Pterigium ditemukan di negara khatulistiwa • Pterigium lebih banyak pada usia tahun • Prevalensi pernah tumbuh ulang. tahun penderita mengeluhkan hal yang sama dan dilakukan operasi kembali. Indikasi pembedahan. Pterygium. *According to (5– 7, 16, 21– 25). The literature contains no evidence- based, randomized studies comparing AMT with the alternative. PTERIGIUM Identitas Nama: Ny. H Umur: 53 tahun. Jenis kelamin: Perempuan Agama: Islam Bangsa: Indonesia Pekerjaan: IRT.
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Amniotic membrane transplantation AMT has a long tradition in ophthalmic surgery and has become very popular recently because of newly developed methods of tissue preservation. We selectively review the literature on recent developments, mechanisms of action, and established indications of AMT in the treatment of various diseases of the ocular surface. Amniotic membrane AM can function in the eye as a basement membrane substitute or as a temporary graft.
It has anti-inflammatory and anti-scarring effects and contains growth factors that idikasi epithelial wound healing on the surface of the eye. AMT has been found to be a good alternative for corneal and conjunctival reconstruction in many clinical situations, including acute burns, persistent epithelial defects of the cornea, and diseases that cause conjunctival scarring.
Nonetheless, there have been no more than a few randomized and controlled trials of AMT to date. Other studies have shown that AM can serve as a culture substrate to expand epithelial progenitor cells for use in ocular inidkasi reconstruction. AMT is an established technique in the treatment of various diseases of the external eye. In the last few pteryhium, AMT has brought about major advances in the reconstructive surgery of the ocular surface. Transplantation of preserved human amniotic membrane AM can be considered one of the major new developments in surgery of the ocular surface.
Although the first ophthalmological use of AM documented in the international literature took place almost 70 years ago, amniotic membrane transplantation AMT has only been performed in larger numbers of patients sincewith promising results 1 — 3.
Amniotic Membrane Transplant – EyeWiki
Various disorders of the ocular surface, including persistent epithelial defects of the cornea, acute chemical burns with long-term loss of integrity of the ocular surface epithelium or conjunctival scarring as a result of the healing of mucous membrane disorders still pose a clinical challenge in ophthalmic surgery.
Since pterygiium preservation methods were introduced, the innermost layer of the placenta, the AM, procured in sterile conditions following a Cesarean section, has experienced a renaissance as a basement membrane substitute.
Today it is hard to imagine reconstructive surgery of the ocular surface without it 1 — 3. Ina total of AMTs were performed in Germany seehttp: Each type of application yields histologically different integration patterns for AM in the host corneal tissue 4. The most important indications in reconstructive surgery of the ocular surface are persistent epithelial defects of the cornea with corneal ulceration ineikasi varying etiology, covering defects after pteyrgium removal of large conjunctival lesions, acute chemical burns, symblepharon and fornix reconstruction in healing conjunctival disorders, and limbal stem cell deficiency of the cornea with simultaneous stem cell grafting 5 — 7.
It reports new indikai, mechanisms of action, and established indications of AMT.
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The AM is the innermost layer of the placenta, located next to the fetus. Histologically, it is a multilayer membrane approximately 0. Appropriate standardized operating guidelines for procuring and manufacturing human AM from donor placenta are currently being developed with the support of the Tissue Transplantation and Biotechnology Section of the German Society of Ophthalmology Deutsche Ophthalmologische Gesellschaft, DOG e1. When appropriately prepared it consists of a relatively thick basement membrane with devitalized amniotic epithelial cells and an avascular, almost acellular stroma.
Cryopreservation involves a cryomedium glycerin: Clinical trials suggest indiiasi AM transplantation promotes epithelialization and differentiation of the epithelium of the ocular surface 5 — 9. The most important growth factors that promote wound healing, which have been isolated idnikasi from the amniotic epithelium but also from the AM stroma, are epidermal growth factor and keratocyte growth factor 89.
Structural proteins such as laminin and type VII collagen in the AM basement membrane explain the observed epitheliotropic effects 9 Intrinsic neurotropic substances make AM an ideal substrate for reconstruction of the epithelium of the ocular surface 11 In the initial phase after AMT, there is typically a significant reduction in inflammation.
In vitro, AM reduces expression of various growth factors and pro-inflammatory cytokines In addition, anti-inflammatory cytokines such as interleukin and interleukin-1 receptor antagonist are released in the epithelium and stroma of the AM and may modulate inflammatory processes. They may play a role in the healing of acute chemical burns operawi the cornea covered by AM 15 AM also has an immunomodulatory effect 17and tissue rejection is therefore rarely observed in clinical use of AM.
As the cells of cryopreserved AM are devitalized after thawing, no enzyme activity appears, and no intact RNA can be extracted, these substances are released from the damaged, devitalized cells. Because these factors are removed after application of cryopreserved AM, longer-term use is problematic. It is therefore advisable to replace an AM used as a patch in ocular surface reconstruction at regular weekly intervals until the desired epithelial wound closure occurs.
Unlike the generally preferred cryopreservation of AM, other AM preparation procedures which are in use, such as acid pretreatment and subsequent air drying 18lead to near-complete loss of its biological properties, and as a result their possibilities for clinical application and their efficacy seem limited This allows procedures to be performed in a sequential manner, such as cornea transplantation with a reduced risk of rejection 5 These aims are achieved using various different surgical procedures for AMT 5indikssi.
In the inlay technique, the AM is applied as a permanent basement membrane substitute.
