A custom-made vitreoretinal surgical simulator using a silicone mold.

PURPOSE: We constructed a custom-made vitreoretinal surgical simulator using a silicone mold and described its practicality. METHODS: We obtained spherical silicone molds, mannequins, and spray material from an internet-based vendor and combined them with expired surgical instruments to complete the simulator. Vitreoretinal experts confirmed the practicality of the simulator after simulated vitrectomy, and the results of the questionnaires were confirmed by nonvitreoretinal experts. RESULTS: Vitreoretinal experts observed that the simulated eyeball and the actual eyeball were similar in size and rigidity and that the intraocular practice swing seemed to be useful for the prevention of complications. The semitransparency and open-sky structure of the silicone material ensured visibility. The simulated membrane, which was spray glue, provided an excellent peeling sensation. In the results of the nonvitreoretinal experts' questionnaires, the average scores of all items were generally high, which supported the claims of the simulator's usefulness. CONCLUSION: This report describes the simplicity and cost-effectiveness of our custom-made simulator and its contribution in creating an ideal training environment that does not necessitate travel to special facilities that offer a large number of pig eyes and vitreous surgical machines. The simple shape seems to allow many possibilities, and further verification at multiple facilities is necessary.

Toxic posterior segment syndrome with retinal vasculitis likely caused by intraocular cotton fiber after vitreoretinal surgery - a case report.

BACKGROUND: Intraocular inflammation is common after anterior or posterior segment surgery. They typically manifest either as non-infectious inflammation of the anterior or posterior segment, known as toxic anterior or posterior segment syndrome (TPSS), or as sterile or infective endophthalmitis. In this report, we describe a rare case of TPSS following vitreoretinal surgery, presenting as hemorrhagic retinal vasculitis. CASE PRESENTATION: A 58-year-old male diagnosed with a left eye acute rhegmatogenous retinal detachment underwent an uneventful primary pars plana vitrectomy with silicone oil endotamponade on the same day of presentation. At presentation, there were no signs of intraocular inflammation, and his visual acuity in the affected eye was 20/200. RESULTS: The retina was well-attached with silicone oil in place on the first post-operative day. Along the inferior retinal periphery, a hemorrhagic occlusive vasculitis was observed. Clinical examination revealed retained intraocular cotton fiber along the inferotemporal quadrant over the retinal surface. In addition to the standard post-operative medications, a course of systemic steroids (40 mg per day of Prednisolone tablets) was started. At the end of the first post-operative week, clinical signs of hemorrhagic retinal vasculitis were beginning to resolve, and by the end of the fourth post-operative week, they had completely resolved. CONCLUSION: This report describes an unusual diagnosis of TPSS after vitreoretinal surgery, most likely due to the presence of an intraocular cotton fiber. This excessive inflammation of the posterior segment usually responds to a course of topical and systemic steroids.

Vitreous Substitutes from Bench to the Operating Room in a Translational Approach: Review and Future Endeavors in Vitreoretinal Surgery.

Vitreous substitutes are indispensable tools in vitreoretinal surgery. The two crucial functions of these substitutes are their ability to displace intravitreal fluid from the retinal surface and to allow the retina to adhere to the retinal pigment epithelium. Today, vitreoretinal surgeons can choose among a plethora of vitreous tamponades, and the tamponade of choice might be difficult to determine in the ever-expanding range of possibilities for a favorable outcome. The currently available vitreous substitutes have disadvantages that need to be addressed to improve the surgical outcome achievable today. Herein, the fundamental physical and chemical proprieties of all vitreous substitutes are reported, and their use and clinical applications are described alongside some surgical techniques of intra-operative manipulation. The major upcoming developments in vitreous substitutes are extensively discussed, keeping a translational perspective throughout. Conclusions on future perspectives are derived through an in-depth analysis of what is lacking today in terms of desired outcomes and biomaterials technology.

THE NOVEL USE OF HIGH-FLOW POLYIMIDE CANNULAS TO IMPROVE SILICONE OIL INJECTABILITY IN VITREORETINAL SURGERY.

