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Presention

  1. 1. OCULAR LASER THERAPY الليزر وتطبيقاته في مجال طب العين اعداد : الدكتور محمد منير الشنواني - الرقه
  2. 2. الله نور السماوات والارض Lasers are a kind of light that is different than light from the sun,
  3. 3. There are also kinds of energy which are invisible to people's eyes Light is energy people can see infrared - this energy can't be seen but is able to be felt as heat radio - people can't see this energy , b ut radio's can turn it into s oun d microwave - this energy can be used to cook food But there are photons which have a wavelength that is just right for the human eye to see. النانومتر هو جزء من مليار جزء من المتر one millionth of a millimetre 1 nanometre = فمتومتر | أنغستروم | نانومتر | ميكرومتر | مليمتر | سينتمتر | ديسيمتر | متر | ديكامتر | هيكتومتر | كيلومتر
  4. 4. عندما يجري تحفيز جهاز الليزر ترتفع طاقة ذراتها من المستوى الادنى إلى المستوى الاعلى ،وتعاود الانخفاض إلى مستوى الطاقة الادنى مرورا بالمستوى الأوسط نتيجة عدم استقرار الجسيمات الواقعة في مسار الطاقة ، عندها تنبعث ا لفوتونات التي تعطي رنينا في جهاز الليزر وتخرج من الجهاز بطاقة كبيرة وصلت اقصى ما وصلت اليه 1700 مليون ميجاواط و يتم التفاعل في ثلاثة على عشرة ملايين ثانية وضغطها مليون وخمسين الف كيلو جرام على السنتيمتر ا لمربع ودرجة الحرارة بين 100-200 الف درجة ). BOHR ATOM´S MODEL nucleus electrons All light, including laser light, is made up of little packets called photon s . Photons aren't all alike, they can be different colors or contain different amounts of energy. ~ 0.1mm
  5. 5. Arabian physicist , Alhazen , in the Book of Optics , held light rays to be streams of minute energy particles , The process which makes lasers possible, Stimulated Emission, was proposed in 1917 by Albert Einstein . 1960 that the first true laser was made by Theodore Maimam , out of synthetic ruby كان " أينشتين " Einstien أول من تنبأ في عام 1916 م بأن الإلكترونات تستطيع أن تطلق نوعاً خاصاً من الضوء، فعندما سقط ضوء المصباح على الياقوتة أهاج ذراتها، وانبعث منها وميض انتشر إلى طرفيها ليصطدم بالفضة التي عكسته كالمرآة، فتردد ذهاباً وإياباً، فزادت قوته وتركيزه، وانطلق شعاع لامع من الضوء الأحمر من نوع غير معهود من قبل ا
  6. 6. تضخيم الضوء بواسطة الأنبعاث المحفز للأشعة . <ul><li>L ight A mplification by the S timulated E mission of R adiation </li></ul>عبارة عن حزمة ضوئية ذات فوتونات تشترك في ترددها وتتطابق موجاتها بحيث تحدث ظاهرة التداخل البناء بين موجاتها لتتحول إلى نبضة ضوئية ذات طاقة عالية والليزر هو حزمة من الضوء المكثف يسير باتجاه مستقيم عكس الضوء الاعتيادي الذي ينتشر بكل الأتجاهات وبأطوال موجية <ul><li>Amplification means that a very bright intense beam of The initial light is amplified to make a very bright compact beam </li></ul><ul><li>Stimulated means that the photons are amplified by stimulating an atom to release more photons ., When the atom relaxes it emits a photon </li></ul>Emission . The excited atom emits a photon when another photon comes by. In 1917, Einstein described this process as Stimulated Emission radiation refers to the photons which are being emition Light is energy people can see . جهاز الليزر عبارة عن مصدر للضوء، يعمل على تجميع الإشعاعات الضوئية، التي تتولد داخل الجهاز، وتركيزها، وتقويتها، على شكل حزمة ضوئية رفيعة جداً في اتجاه واحد مركز، وهي أشعة كهرومغناطيسية متجانسة coherent ومتماسكة، وتستطيع قطع مسافات لا نهائية في خط مستقيم . وتتميز بأنها تزداد شدتها، ويقوي بعضها بعضاً عند الانطلاق تتألف كلمة ليزر من الحروف الأولى لأسم هذه الأشعة بالغة الإنجليزية الذي يعني
