Intravitreal Tamponade Research Articles

Outer retinal degeneration in a non-human primate model using temporary intravitreal tamponade with N-methyl-N-nitrosourea in cynomolgus monkeys

Objective: The main objective of this study was to induce and evaluate drug-dose-dependent outer retinal degeneration in cynomolgus monkeys by application of N-methyl-N-nitrosourea (MNU). Approach: Intravitreal temporary tamponade induced outer retinal degeneration with MNU solutions (2–3 mg ml−1) after vitrectomy in five cynomolgus monkeys. Optical coherence tomography (OCT), fundus autofluorescence (FAF), full-field electroretinography (ffERG), and visual evoked potentials (VEP) were performed at baseline and weeks 2, 6, and 12 postoperatively. At week 12, OCT angiography, histology, and immunohistochemistry were performed. Main results: Outer retinal degeneration was observed in four monkeys, especially in the peripheral retina. Anatomical and functional changes occurred at week 2 and persisted until week 12. FAF images showed hypoautofluorescence dots, similar to AF patterns seen in human retinitis pigmentosa. Hyperautofluorescent lesions in the pericentral area were also observed, which corresponded to the loss of the ellipsoid zone on OCT images. OCT revealed thinning of the outer retinal layer adding to the loss of the ellipsoid zone outside the vascular arcade. Histological findings confirmed that the abovementioned changes resulted from a gradual loss of photoreceptors from the perifovea to the peripheral retina. In contrast, the inner retina, including ganglion cell layers, was preserved. Functionally, a decrease or extinction of scotopic ffERGs was observed, which indicated rod-dominant loss. Nevertheless, VEPs were relatively preserved. Significance: Therefore, we can conclude that temporary exposure to intravitreal MNU tamponade after vitrectomy induces rod-dominant outer retinal degeneration in cynomolgus monkeys, especially in the peripheral retina.

Effect of silicone oil on retinal microcirculation after vitrectomy for rhegmatogenous retinal detachment evaluated by OCT angiography: a literature review.

Silicone oil (SO) has been widely used as intravitreal tamponade agent for rhegmatogenous retinal detachment (RRD) and has been occasionally associated with incomplete retinal structural and functional recovery. The use of Optical Coherence Tomography Angiography (OCT-A) has recently attracted significant attention for detailed analysis of retinal capillary plexus and blood flow changes as predicting factors for postoperative outcomes. A detailed literature search was performed in PubMed database until October 2022. The following keywords were used: rhegmatogenous retinal detachment, silicone oil, optical coherence tomography angiography, macular microvasculature, peripapillary capillary plexus, vessel density, and foveal avascular zone. We identified and reviewed 19 studies referring to microcirculation alterations of the retinal capillary plexus as seen on OCT-A in eyes treated by vitrectomy with intravitreal SO for RRD. A comprehensive update revealed variability of microcirculation characteristics of the retinal capillary plexus including the macular and the peripapillary capillaries. Further studies are warranted to clarify the OCT-A values in an attempt to identify the potential effect of SO on retinal tissue in clinical practice. A review of the existing literature sheds light on the effect of SO on retinal capillary plexus and the potential impact on functional outcomes after vitrectomy for RRD. This article discusses important aspects of key publications on the topic, highlights the importance to identify distinct alterations of the microvasculature status, and proposes the need for further future research in this field.

Intracranial silicone oil migration with encephalopathy: a rare case report

BackgroundIntraocular silicone oil (SiO) tamponade is a popular modality of treatment of rhegmatogenous retinal detachment. It can, however, rarely lead to an incompletely understood phenomenon known as intracranial migration of SiO. Though usually benign, this entity is often misinterpreted as a tumour or haemorrhage.Case presentationWe present a case report of a patient with acute progressive encephalopathy and intracranial migration of intravitreal silicone. We also put forward the possibility of toxic effects of intracranial SiO on the central nervous system.ConclusionClinicians and radiologists should be aware of the rare complication of intravitreal SiO tamponade. Eliciting the history of intraocular SiO tamponade and identifying the key imaging features on ultrasonography of the orbit, CT of the head, and MRI of the brain will help in avoiding unnecessary interventions or delays in the management of the patients from misdiagnosing it as haemorrhage or tumour.

