Tamponade Agent Research Articles

Clinical management of proliferative vitreoretinopathy: an update.

Proliferative vitreoretinopathy (PVR) remains the most significant obstacle to successful retinal reattachment surgery. Preclinical studies continue to add insights into the complex molecular events leading to PVR development, helping to identify new targets for potential prophylactic or therapeutic agents. This article reviews the recent evidence supporting surgical and medical treatments for PVR. PUBMED was used for literature search. Clinical studies regarding surgical management of PVR from January 1, 2000 to August 1, 2014 were included. Clinical studies regarding medical management of PVR from January 1, 2000 to August 1, 2014 were included if the design of study was a randomized controlled trial. Many recent studies have evaluated surgical and medical strategies for the treatment and prevention of PVR. Newer vitreoretinal surgery technology (23- and 25-gauge vitrectomy) and tamponade agents (heavy silicone oils) have been studied. Medical therapies evaluated include antiinflammatory agents, low molecular weight heparin, 5-fluorouracil, 13-cis-retinoic acid, and daunorubicin, amongst others. Surgical management with pars plana vitrectomy, with or without scleral buckle or inferior retinectomy, remains an effective treatment for PVR-related detachments. Consensus regarding a preferred surgical strategy remains controversial. Many medical therapies have been studied but fail to demonstrate a statistically significant benefit in clinical trials. Further studies to clarify the efficacy of available and novel treatment options are warranted.

Clinical and spectral-domain optical coherence tomography findings of patients with incomplete visual recovery after anatomically successful retinal detachment surgery.

Purpose. To identify causes of incomplete visual recovery in patients with anatomically successful retinal detachment surgery. Methods. This was a retrospective study of 61 eyes of 61 patients with at least 12-month follow-up and complete preoperative, intraoperative, and postoperative record. Postoperative visual acuity (VA) more than 0.18 logMAR was considered as incomplete visual recovery. Complete ophthalmic examination and Spectral-Domain OCT (SD-OCT) imaging were performed at last follow-up. Results. Twenty-nine eyes (47.5%) had a postoperative VA < 0.18 logMAR and 32 eyes (52.5%) had a postoperative VA ≥ 0.18 logMAR. Mean follow-up was 32.8 ± 17.3 months. Incomplete visual recovery was strongly correlated with presence of macular pathology (P = 0.002), a detached macula preoperatively (P = 0.02), retinotomy (P = 0.025), and pars plana vitrectomy and use of silicon oil as a tamponade agent (P = 0.009). Also, although there was a strong correlation between ellipsoid zone disruption and incomplete visual recovery, a distinct, more course pathology could be identified in all cases of poor visual recovery related to edema, thickening, or atrophy of the macula. Conclusion. The careful postoperative evaluation of the macula using biomicroscopy and SD-OCT can help in diagnosis of alterations that can be associated with incomplete visual recovery.

Outcomes of Relaxing Retinectomy in Patients with Proliferative Vitreoretinopathy

Purpose: To report the outcomes of relaxing retinectomy for retinal detachment in patients with proliferative vitreoretinopathy (PVR). Methods: Sixty-four cases of relaxing retinectomy for PVR with a minimum follow-up of 6 months were retrospectively reviewed. The outcomes included achievement of complete retinal reattachment, PVR recurrence, the mean number of additional operations, visual acuity and incidence of postoperative complications. We analyzed the influence of intraoperative factors including lens status, retinectomy extent, additional scleral buckling, and tamponade agent on primary retinal reattachment. Results: Complete retinal reattachment was achieved in 47 eyes (74.3%) without an additional surgery. PVR recurred in 19 eyes (29.7%) and an additional operation was performed in 17 eyes (26.6%). Fifty-seven (89.1%) eyes showed complete retinal reattachment and 40 eyes (62.5%) had visual acuity of 0.02 or more at the final follow-up visit. Hypotony was the major complication and developed in 10 eyes (15.6%). Eyes undergoing smaller (< 180 ) retinectomy or silicone oil tamponade had higher primary anatomical success rates than larger (≥ 180 ) retinectomy or gas tamponade (p = 0.043 and 0.013, respectively). Conclusions: Relaxing retinectomy is a useful technique for retinal detachment with PVR, but risk of recurrent proliferation or hypotony should be considered. J Korean Ophthalmol Soc 2015;56(6):900-905

