في وتطبيقاته الليزرالعين طب مجال

الرقه : - الشنواني منير محمد الدكتور اعداد

السماوات نور اللهواالرض

Lasers are a kind of light that is different than light from the sun ,

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, but

radio's can turn it into soundmicrowave - 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.

من جزء مليار من جزء هو المترالنانومتر

one millionth of a millimetre1 nanometre =

| ميكرومترنانومتر | | أنغستروم | فمتومتر

| ديكامتر| متر| ديسيمتر| سينتمتر | مليمتركيلومتر |هيكتومتر

المستوى من ذراتها طاقة ترتفع الليزر جهاز تحفيز يجري عندماالطاقة مستوى إلى االنخفاض ،وتعاود االعلى المستوى إلى االدنىالجسيمات استقرار عدم نتيجة األوسط بالمستوى مرورا االدنىتنبعث عندها ، الطاقة مسار في تعطي لفوتوناتاالواقعة التي

الليزر جهاز في الجهاز رنينا من كبيرة وتخرج وصلت بطاقةاليه وصلت ما ميجاواط 1700اقصى التفاعل ومليون في يتم

ثانية ماليين عشرة على الف وضغطها ثالثة وخمسين مليونالسنتيمتر على جرام الحرارة لمربع اكيلو الف 200-100بين ودرجة

درجة

.)

BOHR ATOM´S MODEL

nucleus

electrons

All light, including laser light, is made up of little packets called photons

.Photons aren't all alike, they can be different colors or

contain different amounts of energy.

~0.1mm

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

" أينشتين " عام Einstienكان في تنبأ من بأن 1916أول مالضوء، من p خاصا p نوعا تطلق أن تستطيع اإللكترونات

وميض منها وانبعث ذراتها، أهاج الياقوتة على المصباح ضوء سقط فعندما ،p وإيابا p ذهابا فتردد كالمرآة، عكسته التي بالفضة ليصطدم طرفيها إلى انتشر

معهود غير نوع من األحمر الضوء من المع شعاع وانطلق وتركيزه، قوته فزادتقبل من

ا

األنبعاث بواسطة الضوء تضخيملألشعةالمحفز .

• LightAmplificationby the

StimulatedEmissionof

Radiation

ذات ضوئية حزمة عن تشترك فوتوناتعبارةظاهرة تحدث بحيث موجاتها وتتطابق ترددها في

البناء نبضة التداخل إلى لتتحول موجاتها بينعالية طاقة ذات ضوئية

باتجاه يسير المكثف الضوء من حزمة هو والليزربكل ينتشر الذي االعتيادي الضوء عكس مستقيم

موجية وبأطوال األتجاهات

• Amplification means that a very bright intense beam of The initial light is amplified to make a very bright compact beam

• Stimulated means that the photons are amplified by stimulating an atom to release more photons., When the atom relaxes it emits a photon

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 .

داخل تتولد التي الضوئية، اإلشعاعات تجميع على يعمل للضوء، مصدر عن عبارة الليزر جهازوهي مركز، واحد اتجاه في rجدا رفيعة ضوئية حزمة شكل على وتقويتها، وتركيزها، الجهاز،

متجانسة كهرومغناطيسية في coherent أشعة نهائية ال مسافات قطع وتستطيع ومتماسكة، . االنطالق عند rبعضا بعضها ويقوي شدتها، تزداد بأنها وتتميز مستقيم خط

يعني الذي اإلنجليزية بالغة األشعة هذه ألسم األولى الحروف من ليزر كلمة تتألف

What is Laser Therapy?