Myopic Traction Maculopathy: Diagnostic and Management Strategies.

Pathologic myopia (PM) is an ocular disorder characterized by a spherical equivalent (SE) of more than – 6.0 diopters (D) or by an axial length (AL) of more than 26.5 millimeters (mm). PM is associated with myopic maculopathy (MM). The ATN classification describes all the aspects of MM which regroups atrophic, tractional and neovascular consequences to the sclera, choroid and retina of highly myopic eyes. The advent of OCT allowed to define the ultrastructural characteristics of the tractional changes in MM, described by the term myopic traction maculopathy (MTM). They include foveoschisis/maculoschisis/retinoschisis (FS/MS/RS), retinal/foveal detachment (RD/FD), lamellar macular holes (LMH) and full-thickness macular holes (FTMH) with or without RD (MHRD). The MTM staging system (MSS) describes all foveal and retinal changes related to MTM and their natural history interpreting them as different stages of a single progressive disorder. The management of MTM can be just observation for the earliest cases with good vision or surgery for the severe stages with vision loss. There are two possible surgical approaches: ab externo, that acts on the alteration of the scleral shape and includes posterior scleral reinforcement and macular buckle. Ab interno, that targets the alteration of the foveal profile and consists in pars plana vitrectomy with removal of all the epiretinal tractions, maneuvers on the internal limiting membrane, and the use of intravitreal tamponade and laser. As they target two different sides of the same pathology, the two techniques have to be selected on the base of the MTM stage, single or combined.

Development and Testing of a Mobile Phone App for Risk Estimation of Gas Volume Expansion and Intraocular Pressure Elevation in Patients With Intravitreous Gas or Air Tamponade: Interobserver Assessment Study

BackgroundPars plana vitrectomy (PPV) with intravitreous tamponade of gas or air has been widely used for a series of vitreoretinal diseases. It is estimated that 100,000 patients per year undergo PPV globally, and half of them were subsequently tamponaded with gas or air. According to Boyle’s law (P1V1=P2V2), patients with an intravitreous remnant of gas or air will be under high risk of intraocular pressure (IOP) elevation and subsequent vision loss owing to the expanded intravitreous gas or air when traveling post operation to a place with a significantly higher altitude. We always explain to patients why postoperative travel is potentially risky. Emergency cases of elevated IOP caused by postoperative traveling would sometimes come to surgeons. However, there have been few disease education or reference tools for both the surgeons and patients to have better communication.ObjectiveThe aim of this study was to introduce and evaluate a mobile phone app developed by surgeons (the authors) for preliminary risk estimation of volume expansion and IOP elevation in patients with intravitreous gas or air when traveling to a place of higher altitude.MethodsThe app was developed on the iOS and Android operating systems. Boyle’s law (P1V1=P2V2) was the theoretical basis of the app. Intravitreous gas or air volume and altitude values were independent factors to deduce the risk report. Consecutive patients underwent vitrectomy, and those with an intravitreous remnant of gas or air were recruited. The surgeons judged the vertical height of the fluid/gas interface through the dilated pupil; the patients were instructed to judge it according to their visual field when looking straight ahead and line it out on a chart included in the app. Finally, all the patients were required to fill a Likert scale–based questionnaire with 2 main items to evaluate the participants’ user experience and attitudes toward the app.ResultsA total of 50 patients were included (30 males and 20 females). All patients could independently operate the app to complete the test. The median heights of the fluid/gas interface independently judged by the surgeon and patients were 40% (range: 10%-75%) and 41% (range: 9%-78%), respectively (P=.63). The median altitude of the participants’ destinations was 150.0 m (range: 0-3490 m). The Bland-Altman analysis revealed a good agreement between the surgeons’ and patients’ judgments (bias of −0.3%), with 95% limits of agreement of −5.8% to 5.3%. Overall, the Likert scale revealed a positive attitude from the patients toward the app.ConclusionsThe app is reliable for patients to have preliminary risk estimation of intravitreous gas or air volume expansion and IOP elevation if travel to a place of higher altitude is planned. The surgeons could also use it as a platform for better disease communication.

