In addition, we feel that the anti-inflammatory properties of TA offer a theoretical benefit to macular edema that is not offered by other vital dyes and find the optimal contrast provided by the white crystals preferrable to the other dyes. Multiple MH grading schemas have previously been proposed to assist in the preoperative assessment.
The proposed metric by Gass, prior to the widespread use of OCT images, utilized slit-lamp biomicroscopic findings to stage MHs on a 1 to 4 scale largely predicated on degree of vitreous attachment or detachment to the macula.
While duration did not appear to be predictive of outcomes there were some signs that acute MHs were more responsive to therapy. First, while having nearly identical SSC rates all of the acute MHs were successfully closed with subsequent interventions, none of the chronic MHs responded. The stage, size, and, to a lesser degree, duration all offer information pre-operatively that are important predictors of successful MH treatment and should routinely be noted when evaluating such patients.
Various intraocular gases and face-down posturing protocols have been proposed for MH repair and, similar to vital dye selection, these choices remain controversial. These gases most significantly differ by their longevity in the eye with studies demonstrating approximately Comparative studies have shown nonsignificant differences in closure rates between these gases, 52 although there are reports of better visual outcomes with the use of C3F8.
We feel that the longer gas fill and tamponade provided by C3F8 is key to the successful closure of MHs and the benefit of quicker visual recovery with SF6 is not outweighed by this point. Our face-down posturing relies on a longer regimen for more complicated cases that have a higher likelihood of reopening. Despite the high percentage of stage 4 MHs, large MHs and those with pathologic myopia, we feel the high closure rate can partially be attributed to the gas selection and face-down posturing regimen.
The complication rates in this study continue to support the previous safety profile of TA-assisted ILM peel. Elhusseiny et al reported a rate of cataract surgery of This cohort of eyes had 2 cases that required Ahmed valve placement for management of glaucoma within the first 3 months after MH surgery. Both of these eyes were on maximal tolerated therapy for primary open-angle glaucoma prior to MH surgery with persistently uncontrollable IOP after MH surgery.
We previously reported a similar rate of glaucoma in eyes treated with TA-assisted ILM peel for epiretinal membranes. The main limitations of this study are in the design both being retrospective and lacking a control or comparative arm. Not having an alternative dye for comparison makes it difficult to make broad statements regarding the BCVA and closure rate results in our group. In addition, having all the surgeries performed by a single surgeon limits the broader applications as varying surgeon skill levels may find different results than those presented.
Also, more recent research has proposed the use of amniotic membranes or inverting the ILM within the MH to assist in larger MHs and those associated with pathologic myopia which was not available in the treatment of any of these eyes. Finally, being a tertiary referral center, complex MHs are often referred from other ophthalmologists and, occasionally, other retina surgeons.
We elected to include all such cases in the study cohort. Triamcinolone acetonide-assisted ILM peel offers a safe treatment for MH with comparable visual acuity results and closure rates to prior reports. These results are consistent after many years of follow-up. When evaluating patients pre-operatively, it is imperative to note the stage, size, and duration of the MH for proper patient education regarding expected outcomes.
Eyes with pre-existing glaucoma may experience progression post-operatively which may be due to the intraoperative steroid exposure or the surgical procedure and gas tamponade. Pathologic myopia offers a challenge to successful macular hole closure and patients may benefit from alternative surgical approaches.
Post-operative macular edema is a significant risk for recurrence and should be managed aggressively. National Center for Biotechnology Information , U. Journal List Clin Ophthalmol v.
Clin Ophthalmol. Published online Apr Author information Article notes Copyright and License information Disclaimer. Received Jan 28; Accepted Mar This work is published and licensed by Dove Medical Press Limited. By accessing the work you hereby accept the Terms.
Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4. Abstract Purpose To evaluate the long-term anatomic and visual outcomes of macular hole MH repair utilizing triamcinolone acetonide TA visualization of the internal limiting membrane ILM treated at a tertiary care retina practice.