  7. 8. What is Laser Therapy? <ul><li>Compressed light of a wavelength from the cold, red part of the spectrum of electromagnetic radiation </li></ul><ul><ul><ul><li>Monochromatic - single wavelength, single color </li></ul></ul></ul><ul><ul><ul><li>Coherent - travels in straight line </li></ul></ul></ul><ul><ul><ul><li>Polarized - concentrates its beam in a defined location/spot </li></ul></ul></ul>يتميز شعاع الليز ر ، أي كانت مادته أو منطقة طيفه ، بالخواص الرئيسية التالية :- ] أحادي اللون Monochromatic ، أي ذو عرض طيفي ضيق ينتج عنه تردد مفرد نقي ، ] توازي الحزم الضوئية COLLIMATION ، أي يكاد التشتت أو التفريق في الحزمة يكون معدوما ] الترابط Coherence ، الترابط بين موجات الحزمة الواحدة مكانياً وزمانياً يساعد الموجات الضوئية أو الفوتونات في تقوية بعضها البعض لتعطي طاقة وقدرة عالية للحزمة الواحدة ا ] الشدة Intensity ، شدة الشعاع عالية ومركزة في خزمة ذات قطر ضيق لا يتجاوز الواحد مليمتر ، وعند استخدام البصريات الملائمة يمكن تعريضها وفق الحاجة . للحصول على أشعة الليزر من الضروري توفر ثلاثة شروط أساسية وهي : 1) حدوث التعداد المعكوس . 2) توفر الانبعاث المحتث . 3) إيحاد التكبير الضوئي . Definition: &quot;Laser therapy” is any treatment using intense beams of light to precisely cut, burn, or destroy tissue <ul><ul><li>has many colors mixed togethe r </li></ul></ul><ul><ul><li>doesn't come in a narrow beam </li></ul></ul><ul><ul><li>cannot be focused to as small a spot </li></ul></ul><ul><ul><li>and cannot be as intense as a laser . </li></ul></ul>
  8. 9. CONSTRUCTION Principal components: 1.Active laser medium 2.Laser pumping energy 3.Mirror(100%) 4.Mirror(99%) 5.Laser beam هذا شكل يوضح أجزاء جهاز الليزر . (1) الوسط المنتج لشعاع الليزر . (2 ) طاقة كهربائية لتحفيز الوسط على أصدار الموجات الضوئية . وعاكس (3) للضوء عال الأداء . وعدسة (4) خروج الشعاع وقد تكون مستوية أوعدسة مقعرة . 5) شعاع الليزر الناتج ليزر الغاز ( CO 2 laser,Excimer LASER) لي زر السائل () ليزر اشباه الموصلات ( Semiconductor LASER) ليزر الحالة الصلبة ( نيوديميوم ياغ Neodymium-YAG LASER) المواد القادرة على اطلاق اشعة الليزر منها المتجمدة ( الياقوت الاحمر و زجاج النيوديميوم ) , والغازية ( الهيليوم والنيون والزينون ) مواد شبه موصلة ( زرنيخ , الجاليوم و انتيمون الانديوم )
  9. 12. APPLICATIONS <ul><li>Consumer electronics, information technology, science, medicine, industry, law enforcement, and the military. </li></ul><ul><li>Medicine </li></ul><ul><li>In medicine, the laser scalpel is used for laser vision correction and other surgical techniques. </li></ul><ul><li>Lasers are also now used in dentistry for caries removal, as well as tooth whitening and oral surgery procedures. </li></ul><ul><li>To treat some skin conditions, including to remove tattoos, birthmarks, scars, wrinkles </li></ul><ul><li>To remove tumors </li></ul><ul><li>To prevent blood loss by sealing small blood vessels </li></ul>
  10. 13. Types of eye surgeries <ul><li>Cataract surgery </li></ul><ul><li>Glaucoma surgery </li></ul><ul><li>Laser trabeculoplasty </li></ul><ul><li>Iridotomy </li></ul><ul><li>Tube-shunt surgery or drainage implant surgery </li></ul><ul><li>Refractive surgery </li></ul><ul><li>عتلال الشبكية السكري . </li></ul><ul><li>انسداد أو تخثر الوريد الشبكي . </li></ul><ul><li>ا لزرق ( إرتفاع ضغط العين ). </li></ul><ul><li>عيو ب الإنكسار ( طول أو قصر النظر واللابؤرية ). </li></ul><ul><li>انسداد القنوات الدمعية . </li></ul><ul><li>بعض الأورام داخل العين . </li></ul><ul><li>عمليات التجميل حول العين . </li></ul><ul><li>حالات تنكس اللطخة الصفراء . </li></ul>
  11. 14. Anatomy of the Eye L I G H T
  12. 15. RK : Radial keratotomy PRK : Photorefractive keratectomy LASIK : Laser assisted in-situ keratomileusis LASEK : Laser epithelial keratomileusis ICRS : Intra-corneal ring segments Lens exchange : following removal of a cataractous or clear lens Phakic IOL (intraocular lens placed in the eye in addition to the crystalline lens LTK : Holmium laser thermokeratoplasty DTK Diode thermokeratoplasty AK : Arcuate Keratotomy Reffractive surgery
  13. 16. History of Laser Refractive Surgery
  14. 17. NEARSIGHTEDNESS FARSIGHTEDNESS ASTIGMATISM REFRACTIVE ERRORS
  15. 18. 70% of the eye's focusing power comes from the cornea and 30% from the l ens .
