Microincision Vitreous Surgery Research Articles

Case Report: Microincision Vitreous Surgery Induces Bleb Failure in Eyes With Functional Filtering Bleb

PurposeTo investigate the effect of microincision vitreous surgery (MIVS) on intraocular pressure (IOP) control in glaucomatous eyes with functional filtering bleb.MethodsWe enrolled 18 patients (15 males; median age, 73 years) who previously had filtering surgery and underwent MIVS with functional filtering bleb. Kaplan–Meier method was used to calculate the survival rate with defined the failure as when more number of preoperative antiglaucoma medication was started or additional glaucoma surgery including bleb revisions were performed, and IOP increase of 20% (criteria 1) and 30% (criteria 2) from preoperative levels after 2 weeks of MIVS.ResultsThe median follow-up duration was 970 days. Preoperative IOP was 13.3 ± 3.8 mmHg (mean ± SD). Postoperative IOP were 14.7 ± 4.9 (P=0.365), 15.2 ± 3.5 (P=0.137), 16.4 ± 5.6 (P = 0.073), 17.6 ± 6.1(P = 0.020), and 14.5 ± 4.0 (P = 0.402) mmHg at 3, 6, 12, and 15 months and final visit, respectively (compared to preoperative IOP). The number of antiglaucoma medications was a median of 1.0 (range 0–4) preoperatively and 0 (0–4) at the final visit (P = 0.238). The survival rates were 55%/61% at 3 months, 50%/61% at 6 months, and 38%/55% at 12 months with criteria 1 and 2, respectively. Four eyes (22%) received additional glaucoma surgery during follow-up.ConclusionAfter several months of MIVS, IOP was likely to increase. We should focus on IOP control by conducting long-term follow-ups.

27 Gauge Vitrectomy; Current Indications and Management

Modern small incision vitrectomy, also known as microincision vitreous surgery, reflects the development of advances in surgical instruments and techniques. Methods for developing less invasive and smaller incision techniques with similar or better effectiveness for surgeons are developing rapidly. The 27-gauge vitrectomy method developed for vitreoretinal surgery has been introduced into our lives since 2010 and its use is becoming common increasingly. This article will discuss the current indication and use of 27-gauge vitrectomy.

Pars plana vitrectomy in uveitis in the era of microincision vitreous surgery.

Pars plana vitrectomy (PPV) in uveitis is indicated for various diagnostic and therapeutic indications. With the advent of microincision vitreous surgery (MIVS), the use of PPV in uveitis has increased with a wider spectrum of indications due to shorter surgical time, less patient discomfort, less conjunctival scarring, and a decreased rate of complications as compared to standard 20G vitrectomy. Because of faster post-operative recovery in terms of visual improvement and reduction of inflammation, and reduced duration of systemic corticosteroids, MIVS has gained popularity in uveitis as an adjunctive therapy to the standard of care medical therapy. The safety and efficacy of MIVS is related to the emerging vitrectomy techniques with better and newer cutters, illuminating probes, and accessory instruments. Because of the instrumentation and fluidics of MIVS, PPV is emerging as a safe and useful alternative for diagnostic challenges in uveitis, aiding in earlier diagnosis and better outcome of inflammatory disease, even in the presence of severe and active inflammation, which was once considered a relative contraindication for performing vitreous surgery. However, for surgical interventions for therapeutic indications and complications of uveitis, it is advisable to achieve an optimum control of inflammation for best results. The increasing reports of the use of MIVS in uveitis have led to its wider acceptance among clinicians practicing uveitis.

BIMANUAL MICROINCISION VITREOUS SURGERY FOR SEVERE PROLIFERATIVE DIABETIC RETINOPATHY: OUTCOME IN MORE THAN 300 EYES.