360° laser retinopexy in preventing retinal re-detachment after 23-gauge vitrectomy for primary repair of retinal detachment

Aims: To evaluate the role of intraoperative 360° laser retinopexy in the prevention of retinal re-detachment in cases of primary rhegmatogenous retinal detachment (RRD). Settings and Design: Prospective randomized controlled trial, 80 eyes of 80 patients with primary RRD. Subjects and Methods: Totally, 80 eyes of 80 patients with primary RRD will be divided into two groups. In Group (A), laser will be applied to all existing breaks as well as 360° laser retinopexy anterior to the equator will be performed while Group (B) laser will be applied only to the retinal breaks and will not receive the 360° laser treatment. Follow-up was for 3 months after clearance of the tamponading agent. Statistical Analysis Used: Backward logistic multi-regression analysis identified significant independent predictors of re-detachment (P < 0.01, Hosmer-Lemeshow, χ2: 7.593, P = 0.474). Results: Backward logistic multi-regression analysis identified significant independent predictors of re-detachment (P < 0.01, Hosmer-Lemeshow, χ2: 7.593, P = 0.474): Duration of detachment and preoperative visual acuity. Specifically, for every day more of duration of detachment, the odds of re-detachment increased by a factor of 1.007 (P < 0.01). Likewise, for every day more of duration of detachment, the odds of re-detachment was increased by a factor of 8.840 if a preoperative visual acuity of hand motion with bad projection (HMBP) or worse was present (P = 0.05). Conclusions: We concluded that prophylactic intraoperative 360° laser retinopexy did not have a statistically significant role in the prevention of retinal re-detachment after primary retinal repair. The statistically significant preoperative risk factors that have a poor prognostic effect on surgical outcomes are preoperative visual acuity of ≤ HMBP or worse and a longer duration of the retinal detachment.

Inverted internal limiting membrane peeling technique with silicone oil tamponade for repair of recurrent large macular holes in vitrectomized Diabetic patients

Purpose : To present a new approach to treatment of large macular holes in already vitrectomized eyes of patients with proliferative diabetic retinopathy, whose ILM has not been removed during primary surgery. Patients and methods : Two eyes of two different patients with proliferative diabetic retinopathy which had undergone vitrectomy with endolaser 1.5 to 2 years before admittance to our department. No data for ILM peeling during surgery were available. Our OCT examinations showed macular holes with upper diameter of 765 I¼m in the first patient and 1160 I¼m in the second one. In both cases we combined two well-known surgical approaches: first, inverted ILM flap technique; second, long-term silicone oil tamponade for a period of 4 months. Results : The macula of both patients was followed up by photographs and regular OCT-s on day one, month one and three months after silicone oil removal. The macular holes remained closed after removal of the tamponade agent. BCVA was 0.5 three months after the last surgery in both patients. During the final examination, macular contour seemed almost normal. Discussion : Large, long-standing macular holes are less likely to be closed after pars plana vitrectomy. The inverted ILM flap technique has been recently reported to be successful in nearly 99% of patients with macular holes more than 400 I¼m in diameter. The position of the inverted ILM flap is much more controllable under silicone oil than under gas tamponade.

Flow behavior of heavy silicone oil during eye movements.

Currently there are various heavy silicone oil (HSO) tamponade agents available for treating inferior retinal diseases. Most of these HSO agents are either homogeneous liquids or a mixture of two components. Variations in their emulsification rates in vivo have been reported. In this study, we investigated their flow behaviors during eye-like movements. A model eye chamber filled with various HSO agents was driven to perform eye-like movements. Five types of HSOs with different formulations together with 2 other tamponade agents were tested. Movements of various HSOs inside the chamber were captured by video recording and analyzed. Oxane HD has a larger movement and higher velocity relative to the eye chamber than the less viscous Densiron 68. The behavior of Densiron 68 is similar to that of homogeneous HSO 1.07 and HSO 1.20. Both Oxane HD and 11% silica fluid show very different behaviors compared to the other HSO agents. In addition, 11% silica fluid shows behavior similar to that of F6H8, a low-viscosity tamponade agent. The viscosity of HSO is not the sole parameter with which to determine the behavior of HSO during eye movements. Various HSOs that are manufactured by mixing different types of base SO and "heavy" additives show distinct flow behaviors. The solubility and stability of the heavy additives in the base SO alter its flow when subjected to eye movements, which may contribute to in vivo emulsification.