  16. 19. In most cases, refractive surgery affects the shape of your cornea to redirect how light is focused onto the retina. Popular procedures include LASIK, LASEK, PRK and CK . For myopia , your corneal tissue is removed centrally in a lenticular (lens-like) pattern, thereby flattening the central cornea and reducing the eye’s focusing power to correct your refractive error For hyperopia , your corneal tissue is removed around the edges, thereby steepening the central cornea and increasing the eye’s focusing power. For astigmatism, your corneal tissue removed in a precise elliptical pattern which steepens the cornea where it is too flat and flattens the cornea where it is too steep, thereby accurately correcting your refractive error .
  17. 20. The first in the line of laser procedures for vision correction was Photorefractive Keratectomy or PRK. PRK is performed with an excimer laser , which uses a cool ultraviolet light beam to ablate tiny bits of corneal surface tissue. sculpt an area of 5 to 9 millimeters in diameter on the surface of the eye . PRK is still the laser vision correction treatment of choice for many eye surgeons for patients with larger pupils and thin corneas . PRK can effectively improve myopia, hyperopia, and astigmatism . First invented in the early 1980�s, PRK received FDA approval in 1995
  18. 21. مد البصر– حرج البصر Astigmātisma H y permetrop ia
  19. 22. <ul><li>Corneal topography : mapping the surface details of the cornea. </li></ul><ul><li>Corneal keratometry : measurement of the form and curvature of the cornea. </li></ul><ul><li>Corneal pachymetry : measurement of corneal thickness. </li></ul>Pachymetry measures corneal thickness The Epi-microkeratome is used in the Epi-LASIK procedure
  20. 23. LASIK , or Laser Assisted In Situ Keratomileusis for people with corneas to thin or too flat
  21. 24. LASIK Laser Eye Surgery LASIK is an acronym for LAS er I n-situ K eratomileusis, which simply means &quot;to shape the cornea within using a laser.&quot;
  22. 25. Surface Ablation <ul><li>Two years ago ( 2005 ) we went </li></ul><ul><li>B to B </li></ul><ul><li>Back to Bowman’s </li></ul><ul><li>Above Bowman </li></ul><ul><li>Epi-LASIK </li></ul>2007 年 04 月 15 日 中國上海國際眼科學術會暨兩岸論壇
  23. 26. Risks <ul><li>Keratectasia - surgeon cuts the flap too deeply or removes too much tissue. </li></ul><ul><li>Dry eye - commonly reported </li></ul><ul><li>Infection - relatively low risk </li></ul><ul><li>Night Vision Problems - These are more common when surgeons use traditional LASIK procedures. </li></ul><ul><li>Over or under correction - results in blurry vision or minor visual disturbances. </li></ul>Clear natural vision E xpanded recreational opportunities E xpanded career opportunities (Pilot, Police, Military, etc ) Elimination of risks of infection, and inflammation associated w ith contact lens overuse. Benefit s
  24. 27. <ul><li>المشرط الضوئي * يشير د . وليد الطويرقي الى أن فكرة المشرط الضوئي تعتمد على حقيقة علمية هي أنه إذا تم تسليط أشعة الليزر لمدة قصيرة جدا فإن الأشعة لاتقوم بحرق الأنسجة ( Photocoagulation) ، ومن هنا جاءت فكرة استخدام أشعة الليزر، وهو ليزر الأشعة تحت الحمراء والتي بمقدورها أن تعالج الأنسجة بدقة عالية وبحرارة أقل بخلاف ما يتولد عن المعالجة بالليزر العادي وهو مايعتبر مكسبا مهما في عالم جراحة العين بالليزر . يقوم جهاز الليزر بإطلاق نبضة ليزر صغيرة جدا لا يتعدى امتدادها المئة مليمتر من أشعة الليزر تحت الحمراء وذلك لمدة قصيرة جدا جدا هذه المدة مقدارها فيمتوثانية ( Femtosecond) أي واحد من مليون مليار جزء من الثانية، فقد وجد أن نبضة الليزر رغم قوة الطاقة الموجودة بها إلا أن تسليطها داخل القرنية لهذه المدة القصيرة يجعلها تتحول إلى فقاعة صغيرة جدا تقوم بفصل الأنسجة عن بعضها البعض دون أن تحدث أي أضرار للأنسجة المجاورة . يستطيع جهاز الليزر أو بعبارة أدق جهاز &quot; ليزر فيمتو ثانية &quot; أن يصنع أي قطع يريده الجراح، فبالإمكان تحديد شكل القطع دائري أو مربع أو بيضاوي أو غير ذلك . كما يمكن تحديد عمق القطع وتحديد مكان الثنية وموقعها وحجمها . كما أن القطع الناتج قطع متساوي وذو سماكة واحدة، وعلى الأقل نظريا يجب أن لا يوجد فرق بين السماكة التي حددها الجراح والسماكة الناتجة بعد القطع بالمشرط الضوئي، وذلك بعكس المشرط الآلي والذي تكون السماكة الناتجة عن القطع مختلفة وأحيانا بشكل كبير عن السماكة المحددة . وعليه فيفترض أن لايواجه الجراح، عند استخدام القطع بالمشرط الضوئي، مضاعفات مثل القطع الناقص أو القطع الكامل بدون ثنية أو ثقوب </li></ul>
