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الكلية كلية الطب
القسم الجراحة
المرحلة 5
أستاذ المادة اسعد جعفر عبد السادة الطائي
4/19/2011 7:03:41 PM
Ocular injuries:
Ocular trauma is a major cause of visual impairment accounting for 4-11% of cases of blindness. Children & young adults are at particular risk, male to female ratio is 4:1.
Foreign bodies (F.B.s):
It is the commonest of ocular injuries, possible sites are:
1- Conjunctiva: a F.B. may lodge in the upper palpebral conjunctival subtarsal sulcus, so always evert the upper lid to examine the sulcus. You may have a hint from linear scratch marks on the upper cornea or even a corneal erosion. Another possible site is deep in the upper or lower fornices.
2- Cornea: It is the most common site for a F.B. in the eye. The F.B. passes before the reflex lid closure (which is the protective mechanism).
Symptoms vary according to the nature of the F.B. They are: pain (F.B. sensation), excessive lacrimation, photophobia, blepharospasm & sometimes even reduced visual acuity (when the F.B. is large & central). O/E: red eye & we can see the F.B. by direct inspection with magnification or by the slit lamp. If the F.B. contains iron, it will be surrounded by a rust ring. Treatment: removal using a surface anaesthetic by a sterile needle or a wet cotton wool swab. In children this should be done under G.A. After removal, use a topical antibiotic for 2 days.
3-Intraocular F.B. (I.O.F.B.): due to blast (war) injuries, hammering, chiseling, etc. It is usually a serious injury causing severe ocular damage ending in visual loss. A small particle penetrates the cornea or the sclera at high velocity sometimes even through the lid.
*Principles of management:
(1) Initial assessment:
i- Determination of the nature & extent of any life threatening problems.
ii- History of the injury, including the circumstances, timing & likely object.
iii- Thorough examination of both eyes & orbits. During the examination don t make the patient squeeze his lids, & it is not allowed to apply pressure on the eye whatsoever. If there is collapse of the eye, or there is fresh bleeding when you try to open the lids stop your examination (these rules apply to examination of all cases of ocular trauma).
(2) Special investigations:
a. Plain radiographs may be taken when a F.B. is suspected.
b. C.T is superior to plain radiography in the detection & localization of I.O.F.Bs. It is also of value in determining the integrity of intracranial, facial & intraocular structures.
N.B.: M.R. should never be performed if a metallic F.B.is suspected.
c. US may be useful in the detection of I.O.F.B.s, globe rupture, suprachoroidal haemorrhage & retinal detachment.
*Tissue reaction to the F.B.:
Iron: causes siderosis bulbi, which is blinding with time, but this is not inevitable because the F.B. may get encapsulated or surgically removed in proper time.
Copper: If the F.B. was of pure copper, or an alloy with a high percentage of it a severe purulent reaction happens causing total destruction & shrinkage of the globe. If less, it causes chalcosis where we find copper deposits in the deep peripheral cornea (Kayser-Fleischer ring) & in the lens (sun flower cataract). As you might recall these signs are found in Wilson s disease, as well as copper deposits in the retina. Chalcosis is not as destructive as siderosis & prognosis for vision is better.
Organic matter: as a F.B. causes no harm apart from granulomatous inflammation, & a risk of secondary infection.
Inert F.B.: Glass, plastic, gold, silver & lead cause relatively no reaction. So we should assess the danger of leaving the F.B. or removing it. Removal of an I.O.F.B. should be done by a specially trained ophthalmologist surgically & under G.A.
Lacerations of the eye:
A laceration is a full thickness wound caused by a sharp object.
(1) Lids: the presence of a lid laceration, however insignificant, mandates careful exploration of the wound & examination of the globe. Any lid defect should be repaired by direct closure whenever possible, even under tension, since this affords the best functional & cosmetic results. If the wound involves the lid margin, it needs suturing by a specialist because if improperly sutured it may end in a notch which causes epiphora or trichiasis. If the medial canthal area is involved, causing canalicular laceration, it should be repaired under G.A using silastic tubes.
(2) Conjunctiva: is often accompanied by scleral laceration.
(3) Cornea: corneal lacerations are fairly common, & they are associated with iris prolapse. We should exclude I.O.F.B. Urgent microsurgical technique under G.A. is essential.
(4) Sclera: lacerations of the sclera are often more dangerous, & again need urgent surgery under G.A. Corneal & scleral lacerations are also termed "perforating eye injuries".
Sympathetic ophthalmitis:
It is a rare bilateral diffuse granulommatous inflammation of the entire uveal tract, a complication of perforating injuries (surgical or non-surgical) involving uveal tissue incarceration. Most of the patients develop it within 3 months of the injury (range 5 days-20 years). It starts by a severe & resistant uveitis of the injured eye, followed by a similar uveitis in the healthy (sympathizing) eye. Treatment: the exciting eye is treated by microsurgical suturing. A badly injured (hopeless) eye should be enucleated in a critical period (2 weeks), after that enucleation will not prevent sympathetic endophthalmitis. The main treatment is systemic, periocular & topical steroids, & immunosuppressive drugs (cyclosporine), trying to control uveitis but often complications develop.
Blunt injuries (contusions) of the eye:
The corneoscleral wall of the globe is intact but intraocular damage may be present, at the site of impact or at a distant site. Examples: a hit by a fist, edge of a table, etc. This is a very common type of injury, & it can lead to serious complications. Below are some examples of what contusion injuries can cause to each particular structure of the eye:
Lids: ecchymosis (panda eyes), traumatic ptosis.
Conjuctiva: subconjunctival haemorrhage (which can hide a scleral laceration).
Sclera: ruptures concentric to the limbus & at a distance behind it. A very severe contusion can lead to rupture of the posterior part of the sclera sometimes clinically undetectable, but we may see a very soft eye (hypotony), or a collapsed, flat eyeball, C.T or ultrasound can show the rupture.
Cornea: abrasion, folds in Descemet membrane, avulsion.
A.C:traumatic iritis, hyphaema.
Iris: iridodialysis (disinsertion of a part of the iris root), traumatic mydriasis (due to rupture of the sphinctor pupillae muscle).
Lens:cataract (characteristically, stellate in shape), subluxation, dislocation (anterior, in the A.C; posterior, in the vitreous).
Glaucoma: due to angle recession as a result of a tear in the base of the cilliary body which is facing anteriorly to the A.C.
Vitreous: haemorrhage.
Retina: haemorrhage, tear, dialysis (a partial disinsertion of the periphery of the retina at the ora serrata), retinal oedema which hasd a special name: commotio retinae, it looks grey white in colour, if it involves the macula the foveola remains red (because the retina is very thin there) giving the appearance of cherry-red spot reducing the visual acuity of the patient. It may end up in a macular hole later on. If the commotion retinae is peripheral it is symptomless.
Optic nerve: swollen disc, avulsion of the optic nerve.
Hyphaema:
Blood in the A.C. where cells may sediment to the bottom due to gravity acquiring a horizontal level (level hyphaema), or the whole A.C is occupied by blood (total hyphaema) obscuring the view of details of the iris & pupil (more serious than level hyphaema). It is a serious condition that necessitate admission to the hospital for specialized care.
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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