Biomaterials for ocular reconstruction

Synthetic materials have played a significant role in ophthalmic applications to improve vision for many years. This has been in four main areas in ophthalmology: ocular surface reconstruction, lens replacement, vitreous replacement and structural support and cell transplantation in the retina. Corneal replacement therapies have been developed using both synthetic acrylic-based materials and more recently naturally derived materials such as amniotic membrane. Intraocular lenses as a replacement for the natural lens post cataract surgery has been used for many years. Newer developments include the opportunity to use gels so that the lenses can accommodate but these need improving in terms of the cross-linking chemistry. Silicone oils have been used as long-term tamponade agents as vitreous replacements but recent developments in their properties has enhanced the clinical outcomes and further research into their use as drug delivery vehicles will be a major advancement. Regenerative medicine therapies to repopulate the retina to repair and replace specific cell layers require the optimisation of synthetic scaffolds and this is a major area for development. Recent developments in biomaterials have emphasised the importance of the physical, chemical and mechanical properties specific to a particular ophthalmic application. Materials science has a critical role in developing strategies to overcome vision loss.

23-gauge sutureless vitreo-retinal surgery for superior rhegmatogenous retinal detachment.

To determine the results of 23-gauge sutureless vitreo-retinal surgery for superior/supero-temporal rhegmatogenous retinal detachment (RRD). Quasi experimental study. LRBT, Free Base Eye Hospital, Karachi, from January 2010 to December 2011. Adult patients who underwent 23-gauge sutureless vitreo-retinal surgery along with use of Perfluoropropane (C3F8) gas as internal tamponading agent for fresh (upto 3 weeks) superior/supero-temporal RRD was reviewed. Major outcome measures were anatomical success, best corrected visual acuity (BCVA) with Log Mar and complications during and after surgery. Postoperative follow-up was done on 1st day and at 1st, 4th, 8th and finally at 12th week. Sixty eyes of 60 patients, age between 30 - 60 years including 37 (61.67%) males and 23 (38.33%) females having superior or superatemporal RRD underwent 23-guage sutureless vitreo-retinal surgery with the use of perfluoropropane (C3 F8) gas as internal temponade at the end of procedure. Anatomical success rate was 81.66% (49 out of 60 eyes) with first surgery and raised to 90% (54 cases) with second surgery. Log Mar BCVA significantly improved from mean baseline 0.93 to 0.49 with mean difference of 0.43 (p < 0.001), 95% confidence interval. Postoperative complications were sub-conjunctival haemorrhage in 11 eyes (18.33%), wound leak in 7 eyes (11.66%), anterior chamber became shallow in 6 eyes (10%), cataract developed in 5 eyes (8.33%), re-retinal detachment in 4 eyes (6.66%), ocular hypotony and sterile inflammatory reaction in 3 eyes (5%) each, while iatrogenic breaks developed in 2 eyes (3.33%). The 23-gauge sutureless vitreo-retinal surgery for superior rhegmatogenous retinal detachment achieved high anatomical success and significant visual improvement. Sub-conjunctival haemorrhage was the most frequent procedural complication.

RATE OF SCLEROTOMY SUTURING IN 23-GAUGE PRIMARY VITRECTOMY

To evaluate the rate of sclerotomy suturing in a large series of primary 23-gauge vitrectomies. Retrospective chart review of 23-gauge transconjunctival pars plana vitrectomies performed between 2008 and 2012 in a multisurgeon retina practice. Patients with a history of retinal surgery, combination of vitrectomy and scleral buckling surgery, or intraoperative conversion of a sclerotomy to 20-gauge were excluded from the study. Vitrectomies were divided into two types according to their degree of complexity and intraoperative use of instrumentation. Demographic and clinical data were gathered from the chart. Location and number of sutured sclerotomies were obtained from the operative report. A total of 589 eyes from 569 patients were included in this study. At least 1 sclerotomy was sutured in 227 eyes (38.5%): 69 (30.4%) had 1 sutured sclerotomy, 52 (22.9%) had 2 sutured sclerotomies, and 106 (46.7%) had 3 sutured sclerotomies. Sclerotomy suturing was significantly related to the surgical technique (P < 0.001), type of tamponade agent (P = 0.048), and complexity of the vitrectomy (P < 0.001). The incidence of postoperative hypotony at Day 1 was 2.2% and all cases returned to normal intraocular pressure at 1 week. There were no recognized complications related to sclerotomies regardless of suturing. The factors that increased the rate of sclerotomy suturing were the absence of tamponade agent and higher complexity of the procedure. There was a high variability in the rate of suturing between the surgeons.