  25. 28. INTRALASIK <ul><li>The Intralasik technique is very similar to Lasik but utilizes a laser, rather than a blade, to create a corneal flap. For Intralasik, its only advantage is consistency of flap depth and reduced risk of flap complication. It may be advertised as a &quot; bladeless &quot; procedure, but it is certainly not &quot;flapless&quot; or without an incision! </li></ul>
  26. 29. Preoperative: Patients wearing soft contact lenses typically are instructed to stop wearing them approximately 7 to 10 days before surgery. The day before surgery, you should stop using: • creams • lotions • makeup • perfumes <ul><li>After Surgery : </li></ul><ul><li>Your eye may burn, itch , or feel like there is something in it. </li></ul><ul><li>You may experience some discomfort , or in some cases, mild pain and your doctor may suggest you take a mild pain reliever. </li></ul><ul><li>Both your eyes may tear or water. </li></ul><ul><li>Your vision will probably be hazy or blurry . </li></ul>The flap can be dislodged by any direct injury to the eye after treatment.  Clarity and quality of vision can de diminished if flap conditions occur.  Poor night vision is the most common side effect.  Light sensitivity A subconjunctival hemorrhage is a common and minor post-LASIK complication. <ul><li>Low oxygen-permeable contact lenses reduce the cornea's absorption of oxygen, which sometimes results in the growth of blood vessels into the cornea, a process known as corneal neovascularization . </li></ul>Factors affecting surgery
  27. 30. Advantages of LASIK <ul><li>a pain free recovery. </li></ul><ul><li>quick restoration of eyesight and </li></ul><ul><li>better results for severe short sight. </li></ul><ul><li>The inner eye is not pierced during the procedure and stitches are not required. </li></ul><ul><li>Clarity of vision within hours of surgery </li></ul><ul><li>Extremely predictable </li></ul><ul><li>No more daily cleaning rituals or recurring costs as with visual aids </li></ul><ul><li>Increases self-confidence </li></ul><ul><li>Broad range of treatable prescriptions </li></ul><ul><li>Both eyes treated on the same day </li></ul>
  28. 31. Epi-Lasik <ul><li>Separation of the epithelium from the basement membrane without cutting the Bowman´s layer </li></ul>patients with very thin corneas or for individuals who participate in high-contact sports or professions
  29. 32. 2006 年 10 月 28 日 中國廈門屈光手術研討會 Epi-LASIK
  30. 33. Epi-LASEK Laser Eye Surgery <ul><li>Epi-LASEK involves lasering the surface of the cornea under the epithelium.  It is a combination of surface PRK and Epiflap.  </li></ul>The Treatment After Treatment Bandage Lenses Possible Side Effects الطبقة بسماكة تتراوح بين 130 الى 180 مايكرونا، وهذه الطبقة شبه دائرية حيث يبقى لها ما يشبه المفصل تقلب حوله ويعمل الليزر لتصحيح
  31. 34. Faster healing <ul><li>PRK - Epithelium after alcohol removal </li></ul><ul><li>Devitalized cells pushed to center of the cornea. </li></ul><ul><li>Pseudodendrites typically visible for one week or more and retard healing. </li></ul><ul><li>Average healing time: 5 days </li></ul><ul><li>Some patients take 7 days or longer. </li></ul><ul><li>Epi-LASIK – Epithelium after use of Epi-K : </li></ul><ul><li>Epithelium adjacent to removed sheet is fully adherent and not traumatized by alcohol or brush debridement. </li></ul><ul><li>Cornea thus re-epithelializes quickly. </li></ul><ul><li>Average healing time: 2.5 to 3.5 days. </li></ul><ul><li>Epi-LASIK: a marriage of two technologies </li></ul><ul><li>Compared to other surface method aviable epithelial flap may : </li></ul><ul><ul><li>Decrease post-op pain </li></ul></ul><ul><ul><li>Restore good acuity faster </li></ul></ul><ul><ul><li>Decrease the formation of post/op healing haze </li></ul></ul><ul><li>Compared to LASIK, a viable epithelial flap may improve custom wavefront surgery results: </li></ul><ul><ul><li>Decrease the irregularity caused by the LASIK flap hinge </li></ul></ul><ul><ul><li>Decrease the adverse biomechanical effects of cutting collagen in LASIK </li></ul></ul><ul><ul><li>Decrease the effects of the LASIK flap being larger than the resultant bed and microstriae </li></ul></ul>