PURPOSE: The injection of high-viscosity silicone oil lengthens injection time. New polyimide cannulas offer a greater inner diameter than conventional metal cannulas at the same gauge. We compared the injection time for polyimide and metal cannulas at 23 G for a variety of silicone oils including a 12,500-mPas prototype oil. METHODS: In this laboratory study, injection time was measured three times per cannula and per oil. Warming the oil before injection to up to 42°C was also evaluated. Finally, the feasibility of polyimide cannulas was tested in vitrectomized porcine eyes. RESULTS: The 23-G polyimide cannula mostly decreased injection times. The time to inject 5 mL of Siluron Xtra and Siluron 5000 decreased by 6:02 (76.9%) minutes (483 vs. 121 seconds) and 12:01 (74.7%) minutes (973 vs. 252 seconds), respectively. Although the 23-G metal cannula failed to inject 12,500 mPas oil, 5 mL was injected in 10:21 minutes using the polyimide cannula. Prewarming Siluron 5000 to 42°C lowered the injection time by 9.0% and by 12.1% when using the metal or polyimide cannula, respectively. CONCLUSION: Polyimide cannulas allow a clinically relevant decrease in injection time. They may not only shorten surgery time but could also ease the use of next-generation ultra-high-viscosity silicone oils. Prewarming silicone oil leads to decreased injection times.

Novel vitreous substitutes: the next frontier in vitreoretinal surgery.

PURPOSE OF REVIEW: After removing the native vitreous during vitreoretinal surgery, an adequate substitute is required to ensure homeostasis of the eye. Current clinically used endotamponades (silicone oil, gases, semifluorinated alkanes) are effective in promoting retinal reattachment, but lead to complications such as emulsification, prolonged inflammation, blurred vision, raised intraocular pressure, cataract formation or the need for revision surgery. The aim of this review is to provide an update on novel vitreous substitutes with a focus on polymer-based systems. RECENT FINDINGS: Polymeric hydrogels provide favourable properties such as high water content, optical transparency, suitable refractive indices and densities, adjustable rheological properties, injectability, biocompatibility and their ability to tamponade the retina via viscosity and swelling pressure, comparable to the native human vitreous body. Here, vitreous replacement strategies can be divided into chemically or physically crosslinked hydrogel systems that are applied as preformed or in-situ gelling matrices. SUMMARY: Several hydrogel-based vitreous substitutes have already been positively evaluated in preclinical tests and have the potential to enter the clinical phase soon.

Benchmarking different brands of silicone oils.

PURPOSE: To compare the analytical quality characteristics of currently available CE-marked silicone oils used as ocular endotamponades in vitreoretinal surgery. METHODS: Thirty-four samples of 12 brands were analysed. To assess the quality characteristics of silicone oils, we measured the oligosiloxane content and polydispersity, widely accepted as purity parameters. UV-active substances (> 220 nm) were analysed to draw conclusions about the integrity of primary packaging components. RESULTS: We identified significant differences in the impurity profiles of the products tested, which revealed oligosiloxane contents ranging from < 0.1 to 491 ppm, polydispersity ranging from 1.6 to 3.0 and UV-active substances (> 220 nm) ranging from 0.2 to 3.8 AU. CONCLUSION: The quality characteristics of the analysed silicone oils vary significantly not only among different brands but also among batches of the same manufacturer. Manufacturers should communicate the purity and quality characteristics of their products in an understandable and clear manner. This involves providing a complete certificate of analysis with special focus on quality characteristics, to enable the vitreoretinal surgeon to differentiate between the effects of the silicone oil itself and those of impurities.

Safety of silicone oils as intraocular medical device: An in vitro cytotoxicity study.

This study aimed to assess the cytotoxic effect of low molecular weight components (LMWC) and conventional silicone oils (SOs) 1000 cSt with different degree of purification (raw, intermediate, and purified) using in vitro cytotoxicity tests. Direct contact cytotoxicity tests were performed in BALB 3T3 and human retinal pigment epithelial cells (ARPE-19) using quantitative and qualitative evaluation according to the ISO 10993-5 (2009) standards. Conventional SOs 1000 cSt in form of raw, intermediate (intermediate product obtained during distillation process), and purified SO (final product after distillation) and a concentrate of LMWC (including siloxane chains with molecular weight up to 1557 g/mol) were directly applied to 100% of cell layer area for 24 h. Cell viability was quantified using 3-(4,5-dimethylthiazole-2-yl)-2,5-28 diphenyltetrazolium bromide (MTT) and neutral red uptake assays in ARPE-19 and BALB3T3, respectively. All tested samples, including the concentrate of LMWC, resulted to be not cytotoxic according to ISO 10993-5 in both qualitative and quantitative evaluations. However, the cellular viability was significantly higher in the intermediate and purified SO compared with the raw SO in ARPE-19 cells. No reduction in cell viability was detected by LMWC. The absence of cytotoxicity was observed for all tested samples in both BALB3T3 and ARPE-19 after 24 h of application. A direct cytotoxic effect is not likely to be involved in the potential complications related to SO and LMWC. Long-term potential adverse effects of SO could be related to the raw material and to different concentrations of LMWC.