• Compressed light of a wavelength from the cold, red part of the spectrum of electromagnetic radiation

• Monochromatic - single wavelength, single color

• Coherent - travels in straight line

• Polarized - concentrates its beam in a defined location/spot

الليز شعاع التالية يتميز الرئيسية بالخواص ، طيفه منطقة أو مادته كانت أي ، :-ر

اللون [ نقي ، Monochromaticأحادي مفرد تردد عنه ينتج ضيق طيفي عرض ذو ، أي

الضوئية [ الحزم معدوما أي، COLLIMATIONتوازي يكون الحزمة في التفريق أو التشتت يكاد

Coherence ، rالترابط [ وزمانيا rمكانيا الواحدة الحزمة موجات بين يساعدالترابطالواحدة للحزمة عالية وقدرة طاقة لتعطي البعض بعضها تقوية في الفوتونات أو الضوئية الموجات

ا

الواحد ، Intensityالشدة [ يتجاوز ال ضيق قطر ذات خزمة في ومركزة عالية الشعاع شدةمليمتر

الحاجة . وفق تعريضها يمكن المالئمة البصريات استخدام وعند ،الضروري من الليزر أشعة على للحصول

وهي أساسية شروط ثالثة :توفرالمعكوس ( 1 التعداد .حدوثالمحتث ( 2 االنبعاث .توفرالضوئي ( 3 التكبير .إيحاد

Definition: "Laser therapy” is any treatment using intense beams of light to precisely cut, burn, or destroy tissue

has many colors mixed together doesn't come in a narrow beam

cannot be focused to as small a spot and cannot be as intense as a laser.

CONSTRUCTION

Principal components:1.Active laser medium2.Laser pumping energy3.Mirror(100%)4.Mirror(99%)5.Laser beam

الليزر جهاز أجزاء يوضح شكل الليزر ( 1). هذا لشعاع المنتج لتحفيز( 2. )الوسط كهربائية طاقةالضوئية الموجات أصدار على األداء( 3وعاكس ). الوسط عال )للضوء الشعاع( 4وعدسة. خروج

مقعرة أوعدسة مستوية تكون الناتج (5 . وقد الليزر شعاع

الغاز ( CO2 laser,Excimer LASER) ليزرلي السائل )( زر

الموصالت اشباه Semiconductor) ليزرLASER )

الصلبة الحالة ياغ ) ليزر نيوديميومNeodymium-YAG LASER ) الليزر اشعة اطالق على القادرة المواد

االحمر ) المتجمدةمنها زجاج الياقوت ووالنيون) والغازيةالنيوديميوم( , الهيليوم

موصلة ( والزينون شبه , مواد الجاليوم) زرنيخ) االنديوم انتيمون و

APPLICATIONS• Consumer electronics, information technology, science,

medicine, industry, law enforcement, and the military.

Medicine• In medicine, the laser scalpel is used for laser vision

correction and other surgical techniques. • Lasers are also now used in dentistry for caries removal,

as well as tooth whitening and oral surgery procedures.• To treat some skin conditions, including to remove

tattoos, birthmarks, scars, wrinkles• To remove tumors• To prevent blood loss by sealing small blood vessels

Types of eye surgeries

Cataract surgeryGlaucoma surgery

Laser trabeculoplasty

IridotomyTube-shunt surgery or

drainage implant surgery

Refractive surgery

o السكري عتالل . الشبكيةo . الشبكي الوريد تخثر أو انسدادoلزرقا .) العين) ضغط إرتفاعoاإلنكسار عيو النظر) ب قصر أو طول

والالبؤرية(. الدمعية انسداد . القنوات

األورام . بعض العين داخلالتجميل . عمليات العين حول

تنكس . حاالت الصفراء اللطخة

Anatomy of the Eye

LIGHT

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 orclear lens Phakic IOL (intraocular lens placed in the eye in additionto the crystalline lens LTK: Holmium laser thermokeratoplasty DTK Diode thermokeratoplasty

AK: Arcuate Keratotomy

Reffractive surgery

History of Laser Refractive History of Laser Refractive SurgerySurgery

NEARSIGHTEDNESS

FARSIGHTEDNESS

ASTIGMATISM

REFRACTIVE ERRORS

70% of the eye's focusing power comes from the

cornea and 30% from the lens.

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.

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

– البصر حرج البصر مد

Astigmātisma

Hypermetropia

• Corneal topography: mapping the surface details of the cornea.• Corneal keratometry: measurement of the form and curvature of the cornea.• Corneal pachymetry: measurement of corneal thickness.