Comparison of Sulfur Hexafluoride and Air for Donor Attachment in Descemet Stripping Endothelial Keratoplasty in Patients With Pseudophakic Bullous Keratopathy

The aim of this study was to evaluate the clinical efficacy and safety of sulfur hexafluoride (SF6) as a tamponading agent after donor placement during Descemet stripping endothelial keratoplasty (DSEK) surgery and to compare the outcomes with those of air. Forty-four eyes of 44 consecutive patients who underwent DSEK were included in the study. Air was used in 22 eyes of 22 patients (air group), and SF6 was used in 22 eyes of 22 patients (SF6 group) to attach the donor lenticule. The complications, corrected visual acuity (CVA), and the endothelial cell density (ECD) results were compared between these 2 groups. Six eyes had graft dislocation in the air group that underwent successful rebubbling on postoperative day 1. There was no graft dislocation in the SF6 group. There was no other complication observed in both the groups. The mean increase in the CVA was 1.09 ± 0.36 logarithm of the minimum angle of resolution in the air group, whereas it was 0.80 ± 0.57 logarithm of the minimum angle of resolution in the SF6 group. The mean increase in the CVA was not statistically different between the 2 groups (P = 0.060). Compared with the mean ECD in donor grafts, the mean decrease in the ECD was 222 ± 86 (44%) cells per square millimeter in the air group and 178 ± 52 (39%) cells per square millimeter in the SF6 group at the 1-year follow-up. The mean decrease in the ECD was statistically significantly higher in the air group compared with that in the SF6 group (P = 0.049). SF6 is comparable to air for attaching the donor graft as a tamponading agent in DSEK surgery.

Air as Tamponade for Retinal Detachments

To determine whether air can be used as a reliable tamponade agent after pars plana vitrectomy in selected primary retinal detachment (RD). Twelve eyes with fresh RD were included. Exclusion criteria were presence of fibrosis, fixed folds, proliferative vitreoretinopathy of grade C or greater, and giant retinal tears. The number, location, and types of breaks, extension of RD, and whether the macula was attached were documented. A 25-gauge 3-port pars plana vitrectomy was carried out. Central and peripheral vitreous was removed to eliminate traction and relieve tractional forces provoked by the air bubble injected at the end. Argon endolaser or cryotherapy was applied around all breaks. Filtered air was used as an internal tamponade. Patients were followed up at 24 hours, 1 week, and 1, 3, 6, and 12 months. Air bubble took 10.7 days (range 7-15 days) to resolve. Visual acuity (VA) improved from 1.35 ± 1.21 logMAR preoperatively to 0.20 ± 0.25 after a follow-up time of 12 months. We achieved a primary postoperative success rate of 100% at 1 month and 91.6% at 12 months. We achieved a good success rate with air tamponade and limited laser. This approach allows for quicker VA recovery associated with a rapid disappearance of air. This may benefit patients who live at higher altitudes.

Tamponade in surgery for retinal detachment associated with proliferative vitreoretinopathy

