strip the epiretinal membrane.There were no serious complications associated with using the hook in delicate ophthalmological procedures.CONCLUSION:The hook,made by bending a conventional needle,is a simple and cost-effective instrument for removing residual posterior vitreous vortex and to create epiretinal and ILM flaps during vitrectomy in eyes with various vitreoretinal diseases.