Electron Microscopic Retina Changes in Rabbit Eyes with Perfluorocarbon Liquids Intravitreal Tamponade

Purpose. Analysis of electron microscopic changes in rabbit eyes with intravitreal tamponade of perfluorocarbon liquids (PFCL) (perfluoro-1,3-dimethylcyclohexane and perfluorodecalin).Material and Methods. The study was performed on Chinchilla breed rabbits. 25G vitrectomy with PFCL intravitreal tamponade was performed on 12 eyes of 6 rabbits (perfluorodecalin (Bausch+Lomb «Dk-line», USA) and perfluoro-1,3-dimethylcyclohexane (ZAO “Optimedservis”, Russia). Standard three-port vitrectomy technique was used. After removal of the vitreous body 2.5 ml of PFCL were injected in vitreous cavity. Research studies were performed in 5, 14 and 30 days after surgery by electron microscopy. Eyes were enucleated in 20 minutes after animal was killed by air embolization. Intact eyes were used as a control. All samples were prepared in same conditions. The damage of the retina architectonics and the presence of intracellular inclusions were evaluated.Results. Tamponade of the vitreous cavity by both types of PFCL in 5, 14 and 30 day caused following similar electron microscopic changes at date: swelling ganglion layer and dystrophy of inner and outer nuclear layer. Electron microscopic changes in outer nuclear layer appeared at 30 days. The photoreceptor neurons were characterized by single ultrastructural changes. Retina pigment epithelium cells had a typical ultrastructure.Conclusion. Intravitreal perfluoro-1,3-dimethylcyclohexane tamponade caused similar electron microscopic changes as well as perfluorodecalin in the experiment and it was relatively harmless to rabbit retina for up to 14 days. Irreversible changes in the retinal ultrastructure were not observed.

Pars plana vitrectomy

Pars plana vitrectomy (PPV) allows the treatment of a multitude of vitreoretinal disorders involving the vitreous, the retina or the choroid. There is a multitude of possible surgical sequences: peeling maneuvers, liquid perfluorocarbone, removal of traction and media opacities, retinopexy or destructive photocoagulation, and as ultima ratio, retinotomies and retinectomies. The intravitreal tamponade serves as a substitute in the vitreous cavity, allowing photoreceptors and retinal pigment epithelium (RPE) to reconnect. Due to the many potential complications, close monitoring is required after pars plana vitrectomy during the early postoperative period. Late-onset complications are usually associated to the dynamics of the underlying disease.

INTRAOCULAR LENS POSITION IN COMBINED PHACOEMULSIFICATION AND VITREORETINAL SURGERY.

To assess the decentration and angle of tilt of the intraocular lens (IOL) according to the intravitreal tamponade types used in combined phacoemulsification and vitreoretinal surgery. This prospective and randomized clinical study involved 73 eyes of 69 patients who underwent combined vitreoretinal surgery. Eyes with intravitreal tamponades formed the study group and eyes without intravitreal tamponades formed the control group. The study group was further divided into silicone oil and gas tamponade subgroups. Cross-sectional IOL images were captured using a Pentacam HR (Oculus, Germany) and tilt and decentration were calculated with Adobe Photoshop software (Adobe, San Jose, CA). The mean angle of tilt and decentration at the vertical meridian were significantly higher in both tamponade groups than in the control group (P < 0.05 for all). No significant difference was observed among the groups regarding IOL position parameters at the horizontal meridian (P > 0.05). When comparing the silicone oil and gas tamponade subgroups, no significant differences were noted on the position of IOL at both meridians (P > 0.05 for all). Intravitreal tamponades have an important effect on the position of IOL in combined vitreoretinal surgery. Silicone oil and gas tamponades may induce postoperative tilt and decentration of one-piece acrylic IOLs.

