A surgical simulator for peeling the inner limiting membrane during wet conditions.
ABSTRACT: The present study was performed to establish a novel ocular surgery simulator for training in peeling of the inner limited membrane (ILM). This simulator included a next-generation artificial ILM with mechanical properties similar to the natural ILM that could be peeled underwater in the same manner as in actual surgery. An artificial eye consisting of a fundus and eyeball parts was fabricated. The artificial eye was installed in the eye surgery simulator. The fundus part was mounted in the eyeball, which consisted of an artificial sclera, retina, and ILM. To measure the thickness of the fabricated ILM on the artificial retina, we calculated the distance of the step height as the thickness of the artificial ILM. Two experienced ophthalmologists then assessed the fabricated ILM by sensory evaluation. The minimum thickness of the artificial ILM was 1.9 ± 0.3 ?m (n = 3). We were able to perform the peeling task with the ILM in water. Based on the sensory evaluation, an ILM with a minimum thickness and 1000 degrees of polymerization was suitable for training. We installed the eye model on an ocular surgery simulator, which allowed for the performance of a sequence of operations similar to ILM peeling. In conclusion, we developed a novel ocular surgery simulator for ILM peeling. The artificial ILM was peeled underwater in the same manner as in an actual operation.
Project description:PURPOSE:To investigate the long-term results of a modified technique for parafoveal multiple curvilinear internal limiting membrane (ILM) peeling to preserve the epi-foveal ILM in myopic foveoschisis surgery. METHODS:Thirty-two consecutive patients (36 eyes) were retrospectively reviewed. Patients were divided into two groups according to the extent of ILM peeled: the fovea-sparing ILM peeling group (FS) (18 eyes) and total ILM peeling group (TP) (18 eyes). Patients were followed up for at least 12 months. The main outcome measures were best-corrected visual acuity changes, evolution of macular schisis and the factors associated with the development of a full-thickness macular hole (FTMH). RESULTS:FTMH developed in 1 of 18 eyes (5.6%) in the FS group and 3 of 18 eyes (16.7%) in the TP group (P = 0.28). Long-term follow-up showed visual improvement was better in the FS group than in the TP group (0.94 vs. 0.58 logMAR). Macular schisis disappeared in 13 of 18 eyes (72.2%) in the FS group, but disappeared in 7 of 18 eyes (38.9%) in the TP group (P = 0.04). Logistic regression analysis showed that only the preoperative outer lamellar macular hole (P = 0.016) was a significant risk factor for development of postoperative FTMH. CONCLUSIONS:Fovea-sparing ILM peeling achieves a higher rate of macular schisis resolution over total peeling. A preoperative outer lamellar macular hole can be a risk factor for the development of a macular hole.
Project description:We report intensely staining epiretinal membrane (ERM) with Brilliant Blue G (BBG) under air for two minutes. ERM peeling was performed in 21 cases. After removal of posterior hyaloid, 0.2?mL BBG was first applied on the macula, to stain ERM under air conditions for 2 minutes. Internal limiting membrane (ILM) was intensely stained and peeled in all cases following ERM removal. In 4 cases, the ERM was also observed to be intensely stained with BBG and peeled with an ILM forceps. Postoperatively, the ganglion cell layer thickness was lower in three of the cases, however VA improved in all cases and multifocal electroretinogram revealed no toxicity. Light microscopy of ERM revealed masses of cells whereas; the ILM did not. The increased staining characteristics of ERM and ILM may be resulted from longer contact time of BBG under air pressure.