To evaluate the visual and anatomical outcomes and safety of bimanual microincision vitreous surgery for severe proliferative diabetic retinopathy. Retrospective review of 315 eyes of 282 patients who underwent 23-gauge or 25-gauge pars plana vitrectomy with bimanual membrane dissection for diabetic tractional detachment from January 2007 to September 2016. Minimum follow-up was 3 months, and the average duration of follow-up was 23 months (range 3-100 months; median 15 months). Outcome measures were best-corrected visual acuity, anatomical success, and postoperative complications. Postoperatively, 84.3% of eyes improved (>2 lines), 10.5% were stable, and 5.4% worsened (>2 lines). Comparing gauges, two-line improvement was seen in 87.4% of 23-gauge eyes compared with 79.7% of 25-gauge eyes (P = 0.029). Mean peak best-corrected visual acuity improved from 20/930 (1.67 ± 0.63) preoperatively to 20/120 (0.78 ± 0.63) postoperatively (P < 0.001). Primary reattachment was achieved in 310 eyes (98.4%) and final reattachment in 312 eyes (99%). Recurrent vitreous hemorrhage was the commonest postoperative complication (18.4%). Lower incidence of recurrent vitreous hemorrhage was seen with 25 gauge (13.5%) compared with 23 gauge (22%, P = 0.038). Epiretinal membrane formation (7.9%), intractable glaucoma (2.5%), and endophthalmitis (0.6%) were some of the other postoperative complications. Sustained visual improvement, anatomical restoration, and low complication rates were obtained in complex situations with bimanual microincision vitreous surgery in a large series. Visual outcomes were poorer in older age group, tractional retinal detachments involving macula, and eyes with extensive membranes and with silicone oil as tamponade. Both 23-gauge and 25-gauge groups were comparable in relation to visual improvement, anatomical success, and intraoperative and postoperative complications.

Sutureless biplanar closure of leaking wounds in micro-incision vitreous surgery: A novel technique.

To describe a novel technique for sutureless hermetic closure of leaking scleral wounds in micro-incision vitreous surgery. This study is a two-centre, non-comparative, interventional case series. We studied 1240 scleral incisions on 870 eyes using different gauges (20, 23, 25) to evaluate the effectiveness of a new technique to seal scleral wounds without sutures. If wounds were found leaking after removing the trocar, we used the same trocar (or microvitreoretinal) blade to make an adjacent trans-scleral entry in the same direction as the main incision to access its internal flap supporting it from inside. Simultaneously, we applied a blunt smooth-surface instrument to massage the scleral wound from outside to close it hermetically. We treated 870 eyes using three types of tamponading agents, namely, silicone oil in 654 (75%) eyes, non-expansible gas in 128 (15%) eyes, and air in 88 (10%) eyes. We performed optical coherence tomography in the first 100 sclerotomies on the post-operative Day 1. We closed leaking incisions at the first attempt in 1231 (99.3%) cases; in 9 (0.7%) cases of 20-gauge incisions, we closed the wounds at the second attempt. We observed no hypotony at the end of surgery. The mean intraocular pressure was 16 mmHg (8-51 mmHg) on the post-operative Day 1. Our results show the biplanar closure technique may be used as an effective, quick, sutureless approach to close leaking wounds hermetically in micro-incision vitreous surgery procedures. It is safe, less traumatic, cost-effective, and easy-to-perform typical surgical settings.

Early postoperative evaluation of retinal function by electroretinography after vitreous surgery for idiopathic epimacular membrane.

In this study, we used the PuREC to carry out electroretinography (ERG) measurements using skin electrodes to assess changes before and after microincision vitreous surgery (MIVS) for epiretinal membrane (ERM) and evaluate the stress on retinal function soon after MIVS. The study subjects were 18 eyes of 18 patients who underwent MIVS for ERM simultaneously with cataract surgery. ERG measurements were performed using a skin electrode on the day before vitreous surgery, on the day after surgery, and 1week later. The amplitude and implicit time of each waveform were measured, and the changes between preoperative results and those 1day and 1week postoperatively were investigated. Preoperatively, the dark-adapted (DA) 0.01 ERG, the DA 3.0 ERG a-wave amplitude, and the light-adapted (LA) 3.0 ERG b-wave amplitude were significantly smaller in affected eyes compared with their fellow eyes (P<0.05, Wilcoxon's signed-rank test). The day after surgery, all-wave amplitude showed no significant difference compared to preoperatively (repeated-measures analysis of variance (ANOVA) post hoc test). One week after surgery, the LA 3.0 ERG for b-waves and flicker ERG amplitude had improved from the value on the day after surgery (P<0.05, ANOVA post hoc test). Cone ERG components have improved within 1week after surgery by MIVS for ERM.