22

Pachymetry measures corneal thickness The Epi-microkeratome is used in the Epi-LASIK

procedure

LASIK, or Laser Assisted In Situ Keratomileusis

for people with corneas to thin or too flat

LASIK Laser Eye Surgery

LASIK is an acronym for LASer In-situ Keratomileusis, which simply means "to shape the cornea within using a laser."

2007 年 04 月 15 日 中國上海國際眼科學術會暨兩

岸論壇

Surface Ablation

• Two years ago ) 2005 ( we went

B to BBack to Bowman’s

Above BowmanEpi-LASIK

Risks• Keratectasia - surgeon cuts the flap too deeply or removes too much tissue.• Dry eye - commonly reported• Infection - relatively low risk• Night Vision Problems - These are more common when surgeons use traditional

LASIK procedures. • Over or under correction - results in blurry vision or minor visual disturbances.

Clear natural visionExpanded recreational opportunities

Expanded career opportunities (Pilot, Police, Military, etc)Elimination of risks of infection, and inflammation associated with contact

lens overuse.

Benefits

• الضوئي المشرط

* . األنسجة بحرق التقوم األشعة فإن جدا قصيرة لمدة الليزر أشعة تسليط تم إذا أنه هي علمية حقيقة على تعتمد الضوئي المشرط فكرة أن الى الطويرقي وليد د يشير )Photocoagulation) العين ، جراحة عالم في مهما مكسبا مايعتبر وهو العادي بالليزر المعالجة عن يتولد ما بخالف أقل وبحرارة عالية بدقة األنسجة تعالج أن بمقدورها والتي الحمراء تحت األشعة ليزر وهو الليزر، أشعة استخدام فكرة جاءت هنا ومنبالليزر.

فيمتوثانية مقدارها المدة هذه جدا جدا قصيرة لمدة وذلك الحمراء تحت الليزر أشعة من مليمتر المئة امتدادها يتعدى ال جدا صغيرة ليزر نبضة بإطالق الليزر جهاز أن (Femtosecond( يقوم دون البعض بعضها عن األنسجة بفصل تقوم جدا صغيرة فقاعة إلى تتحول يجعلها القصيرة المدة لهذه القرنية داخل تسليطها أن إال بها الموجودة الطاقة قوة رغم الليزر نبضة أن وجد فقد الثانية، من جزء مليار مليون من واحد أي . . " " . القطع بعد الناتجة والسماكة الجراح حددها التي السماكة بين فرق يوجد ال أن يجب نظريا األقل وعلى واحدة، سماكة وذو متساوي قطع الناتج القطع أن كما وحجمها وموقعها الثنية مكان وتحديد القطع عمق تحديد يمكن كما ذلك غير أو بيضاوي أو مربع أو دائري القطع شكل تحديد فباإلمكان الجراح، يريده قطع أي يصنع أن ثانية فيمتو ليزر جهاز أدق بعبارة أو الليزر جهاز يستطيع المجاورة لألنسجة أضرار أي تحدث

. الضوئي، بالمشرط القطع استخدام عند الجراح، اليواجه أن فيفترض وعليه المحددة السماكة عن كبير بشكل وأحيانا مختلفة القطع عن الناتجة السماكة تكون والذي اآللي المشرط بعكس وذلك الضوئي، ثقوب بالمشرط أو ثنية بدون الكامل القطع أو الناقص القطع مثل مضاعفات

INTRALASIK • 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 "bladeless" procedure, but it is certainly not "flapless" or without an incision!

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

After Surgery :

• Your eye may burn, itch, or feel like there is something in it.• You may experience some discomfort, or in some cases, mild pain and

your doctor may suggest you take a mild pain reliever. • Both your eyes may tear or water.• Your vision will probably be hazy or blurry.

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.

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 .