  32. 35. Case 1 pre- and postoperatively Mike P. Holzer, MD <ul><li>patient 1, 66 years </li></ul><ul><li>OD Fuchs endothelial dystrophy </li></ul><ul><li>preop -1.0 / -0.25 / 140° = 20/150 </li></ul><ul><li>OD PKP (20.09.05) </li></ul><ul><li>diameter 7.8 / 8.0mm </li></ul><ul><li>4 weeks postop: -1.0 / -0.5 / 20° = 20/80 </li></ul>
  33. 36. Femtosecond lasers assisted penetrating keratoplasty Mike P. Holzer, MD A B C Femtec (20/10 Perfect Vision, Germany) femtosecond laser (A) which was used for cut of donor and recipient cornea (B). Preparation of corneal donor button (C).
  34. 37. But now, a new approach to refractive surgery- Wavefront Guided Custom LASIK- Instead of just correcting defocus (spherical and cylindrical) errors, we can now take a wavefront image- literally a 'fingerprint' of each person's optical pathway- and use the information to reduce or even eliminate higher order aberrations. not only improve how much a person sees , but also the quality of vision in terms of improvement in contrast sensitivity and fine detail. Risk of post-Lasik complications, such as glare , halos , and poor night vision , are significantly reduced, and if these conditions are pre-existing they can often be treated with Wavefront Lasik procedures.
  35. 38. Glaucoma <ul><li>Definition : Glaucoma is a group of diseases affecting the optic nerve that results in vision loss and is frequently characterized by raised intraocular pressure (IOP). </li></ul>
  36. 39. <ul><li>There are four major types of glaucoma </li></ul><ul><li>Open angle (chronic) glaucoma </li></ul><ul><li>Angle closure (acute) glaucoma </li></ul><ul><li>Congenital glaucoma </li></ul><ul><li>Secondary glaucoma </li></ul>The same view with advanced vision loss from glaucoma A normal range of vision .
  37. 40. TREATMENT <ul><li>Laser trabeculoplasty </li></ul><ul><li>Laser Iridotomy </li></ul>
  38. 42. Cataract surgery <ul><li>Cataract surgery </li></ul><ul><li>Cataract A cataract is an opacification or cloudiness of the eye's crystalline lens due to aging, disease, or trauma that typically prevents light from forming a clear image on the retina. </li></ul>Light passes through the clear lens implant
  39. 43. <ul><li>Capsule thickening </li></ul>Laser makes a small hole in the capsule. Light can then pass directly onto the retina, without being scattered. LASER TREATMENT
  40. 44. <ul><li>After laser </li></ul><ul><li>Complications : </li></ul><ul><li>Less often, the laser can disturb the retina. </li></ul><ul><li>Very rarely a little fluid can build up in the retina. </li></ul><ul><li>flashes of light during the daytime </li></ul><ul><li>floaters in your vision (it is normal to have these in the weeks after the laser) </li></ul>Floaters after laser capsulotomy
  41. 45. Laser Treatment Highly Effective in Treating Diabetic Retinopathy <ul><li>Laser photocoagulation for diabetic retinopathy </li></ul><ul><li>Laser photocoagulation uses the heat from a laser to seal or destroy abnormal, leaking blood vessels in the retina . One of two approaches may be used when treating diabetic retinopathy : </li></ul><ul><li>Focal photocoagulation </li></ul><ul><li>Focal treatment is used to seal specific leaking blood vessels in a small area of the retina, usually near the macula . The ophthalmologist identifies individual blood vessels for treatment and makes a limited number of laser burns to seal them off. </li></ul>Scatter (pan-retinal) photocoagulation : Scatter treatment is used to slow the growth of new abnormal blood vessels that have developed over a wide area of the retina. The ophthalmologist may make hundreds of laser burns on the retina to stop the blood vessels from growing Panretinal treatment reduces growth of new capillaries throughout the retina.