(Invited) Instantly Formative Hydrogels with Super-Low Polymeric Component

Hydrogels are water-filled materials with characteristics similar to those of biological soft tissues and have broad application as biomaterials. However, the safety of hydrogels is difficult to guarantee throughout the full life cycle in vivo due to the inevitability of degradation-induced swelling. Indeed, the swelling pressure exerted by conventional hydrogels is sufficiently large to cause severe adverse reactions to surrounding tissues. In this respect, we report here a new class of in situ forming hydrogels that guarantee safety throughout the full life cycle. The oligo-TetraPEG hydrogel has an extremely high water content and a polymer content of only 4.0 g/L, resulting in an exceptionally low swelling pressure. The oligo-TetraPEG hydrogel was successfully injected and gelled inside a living body within a clinically relevant manipulation time and little cytotoxicity. The oligo-TetraPEG hydrogel exhibited an appropriate stiffness, similar to that of soft tissue, with extremely low swelling pressure thus being compatible with living tissues. The oligo-TetraPEG hydrogel functioned as an artificial vitreous body for over a year without any adverse effects, and was effective for treating retinal detachment as an intravitreous tamponade material．The present concept provides new guidance for the safety of biomaterials in vivo. Figure 1

Risk factor analysis of persistent corneal epithelial defects after vitrectomy in patients with proliferative diabetic retinopathy

Objective To analyze the risk factors for persistent corneal epithelial defects (PCED) after pars plana vitrectomy (PPV) in patients with proliferative diabetic retinopathy (PDR). Methods A total of 201 PDR patients (201 eyes) who received PPV were enrolled in this retrospective study. There were 86 males (86 eyes) and 115 females (115 eyes). The patients aged from 30 to 81 years, with the mean age of (57.94±9.65) years. Among them, 159 patients were ≥50 years of age, and 42 patients were 1000 points were performed in 123 eyes. Sixty-one eyes involved intravitreal silicone oil tamponade, 18 eyes involved intravitreal tamponade with C3F8, and 122 eyes were not involved with intraocular tamponade. Postoperative persistent intraocular hypertension was defined as an intraocular pressure (IOP) ≥21 mmHg (1 mmHg=0.133 kPa) after PPV with necessary treatment using IOP-lowering medications for ≥2 weeks. The diagnostic criteria for corneal epithelial defects were taken from the Expert Consensus on Clinical Diagnosis and Treatment of Corneal Epithelial Defect in China (2016). The corneal epithelial defect was diagnosed as PCED if it was treated with common methods such as a lacrimal substitute or corneal contact lens, but showed no improvement and no signs of healing for ≥2 weeks. The incidence of PCED after eye surgery was recorded and its related risk factors were analyzed. A multivariate logistic regression was used to analyze the risk factors for PCED, which were expressed as a odds ratio (OR) and a 95% confidence interval (CI). Results Of 201 eyes, 16 eyes (7.96%) presented with PCED after surgery and 185 eyes (92.04%) with no PCED. There was no significant difference in the age, sex, and eyes between the patients with or without PCED (χ2=6.548, 0.927, 0.044; P=0.011, 0.336, 0.833). A multivariate logistic regression showed that intraoperative epithelial debridement (OR=13.239, 95%CI 2.999−58.442, P=0.001), intraoperative treatment in combination with cataract surgery (OR=7.448, 95%CI 1.975−28.091, P=0.003), intravitreal tamponade with C3F8 (OR=11.344, 95%CI 2.169−59.324, P=0.004), and postoperative persistent intraocular hypertension (OR=10.462, 95%CI 2.464−44.414, P=0.001) were risk factors for PCED after PPV. Conclusion Intraoperative epithelial debridement, intraoperative treatment in combination with cataract surgery, intravitreal tamponade with C3F8, and postoperative persistent intraocular hypertension are risk factors for PCED in patients with PDR after PPV. Key words: Epithelium, corneal/injuries; Vitreoretinal surgery; Diabetic retinopathy

The efficacy of corticosteroid in vitrectomy for the treatment of acute retinal necrosis