Excellent results of scleral buckling in the era of microincision vitreous surgery

Purpose: The purpose of this study is to evaluate the anatomical and functional outcomes of sutureless scleral buckling for the repair of rhegmatogenous retinal detachment (RD). Materials and Methods: Retrospective analysis of fifty eyes of fifty patients with rhegmatogenous RD, who underwent sutureless scleral buckling from January 2014 to August 2015. Results: Primary retinal reattachment rate of 41 patients was achieved with single surgery, but final anatomical success was 94% with additional pars plana vitrectomy with silicone oil injection and with vitrectomy with epiretinal membrane removal. The mean follow-up was 6 months. Conclusion: Sutureless scleral buckling achieves excellent anatomical and functional success in majority of the patients with rhegmatogenous RD.

Autoregulation of Optic Nerve Head Blood Flow Induced by Elevated Intraocular Pressure during Vitreous Surgery

ABSTRACTPurpose: To investigate optic nerve head (ONH) blood flow changes resulting from intraocular pressure (IOP) elevation in subjects without systemic disorders.Materials and Methods: Eighteen eyes of 18 patients who underwent vitrectomy to treat an epiretinal membrane or macular hole at Toho University Sakura Medical Center were included. Following standard 25-gauge microincision vitreous surgery, mean blur rate (MBR) in tissue (MT), an index of ONH blood flow, was measured using laser speckle flowgraphy. Measurements were taken before and 5 and 10 minutes after a 15 mmHg IOP elevation.Results: The ONH blood flow was initially lower than baseline (P = 0.001) after elevating IOP from 14.8 ± 2.8 mmHg to approximately 30 mmHg. Between 5 and 10 minutes after elevating IOP, ONH blood flow partially recovered (P = 0.004), even though ocular perfusion pressure was 20.2% lower than at baseline.Conclusions: The ONH blood flow in subjects without systemic disorders was initially lower, but began to recover 5–10 minutes after a 15 mmHg elevation in IOP. These results indicate that autoregulatory mechanisms of ONH blood flow may help to minimize the effects of IOP elevations and fluctuations during vitreous surgery.

Safety and Outcome of Microincision Vitreous Surgery in Uveitis

ABSTRACTPurpose: To report the outcome of microincision vitreous surgery (MIVS) in uveitis.Methods: In total, 103 patients (106 eyes) underwent diagnostic MIVS between March 2012 and April 2015. Postoperative evaluation included vitreous haze grading from clinical/electronic records, best-corrected visual acuity (BCVA), and complications.Results: Mean age was 36.8 ± 13.9 years (range: 8–80 years). Mean follow-up after MIVS was 12.2 ± 7.2 months (median 12 months). Mean vitreous haze grading was 2.39 ± 0.98 (preoperatively), 0.36 ± 0.73 postoperatively (1 week), and 0.02 ± 0.2 at 1 month (p < 0.001). Mean BCVA was 1.5 ± 1.0 logMAR preoperatively and 0.72 ± 0.68 logMAR at 1 month (p = 0.000). Postoperative complications included cataract (14.6%), rise in intraocular pressure (13.2%), vitreous hemorrhage (4.7%), hypotony (3.2%), retinal detachment (2.8%), epiretinal membrane (2.8%), and worsening of inflammation (0.9%).Conclusions: MIVS is safe and may have a therapeutic role in uveitis.

Pupil-expansion ring implantation through a 0.9 mm incision

Disposable square and hexagonal Bhattacharjee pupil-expansion rings are made of 5-0 nylon, have notches at the corners, and flanges at the sides in a single 0.1 mm thin plane. To insert the ring, a flange is held with a 23-gauge forceps and the ring is inserted through a 0.9 mm (20-gauge) or larger main- or side-port incision. Alternate flanges are tucked under the iris using a Kuglen hook. A 23-gauge forceps and an iris hook can also be used to tuck the flanges bimanually. The ring is removed by disengaging 2 notches and pulling it out of a 0.9 mm (20-gauge) incision. No snagging of the incision occurs at insertion or removal. No injector is required. The device is useful in standard coaxial phacoemulsification, femtosecond laser-assisted cataract surgery, biaxial microincision cataract surgery (MICS), coaxial sub-2.0 mm MICS, and small-pupil microincision vitreous surgery and in eyes with shallow anterior chambers. Dr. Bhattacharjee has a pending international patent application (PCT-WIPO) for the pupil-expansion devices.