Retinal detachment (RD) with proliferative vitreoretinopathy (PVR) often requires surgery to restore normal anatomy and to stabilize or improve vision. PVR usually occurs in association with recurrent RD (that is, after initial retinal re-attachment surgery) but occasionally may be associated with primary RD. Either way, a tamponade agent (gas or silicone oil) is needed during surgery to reduce the rate of postoperative recurrent RD. The objective of this review was to assess the relative safety and effectiveness of various tamponade agents used with surgery for retinal detachment (RD) complicated by proliferative vitreoretinopathy (PVR). We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2013), EMBASE (January 1980 to June 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to June 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 26 June 2013. We included randomized controlled trials (RCTs) of participants undergoing surgery for RD associated with PVR that compared various tamponade agents. Two review authors screened the search results independently. We used the standard methodological procedures expected by The Cochrane Collaboration. The review included 516 participants from three RCTs. One study was conducted in the USA and consisted of two trials: the first trial randomized 151 adults to receive either silicone oil or sulfur hexafluoride (SF6) gas tamponades; and the second trial randomized 271 adults to receive either silicone oil or perfluropropane (C3F8) gas tamponades. The third trial was a multi-center international trial and randomized 94 participants (age range not specified) to receive heavy silicone oil (a mixture of perfluorohexyloctane (F6H8) and silicone oil) versus standard silicone oil (either 1000 centistokes or 5000 centistokes, per the surgeon's preference).In participants with RD associated with PVR, outcomes after pars plana vitrectomy and infusion of either silicone oil, perfluropropane gas, or sulfur hexafluoride gas appeared comparable for a broad variety of cases. There were no significant differences between silicone oil and perfluoropropane gas in terms of the proportion of participants achieving at least 5/200 visual acuity (risk ratio (RR) 0.97; 95% confidence interval (CI) 0.73 to 1.31) or achieving macular attachment (RR 1.00; 95% CI 0.86 to 1.15) at a minimum of one year. Although sulfur hexafluoride gas was reported to be associated with significantly worse anatomic and visual outcomes than was silicone oil at one year (quantitative data not reported), there were no significant differences between silicone oil and sulfur hexafluoride gas in terms of achieving at least 5/200 visual acuity at two years (RR 1.57; 95% CI 0.93 to 2.66). For macular attachment, participants treated with silicone oil received significantly more favourable outcomes than did participants who received sulfur hexafluoride at both one year (quantitative data not reported) and two years (RR 1.37; 95% CI 1.01 to 1.86). The first two trials did not perform any sample size calculation or power detection. In the third trial, which had a power of 80% to detect differences, heavy silicone oil was not shown to be superior to standard silicone oil. There were no significant differences between standard silicone oil and heavy silicone oil in the change in visual acuity at one year using adjusted mean logMAR visual acuity (mean difference -0.03 logMAR; 95% CI -0.35 to 0.29). Adverse events were not reported for the first two trials. For the third trial, only the total number of adverse events was reported, and adverse events for each group were not specified. Of the 94 participants, four died, 26 had recurrent retinal detachment, 22 developed glaucoma, four developed a cataract, and two had capsular fibrosis.All three trials employed adequate methods for random sequence generation and allocation concealment. None of the trials employed masking of participants and surgeons, and only the third trial masked outcome assessors. The first trial had a large portion of participants excluded from the final analyses, while the other two trials were at low risk of attrition bias. All trials appear to be free of reporting bias. The first two trials were funded by the National Eye Institute, and the third trial was funded by the German Research Foundation. The use of either perfluropropane or standard silicone oil appears reasonable for most patients with RD associated with PVR. Because there do not appear to be any major differences in outcomes between the two agents, the choice of a tamponade agent should be individualized for each patient. Heavy silicone oil, which is not available for routine clinical use in the USA, has not demonstrated evidence of superiority over standard silicone oil.

Heavy silicone oil and intraocular inflammation.

In the past two decades, many advances have been made in vitrectomy instrumentation, surgical techniques, and the use of different tamponade agents. These agents serve close retinal breaks, confine eventual retinal redetachment, and prevent proliferative vitreoretinopathy (PVR). Long-acting gases and silicone oil are effective internal tamponade agents; however, because their specific gravity is lower than that of the vitreous fluid, they may provide adequate support for the superior retina but lack efficacy for the inferior retina, especially when the fill is subtotal. Thus, a specific role may exist for an internal tamponade agent with a higher specific gravity, such as heavy silicone oils (HSOs), Densiron 68, Oxane HD, HWS 45-300, HWS 46-3000, and HeavySil. Some clinical evidence seems to presume that heavy tamponades are more prone to intraocular inflammation than standard silicone if they remain in the eye for several months. In this review, we discuss the fundamental clinical and biochemical/molecular mechanisms involved in the inflammatory response after the use of heavy tamponade: toxicity due to impurities or instability of the agent, direct toxicity and immunogenicity, oil emulsification, and mechanical injury due to gravity. The physical and chemical properties of various HSOs and their efficacy and safety profiles are also described.