Objective To investigate the efficacy of corticosteroid combined with early vitrectomy in the treatment of acute retinal necrosis(ARN). Methods Twenty-two eyes of 22 cases of ARN were analyzed retrospectively and they were randomly divided into 2 groups: the corticosteroid group, 13 cases, and the non-corticosteroid group, 9 cases.The best corrected visual acuity (BCVA) preoperative, time from diagnosis to vitrectomy, intravitreal tamponade, occurrence of retinal detachment (RD), ocular hypotony, the BCVA at final follow-up and complications were analyzed. Results The difference of common data between the 2 groups were not statistically significant. The time from diagnosis to vitrectomy in the corticosteroid group was longer than that of non-corticosteroid group (P=0.042), rate of silicon oil tamponade in corticosteroid group was higher than that of non-corticosteroid group (P=0.018), and the eyes of BCVA≥0.1 in corticosteroid group were less than those of non-corticosteroid group (P=0.041). Conclusion Prophylactic vitrectomy is recommended for the treatment of ARN, but the corticosteroid should be used with caution. Key words: Retinal necrosis, acute; Treatment, vitrectomy, corticosteroid

Clinical observation on the efficacy of surgery for high myopia macular retinoschisis

Objective To observe the efficacy of vitrectomy combined with internal limiting membrane peeling for the treatment of high myopia macular retinoschisis. Methods Forty-two eyes of 36 patients were treated by vitrectomy combined with internal limiting membrane peeling and intravitreal tamponade of gas , silicone oil or balanced salt solution. All patients were followed up for 1 year.The efficacy was observed. Results The difference in the thickness of the macular area, the visual acuity and visual function related to the quality of life were statistically significant between preoperative and postoperative(P<0.05). The postoperative visual acuity of 3 kinds of intravitreal tamponade were improved.The differences were statistically significant among them (P<0.05). Conclusion The treatment of high myopia macular retinoschisis by vitrectomy combined with retinal internal limiting membrane peeling and intravitreal tamponade is effective. Key words: Myopia, high; Retinoschisis, macular; Retinal internal limiting membrane peeling; Intravitreal tamponade

Silicone Oil-Related Visual Loss

Background: Silicone oil (SO) is used as an intravitreal tamponade agent in vitreoretinal surgery for rhegmatogenous retinal detachment (RRD) complicated by proliferative vitreoretinopathy or with large, multiple retinal tears. Usually, SO is left in the eye for at least 3 months. Although its use can lead to well-known complications, intraocular SO is generally well tolerated. Some studies have reported unexpected central vision loss after SO use or removal. Objective: To investigate and analyze the reason for visual loss after the use or removal of intraocular SO in patients who underwent vitrectomy surgeries for RRD. Patients and Methods: A retrospective observational case series of 12 patients with macula-on RRD who reported visual loss after the use or removal of SO was reviewed. Investigations carried out included fundus fluorescein angiography, optical coherence tomography (OCT) of the macula and optic disc, perimetry, and electrophysiological study. Electrolyte levels were measured in retro-oil fluid and compared with their levels in the vitreous humor of patients who underwent vitrectomy for macular holes, floaters, dropped intraocular lenses, or dropped crystalline lens fragments. Results: Visual acuity levels dropped by at least 2 Snellen chart lines. None of the 12 cases had macular detachment at any stage. Fundus fluorescein angiography and OCT results were unremarkable in most of the cases. Mean levels of electrolytes in retro-oil fluids and vitreous humor were similar. Conclusion: Visual loss is a possible complication after SO use or removal. This still remains a mysterious issue which needs further research and investigation.