HIGHER-ORDER ABERRATIONS IN EYES WITH SILICONE OIL TAMPONADE.

PURPOSE: To investigate the changes in higher-order aberrations (HOAs) after silicone oil removal and to evaluate their associations with visual acuity. METHODS: Fifty-nine eyes of 58 patients who underwent SO removal were included. Total, corneal, and internal optic HOAs, and best-corrected visual acuity were measured before and 1 month after SO removal, and changes were compared between phakic and pseudophakic eyes. RESULTS: Total ocular and internal optic HOAs decreased significantly after SO removal both in pseudophakic (n = 40, all P < 0.001) and phakic eyes (n = 19, P = 0.017, P = 0.004). Preoperative HOAs (P < 0.001) and changes in HOAs (P = 0.006) were greater in pseudophakic eyes than in phakic eyes. Best-corrected visual acuity was significantly improved after SO removal, from 20/105 to 20/78 (P < 0.001) in pseudophakic eyes, whereas there was no difference in phakic eyes (P = 0.714). Preoperative HOAs and the reduction in HOAs after SO removal were greater in best-corrected visual acuity-improved eyes than best-corrected visual acuity-unchanged eyes (P < 0.001). CONCLUSION: Silicone oil tamponade induced an increase in HOAs, and these increases were greater in pseudophakic eyes than in phakic eyes. Silicone oil may cause additional visual impairments because of HOAs, beyond those caused by retinal diseases, particularly in pseudophakic eyes.

A Two-Port Inexpensive and Effective Method for Silicone Oil Removal.

BACKGROUND: There are several ways to remove silicone oil (SO) from the vitreous cavity. OBJECTIVES: To describe a simple, safe and inexpensive method of 2-port SO removal. METHODS: Medical charts of 33 patients who underwent SO removal combined with cataract extraction were retrospectively reviewed, from a cohort of 119 patients who had silicone oil removal. The primary outcome was the rate of re-detachment, secondary outcomes included visual acuity (VA) and intraoperative and postoperative complications. RESULTS: Mean follow-up time was 27.6 months (0.25-147 ± 33.1), and mean tamponade duration prior to SO removal was 16.77 months (4-51.5 ± 14.6). The re-detachment rate was 3% (one patient). Postoperatively, seven patients (20%) had epiretinal membrane (ERM), eight patients had posterior capsule opacification (24%), and proliferative vitreoretinopathy (PVR) was diagnosed in two patients (6%). Compared to the mean VA (logarithm of the minimum angle of resolution [LogMAR]) at the preoperative examination, the mean VA (LogMAR) improved significantly at the last visit when including all ranges of VA (n=32, LogMAR 1.52 vs. 1.05 P = 0.0002 [Student's t-test] and P = 0.001 [Wilcoxon test]). CONCLUSIONS: The technique described is fast and simple, keeping the posterior capsule intact in pseudophakic patients, which is advantageous in the event of future re-detachment necessitating SO reinjection. Rates of re-detachment and postoperative ERM and PVR were low. Furthermore, our method does not require the use of a surgical microscope with posterior segment viewing systems, or opening a full disposable vitrectomy set, thus drastically reducing the procedure's cost.

Multifocal electroretinogram in eyes with intravitreal silicone oil and changes following silicone oil removal.

PURPOSE: To determine the effect of intravitreal silicone oil (SO) on multifocal electroretinogram (mfERG) and the changes in mfERG following SO removal. METHODS: Twelve eyes of 12 patients with SO in vitreous cavity with corrected distance visual acuity (CDVA) > 20/200 were prospectively enrolled as cases over a period from July 2016 to June 2018. The fellow normal eyes served as control. The eyes were evaluated with P1 and N1 wave amplitude and implicit time on mfERG at baseline, 1 and 4 weeks after SO removal. RESULTS: The mean age was 44.9 ± 18.9 (range 18-74) years. The indication for SO injection was retinal detachment (n = 9, three macula-on eyes, six macula-off eyes) and endophthalmitis (n = 3). The median (range) LogMAR CDVA at baseline was 0.54 (0.18-0.78) in cases and did not change post-SO removal (p = 0.29). There was a significant decrease in average P1 and N1 wave amplitude (p = 0.0001 and 0.0001, respectively) and delay in average P1 and N1 wave implicit time (p = 0.0002 and 0.021, respectively) in cases as compared to controls. The macular status and duration of SO tamponade did not have a significant correlation with mfERG parameters. There was a significant increase in average P1 and N1 wave amplitude (p = 0.009 and 0.003, respectively) at 1 week following SO removal but no change in average P1 and N1 wave implicit time (p = 0.41 and 0.37, respectively). CONCLUSION: mfERG may be reliably performed for the assessment of macular function in SO-filled eyes. Intravitreal SO exerts an insulating effect on the density of the electric potentials.