Project description:<h4>Background</h4>Internal limiting membrane (ILM) peeling increases the idiopathic macular hole (IMH) closure rate but causes the inner retina dimplings. This study is to introduce a method to minimally peel the ILM, and with the ILM flap to ensure the IMH closure.<h4>Methods</h4>Twelve consecutive IMH eyes were treated with the minimal ILM peeling with ILM flap technique. The ILM around the MH is peeled off in an annular shape with a width of approximately 200 to 300??m. A tongue-shape ILM flap is created in the superior retina and the inferior margin of ILM is not peeled off. The ILM flap is then inverted to cover the MH, followed by fluid-air exchange and air or silicon tamponade. Spectral domain-optical coherence tomography (SD-OCT) and en face OCT for morphological assessment, best corrected visual acuity (BCVA) and multifocal electroretinogram (ERG) for functional evaluation were performed at baseline and at each postoperative follow-up.<h4>Results</h4>All the 12 eyes achieved macular hole closure on SD-OCT after surgery (100%). At baseline, the mean preoperative BCVA was 0.83?±?0.33 and it improved to 0.39?±?0.28 postoperatively (p?<? 0.001). En face OCT showed the inner retinal dimplings were localized only in superior ILM-free retinas (7 eyes). The mERG response density in the central (R1), para-central (R2), R1/R2 ring ratios were remarkably improved at the last follow-up (p?=?0.001, p?=?0.033, p?=?0.018, respectively).<h4>Conclusions</h4>The minimal ILM peeling with ILM flap technique can achieve favorable MH closure with less inner retinal dimplings and has promising visual recovery for IMH eyes.
Project description:BACKGROUND:A full-thickness macular hole (FTMH) is a common retinal condition associated with impaired vision. Randomised controlled trials (RCTs) have demonstrated that surgery, by means of pars plana vitrectomy and post-operative intraocular tamponade with gas, is effective for stage 2, 3 and 4 FTMH. Internal limiting membrane (ILM) peeling has been introduced as an additional surgical manoeuvre to increase the success of the surgery; i.e. increase rates of hole closure and visual improvement. However, little robust evidence exists supporting the superiority of ILM peeling compared with no-peeling techniques. The purpose of FILMS (Full-Thickness Macular Hole and Internal Limiting Membrane Peeling Study) is to determine whether ILM peeling improves the visual function, the anatomical closure of FTMH, and the quality of life of patients affected by this disorder, and the cost-effectiveness of the surgery. METHODS/DESIGN:Patients with stage 2-3 idiopathic FTMH of less or equal than 18 months duration (based on symptoms reported by the participant) and with a visual acuity </= 20/40 in the study eye will be enrolled in this FILMS from eight sites across the UK and Ireland. Participants will be randomised to receive combined cataract surgery (phacoemulsification and intraocular lens implantation) and pars plana vitrectomy with postoperative intraocular tamponade with gas, with or without ILM peeling. The primary outcome is distance visual acuity at 6 months. Secondary outcomes include distance visual acuity at 3 and 24 months, near visual acuity at 3, 6, and 24 months, contrast sensitivity at 6 months, reading speed at 6 months, anatomical closure of the macular hole at each time point (1, 3, 6, and 24 months), health related quality of life (HRQOL) at six months, costs to the health service and the participant, incremental costs per quality adjusted life year (QALY) and adverse events. DISCUSSION:FILMS will provide high quality evidence on the role of ILM peeling in FTMH surgery. TRIAL REGISTRATION:This trial is registered with Current Controlled Trials ISRCTN number 33175422 and Clinical Trials.gov identifier NCT00286507.
Project description:BACKGROUND:The epiretinal membrane (ERM) is a degenerative condition associated with age, which can cause loss of vision and/or metamorphopsia. The treatment of symptomatic ERM involves surgical removal including a vitrectomy followed by peeling of the ERM using a microforceps. As the internal limiting membrane (ILM) is adherent to the ERM, it is sometimes removed with it (spontaneous peeling). If ILM remains in place, it can be removed to reduce ERM recurrence. However, it is important to clarify the safety of ILM peeling, while it increases surgical risks and cause histological disorganization of the retina that can lead to microscotomas, may be responsible for definitive visual discomfort. METHODS:PEELING is a prospective, randomized, controlled, single-blind, and multicentered trial with two parallel arms. This study investigates the benefit/risk ratio of active ILM peeling among individuals undergoing ERM surgery without spontaneous ILM peeling. Randomization is done in the operating room after ERM removal if ILM remains in place. After randomization, the two groups-"active peeling of the ILM" and "no peeling of the ILM"-are compared during a total of three follow-up visits scheduled at month 1, month 6, and month 12. Primary endpoint is the difference in microscotomas before surgery and 6?months after surgery. Patients with spontaneous peeling are not randomized and are included in the ancillary study with the same follow-up visits and the same examinations as the principal study. Relevant inclusion criteria involve individuals aged >?18?years living with idiopathic symptomatic ERM, including pseudophakic patients with transparent posterior capsule or open capsule or lensed patients with age-related cataracts. The calculated sample size corresponds to 53 randomized eyes (one eye/patient) per arm that means 106 randomized eyes (106 randomized patients) in total and a maximum of 222 included patients (116 spontaneous peeling). DISCUSSION:ILM peeling is often practiced in ERM surgery to reduce ERM recurrence. It does not impair postoperative visual acuity, but it increases the surgical risks and causes anatomical damages. If active ILM peeling is significantly associated with more microscotomas, it may contraindicate the ILM peeling during primitive idiopathic ERM surgery. TRIAL REGISTRATION:ClinicalTrials.gov, NCT02146144. Registered on 22 May 2014. Recruitment is still ongoing.