The efficacy of scleral buckling surgery for the treatment of"no-tear" retinal detachment

Objective To observe the efficacy of scleral buckling surgery under microscope for the treatment ofno-tear retinal detachment. Methods It was a retrospective study.Eighteen eyes of 18 patients withno-tear retinal detachment were treated with scleral buckling surgery under the microscope.The tear in serrated edge was found during the operation. Twelve cases underwent scleral buckling combined with scleral encircling and 6 cases received scleral buckling only. All cases received scleral tapping. At the end of the surgery 14 eyes with intraocular hypotension underwent intravitreal tamponade of gas. Results Postoperative follow-up for 6 months, 17 eyes were cured upon the operation with completely retinal reattachment(94.4%), 1 eye was successful with retinal reattachment after a second vitrectomy operation. No intraoperatively or postoperatively serious complication occurred. Conclusion Scleral buckling surgery under microscope in the treatment ofno-tear retinal detachment is simple, safe and effective. Key words: Retinal detachment,no-tear; Scleral buckling, microsurgery

Yirmi üç gauge pars plana vitrektomi ile birlikte fakoemülsifikasyon ve göz içi lens implantasyonu ameliyatlarının cerrahi sonuçları

Objective: To present the surgical results of pars plana vitrectomy and phacoemulsification (phacovitrectomy) plus intraocular lens (IOL) implantation in eyes with vitreoretinal pathology Material and Method: This retrospective study included 91 eyes of 80 (44 female/36 male) consecutive patients undergoing phacovitrectomy plus IOL implantation during a 3-year period. Baseline and last best corrected visual acuity (BCVA), retinal pathologies, presence of systemic disease, preoperative lens status, history of any therapeutic intervention prior to surgery, type of intravitreal tamponade used, need for additional intervention, complications and the latest ocular examination results were considered. Results: Mean age was 64.8±9.5 years. Diabetes mellitus (DM), hypertension (HT), DM+HT and coronary artery disease (CAD) were the accompanying systemic diseases, observed in 74%, 56%, 45% and 18.7% of the patients, respectively. Indications for phacovitrectomy were macular surface disease in 52%, vitreus hemorrhage (VH) in 31%, tractional retinal detachment (TRD), diabetic retinopathy or proliferative vitreoretinopathy (PVR) in 11% and rhegmatogenous retinal detachment (RRD) in 5.5% of the eyes. Mean preoperative and postoperative BCVA were 0.10±0.14, 0.22±0.22, (p

The clinic characteristics of ocular hypertension in the unoperated opposite eye after vitrectomy

Objective To observe the clinic characteristics of ocular hypertension in the unoperated opposite eye after vitrectomy. Methods The clinical data of 5 cases with ocular hypertension in the unoperated opposite eye after vitrectomy were analyzed retrospectively. Ultrasonic biomicroscopy, axial lengths, intraocular pressure and diopter were observed. Results The causes of 5 patients were intraocular foreign body, vitreous haemorrhage, retinal detachment, and idiopathic macular hole (IMH). Three patients received 16% C3F8 intravitreal tamponade and two patients received silicone oil tamponade. All five patients kept the prone position for more than a week after the operation, and then, the intraocular pressure of unoperated opposite eye of four patients was from 48 to 55 mmHg and they had short axial lengths and hypermetropia. Some of these 4 patients had ciliochoroidal detachment which was considered as the acute attack of primary angle-closure glaucoma. The intraocular pressure of the unoperated opposite eye of one patient was 25 mmHg, and this patient also had ciliochoroidal detachment which was considered as temporary increase of intraocular pressure. Conclusion The patient with high risk factors of primary angle-closure glaucoma might have the risk of an acute attack of primary angle-closure glaucoma in the unoperated opposite eye when keeping prone position for long time after vitrectomy. Key words: Vitrectomy; Ocular hypertension; Unoperated opposite eye; Position, prone

The Royal College of Ophthalmologists’ National Ophthalmology Database Study of Vitreoretinal Surgery