  42. 46. Diabetic retinopathy Neovascularization Hemorrhage
  43. 47. AGE RELATED MACULAR DEGENERATION
  44. 50. <ul><li>Risks </li></ul><ul><li>Laser photocoagulation burns and destroys part of the retina and often results in some permanent vision loss. </li></ul><ul><li>Treatment may cause mild loss of central vision, </li></ul><ul><li>reduced night vision </li></ul><ul><li>And decreased ability to focus </li></ul><ul><li>Pain in or around the eye </li></ul><ul><li>Retinal bleeding </li></ul><ul><li>Watery eyes </li></ul><ul><li>Dilated pupils </li></ul><ul><li>Mild headache Double or blurry vision </li></ul>
  45. 51. <ul><li>What are the advantages of laser therapy? </li></ul><ul><li>Less pain, bleeding, swelling, and scarring. </li></ul><ul><li>With laser therapy, operations are usually shorter. </li></ul><ul><li>In fact, laser therapy can often be done on an outpatient basis. </li></ul><ul><li>It takes less time for patients to heal after laser surgery, and they are less likely to get infections. </li></ul>
  46. 52. <ul><li>What are the disadvantages of laser therapy? </li></ul><ul><li>Laser therapy is expensive and requires bulk equipment. </li></ul><ul><li>In addition, the effects of laser therapy may not last long, so doctors may have to repeat the treatment for a patient to get the full benefit. </li></ul>
  47. 53. Visual acuity
  48. 54. THANK YOU
  49. 55. <ul><li>تراجع القدرات البصرية عوضًا عن تحسنها . - جفاف العين . - فقدان القدرة على قيادة السيارة ليلاً واحمرار العين .. وربما مشاهدة الأشياء مكررة عدة مرات أو تظهر الصورة غير كاملة . - الإحباط .. </li></ul>
  50. 56. <ul><li>laser usagein glaucoma surgery t </li></ul><ul><li>Surgical treatment of glaucoma is not usually recommended unless medical treatment has failed to stop vision loss. As is the case with medical treatment, vision that has already been lost cannot be restored. The goal of surgical treatment is to lower the IOP. Argon Laser Trabeculoplasty (ALT) The argon laser is used to make a number (50-100) of small burns in the trabecular meshwork in the angle of the eye. In about 75% of the patients treated, this method works to significantly lower the IOP by increasing the outflow of aqueous, although it is not understood exactly how this treatment works to lower the IOP. For about half the patients, the pressure lower effect lasts less than 5 years. The eye is not dilated for this procedure, so that there is a clear view into the angle. A gonioscopy lens is placed on the anesthetized cornea and a slit lamp biomicroscope is used to aim the laser beam into the angle by reflection on one of the gonio mirrors. </li></ul>
  51. 57. <ul><li>The complete circle of the angle (360 degrees) is available for treatment. Treatment of half the angle (180 degrees) may be done in one session in order to judge the response of the eye before the other half is done on another day. The ALT treatment can only be repeated one time. The patient typically will still need to use drops to control the IOP. The treatment is painless and takes less than 15 minutes. The IOP is checked about an hour after the procedure, before the patient is sent home. The patient may be given a steroid drop to use for a few days to reduce post-operative inflammation. Selective Laser Trabeculoplasty (SLT) SLT works by using a short pulsed laser of a specific wavelength to target only the melanin-containing cells in the trabecular meshwork. Non-pigmented trabecular meshwork cells are not damaged. This treatment is thought to release cytokines that trigger macrophage recruitment and other changes that lead to IOP reduction. ALT can only be repeated once, but SLT can be repeated several times. </li></ul>