[Analysis of unplanned reoperation following vitreoretinal surgery].

Objective: To determine the incidence of unplanned reoperation following vitreoretinal surgery and identify the reasons for unplanned reoperations. Methods: Case records of all patients undergoing vitreoretinal surgery at Peking Union Medical College Hospital between June 2014 and June 2017 were reviewed to determine the incidence of unplanned reoperations during the primary admission and within 90 days following vitreoretinal surgery. Results: A total of 3 356 case records were reviewed. During the primary admission, 97 times of unplanned reoperation occurred in 81 cases [45 males and 36 females, aged (47.3±16.8) years].The incidence of unplanned reoperation was 2.4% (81/3 356). The most common primary diseases were retinal detachment (25 cases, 30.9%), proliferative diabetic retinopathy (23 cases, 28.4%) and silicone oil filled eye (17 cases, 21.0%). The most common reasons for unplanned reoperation were new onset or recurrent retinal detachment (33 times, 34.0%), increased intraocular pressure (23 times, 23.7%), as well as hyphema and inflammation (16 times, 16.5%). The percentages of the primary diseases and reasons for unplanned reoperation within 90 days following vitreoretinal surgery were not significantly different when compared with those during the primary admission. Desired results could be achieved in all cases after unplanned reoperation. Conclusions: The primary diseases of unplanned reoperation for vitreoretinal surgery are complicated retinal detachment, diabetic retinopathy and silicone oil filled eyes. New onset or recurrent retinal detachment, increased intraocular pressure, hyphema and inflammation are common causes of reoperation.

A quality of life survey in patients with long-term silicone oil or phthisis bulbi.

AIM: The aim of this study is to determine whether there is any difference in the quality of life of patients with a blind eye with long-term silicone oil compared to without. METHOD: Patients with either long-term silicone oil in situ (N = 17), defined as a period greater than 6 months duration with no plan for future removal, or those with a phthisical, non oil-filled eye were identified (N = 13). Two validated questionnaires (NEI VFQ-25 and the FACE-Q) that cover indicators for visual function, pain and cosmesis were sent to all patients in the two cohorts. RESULTS: There was no significant difference found in quality of life outcomes between the two groups in terms of visual function, pain or cosmesis. CONCLUSION: The results of this study support a holistic approach to the consent process before vitreoretinal surgery. Patients that may need to undergo multiple vitreoretinal procedures, where the endstage result is a long-term silicone oil fill, should be informed that their functional outcome may be similar to having no surgical intervention.

Safety and efficacy of transpupillary silicone oil removal in combination with micro-incision phacoemulsification cataract surgery: comparison with 23-gauge approach.

BACKGROUND: To evaluate safety and efficacy of transpupillary silicone oil removal combined with micro-incision phacoemulsification cataract surgery, and to compare results of transpupillary with 23-gauge three-port vitrectomy approach. METHODS: Consecutive cases that underwent silicone oil removal using either transpupillary or three-port approach in combination with micro-incision phacoemulsification cataract surgery were retrospectively reviewed. The main outcome measures were postoperative detachment rate, silicone oil residuals, best corrected visual acuity (BCVA) and intraocular pressure (IOP). RESULTS: A total of 64 cases were included, 19 in transpupillary and 45 in three-port. Postoperative detachment rate within 3 months in transpupillary versus three-port was 15.8% versus 4.4% (p = 0.14), Silicone oil residuals was 7.4 ± 3.2% versus 7.1 ± 2.8% (transpupillary vs. three-port, p = 0.71). Preoperative versus postoperative BCVA (logMAR) was 1.49 ± 0.61 versus 1.42 ± 0.61 in transpupillary approach (p = 0.28) and 1.53 ± 0.48 versus 1.45 ± 0.57 in three-port approach (p = 0.11). Transpupillary approach resulted in lower IOP at postoperative day 2 (12.2 ± 2.3 mmHg vs. 13.5 ± 2.2 mmHg, p < 0.05), while postoperative follow-up at 1 month revealed no significant difference (p = 0.21). CONCLUSIONS: Transpupillary silicone oil removal combined with micro-incision phacoemulsification cataract surgery is less invasive and can be an alternative in some circumstances.