Methods Retrospective chart review of eyes undergoing MH repair with ILM peel utilizing TA visualization followed by gas tamponade and facedown positioning between and Results Seventy-eight eyes were followed for 2. Keywords: macular hole, triamcinolone acetonide, internal limiting membrane. Introduction Peeling of the internal limiting membrane ILM has become a standard surgical procedure in the management of macular holes MH.
Methods This retrospective interventional case series included all patients who underwent pars plana vitrectomy for MH with TA-assisted ILM peel between January and January with at least 6 months of follow-up. Procedure A standard gauge three port vitrectomy technique was utilized to peel epiretinal membrane and the underlying ILM. Open in a separate window. Figure 1. Statistical Analysis All data were recorded on Microsoft Excel and statistical analysis was performed using Data Analysis Toolpak software.
Table 1 Demographics. Table 2 Outcomes. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Table 3 Complications. Discussion We present the largest and longest study of eyes undergoing macular hole repair with triamcinolone acetonide-assisted internal limiting membrane peel. Vital Dye Selection As previously discussed, while ILM peeling has become a commonplace practice in the treatment of MHs the choice of vital dye for visualization is controversial. Predictors of Outcomes Multiple MH grading schemas have previously been proposed to assist in the preoperative assessment.
Intraocular Gas and Face-Down Posturing Various intraocular gases and face-down posturing protocols have been proposed for MH repair and, similar to vital dye selection, these choices remain controversial. Complications The complication rates in this study continue to support the previous safety profile of TA-assisted ILM peel. Limitations The main limitations of this study are in the design both being retrospective and lacking a control or comparative arm.
Conclusion Triamcinolone acetonide-assisted ILM peel offers a safe treatment for MH with comparable visual acuity results and closure rates to prior reports. Disclosure The authors report no conflicts of interest in this work. References 1. Vitrectomy with internal limiting membrane peeling versus no peeling for idiopathic full-thickness macular hole.
Outcomes of 4 surgical adjuvants used for internal limiting membrane peeling in macular hole surgery: a systematic review and network meta-analysis. Int J Ophthalmol. Vital staining with indocyanine green: a review of the clinical and experimental studies relating to safety.
Eye Lond. Indocyanine green-assisted internal limiting membrane peeling in macular hole surgery: a meta-analysis. PLoS One. Toxic effects of indocyanine green, infracyanine green, and trypan blue on the human retinal pigmented epithelium. Graefes Arch Clin Exp Ophthalmol. Functional outcome of macular hole surgery with and without indocyanine green-assisted peeling of the internal limiting membrane.
Macular toxicity following brilliant blue G-assisted macular hole surgery - a report of three cases. Nepal J Ophthalmol.
Triamcinolone-assisted pars plana vitrectomy improves the surgical procedures and decreases the postoperative blood-ocular barrier breakdown. Periocular triamcinolone vs. Hahn P. Accidental subretinal brilliant blue G migration during internal limiting membrane peeling surgery. JAMA Ophthalmol. Combined brilliant blue G and xenon light induced outer retinal layer damage following macular hole surgery.
Indian J Ophthalmol. Gass JD. Reappraisal of biomicroscopic classification of stages of development of a macular hole. Am J Ophthalmol. The International Vitreomacular Traction Study Group classification of vitreomacular adhesion, traction, and macular hole.
Insight into high myopia and the macula. Optical coherence tomographic findings in highly myopic eyes. J Ophthalmic Vis Res. Comparative evaluation of anatomical and functional outcomes using brilliant blue G versus triamcinolone assisted ILM peeling in macular hole surgery in Indian population. Long-term outcomes after macular hole surgery.
Ophthalmol Retina. Safety of Triamcinolone acetonide TA -assisted pars plana vitrectomy in macular hole surgery. Brilliant blue G-assisted internal limiting membrane peeling for macular hole: a systematic review of literature and meta-analysis. Long-term outcomes of 3 surgical adjuvants used for internal limiting membrane peeling in idiopathic macular hole surgery.
