ocular trauma Flashcards
what is lefort fractures
LEFORT I
Horizontal fracture of the maxilla. The fracture passes through the alveolar ridge of the upper teeth, lateral nose and the walls of maxillary sinus.
LEFORT II
Fracture through the medial wall of maxilla, inferior orbital rim, nasal and lacrimal bones and through or near the infraorbital foramen.
LEFORT III
Fracture passes through the nasofrontal and frontomaxillary sutures, ethmoid air cells, and zygomatic arch.
what is orbital floor fracture
An indirect blowout fracture to the orbital floor is commonly caused by a rapid increase in intraorbital pressure leading to compression of the globe posteriorly and a fracture of the orbital floor, typically the maxillary bone.
features of an orbital floor flrture
● Eyelids: Ecchymosis (racoon eyes) and oedema.
● Vertical diplopia: Entrapment of the IR muscle causes inability to upgaze.
Children can develop oculocardiac syndrome, which is a drop in heart rate with movement of the extraocular muscles. This may lead to cardiac arrest in extreme circumstances.
● Hypoesthesia over the distribution of the infraorbital nerve.
● Enophthalmos.
Ix and Mx of orbital floor fracture
● Visual function tests and acuity should be examined.
● Hess charts: To examine and monitor eye movements.
● CT scans: Show a ‘teardrop’ sign in cases of soft tissue prolapse in the
maxillary antrum
● Observation to allow swelling to subside.
● Surgical repair for persistent diplopia.
what is intraocular foreign ABs
Intraocular foreign bodies (IOFB) are common and may be present following open globe injuries. The most toxic IOFB are copper and contaminated organic material. Important to note that penetrating trauma cannot be excluded even if there are no entry wounds on examination.
Examination of intraocular foreign ABs
Ix
● Both eyes must be examined even if the other eye is asymptomatic.
● Examination of the eyelids for any lacerations.
● Fluorescein drops are helpful to determine the site of injury, and a slit lamp
examination can be used.
● Funduscopy: Assess the posterior segment.
Ix
● CT: To detect the IOFB and its location. It is considered superior to an x-ray, as x-rays are less able to detect radiolucent materials (e.g. glass). However, x-rays can be used to rule out IOFB.
● MRI: Contraindicated in metallic IOFB.
Mx of intraocular foreign ABs
complications
● Prophylactic antibiotics such as systemic ciprofloxacin. In cases of contaminated IOFB, intravitreal antibiotics (vancomycin + ceftazidime) are considered.
● Surgical removal with the use of magnets or forceps.
● Sympathetic ophthalmia in the fellow eye.
● Endophthalmitis.
● Angle recession glaucoma.
● Red cell glaucoma.
what is chemical injury
Chemical injuries can either be alkali or acidic. Alkali materials are lipophilic and are more destructive due to their penetrative potential. Acidic causes coagulation of the surface protein impeding their own progression. One exception, however, is hydrofluoric acid, which can rapidly penetrate the eye.
features of chemical injuries
● Severe pain, lacrimation and dVA.
● Lid oedema.
● Conjunctiva: Epithelial loss, injection chemosis, ischaemia (eye may look
‘white and quiet’ due to severe ischaemia), necrosis.
● Cornea: Epithelial damage, oedema, necrosis.
● Anterior chamber: Flare, mydriasis, increased IOP.
● Limbal ischaemia is useful to assess prognosis.
Mx of chemical injury
● Irrigation: Should be done immediately before any examination is performed. Test the pH, then instill topical anaesthetic and irrigate with water.
16.4 Chemical injury 185
186 Ocular trauma
● Topical/oral antibiotics + topical steroids + cycloplegia + preservative-free artificial tears must be given.
● For more severe injuries, early surgery is necessary.
what is shaken baby syndrome
Also called abusive head trauma; commonly presents with multilayered retinal haemorrhages in children under the age of 2 years. Associated with irritability, vomiting and cerebral bleeds.
what is purtscher retinopathy
Usually bilateral disease originally described in association with severe trauma. Can be seen in association with acute pancreatitis (Purtscher-like retinopathy). Presents with sudden painless dVA, cotton wool spots, Purtscher flecken (areas of retinal whitening) and haemorrhages.