Slow-Release Dexamethasone in Proliferative Vitreoretinopathy: A Prospective, Randomized Controlled Clinical Trial.

PURPOSE: To test the hypothesis that adjunctive slow-release dexamethasone implant (Ozurdex; Allergan Inc, Irvine, CA) can improve the outcomes of vitreoretinal surgery for established proliferative vitreoretinopathy (PVR). DESIGN: A 2-year, single-center, prospective, participant- and surgeon-masked randomized controlled clinical trial (EudraCT No. 2011-004498-96). PARTICIPANTS: A total of 140 patients requiring vitrectomy surgery with silicone oil for retinal detachment with established PVR (Grade C) were randomized to standard (control) or study treatment (adjunct) in a 1:1 allocation ratio. METHODS: Intraoperatively, the adjunct group received an injection of 0.7 mg of slow-release dexamethasone (Ozurdex) at the time of (1) vitrectomy surgery and (2) silicone oil removal. The control group received standard care. MAIN OUTCOME MEASURES: Primary outcome measure was the proportion of patients with a stable retinal reattachment with removal of silicone oil without additional vitreoretinal surgical intervention at 6 months. Secondary outcomes included (1) final visual acuity (VA) (median and Early Treatment Diabetic Retinopathy Study [ETDRS] of 55 letters or better); (2) cystoid macular edema (CMO), foveal thickness, and macular volume; (3) development of overt PVR recurrence; (4) complete and posterior retinal reattachment; (5) tractional retinal detachment; (6) hypotony/increased intraocular pressure (IOP); (7) macula pucker/epiretinal membrane; (8) cataract; and (9) quality of life. RESULTS: All 140 patients were recruited within 25 months of study commencement; 138 patients had primary outcome data. Primary outcome assessment showed similar results in anatomic success between the 2 groups (49.3% vs. 46.3%, adjunct vs. control; odds ratio, 0.89; 95% confidence interval, 0.46-1.74; P = 0.733). Mean VA at 6 months was 38.3 ETDRS letters and 40.2 letters in the adjunct and control groups, respectively. Secondary anatomic outcomes (complete/posterior reattachment rates and PVR recurrence) were comparable between the 2 groups. At 6 months, fewer adjunct patients had CMO (42.7%) or a foveal thickness of >300 µm (47.6%) compared with controls (67.2% and 67.7%, respectively, P = 0.004, P = 0.023). CONCLUSIONS: A slow-release dexamethasone implant did not improve the primary anatomic success rate in eyes undergoing vitrectomy surgery with silicone oil for PVR. Further clinical trials are indicated to improve anatomic and visual outcomes in these eyes, but this study suggests that there is a greater reduction in CMO observed at 6 months in vitrectomized eyes treated with slow-release dexamethasone.

Polydimethyl Siloxane as an Internal Tamponade for Vitreoretinal Surgery.

PURPOSE: To report the efficacy and safety of polydimethyl siloxane (Siluron Xtra®) as an internal tamponade. DESIGN: Audit and adverse event screening of procedures (March 2014-2015). METHODS: Patients who had undergone vitreoretinal procedures with Siluron Xtra® tamponade were retrospectively analysed with respect to anatomical outcome, visual outcomes, and perioperative complications, in particular intraocular pressure. INCLUSION CRITERIA: all patients who had undergone Siluron Xtra® tamponade. EXCLUSION CRITERIA: No cases were excluded; however, there were no paediatric or pregnant patients within this cohort. All vitreoretinal cases were included, including retinal detachments, but also trauma, endophthalmitis, and intraocular foreign bodies. RESULTS: Twenty-eight patients had polydimethyl siloxane as an intraocular tamponade; 24 retinal detachments (83% complicated by proliferative vitreoretinopathy ≥grade C), 12 had previous failed surgery, and 4 had procedures for intraocular lymphoma, endophthalmitis, or trauma. Follow-up was 14-20 months, and mean duration of tamponade was 6.8 months (3-12 months). Anatomical success was 79% after polydimethyl siloxane injection, 58% 3 months following removal (14/24), 5 remain with long-term tamponade, and 5 with redetachment under tamponade required further intervention. Five required topical anti-glaucomatous agents, and 1 following trauma required glaucoma surgery. Cataract developed in 3/6 phakic patients, and visible emulsification occurred in a single patient. CONCLUSION: Polydimethyl siloxane seems to be an acceptable alternative tamponade agent for the management of complex retinal detachments with comparable anatomical success and comparable rates of raised intraocular pressure to other low-viscosity silicone oil agents, but more importantly, with a lower rate of emulsified oil-related complications, which is important particularly for cases requiring long-term tamponade.