  52. 58. <ul><li>Filtering Microsurgery (Trabeculectomy) When medical therapy and laser therapy fail to adequately control the IOP, an alternate drainage route can be made surgically. The procedure is called a trabeculectomy, or a &quot;trab&quot; for short. A small opening, called a sclerostomy, is made in the sclera at the limbus. The opening is connected to the peripheral anterior chamber. The hole is covered by conjunctiva and the aqueous passes through the opening into the subconjunctival space where it is absorbed. When the trab is working correctly, a small blister or &quot;bleb&quot; is formed. The opening is placed such that the bleb is hidden by the upper eyelid. The figure to the right shows the approximate size and position of the bleb from a front view and and a side view. The surgery is done on a outpatient basis under local anesthesia </li></ul><ul><li>The most common complication is failure due to scarring and closure of the opening. Drugs (5-FU and mitomycin-C) can be used to inhibit scarring. Other possible complications include bleeding, infection, chronic inflammation, cataract formation, and hypotony (the IOP is too low). The Tube-Shunt In an eye that is not suitable for the filtering procedure, or the filtering procedure has failed, a drainage implant can be used. A small tube is surgically inserted onto the anterior chamber. The tube connects to a small plate that is inserted next to the sclera and is covered by the conjunctiva. Possible complications include the tube coming into contact with the cornea, blockage of the tube by the iris, choroidal hemorrhage, hypotony, infection, and chronic inflammation Ciliary Body Ablation (destruction of the ciliary body) These treatments are only used in cases of refractory glaucoma. The term &quot;refractory&quot; means &quot;resistant to treatment&quot;. Medical and other surgical treatments have failed to sufficiently lower the IOP. YAG Laser Cyclophotocoagulation (YAG CP): The YAG laser causes a localized destruction of tissue within the eye and most commonly is used to open a hole in an opacified posterior capsule follog cataract surgery. This laser can also be used to destroy part of the ciliary body. Cyclocryotherapy: A cryo (freezing) probe can be used to destroy the ciliary body. The probe is placed on the outside of the eye, over the ciliary body. Endo-laser Cyclophotocoagulation: A laser can be used within the eye, usually in conjunction with another surgery, to destroy the ciliary body. Transcleral Diode Laser Cyclophotocoagulation: A diode laser probe can be used externally, through the sclera, to ablate the ciliary body </li></ul>
  53. 59. <ul><li>UV crosslinking of the cornea represents a new treatment method based on molecular cross-linking of corneal collagen. The biomechanical properties of the cornea are primarily determined by the collagen fibers and the degree of interfibrillar linkage. The treatment technique involves the use of UV light and riboflavin (vitamin B2, a non toxic photosensitizing solution) for inducing cross-linking to increase biomedical rigidity of the cornea. This allows, in case of keratoconus, to slow down or even to stop the progressive thinnening of the cornea THE AIM OF THE TREATMENT The aim of the uv cross-linking treatment is to rise the biomechanical and biochemical stability of the tissues; biomechanical by increasing the interfibrillar linkages of the collagen and biochemical by increasing the resistance to enzymatic digestion. The treatment allows stabilizing and solidifier the cornea, intends to postpone the point of time where corneal transplantation becomes necessary in patients with keratoconus, and in some cases, even to avoid surgery. Keratoconus is a no inflammatory ectasia of the cornea. In general, keratoconus affects both eyes and leads to a progressive irregular deformation of the cornea caused by reduced stiffness of the corneal rigidity. This corneal deformation goes together with a drastic impairmement of vision ability . The UV cross linking treatment could also be useful for the treatment of iatrogenic keractectasia. A rare complication after LASIK. Other potential indications are le kératocône frustre (une forme modérée et non évolutive du kératocône), la dégénérescence marginale fellucide, les cornées déstabilisées après kératotomie radiale , etc. PROCEDURE The procedure takes place ambulatory and takes about 45 minutes and the anesthesia consists of drops. At first, the epithelium of the cornea (thin surface layer) will be abrased, in order to allow penetration of riboflavin into the corneal stroma. The riboflavin solution is applied onto the cornea during 10 to 15 minutes. Next, the cornea will be irradiated during 30 minutes with UV light (365 nm). During the irradiation, a drop of serum physiologique is applied every 2 minutes to irrigate the cornea </li></ul>
