Induction of posterior vitreous detachment (PVD) is one of the most critical steps for the success of retinal detachment (RD) surgery. Failure to completely remove the vitreous can result in re-detachments. We describe a novel technique to induce PVD. After core vitrectomy, perfluorocarbon liquid (PFCL) is injected. The vitreous on the posterior pole is gently stroked, with a diamond-dusted membrane scraper, to create a defect in it. This defect is gradually enlarged to create a ring of rolled out vitreous. The entire vitreous is removed in form of a sheet by lifting the edges of the ring using an internal limiting membrane peeling forceps. PFCL naturally slides into the potential space, gradually extending the vitreous detachment peripherally. With this technique, the vitreous sheet in case of RD can easily, effectively and safely be removed with this technique.
Keywords: Mega Weiss ring, posterior vitreous detachment (PVD), retinal detachment
How to cite this article: Babu N, Kumar J, Kohli P, Ramasamy K. Perfluoro-n-octane-assisted mega Weiss-ring technique for posterior vitreous detachment induction in retinal detachment. Indian J Ophthalmol 2019;67:1463-5
Induction of posterior vitreous detachment (PVD) is one of the most critical steps for the success of retinal detachment (RD) surgery. Failure to completely remove the vitreous can result in re-detachments, even after a successful surgery.,
Han et al. first described PVD induction by incising the posterior hyaloid with a knife blade. Kelly and Wendel performed PVD induction with the help of active suction applied through silicon-tip needle. Over the years, application of high-vacuum active aspiration over the optic disc margin has become the most commonly practiced technique for PVD induction. However, in cases where the posterior hyaloid is firmly adherent, a layer of cortical vitreous is left behind. Removing the remnant vitreous in these cases is a big challenge and is often accomplished in multiple small pieces.
Various instruments have been described for inducing PVD in cases of an adherent posterior hyaloid. Peyman et al.used a 10-0 nylon adjustable-tip brush to rub and create microholes in the posterior hyaloid, following which a vitrector was used to complete the PVD. Similarly, Otani et al.used a silicon-tip needle to create holes in the posterior vitreous by gently sweeping it over the vitreous cortex. Desai et al.advocated the use of 20-gauge microvitreoretinal (MVR) blade, with its distal end bent at an angle of 120–135°, to engage and lift the posterior cortical vitreous. Ellabban et al.described a 25-gauge micropick, angled at 45°, to penetrate into the subhyaloid space and then lift the posterior cortical vitreous with the help of the connected active suction. Garg et al.performed similar maneuvers using a self-made pick by bending a 25-gauge needle. Takeuchi et al. created breaks in the posterior vitreous by scraping a diamond-dusted membrane scraper (DDMS) against it and then lifting the posterior hyaloid by inserting the scrapper through the created break.
All these techniques are potentially dangerous as a sharp instrument is inserted below the posterior vitreous and can damage the detached fluttering retina.,,,, We describe a novel technique to completely and safely remove vitreous in the form of a single sheet [Supplemental video 1]. We have named it “The Mega Weiss Ring” technique.
Core vitrectomy is followed by injection of 0.2–0.3 ml triamcinolone acetonide (TA) suspension. The posterior cortex is stained by the TA particles, while the rest of the TA is washed. Perfluorocarbon Liquid (PFCL) is then injected on the posterior pole. The TA-stained vitreous is gently stroked in a circumferential manner with the help of a DDMS, till a defect is noted in the cortical vitreous sheet [Figure 1]. Stroking of the vitreous sheet is continued around this defect in a centrifugal fashion, so as to enlarge the defect and form a ring of around 4–5 disc-diameter (DD) size with rolled-out edges.
Figure 1: The triamcinolone-stained vitreous is gently stroked in a circumferential manner with the help of a diamond-dusted membrane scraper, till a defect in the vitreous is noted
The sheet is then lifted from the edges of the ring, using an internal limiting membrane (ILM) peeling forceps [Figure 2]. Once the edges of the ring are lifted, the potential space created between the vitreous sheet and the detached retina is automatically filled by PFCL [Figure 3]. This causes a gradual peripheral extension of vitreous detachment in all quadrants. TA is again injected to ensure the complete vitreous removal.
Figure 2: The vitreous sheet is lifted using an internal limiting membrane (ILM) peeling forceps to induce the PVD
This technique can also be used to remove the remnant cortical vitreous in cases where complete vitreous could not be removed after PVD induction by active aspiration. Complications while performing this technique are very rare and include failure to induce PVD, retinal bleed, and retinal tears.
We describe a simple technique to completely remove the posterior cortical vitreous in form of a single sheet. Due to the cushion provided by vitreous, a defect is easily made in it using DDMS, without damaging the retina. Enlarging the defect in the vitreous sheet makes its edges thick enough for manipulation with an ILM peeling forceps. Using the technique, a ring similar to the natural Weiss ring formed during natural PVD, but with a larger size, is created. Hence, we have termed our technique as “The Mega Weiss Ring technique”.
As the edges of the ring are rolled-out, unlike previously described techniques of PVD induction with sharp instruments, it is possible to lift the vitreous sheet without going under it. This makes the technique safe in the presence of underlying mobile retina. As the posterior cortical vitreous is removed in form of a single sheet, the cleavage plane between the vitreous sheet and retina is automatically filled with PFCL, which naturally slides into the potential space and stabilizes the detached retina. Hence, vitreous detachment can easily be extended till the periphery without the risk of creating additional breaks or accidental aspiration of the peripheral mobile retina.
Success of this technique depends on effective flattening of the neurosensory retina against retinal pigment epithelium (RPE), so that DDMS gets a good counter traction while scraping the vitreous cortex off the retinal surface. Hence, this technique is not suitable for the eyes where PFCL is potentially unable to flatten the neurosensory retina against the RPE. These include eyes with advanced posterior proliferative retinopathy changes, stiff retina due to long-standing RD and traumatic RD with extensive subretinal gliosis. Caution should be exercised while using this technique in the presence of large posterior tears with PVR, as the PFCL might migrate subretinally at the start of the maneuver.
We have used this technique in more than 100 cases over the last 5 years. The technique is easy to perform. In appropriate cases, even the less experienced surgeons feel comfortable using this technique to induce PVD. The technique is especially helpful in pediatric cases with no pre-existing PVD, macular hole-associated RD, myopic RD, and in cases with peripheral breaks and partial PVD.
This technique needs to be executed carefully. Carelessness during any step can lead to both failure of the technique as well as further complications. The cortical vitreous sheet should be stroked gently, else it can lead to retinal bleed and even retinal breaks. The vitreous sheet should be stroked patiently till a ring of adequate-size is created, to ensure that its edges gain thickness sufficient enough for manipulation. If PVD induction is attempted in a small-sized ring with thin edges, the ring may give away. While lifting the ring, it should be ensured that the surrounding retina is not caught in the ILM peeling forceps, along with the edges of the ring, as this might cause retinal bleed and retinal breaks.
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