انت هنا الان : شبكة جامعة بابل > موقع الكلية > نظام التعليم الالكتروني > مشاهدة المحاضرة
الكلية كلية الطب
القسم الجراحة
المرحلة 5
أستاذ المادة اسعد جعفر عبد السادة الطائي
4/19/2011 8:40:46 PM
Uvea
Congenital anomalies
Coloboma
A localized defect involving any one or a combination of the components of the uveal tract. Classically it occurs inferonasally. It may be sporadic or autosomal dominant. An iris coloboma may be associated with microphthalmos.
Aniridia
Total or partial absence of the iris, either heriditary ( 2/3rds ) or sporadic ( 1/3rd ). 50% of cases develop glaucoma, so we should measure intraocular pressure periodically. Patients are prone to cataract & macular or optic nerve hypoplasia. 20% of sporadic cases develop Wilm s tumour of the kidney. Therefore we should do ultra-sound for every case with aniridia.
Treatment:(1) correct refractive errors with dark glasses.(2) treat complications like cataract or glaucoma.
Uveitis
Definition: endogenous or exogenous inflammation of the uvea.
Classification:
(1) Anatomical:
anterior ( iritis, cyclitis, iridocyclitis ),
intermediate ( parsplanitis ),
posterior ( choroiditis, retinitis, chorioretinitis, retinochoroiditis ),
diffuse ( panuveitis ) which is defined as: inflammation of all the 3 components of the uveal tract,
endophthalmitis, which is a violent inflammation of all ocular cavities & tissues & lastly
panophthalmitis which equals endophthalmitis plus extraocular involvement by the inflammation.
(2) Aetiological:
(1) Idiopathic 30%.
(2) Secondary to systemic disease:
a- Seronegative spondyloarthritides: ankylosing spondylitis, Reiter s disease, psoriatic arthritis, Behcet syndrome & juvenile chronic arhtritis ( JCA ).
b- Gastrointestinal disorders : ulcerative colitis, Crohn s disease.
c- Respiratory disorders: tuberculosis, sarcoidosis.
d- Venereal diseases : syphillis, gonorrhoea, AIDS.
(3) Infectious causes :
a- Viral : herpes simplex, herpes zoster, chicken pox, cytomegalovirus ( CMV ).
b- Bacterial : T.B, syphillis, G.C, leprosy, Malta fever.
c- Parasitic : toxoplasmosis, toxocariasis, onchocerciasis.
d- Fungal : Candidiasis, histoplasmosis.
(4) Lens induced : phakoantigenic ( phakoanaphylactic ) endophthalmitis.
(5) Traumatic :surgical or non surgical trauma.
(6) Specific uveitis entities : Fuch s heterochromic cyclitis, Vogt- Koyonagi Harada syndrome, sympathetic ophthalmitis.
(7) Tumours : masqurade syndrome ( necrotic ocular tumours presenting as uveitis ).
(3) Pathological :
(a) Suppurative : pus forming.
(b) Non suppurative :
1- non granulomatous : plastic, no nodule formation.
2- granulomatous : characterized by nodular aggregations consisting of monocytes, macrophages & their epithelioid cell & giant cell derivatives plus lymphocytes, plasma cells & eopsinophils, clinically manifested as iris nodules or mutton fat keratic precipitates (K.P.s). Examples of granulomatous uveitis : sarcoidosis, phakoantigenic endophthalmitis & sympathetic ophthalmitis.
(4) Clinical :
Acute & subacute which are usually recurrent, & chronic, which is usually low grade.
Anterior uveitis :
Clinical features:
Symptoms :
Pain, reddness, photophobia, reduced visual acuity & excessive lacrimation ( watery & not sticky ).
Signs :
1- Congestion :deep, limbal ( ciliary flush ), circumorneal.
2- Intraocular pressure : usually reduced but may be normal or elevated.
3- Corneal signs : K.P. s, band keratopathy.
4- Anterior chamber : flare, cells, hypopyon ( pus level in the anterior chamber )
5- Iris signs : synechia, which refers to adhesions to the lens ( posterior ) or to the cornea ( anterior ) which are if peripheral & wide-spread can occlude the chamber angle causing glaucoma ( we call them peripheral anterior synechia P.A.S ). Other iris signs are : nodules, atrophy, & rubeosis iridis ( visible blood vesseles on the surface of the iris ).
6- Pupil : is usually small & irregular due to posterior synechia.
7- Lens : secondary cataract.
Posterior uveitis :
Clinical features:
Symptoms :
a- floaters. a- reduced visual acuity.
Signs :
1- chorioretinitis : a- focal: toxoplasmosis. b- multifocal: T.B, syphillis & AIDS.
2- vasculitis : arteritis or phlebitis in the form of perivascular sheathing.
3- vitreous haemorrhage.
4- optic nerve head inflammation, & these last 2 signs can cause rapid drop in vision.
5- serous retinal detachment &/or fibrosis which also threaten vision.
Investigations in uveitis :
X- ray:
- lumbosacral spine in ankylosing spondylitis.
- calcaneal spur in Reiter s disease.
- chest in T.B & sarcoidosis.
- skull in toxoplasmosis & CMV in children.
serum :
ANA, VDRL, ELISA, HLA studies.
skin test:
tuberculin(T.B),Kviem(sarcoidosis),Histoplasmin(histoplasmosis)& pathergy test(Behcet).
Treatment of uveitis :
Corticosteroids :
They are the mainstay of treatment used in the majority of cases.They are used topically &/or periocularly &/or systemically Side effects of prolonged topical or long acting periocular steroids are: steroid induced glaucoma,exacerbation of ulcerative keratitis,keratomalacia& risk of corneal perforation in predisposed(thin) corneas in addition to reduction of local corneal resistance to invasion by microrganisms. Systemic steroids cause cataract.
Cycloplegics :
In a decreasing order of duration of action: atropine,homatropine,cyclopentolate& tropicamide.Atropine breaks synechia,relaxes ciliary spasm, dilates the pupil & reduces blood vessle permeability.
Immunosuppressives :
Are useful in very severe or resistant cases e.g:cyclosporin, methotrexate.
Non steroidal anti inflammatory drugs :
Topically are vry helpful as steroid sparing agents.
Tumours of the choroid:
Malignant melanoma :
It is the most common primary malignant tumour of the eye.It affects most commonly patients of the 5th-6th decades, but may be seen in the young.It is very rare in blacks.It usually presents as unilateral pigmented lesion, elevated solid mass,not mobile & not cystic. If clinically diagnosed we must think of distant metastasis, most commonly to the liver & then the lung. Local extrascleral extension can present as a blackish mass under the conjunctiva.
Treatment:
Small lesion: just follow up beause progress of the lesion is often very slow. If the progress of the lesion is rapid we laser it if it is posterior to the equator, or cryo it if it is anterior to the equator.
Medium sized: a- local excision ( in specialized centers ). b- radiotherapy: i. external beam irradiation. ii. brachytherapy ( radioactive plaque ).
Large sized: enucleation.
Choroidal haemangioma :
Benign reddish brown mass in the posterior pole that usually leads to serous retinal detachment. It is associated with facial port wine naevus (naevus flammeus) in the distribution of the first or second division of the trigeminal nerve, glaucoma, epilepsy & mental retardation, it then represents the rare (Sturge Weber syndrome).
Metastatic tumour:
This is the most common intraocular tumour. Choroid is the most common ocular site where distant metastases can lodge. Multiple (or single) creamy white, oval lesions are usually found close to the optic nerve head & macula. We must search for the primary.
Treatment: external beam irradiation or chemothrerapy.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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