Factors affecting surgery

Advantages of LASIK

a pain free recovery. quick restoration of eyesight and better results for severe short sight. The inner eye is not pierced during the procedure and stitches are not required. Clarity of vision within hours of surgery Extremely predictable No more daily cleaning rituals or recurring costs as with visual aids Increases self-confidence Broad range of treatable prescriptions Both eyes treated on the same day

Epi-LasikEpi-Lasik• Separation of the epithelium from the basement membrane without cutting

the Bowman´s layer

patients with very thin corneas or for individuals who participate in high-contact sports or

professions

2006 年 10 月 28 日 中國廈門屈光手術研討會

Epi-LASIKEpi-LASIK

Epi-LASEK Laser Eye Surgery Epi-LASEK involves lasering the surface of the

cornea under the epithelium.  It is a combination of surface PRK and Epiflap. 

The Treatment

After Treatment

Bandage Lenses

Possible Side Effects

بين تتراوح بسماكة الى 130الطبقةدائرية 180 شبه الطبقة وهذه مايكرونا،

تقلب المفصل يشبه ما لها يبقى حيثلتصحيح الليزر ويعمل حوله

Faster healing

PRK - Epithelium after alcohol removal

•Devitalized cells pushed to center of the cornea.

•Pseudodendrites typically visible for one week or more and retard healing.

•Average healing time: 5 days

• Some patients take 7 days or longer.

Epi-LASIK – Epithelium after use of Epi-K:

•Epithelium adjacent to removed sheet is fully adherent and not traumatized by alcohol or brush debridement.

•Cornea thus re-epithelializes quickly.

•Average healing time: 2.5 to 3.5 days.

Epi-LASIK: a marriage of two technologiesCompared to other surface method aviable epithelial flap may:

Decrease post-op painRestore good acuity fasterDecrease the formation of post/op healing haze

Compared to LASIK, a viable epithelial flap may improve custom wavefront surgery results:

Decrease the irregularity caused by the LASIK flap hingeDecrease the adverse biomechanical effects of cutting collagen in LASIK

Decrease the effects of the LASIK flap being larger than the resultant bed and microstriae

Case 1 pre- and postoperativelyCase 1 pre- and postoperatively

Mike P. Holzer, MD

•patient 1, 66 years

•OD Fuchs endothelial dystrophy

•preop -1.0 / -0.25 / 140° = 20/150

•OD PKP )20.09.05(

•diameter 7.8 / 8.0mm

•4 weeks postop:-1.0 / -0.5 / 20° = 20/80

Femtosecond lasers assisted penetrating keratoplastyFemtosecond 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(.

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.

Glaucoma• 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).

• There are four major types of glaucoma

Open angle )chronic) glaucoma Angle closure )acute) glaucoma Congenital glaucoma Secondary glaucoma

The same view with advanced vision loss from glaucoma

A normal range of vision.

TREATMENT

Laser trabeculoplasty

Laser Iridotomy

Cataract surgery

Cataract surgery

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.

Light passes through the clear lens implant

•Capsule thickening

Laser makes a small hole in the capsule. Light can then pass directly onto the retina, without being scattered.

LASER TREATMENT

• After laser

Complications :

• Less often, the laser can disturb the retina.• Very rarely a little fluid can build up in the retina.• flashes of light during the daytime • floaters in your vision )it is normal to have these in the weeks after the laser)

Floaters after laser capsulotomy

Laser Treatment Highly Effective in Treating Diabetic Retinopathy

Laser photocoagulation for diabetic retinopathy

• 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: Focal photocoagulation

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.

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.

Diabetic retinopathyNeovascularization

Hemorrhage

AGE RELATED MACULAR DEGENERATION

Risks

Laser photocoagulation burns and destroys part of the retina and often results in some permanent vision loss. Treatment may cause mild loss of central vision, reduced night vision And decreased ability to focus Pain in or around the eye Retinal bleeding Watery eyes Dilated pupils Mild headache Double or blurry vision

What are the advantages of laser therapy?

Less pain, bleeding, swelling, and scarring.

With laser therapy, operations are usually shorter.

In fact, laser therapy can often be done on an outpatient basis.