VITRECTOMY COMBINED WITH PERIOCULAR/INTRAVITREAL INJECTION OF STEROIDS FOR RHEGMATOGENOUS RETINAL DETACHMENT ASSOCIATED WITH CHOROIDAL DETACHMENT

To study the anatomical outcome of rhegmatogenous retinal detachment combined with choroidal detachment after pars plana vitrectomy with periocular/intravitreal injection of steroids. Seventy-seven eyes that have rhegmatogenous retinal detachment combined with choroidal detachment were treated by pars plana vitrectomy with oral prednisolone (Group A) or periocular/intravitreal injection of steroids (Group B) and then divided into 5 subgroups according to different intraocular tamponade agents; Group A1: oral steroids and silicone oil, Group A2: oral steroids and C(3)F(8), Group B1: periocular/intravitreal steroid injections and silicone oil, Group B2: periocular steroid injection and silicone oil, and Group B3: periocular steroid injection and C(3)F(8). Anatomical reattachment of the retina was measured at 12 months after surgery. There was no significant difference in retinal reattachment rate between eyes in Group A and eyes in Group B (77.4% vs. 73.9%, P = 0.726). The retinal reattachment rates were 83.3% in Group A1, 69.2% in Group A2, 82.4% in Group B1, 73.3% in Group B2, and 64.3% in Group B3. There was no statistical difference in the retinal reattachment rates between any of the groups. For the treatment of rhegmatogenous retinal detachment combined with choroidal detachment, pars plana vitrectomy with periocular/intravitreal corticosteroids was comparable in reattachment rate to pars plana vitrectomy with systemic steroids, suggesting an acceptable alternative for patients with this condition who cannot tolerate systemic steroids.

Heavy silicone oil as a long-term endotamponade agent for complicated retinal detachments.

We retrospectively evaluated a heavy silicone oil (HSO) as a long-term intraocular endotamponade agent to treat complicated RD by inferior PVR in 25 eyes of 25 patients. Patients underwent PPV and injection of Oxane HD as an internal tamponade agent. A comparison of preoperative and postoperative BCVA at month 1, month 6, and last visit was made in the group in which HSO was removed and in the group in which HSO was not removed. Statistical calculations were performed using the Wilcoxon test. The HSO was removed from 11 patients after a mean of 26.55 ± 21.38 months. The HSO remained inside the vitreous cavity in 14 eyes due to a high chance of PVR recurrence (mean follow-up period, 11.07 ± 7.44 months). Anatomic success was achieved in 92%. The BCVA in the group, in which HSO was not removed, improved significantly during the first 6 months. Among the patients who had the oil removed, there was improvement in BCVA after 1 month. Oil emulsification was the most common adverse effect in 52% of eyes. HSO is an effective tamponade in complex rhegmatogenous and tractional RD complicated by PVR. HSO can remain in the eye for long periods with relative tolerability and safety.

Vitreous tamponades in highly myopic eyes.

The use of endotamponade agents has gained a major role in the management of macular complications of high myopia. Myopic foveoschisis and macular hole are the main macular complication of pathologic myopia, this growing condition that is a main cause of visual loss, especially in patients at a younger age. We discuss the physical properties and advantages and disadvantages of the main ocular tamponade agents used in the treatment of these diseases.

Novel Heavy Tamponade for Vitreoretinal Surgery

The aim of this study was to produce a heavy tamponade with a specific gravity greater than 1.06 g/mL that was optically transparent, could be manufactured using simple processing, could be injected using standard clinical equipment, and would have appropriate biocompatibility. Aerosil silica was added to a phenyl trimethicone and mixed via a roller, overhead stirring, and ultrasonics. The refractive index, visible absorbance, and shear viscosity were measured. The injectability of the solutions was evaluated using the Accurus Viscous Fluid Injection system. The tamponade efficiency was assessed using a model eye chamber and compared with that of Densiron 68, Oxane HD, and F6H8. The biocompatibility was evaluated in vitro and in vivo in rabbits. Tamponade agents were produced with specific gravities of 1.10, 1.11, 1.13, and 1.16 g/mL that had good optical clarity. Mixing using overhead stirring was sufficient to produce tamponade agents with shear viscosities in the range 1000 to 5000 mPa·s that were reproducible and stable during storage. The solutions were easier to inject using the Accurus Viscous Fluid Injection system than silicone oil 1000 mPa·s. The 11% silica solution had greater tamponade efficiency than Densiron 68 or Oxane HD. There was no evidence of cytotoxicity in vitro. Silica solution 11% induced cataract earlier than Polydimethylsiloxane 1000 (PDMS 1000). Silica solution 11% and phenyl trimethicone reduced the a-wave value at 1 week after vitrectomy, but recovery was observed at later time points. Silica solution 11% caused inner nuclear layer (INL) nuclei dropdown in inferior retina from 4 weeks postoperation. Polydimethylsiloxane 1000 induced a similar phenomenon in superior retina 12 weeks postoperation. We have produced a heavy tamponade with good clarity that has appropriate shear viscosity, injectibility, enhanced tamponade efficiency, and biocompatibility similar to that of PDMS 1000.