Ocular Blood Flow Before, During, and After Vitrectomy Determined by Laser Speckle Flowgraphy

Vitrectomy markedly alters the intraocular milieu, which can then affect the physiology of the retina and choroid. This study investigates whether vitrectomy also alters ocular blood flow as determined by laser speckle flowgraphy (LSFG). Twenty eyes of 20 patients that underwent vitrectomy for idiopathic macular hole or epiretinal membrane were studied. Standard 23-gauge microincision vitreous surgery was performed. Ocular blood flow of the optic nerve head, retinal vessels, and choroid was determined by LSGF before, during, and 2 weeks and 1 month after vitrectomy. Postoperative blood flow of the optic nerve head, retinal vessels, and choroid did not differ significantly from preoperative values. Intraoperative blood flow of the optic nerve head and retinal vessels decreased significantly from baseline with increasing infusion pressure from 20 mm Hg to 40 mm Hg (P < .01), and choroidal blood flow decreased significantly when the infusion pressure increased from 8 mm Hg to 20 mm Hg and from 20 mm Hg to 40 mm Hg (both P < .01). Blood flow did not differ significantly postoperatively versus preoperatively, but it was significantly reduced during vitrectomy with increasing infusion pressure. Careful attention should be paid to infusion pressure during vitrectomy.

Stickler Syndrome Type 1 Accompanied by Membranous Vitreous Anomaly in Two Japanese Sisters

ABSTRACTWe report two cases of Stickler syndrome type 1 accompanied by a membranous vitreous anomaly in two Japanese sisters. A nine-year-old girl was referred to us for a rhegmatogeneous retinal detachment in her right eye. She had moderate myopia and a membranous vitreous anomaly in both eyes. She also had micrognathia and a saddle nose, leading to a diagnosis of Stickler syndrome type 1. The retinal detachment persisted even after scleral buckling surgery; however, the retina was reattached after 25-gauge microincision vitreous surgery 11 days later. Her seven-year-old sister had been diagnosed with Pierre Robin sequence due to micrognathia, cleft palate, and saddle nose. She was myopic by about −9.0 diopters with a membranous vitreous anomaly in both eyes and circumferential perivascular retinal degeneration in the right eye. Genetic analyses showed that both sisters and their mother carried the same mutation in the COL2A1 gene. The findings in these sisters indicate that retinal detachment is associated with Stickler syndrome type 1. Micro-incison vitreous surgery might be effective for rhegmatogeneous retinal detachment with high vitreous liquefaction.

Modified Technique for Inducing Posterior Vitreous Detachment through the Posterior Precortical Vitreous Pocket during Microincision Vitreous Surgery with a Wide-Angle Viewing System

Purpose: To introduce a simple technique to create a posterior vitreous detachment (PVD) through the posterior precortical vitreous pocket (PPVP) during microincision vitreous surgery using a wide-angle viewing system (WAVS). Methods: This study included 20 eyes of 20 consecutive patients (mean age, 65.6 years; range, 56-76) with a stage 2 or 3 idiopathic macular hole who underwent 25-gauge microincision vitreous surgery using a WAVS and phacoemulsification surgery. A triamcinolone suspension was injected into the vitreous cavity. The triamcinolone facilitated visualization of the posterior wall of the PPVP. Using a vitreous cutter, we suctioned the outer margin of the PPVP. After a resultant small break of the posterior hyaloid membrane developed and enlarged rapidly, a PVD easily expanded at the periphery. Results: Using this technique, we induced a PVD without close proximity to the optic disk and macula. Conclusion: This technique is an easy and safe method for creating a PVD during microincision vitreous surgery using a WAVS.