It takes less time for patients to heal after laser surgery, and they are less likely to get infections.

What are the disadvantages of laser therapy?

Laser therapy is expensive and requires bulk equipment.

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.

Visual acuity

• عن ا rعوض البصرية القدرات تراجعتحسنها.

. العين- جفاف

-r ليال السيارة قيادة على القدرة فقدان .. األشياء مشاهدة وربما العين واحمرارغير الصورة تظهر أو مرات عدة مكررةكاملة.

اإلحباط- ..

• laser usagein glaucoma surgery t

•

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.

• 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.

•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 "trab" 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 "bleb" 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

•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 "refractory" means "resistant to treatment". 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•

•

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

• Thin corneas < 480 μ

• Steep corneas > 47D

• RST< 250 μ )reaidual stromal thickness)

• Asymmetric bow ties

• Unusual looking corneas

• Epithelial basement membrane dystrophy

Poor candidates for LASIKPoor candidates for LASIK

Stromal opacity post LASIK

1. Non-infective• Diffuse lamellar keratitis )SOS(• MK• Epithelial ingrowth

2. Infective• Bacterial – G+ve cocci, atypical mycobacteria• Fungal - HSV• Viral, reactivation of post-viral SEIs• Protozoal – microsporidial, rare

• : مجموعات أربعة إلي اإلنكسارية العيوب تصحيح عمليات

القرنية . :(Ablation( إستئصال العمليات من النوع هذا اإلكسايمر ليزر من باإلستفادة القرنية نسيج من قسم نزع العملية هذه في يتمليزيك علي (LASIK( يشتمل ، الزك (PRK( ليزر . (LASEK( و البصر انحراف و البصر بعد البصر، قصر لتصحيح

: Implant الزراعة حلقات زراعة مثل القرنية . في من النوع البصربهذا بعد معالجة نستطيع ال البصر قصر معالجة نستطيع الشكل بهذا و قطرها و محيطها مع تتناسب القرنية داخللهم. اإلكسايمر ليزر إستعمال أن حيث متوسط أو خفيف بشكل القرنية في بإنحناء المبتليين للمرضي أيضا و الخفيف البصر قصر لتصحيح يكون ما أكثر العمليات من النوع هذا إستعمال العملياتممنوع.

: مثل حرارية بمسبر CK أو Conductive Keratoplasty عمليات القرنية حرارة درجة رفع يتم . CK حيث أيضا يتم كما المتوسط و الخفيف البصر بعد تصحيح يتم حتي القرنية لنسيج المكونة األلياف لتقصير. إستعمال أي لها يوجد فال البصر قصر حالة في أما البصر كهولة لتصحيح العمليات من النوع هذا من اإلستفادة

الشق . RK مثل :(Incisional( عمليات و المتطورة البصر بعد حالة في خاصة و الجانبية مضاعفاته بسبب العمليات من النوع هذا البصر إنحراف و البصر قصر لتصحيح القرنية في شعاعية شقوق بإجراءاأليام هذه قليل بشكل منها يستفاد اإلكسايمر ليزر من اإلستفادة في الالزمة الدقة .بسبب

A) Retinal examination revealed a stage 4 macular hole (arrow) in the left eyeassociated with a posterior pole retinal detachment, and a BCVA of counting fingers.

B) OCT image showing features of both foveal retinal detachment and retinoschisis.

C) OCT after vitrectomy reveals a closed macularhole with a BCVA of 20/150.

Penicillium sp.

• Septate, filamentous fungi except Penicillium marneffei )dimophic(

• Widespread in soil, decaying vegetation & the air

• Corneal infections usually post traumatic

• Mycotoxin, ochratoxin A nephrotoxic and carcinogenic

Peripheral iridoplasty and Pupilloplasty

Complications :• A brief period of inflammation of the colored part of the eye )iris).

• Cloudiness of the clear covering )cornea) over the iris. This usually does not last long.

• Blockage of the drainage angle when the cornea and the iris stick together.

• Pain.

• Decreased vision.

Laser ciliary body

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