  54. 60. <ul><li>Thin corneas < 480 μ </li></ul><ul><li>Steep corneas > 47D </li></ul><ul><li>RST< 250 μ (reaidual stromal thickness) </li></ul><ul><li>Asymmetric bow ties </li></ul><ul><li>Unusual looking corneas </li></ul><ul><li>Epithelial basement membrane dystrophy </li></ul>Poor candidates for LASIK
  55. 61. Stromal opacity post LASIK <ul><li>Non-infective </li></ul><ul><ul><li>Diffuse lamellar keratitis (SOS) </li></ul></ul><ul><ul><li>MK </li></ul></ul><ul><ul><li>Epithelial ingrowth </li></ul></ul><ul><li>Infective </li></ul><ul><ul><li>Bacterial – G+ve cocci, atypical mycobacteria </li></ul></ul><ul><ul><li>Fungal - HSV </li></ul></ul><ul><ul><li>Viral, reactivation of post-viral SEIs </li></ul></ul><ul><ul><li>Protozoal – microsporidial, rare </li></ul></ul>
  56. 62. <ul><li>عمليات تصحيح العيوب الإنكسارية إلي أربعة مجموعات : إستئصال القرنية ( Ablation): يتم في هذه العملية نزع قسم من نسيج القرنية بالإستفادة من ليزر الإكسايمر . هذا النوع من العمليات يشتمل علي ليزيك ( LASIK) ، ليزر ( PRK) و لازك ( LASEK) لتصحيح قصر البصر، بعد البصر و انحراف البصر . الزراعة Implant في القرنية : مثل زراعة حلقات داخل القرنية تتناسب مع محيطها و قطرها و بهذا الشكل نستطيع معالجة قصر البصر . لا نستطيع معالجة بعد البصربهذا النوع من العمليات . إستعمال هذا النوع من العمليات أكثر ما يكون لتصحيح قصر البصر الخفيف و أيضا للمرضي المبتليين بإنحناء في القرنية بشكل خفيف أو متوسط حيث أن إستعمال ليزر الإكسايمر لهم ممنوع . عمليات حرارية : مثل Conductive Keratoplasty أو CK حيث يتم رفع درجة حرارة القرنية بمسبر CK لتقصير الألياف المكونة لنسيج القرنية حتي يتم تصحيح بعد البصر الخفيف و المتوسط . كما يتم أيضا الإستفادة من هذا النوع من العمليات لتصحيح كهولة البصر أما في حالة قصر البصر فلا يوجد لها أي إستعمال . عمليات الشق ( Incisional): مثل RK بإجراء شقوق شعاعية في القرنية لتصحيح قصر البصر و إنحراف البصر . هذا النوع من العمليات بسبب مضاعفاته الجانبية و خاصة في حالة بعد البصر المتطورة و بسبب الدقة اللازمة في الإستفادة من ليزر الإكسايمر يستفاد منها بشكل قليل هذه الأيام . </li></ul>
  57. 63. <ul><li>Retinal examination </li></ul><ul><li>revealed a stage 4 macular hole </li></ul><ul><li>(arrow) in the left eye </li></ul><ul><li>associated with a posterior </li></ul><ul><li>pole retinal detachment, and a </li></ul><ul><li>BCVA of counting fingers. </li></ul><ul><li>B) OCT image showing </li></ul><ul><li>features of both foveal </li></ul><ul><li>retinal detachment and </li></ul><ul><li>retinoschisis. </li></ul><ul><li>C) OCT after vitrectomy </li></ul><ul><li>reveals a closed macular </li></ul><ul><li>hole with a BCVA of 20/150. </li></ul>
  58. 64. Penicillium sp. <ul><li>Septate, filamentous fungi except Penicillium marneffei (dimophic) </li></ul><ul><li>Widespread in soil, decaying vegetation & the air </li></ul><ul><li>Corneal infections usually post traumatic </li></ul><ul><li>Mycotoxin, ochratoxin A  nephrotoxic and carcinogenic </li></ul>
  59. 65. <ul><li>Peripheral iridoplasty and Pupilloplasty </li></ul><ul><li>Complications : </li></ul><ul><li>A brief period of inflammation of the colored part of the eye (iris). </li></ul><ul><li>Cloudiness of the clear covering (cornea) over the iris. This usually does not last long. </li></ul><ul><li>Blockage of the drainage angle when the cornea and the iris stick together. </li></ul><ul><li>Pain. </li></ul><ul><li>Decreased vision. </li></ul><ul><li>Laser ciliary body </li></ul>
  60. 66. Maculopathies & LASIK Frequency of MH and SF-CNV 0.02% 0.01% Myopia is a risk factor for MH formation 0.5-1.3% in > -8 D LASIK does not seem to increase the incidence of MH and SF-CNV in myopes LASIK is a safe procedure with a low incidence of vitreo-retinal complications

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