Project description:Purpose:To investigate the efficacy of management of high myopic foveoschisis (MF) with a modified surgical technique of arc-shaped foldback fovea-sparing internal limiting membrane (ILM) peeling. Methods:A 23-gauge vitrectomy was performed in five patients with high MF. A long strip of ILM was peeled at the temporal side of the central fovea. Next, an ILM forceps was used to grasp the outer side of the ILM flap, and it was moved forward slowly from the outside to the paracentral fovea, followed by folding ILM back in an arc-shaped manner and then removing it. The above operations were repeated, and all ILM flaps were removed from the outside to paracentral fovea until a narrow strip of ILM remained. Finally, the narrow strip of ILM was excised using a vitreous cutter. Results:At the patients' last visits, the foveoschisis almost disappeared completely and the fovea reattached. The central macular thickness statistically decreased from 399.0?±?96.33??m preoperatively to 164.60?±?34.20??m postoperatively (t?=?4.289; P=0.013). The preoperative mean logarithm of the minimum angle of resolution best-corrected visual acuity (1.64?±?0.65) significantly improved to 0.72?±?0.18 postoperatively (t?=?3.265, P=0.031). The average follow-up time was 11.80?±?3.35 months (range; 8-16 months). Conclusion:The arc-shaped foldback fovea-sparing ILM peeling technique for high MF is safe and effective.
Project description:Purpose:To assess the safety and effectiveness of the single-layered inverted internal limiting membrane (ILM) flap technique for treating chronic, large, or highly myopic macular holes (MHs). Methods:The medical records of 20 eyes of 20 consecutive Japanese patients with large MHs (n=6) (minimal diameter, >400??m), chronic MHs (n=2) (symptom duration, >24?months), MHs in high myopia (n=11) (axial length, >26?mm), and MHs in a patient unable to maintain prone positioning postoperatively (n=1) were reviewed retrospectively. All patients underwent 25-gauge pars plana vitrectomy and the temporal inverted ILM flap technique. A semicircular ILM notch was made temporally two disc diameters from the MH using a 25-gauge knife, and the ILM was peeled temporally to create a semicircular ILM flap using a 25-gauge forceps. The single-layered ILM flap was inverted in a nasal direction to cover the MH. When an epiretinal membrane (ERM) was present, it was peeled before the ILM flap was inverted. Results:The MHs closed successfully in all (100%) eyes postoperatively. In the MHs associated with an ERM, after hole closure, gradual foveal deformation occurred in both the area from which the ILM was not peeled and the ILM flap inverted side. Conclusions:The single-layered inverted ILM flap technique, a simple surgery to treat MHs, provides scaffolding for retinal gliosis and may facilitate bridge formation between the walls of the MH under the flap. Considering the 100% success rate of MH closure, this technique seems to be effective and safe for treating chronic, large, or highly myopic MHs and MHs in patients unable to maintain postoperative prone positioning. In the MHs associated with ERMs, gradual foveal deformation was observed after ERM peeling. Further studies are needed to minimize surgical complications and understand the mechanism of this technique. This trial is registered with UMIN000035091.