Long‐term results and prognostic factors for visual acuity after diabetic vitrectomy: A 10‐year follow‐up study

AbstractPurpose To report long‐term results and estimate long‐term prognostic factors for visual acuity following modern diabetic vitrectomy.Methods Retrospective review of patient files from a large diabetes center between 1996 and 2010. Surgical history was obtained from the Danish National Patient Register. Follow‐up intervals were 3 months and 1, 3, 5 and 10 years after surgery.Results In total, 167 patients had diabetic vitrectomy. Surgery indications were non‐clearing vitreous hemorrhage (47%) or tractional retinal detachment (53%). Median visual acuity increased from 0.06 before surgery to 0.21 after surgery (p&lt;0.001) and stabilized. The proportion of patients with reading ability stabilized as from the 3‐month follow‐up. After 10 years, 66% of the operated eyes were pseudophakic or aphakic and 13% carried silicone oil. Preoperative iris rubeosis was correlated with inability to read after 1 and 3 years (p&lt;0.04). Use of silicone oil was correlated with inability to read at all follow‐up examinations (p&lt;0.05).Conclusion After diabetic vitrectomy, visual acuity improved and stabilized as from the 3‐month follow‐up. The most consistent long‐term predictor of unfavorable visual acuity was use of silicone oil as tamponade agent. The results can be used to counsel patients on the risk of complications after surgery.

Suprachoroidal Silicone Oil Migration Following Retinal Detachment Repair

Silicone oil is a commonly used tamponade agent. We report the rare complication of a patient who presented with silicone oil in the suprachoroidal space following retinal detachment repair. The silicone oil was subsequently removed without any long-term complications.

Vitrectomy combined with silicone oil tamponade in the treatment of severely traumatized eyes with the visual acuity of no light perception.

To evaluate the efficacy of surgical treatment of vitrectomy combined with silicone oil tamponade in the treatment of severely traumatized eyes with the visual acuity of no light perception (NLP). This was a retrospective uncontrolled interventional case-series of 19 patients of severely traumatized eyes with NLP who underwent vitrectomy surgery at the Affiliated Hospital of Medical College, Qingdao University (Qingdao, China) during a 3-year period. We recorded perioperative factors with the potential to influence functional outcome including duration from the injury to intervention; causes for ocular trauma; open globe or closed globe injury; grade of vitreous hemorrhage; grade of endophthalmitis; grade of retinal detachment; size and location of intraocular foreign body (IOFB); extent and position of retinal defect; grade of proliferative vitreoretinopathy (PVR); type of surgery; perioperative complications and tamponade agent. The follow-up time was from 3 to 18 months, and the mean time was 12 months. After a mean follow-up period of 12 months (3-18 months) 10.53% (2/19) of eyes had visual acuity of between 20/60 and 20/400, 52.63% (10/19) had visual acuity less than 20/400 but more than NLP, and 36.84% (7/19) remained NLP. Visual acuity was improved from NLP to light perception (LP) or better in 63.16% (12/19) of eyes and the rate of complete retinal reattachment was 73.68% (14/19). Good visual acuity all resulted from those patients of blunt trauma with intact eyewall (closed globe injury). The perioperative factors of poor visual acuity prognosis included delayed intervention; open globe injury; endophthalmitis; severe retinal detachment; large IOFB; macular defect; a wide range of retinal defects and severe PVR. The main reasons of NLP after ocular trauma are severe vitreous hemorrhage opacity; refractive media opacity; retinal detachment; retinal and uveal damages and defects, especially defects of the macula; PVR and endophthalmitis. NLP after ocular trauma in some cases does not mean permanent vision loss. Early intervention of vitrectomy combined with silicone oil tamponade and achieving retinal reattachment of the remaining retina, may make the severely traumatized eyes regain the VA of LP or better.