Jpn J Ophthalmol. Macular hole surgery with triamcinolone acetonide-assisted internal limiting membrane peeling: one-year results. Williamson TH, Lee E. Idiopathic macular hole: analysis of visual outcomes and the use of indocyanine green or brilliant blue for internal limiting membrane peel. Anatomical outcomes of surgery for idiopathic macular hole as determined by optical coherence tomography. Arch Ophthalmol.
The macular hole: report of an Australian surgical series and meta-analysis of the literature. Clin Exp Ophthalmol. Outcomes of macular hole surgery: implications for surgical management and clinical governance. Indocyanine green enhanced maculorhexis in macular hole surgery. Macular hole surgery in high myopia. Internal limiting membrane peeling and air tamponade for stage III and stage IV idiopathic macular hole. Inverted ILM flap technique versus conventional ILM peeling for idiopathic large macular holes: a meta-analysis of randomized controlled trials.
Amniotic membrane plug to promote chronicpost-traumatic macular hole closure. Ophthalmic Surg Lasers Imaging Retina. Reopening of previously closed macular holes after cataract extraction. Long-term incidence of reopening of macular holes. Recurrent macular holes in the era of small-gauge vitrectomy: a review of incidence, risk factors, and outcomes. Comparison of anatomical and visual outcomes of macular hole surgery in patients with high myopia vs.
Vitrectomy outcomes in eyes with high myopic macular hole without retinal detachment. Foveal anatomical status and surgical results in vitrectomy for myopic foveoschisis. Inverted internal limiting membrane flap technique for surgical repair of myopic macular holes. Adjustable macular buckling for full-thickness macular hole with Foveoschisis in highly myopic eyes: long-term anatomical and functional results. Macular hole closure with triamcinolone-assisted internal limiting membrane peeling.
Long-term visual outcomes in patients with successful macular hole surgery. Internal limiting membrane peeling with different dyes in the surgery of idiopathic macular hole: a systematic review of literature and network meta-analysis. Prior to soldering, degrease all parts with hot soapy water and clean with Scotchbrite or wire wool to ensure the surface will solder perfectly.
First solder the reflector on the waveguide, see the picture below. Don't use excessive solder. Flux paste will aid the process. Next, attach the feed connector. Connector mounting screws should not protrude above the reflector surface or they will act as unwanted tuning screws. If they protrude, grind them down or they will affect the matching of the patch. Finally, press the patch itself around the waveguide and use 3mm thick metal spacers to solder the patch and feed point, see the picture below.
It is important to get the spacing accurate. Aim for 3. How to mount the LNB to the waveguide depends on its inner or outer diameter. If the LNB has a horn like most do this horn has to be cut off. LNB's having an outer diameter of 20mm are also available.
Using some sandpaper it can be squeezed into the waveguide. Most LNB's have a somewhat larger outer diameter. In these cases the waveguide internal diameter of the copper pipe has to be increased e. If the patch is made precisely enough it should show two resonances just below and above MHz. When the overall maximum return loss is too low or too high in frequency, bending the distances of the patch corners from or to the reflector plate helps centering the maximum return loss around MHz.
In practice, there will probably be only a single shallow dip of around 20 dB. Any higher is suspicious as it implies that both resonances are the same frequency, which will not give good circular polarization. The pictures below shows modelled return loss and the measured return loss of a sample antenna. In order to illuminate properly most LNB's have horns.
However, there are LNB's on the market destined to be placed close to each other so that with multiple LNB's multiple satellites can be received simultaneously using a single dish. These LNB's use a dielectric lens and are useful in this application as they do not disturb the 2.
They are complex structures designed to optimally illuminate the dish. Another approach is to produce a lens yourself on a lathe. The final dimensions of the lens is still work in progress. The design is reproducible and strikingly simple. Although precision is the main virtue, this dual band feed already serves as the de facto standard for a single QO dish. The modelled dB opening angle of the 2. Don't use chassis connectors which protrude the reflector plate too much.
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