The main indications for this are persistent epithelial defects, corneal ulceration or to cover defects following excision of conjunctival tumors 5620 — 23e2 Box. In pterygiym defects, e. Epithelialization of the AM integrates AM into the host tissue 4. It remains detectable for months, sometimes years, and in defects of the cornea is even colonized by local keratocytes 4.
Amniotic Membrane Transplant
The literature contains no evidence-based, randomized studies comparing AMT with the alternative options pteerygium these indications. Unlike the inlay technique, where the AM remains permanently on the cornea, with the onlay technique the AM patch typically becomes detached from the surface of the cornea after one to two weeks.
Classical indications range from acute burns to acute herpetic keratitis and the acute stage of Stevens-Johnson syndrome 561620 If delayed wound healing is demonstrated clinically, on the basis of the above-mentioned experimental data it seems to be advisable to change the AM patch weekly until the wound closes as desired.
The orientation of the AM plays only a minor role with this surgical procedure: This technique, also called the sandwich technique, is a combination of the two described above and is used mainly in serious disorders of the ocular surface such as deep and extensive corneal ulceration, or in surgical revisions 56.
The main purpose of the onlay is to protect the inlay and promote its epithelialization 45. The AM has only recently been described as a culture substrate for ex vivo expansion of the epithelium of the ocular surface 725e3 — e5.
Here operasl AM functions as a biomatrix and is placed on the surface indikasu the eye together with pterhgium cultivated cells e3e4.
This technique is mainly used to treat limbal stem cell deficiency, but also in reconstruction of major surface defects of the outer eye 725e5e6. So many indications of AMT have already been described in the literature that they would go well beyond the boundaries of this review article 5 — 71621 — 25e2e5e6. The main indications of AMT are therefore summarized in the Box. Unfortunately, opersi clinical data have only been published in small to medium numbers of cases, with a relatively short follow-up period, and overwhelmingly in retrospectively analyzed case series e6probably due to the low incidence of operasj disorders of the ocular surface.
There are no Cochrane Reviews or meta-analyses available from either the Cochrane Library or PubMed on the subjects lterygium in this review article. The treatment of corneal ulcers still poses a major challenge in ophthalmology, despite various conservative and surgical options 520 An intact corneal epithelium is a decisive pterygiuj in ocular surface stability. Simple epithelial defects generally heal with no complications.
If they are untreated or inappropriately treated, corneal ulceration, descemetocele, and even perforation can quickly develop. AM is used clinically as a basement membrane substitute in patients with persistent epithelial defects both with and without ptwrygium ulceration 5 After a median follow-up time of 18 months, Seitz et al. The success rate of AMT can be significantly improved using subsequent measures such as inducing upper eyelid ptosis via Botox injection or tarsorrhaphy 5 Ineikasi reoperation rate then falls from approx.
Amniotic membrane transplantation AMT in infectious corneal ulceration see area marked with stars: Signs of inflammation have significantly decreased. Modified with the permission of Dr. Kaden-Verlag publishersHeidelberg. A multilayer technique is used to treat deep corneal ulceration, descemetocele, and small corneal perforations 21e2.
After AMT, corneal transplantation keratoplasty is required for further restoration of vision. Prognosis is substantially improved if an intact surface epithelium has formed on the surface of the eye and signs of inflammation have decreased 520 Chemical burns to the ocular surface are a common problem in acute ophthalmological care. These can lead to complete corneal erosion and blood vessel rupture at the limbus and in the conjunctiva.
The overriding aims of treatment are to prevent necrosis and scarring and to achieve swift epithelialization. Early AMT improves functional outcomes after chemical burns 216 Symblepharon occurred in only one case of slight to moderate chemical burns treated with prompt AMT 216 In a prospective randomized controlled trial Tamhane et al.
For severe chemical burns, however, stem cell deficiency of the cornea with long-term, serious loss of visual acuity is often impossible to prevent 16e7. The corneal surface is very important to eyesight. Maintaining a functional corneal epithelium is therefore essential to vision. Epithelial stem cells of the corneal epithelium are located in the limbus, which forms an anatomical bridge between the conjunctiva and the cornea. Various disorders of the surface of the eye can lead to limbal stem cell deficiency as a result of destruction of limbal stem cells.
Limbal stem cell deficiency is characterized by formation of fibrovascular pannus tissue on the corneal surface, increased glare sensitivity, and loss of vision.
Long-term success of surface reconstruction can only be achieved by restoring the limbal stem cell population e6. For many years the results of conventional limbus transplantation, which are not yet satisfactory, have given rise to a demand for stem cells from cell cultivation e6.
Amniotic Membrane Transplantation in the Human Eye
Further development of methods reliant on cell biology, particularly tissue engineering, now also make it possible to cultivate limbus stem cells. Autologous ex vivo expansion of limbal epithelial cells on AM has only recently been developed as a new procedure 725e3 — e5 Figure 2: Vascularization as a sign of recurring stem cell deficiency did not occur within the described follow-up period.
Many subsequent publications, some of which concern different cell cultivation procedures, have also described notable treatment success 7e5. Unfortunately, there is currently no standardized procedure available, which makes the published studies harder to compare.
Other disadvantages are the small, sometimes heterogeneous patient groups and usually short follow-up times, as yet preventing conclusive evaluation of this new form of treatment 7e5e6.
Autologous transplantation of limbal epithelium cultivated ex vivo: Visual acuity sufficient to perceive hand movements. Visual acuity has increased to 0. Modified according to Dev Ophthalmol ; Excision of a squamous cell carcinoma or a melanoma from the area of the conjunctiva, for example, often causes major surface defects. After complete tumor removal, defects can be covered with an AM 22 Further adjuvant measures to eradicate the tumor, such as radiation or local chemotherapy, can then follow.