Patients and clinicians need to accurately assess the risks and benefits of pars plana vitrectomy for proliferative diabetic retinopathy, but clinical trial data may not reflect real-world experience. To prospectively audit the complications of vitrectomy for proliferative diabetic retinopathy and help establish benchmarks. Royal College of Ophthalmologists' National Ophthalmology Database study of 939 eyes of 834 patients undergoing primary vitrectomy for proliferative diabetic retinopathy at 16 different vitreoretinal units in the United Kingdom. Data were obtained for the period from January 2001 to November 2010. Pars plana vitrectomy with or without delamination/segmentation. Descriptions of the primary procedures performed, intraoperative complication rate, and proportion of eyes undergoing further surgery. An exploratory analysis of visual outcome was undertaken, with visual success and visual loss defined as a gain or reduction of 0.3 logMAR or more, respectively (approximately 2 Snellen lines), 6 to 12 months after surgery. Of 420 eyes (among 408 patients) that underwent vitrectomy without delamination, the intraoperative complication rate was 13.1% (95% CI, 10.2%-16.7% [55 of 420 eyes]), with 126 eyes (30.0%) requiring an intravitreal tamponade and 49 eyes (11.7%) undergoing further vitrectomy (median follow-up, 6.9 months); 17.9% of 127 phakic eyes developed cataracts within a year, with 63.6% achieving visual success and 8.2% visual loss. Of 519 eyes (among 463 patients) that underwent vitrectomy with delamination, the intraoperative complication rate was 30.4% (95% CI, 26.6%-34.5% [158 of 519 eyes]), with 299 eyes (57.6%) requiring an intravitreal tamponade and 78 eyes (15.0%) undergoing further vitrectomy (median follow-up, 7.1 months); 21.2% of 126 phakic eyes developed cataracts within a year, with 62.8% achieving visual success and 14.9% visual loss. Diabetic vitrectomy has an appreciable complication rate, particularly if delamination or segmentation are required. Nonetheless, the data available on visual acuity suggest that a majority of patients achieve clinically meaningful gains in vision.

PERSISTENT CORNEAL EPITHELIAL DEFECT AFTER PARS PLANA VITRECTOMY.

To investigate the incidence, risk factors, and clinical course of persistent corneal epithelial defects (PCED) after pars plana vitrectomy (PPV). The charts of 426 consecutive patients (511 eyes) who received PPV from January 2008 to December 2011 were reviewed. Corneal complications were defined as the presence of corneal epithelial defects, corneal edema, or superficial punctate keratopathy at least 1 week after vitrectomy. The PCED was defined as corneal epithelial defects lasting longer than 2 weeks after vitrectomy despite conventional treatment. The demographic, preoperative, intraoperative, and postoperative data were compared between PCED and non-PCED corneal complication groups to evaluate the risk factors and clinical outcomes. Postoperative corneal complications developed in 103 of 460 (22.4%) eyes. Diabetes was associated with postoperative corneal epithelial defects (P = 0.021) and superficial punctate keratopathy (P = 0.022) but not corneal edema (P = 0.925). Among 103 eyes with corneal complications, 21 eyes developed PCED. The eyes with PCED had poor final visual acuity, with 23.8% (5/21) of the eyes in the PCED group having visual acuity of 20/200 or better compared with 51.2% (42/82) of the eyes in the non-PCED group (P = 0.024). Logistic regression analysis demonstrated that diabetes mellitus (P = 0.025), use of perfluoropropane (P = 0.001), and assistance of a first-year resident (P = 0.029) were statistically significant risk factors for PCED after PPV. There was also a high incidence of geographic herpes simplex virus epithelial keratitis among recalcitrant PCEDs lasting longer than 4 weeks (36%, 4/11 eyes). The overall incidence of PCED after PPV was 4.8%. Diabetes mellitus, intravitreal tamponade with perfluoropropane, and assistance of a first-year resident were risk factors for PCED after PPV. Persistent corneal epithelial defects after PPV were correlated with poor postoperative visual outcomes. Early and aggressive management is necessary for patients presenting with corneal epithelial defects after vitrectomy to prevent poor outcomes.