A cross-linked hyaluronic acid hydrogel (Healaflow(®)) as a novel vitreous substitute.

PURPOSE: Vitrectomy requires the substitution of the natural vitreous, as well as tamponading of retinal breaks. Clinically available alternatives such as gas and silicone oil have side effects such as inflammation, secondary glaucoma, cataract, and a need for head posturing. In this study, a hydrogel of cross-linked sodium hyaluronic acid (Healaflow(®)) is evaluated for use as a novel vitreous substitute. METHODS: A combined 25-20-gauge pars plana vitrectomy with posterior vitreous detachment was performed in the right eye of twelve pigmented rabbits, with subsequent injection of approximately 1 ml Healaflow(®). Clinical evaluation, measurement of intraocular pressure (IOP), and full-field ERG were performed postoperatively. The rabbits were sacrificed at different time-points between 42 and 105 days. After enucleation, the eyes were examined macroscopically, photographed, and prepared for histological examination with routine microscopy and immunohistochemistry. RESULTS: Healaflow(®) was successfully used with standard surgical procedures and remained translucent but did lose most of its viscosity during the postoperative period. One rabbit was lost due to unrelated causes. In two eyes iatrogenic partial retinal detachments were seen, and in two eyes significant cataract developed due to intra-operative complications. ERG-recordings revealed no toxic effect on rod or cone function. Routine microscopy and immunohistochemistry demonstrated normal morphology with some Müller cell activation (up-regulation of glial acidic fibrillary protein, GFAP) compared to unoperated eyes and no significant DNA-fragmentation (TUNEL-assay). CONCLUSIONS: Healaflow® did not affect retinal morphology or function negatively during long-term use as a vitreous substitute, making it highly interesting in this setting. An estimated retention time of a few weeks suggests potential for use as a short-term tamponade. Future work will include an increased ratio of cross-linking to prolong the structural integrity of the gel.

Long-term outcomes of glaucoma drainage devices for glaucoma post-vitreoretinal surgery with silicone oil insertion: a prospective evaluation.

PURPOSE: To evaluate long-term success of the Ahmed glaucoma valve (AGV) for refractory glaucoma after vitreoretinal surgery with silicone oil insertion. METHODS: Prospective non-comparative evaluation of patients who underwent AGV insertion for management of post-vitreoretinal surgery glaucoma, post-silicone oil removal. Intraocular pressure (IOP), visual acuity, and glaucomatous neuropathy status were evaluated preoperatively and at multiple follow-up visits postoperatively. Success, using Kaplan-Meier analysis, was determined at the 12-month follow-up visit and at the last follow-up. Factors associated with failure were analysed. RESULTS: Twenty-seven eyes of 27 patients with a mean age of 28.3 ± 15.2 years underwent a superior AGV implantation. The average follow-up after AGV implantation was 17.11 ± 8.36 months (range: 9-60 months). Kaplan-Meier survival analysis revealed a 62 % success at 12 months and 37 % at 5 years. A 48 % rate of complications was noted, 22 % of which were vision-threatening. Factors analysed, including patient age, interval between vitreoretinal surgery and silicone oil removal, interval between vitreoretinal surgery and AGV implantation, and phakic status, were not found to be associated with higher failure rates. CONCLUSION: Long-term success of AGV implantation for glaucoma after vitreoretinal surgery with silicone oil insertion is better than that reported for trabeculectomy, though complication rates remain high.

VITREORETINAL SURGERY WITH SILICONE OIL TAMPONADE IN PRIMARY UNCOMPLICATED RHEGMATOGENOUS RETINAL DETACHMENT: Clinical Outcomes and Complications.