Project description:Differences in the pathogenesis and clinical characteristics between lamellar macular hole (LMH) with and without LMH-associated epiretinal proliferation (LHEP) can have surgical implications. This study investigated the effects of treating LHEP by foveolar internal limiting membrane (ILM) non-peeling and epiretinal proliferative (EP) tissue repositioning on visual acuity and foveolar architecture. Consecutive patients with LHEP treated at our institution were enrolled. The eyes were divided into a conventional total ILM peeling group (group 1, n?=?11) and a foveolar ILM non-peeling group (group 2, n?=?22). In group 2, a doughnut-shaped ILM was peeled, leaving a 400-?m-diameter ILM without elevated margin over the foveola after EP tissue repositioning. The EP tissue was elevated, trimmed, and inverted into the LMH. Postoperatively, the LMH was sealed in all eyes in group 2, with significantly better best-corrected visual acuity (-0.26 vs -0.10 logMAR; p?=?0.002). A smaller retinal defect (p?=?0.003), a more restored ellipsoid zone (p?=?0.002), and a more smooth foveal depression (p?<?0.001) were achieved in group 2. Foveolar ILM non-peeling and EP tissue repositioning sealed the LMH, released the tangential traction, and achieved better visual acuity. The presumed foveolar architecture may be reconstructed surgically. LMH with LHEP could have a combined degenerative and tractional mechanism.
Project description:Purpose:To report the intraoperative optical coherence tomography (OCT)-guided surgery of a consolidated sub-internal limiting membrane (ILM) hemorrhage that developed into a sub-ILM fibrotic membrane in a child with a history of Terson syndrome. Observations:A one year-old boy with a history of Terson syndrome due to a motor vehicle accident presented three months after trauma with a white feather-shaped membrane in the left macula. Preoperative OCT showed a preretinal hyperreflective tissue at the foveal center. The patient underwent pars plana vitrectomy. After separation of the posterior hyaloid, intraoperative OCT did not show any change in structural components. After peeling the ILM, the fibrotic membrane persisted. A bent 30-gauged needle was used to create a plane of dissection in the adherent sub-ILM membrane, which was then peeled with ILM forceps without complication. Post-operative OCT confirmed complete excision without evidence of macular edema. Pathology results indicated presence of fibrocellular tissue that contained hemosiderin, consistent with old organized hemorrhage as a component of the membrane. Conclusion and importance:Sub-ILM hemorrhage may persist as a tautly adherent fibrotic membrane that can mimic the appearance of an epiretinal membrane or a chronic subhyaloidal hemorrhage during examination, especially in young children. Intraoperative OCT may aid in select complex macular surgery cases to better delineate the planes of dissection during sub-ILM fibrosis excision.
Project description:PurposeTo determine whether the inverted internal limiting membrane (ILM) flap technique contributes to high reattachment and closure rates in patients with macular hole-associated retinal detachment (MHRD).Patients and methodsIn all, 15 eyes of 15 patients with MHRD undergoing 25-gauge pars plana vitrectomy with the inverted ILM flap technique or ILM peeling. The patients were divided into the inverted ILM flap technique group (6 eyes) and ILM peeling group (9 eyes). The logarithm of minimal angle of resolution best-corrected visual acuity (BCVA) and retinal attachment and macular hole closure rates were compared between the two groups before and after surgery.ResultsNo significant differences were found in the pre- and postoperative BCVA at 1 and 3 months after surgery in either group (inverted ILM flap technique group, preoperatively 1.04±0.55, 1 month 0.95±0.30, 3 months 0.83±0.22; ILM peeling group, preoperatively 1.00±0.44, 1 month 1.05±0.38, 3 months 1.06±0.49; P>0.05, respectively). The postoperative BCVA at 6 months after surgery was significantly better in the inverted ILM flap technique group than in the ILM peeling group (inverted ILM flap technique group, 0.62±0.35; ILM peeling group, 1.02±0.41, P=0.045). The improvement in BCVA was significantly better in the inverted ILM flap technique group than in the ILM peeling group (inverted ILM flap technique group, -0.41±0.29; ILM peeling group, 0.02±0.36; P=0.021). The primary macular hole closure rates were 100% in the inverted ILM flap technique group and 55.5% in the ILM peeling group. The primary reattachment rates were 100% in the inverted ILM flap technique group and 55.5% in the ILM peeling group. The primary macular hole closure and reattachment rates were not significantly different in both groups (P=0.056, respectively).ConclusionThe inverted ILM flap technique is a useful procedure for MHRD in highly myopic eyes.