Effects of C3F8 or silicon oil tamponade on postoperative vitreous hemorrhage and visual prognosis after vitrectomy for proliferative diabetic retinopathy

Objective To compare the effects of intravitreal tamponade of C3F8 with silicon oil on postoperative vitreous hemorrhage and visual prognosis after vitrectomy for proliferative diabetic retinopathy (PDR). Methods The clinical data of 121 patients (127 eyes) who underwent primary vitrectomy due to PDR were analyzed retrospectively. All the patients were divided into two groups according to different intravitreal tamponade, including C3F8 tamponade group (53 patients with 56 eyes) and silicone oil tamponade group (68 patients with 71 eyes). There was no difference of gender (χ2=0.956), age (t=1.122), duratiion of diabetes (t=0.627), fasting blood glucose (t=1.049), systolic pressure (t=1.056), diastolic pressure (t=0.517), history of hypertension (χ2=0.356), nephropathy (χ2=1.242), preoperative laser photocoagulation (χ2=1.225) and All the patients underwent three port pars plana vitrectomy. The mean follow-up was 2 years ranging from 6 months to 4 years. And then the incidence and onset time of postoperative vitreous hemorrhage and postoperative BCVA of the two groups were compared. Results Postoperative vitreous hemorrhage occurred in 14 of 56 eyes (25.00%) in C3F8 tamponade group. The average onset time of postoperative vitreous hemorrhage were (64.64±59.09) days ranging from 7 - 225 days and mostly were within 30 - 60 days (35.71%, 5/14). Postoperative vitreous hemorrhage also occurred in 7 of 71 eyes (9.89%) of silicone oil tamponade group after silicone oil removal with an average onset time of (25.29±20.46) days ranging from 3-65 days and were mostly within 15 - 30 days (42.86%, 3/7). There was a significant difference in the incidence of postoperative vitreous hemorrhage between the two groups (χ2=5.200, P<0.05). BCVA of the two groups was improved significantly after operation (Z=2.472, 3.114; P<0.05). Postoperative BCVA of silicone oil tamponade group was poorer than C3F8 tamponade group (Z=1.968, P<0.05). Conclusion Both C3F8 and silicone oil tamponade can improve the visual acuity after vitrectomy for PDR. Compared with C3F8, silicone oil tamponade had lower incidence and late onset of postoperative vitreous hemorrhage after vitrectomy for PDR. Key words: Diabetic retinopathy/surgery; Noble gases/therapeutic use; Silicone oils/therapeutic use; Vitreous hemorrhage; Vitreoretinal surgery

23 gauge pars plana vitrectomy for the removal of retained intraocular foreign bodies.

BackgroundTo evaluate the morpho-functional outcomes and safety of transconjuctival 23-gauge pars plana vitrectomy(PPV) for removal of intraocular foreign bodies (IOFBs).MethodsA retrospective study of 36 consecutive cases (mean age; 34,2 ± 10,9 years (between 15 and 60), 27 M,9 F) of 23-G PPV for the removal of IOFBs during the period of April 2009 and December 2011 and followed 9,4 ± 6,4(2–27) months were conducted. Visual outcomes, slit lamp biomicroscopy, intraocular pressure (IOP), and posterior segment visualization by indirect ophthalmoscopy, A-B mode ultrasonography, and computed orbital tomography were performed for all cases. Main outcomes including anatomic and visual outcomes, and both intraoperative and postoperative complications were recorded.ResultsOf the 36 cases available for the study, the IOFBs (size range, 3 to 12 mm) could be removed in all eyes. Mean preoperative LogMAR BCVA was 1.44 ± 138 (range, 1.00 to 0.00) and mean postoperative LogMAR BCVA at final visit was 0,78 ± 0,98 (range, 1.00 to 0.00). (P = 0,007) Anatomic success was obtained in 97.2 % of eyes. 16 patients needed primary wound repair due to the leakage in insertion sites before the PPV, however remaining 20 cases were not. Fibrin reaction was seen in 8 (22.2 %) patients in early postoperative period, intraocular pressure elevation was detected in 12 (33.3 %) patients in which the silicone oil was used as an intravitreal tamponade, one patient with silicone oil tamponade developed band keratopathy and phthisis bulbi.Conclusions23-Gauge PPV is a feasible, effective approach in the surgical management of the patients with posterior segment intraocular foreign bodies.