BACKGROUND: To determine the anatomical and functional outcomes and possible complications after pars plana vitrectomy (PPV) with silicone oil (SO) tamponade in primary uncomplicated rhegmatogenous retinal detachments. METHODS: This is a prospective observational study. Overall, 62 consecutive patients who underwent surgical repair by PPV and SO injection for primary uncomplicated rhegmatogenous retinal detachment between January 01, 2006 and April 30, 2012 were followed. In general, PPV was chosen over scleral buckling when a significant cataract or a vitreous hemorrhage prevented adequate fundus visualization. Silicone oil was chosen over gas tamponade in patients living at 1,000 meters above the sea level, where SF6 or C3F8 tamponade could not be performed because of the risk of acute increase of intraocular pressure (IOP). One thousand centistokes SO was used in all eyes. At all visits, patients had a detailed ocular history and thorough bilateral evaluation, including best-corrected visual acuity, anterior segment examination, and IOP measurements by aplanation and fundus examination. Outcomes were assessed at 1 day, 1 week, 1 month, 3 months, 6 months, and every 6 months thereafter. Increased IOP was defined as an IOP of more than 21 mmHg. RESULTS: Anatomical success rate, final best-corrected visual acuity, IOP elevation, cataract formation, and other complications were the main outcome measures. This study included 62 eyes of 62 patients (41 men and 21 women) that underwent retinal detachment repair by PPV and SO injection. The age at the time of intervention was 57.6 ± 10.5 years (mean ± standard deviation; range, 34-79 years). All patients were whites. Mean follow-up was 24.5 ± 17.3 months (range, 6-70 months). Anatomical success rate defined as retinal reattachment 6 months after SO removal was 93.5%. Final BCVA was improved in 55 eyes (88.7%), with a mean of 4 Snellen lines, unchanged in 5 (8.1%), and worse in 2 eyes (3.2%), with a mean of 3 Snellen lines. Mean duration of SO tamponade was 5.12 ± 2.37 months (range, 2-12 months). From the 30 eyes that were still phakic after vitrectomy, 24 eyes (80.0%) underwent cataract surgery within a period of 7.37 ± 3.00 months (range, 2-13 months). Thirty-five eyes (56.5%) had an increase in IOP during the follow-up period. Thirty-one patients had transient ocular hypertension requiring topical treatment during the immediate postoperative period (one month). Only 1 eye (2.9%) required filtrating drainage surgery for IOP control. No eyes developed optic neuropathy secondary to IOP elevation. CONCLUSION: Pars plana vitrectomy with SO injection seems to be a safe and efficient surgical approach in the treatment of primary uncomplicated rhegmatogenous retinal detachment in patients living in high altitude (>1,000 m). Also, PPV and SO injection are associated with good anatomical and functional outcomes in our series. Reattachment rates are high, and rates of proliferative vitreoretinopathy are low. Cataract formation and elevated IOP represent frequent but successfully controlled complications.

VARIATION OF 24-HOUR INTRAOCULAR PRESSURE IN SILICONE OIL-FILLED EYES.

PURPOSE: To evaluate the variation of 24-hour intraocular pressure (IOP) in silicone oil (SO)-filled eyes. METHODS: Prospective, nonrandomized comparative case series of 42 eyes of 21 patients, each with an SO-filled eye after vitrectomy. The fellow eyes served as controls. Each subject slept the usual 8 hours, and IOPs were measured at 4-hour intervals over 24 hours, twice before sleep (5:30 and 9:30 PM), twice during sleep (1:30 and 5:30 AM), and twice after sleep (9.30 AM and 1:30 PM). Intraocular pressure was measured in the sitting position using a Goldmann applanation tonometer. The SO-filled eyes and fellow eyes were compared with respect to diurnal-to-nocturnal and nocturnal-to-diurnal IOP changes. RESULTS: At all 6 time points, SO-filled eyes had higher mean IOPs than fellow eyes (all P < 0.05). For both groups, mean nocturnal IOP was higher than mean diurnal IOP (both P < 0.001). Changes in diurnal-to-nocturnal IOP and nocturnal-to-diurnal IOP between SO-filled eyes and fellow eyes did not differ significantly (P > 0.05, respectively). The peak IOP occurred in the nocturnal period for all fellow eyes and for 94.7% of SO-filled eyes. CONCLUSION: The IOP of SO-filled eyes varied over a 24-hour period, peaking largely in the nocturnal period, as observed for the IOP of fellow eyes.