Australian Doctor 14th February 2025 | Page 32

32 HOW TO TREAT : ACUTE CORNEAL CONDITIONS

32 HOW TO TREAT : ACUTE CORNEAL CONDITIONS

14 FEBRUARY 2025 ausdoc . com . au
TRAUMATIC HYPHAEMA
HYPHAEMA is defined by the accumulation of red blood cells in the anterior chamber . When a visible blood layer is absent , this condition is referred to as microhyphaema . The most common cause is blunt trauma , such as punches , falls , blunt objects , work or sporting equipment , or motor vehicle accidents that damage intraocular vascular structures , for example the iris , ciliary body or trabecular meshwork , through shearing forces . Lacerating trauma , ophthalmic surgical and spontaneous causes can also occur .
Figure 6 . Hyphaema in the anterior chamber demonstrating a blood level of 2mm measured from 6 o ’ clock at the limbus .
History
The severity of the blunt force can
be an indicator of the extent of the
intraocular damage . The hyphaema
causes blurred vision because of
obstruction of the visual axis . Blood
in the anterior chamber is painless ;
however , it will become painful if it
results in high intraocular pressure .
Loss of vision , particularly if more
than expected from the hyphaema
alone , can indicate collateral ocular damage including lens dislocation , retinal detachment , traumatic optic
Figure 7 . Corneal burns .
neuropathy and / or globe rupture . Diplopia is an indicator of blowout fracture resulting in orbital content herniation . It is important to note the eye history , such as the previous level of vision , surgery , medications such as anticoagulants , and any bleeding diatheses or abnormalities such as sickle cell trait or disease . The latter is more common in patients of African descent .
Examination
Sit the patient upright and still for 30 minutes and then assess the level of
A
B
A and B . A burn from shampoo containing salicylic acid . This has resulted in disruption of the corneal epithelium , conjunctival injection and eyelid swelling , with diffuse punctate staining on fluorescein staining and cobalt blue light .
vision . This allows the blood to settle in the anterior chamber and the pupillary axis to clear . The level of blood can then be measured from the 6 o ’ clock position at the limbus ( see figure 6 .) The pupil may be dilated from rupture of the iris sphincter muscle , a condition known as traumatic mydriasis , or irregular in shape from damage to the iris root , which is known as iridodialysis . Also assess for limitation of movement of the extraocular muscles and exclude significant facial and intracranial injury .
Management
Ensure the patient remains calm and quiet and cover the eye with a hard shield to avoid any pressure on
C
D
C . Alkali / thermal burn to the left eye caused by hot radiator fluid . The image shows opacification of the cornea , swelling of the conjunctiva ( chemosis ) and burns to the eyelid skin .
D . Hydrochloric acid burn with opacification of the corneal epithelium , and a large epithelial defect with underlying clear corneal stroma .
the eye . If the hyphaema involves
less than one-third of the anterior chamber , refer the patient for urgent ophthalmic assessment and man-
days . The pupil is dilated to immobilise the iris and stabilise clots , and inflammation treated with topical
being more severe . The severity of burns ranges from mild , such as irritation from shampoo ( see figure 7A )
UV exposure caused by inadequate eye protection , for example , during arc welding or from the reflection off
Also exclude other life-threatening pathology such as respiratory burns in thermal injury .
agement . If the hyphaema is greater
steroids . Elevated intraocular pres-
to sight-threatening injuries ( see
snow or water . Corneal burns pres-
Following copious irrigation ,
than one-third or if the patient is
sure requires glaucoma medications .
figure 7C ) and may involve the sur-
ent with pain , blurred vision , the
assess the level of vision . Signs of
less co-operative , arrange for hospital admission . Further ophthalmic assessment includes the level of vision , the presence of a relative
Prognosis
Hyphaema usually resolves with conservative treatment ; however ,
rounding eyelid tissues .
History
It is important to establish the time
sensation of an FB and photophobia . Flash burns often cause bilateral eye pain , with these symptoms occurring 4-8 hours post-exposure .
more severe burns include eyelid swelling , corneal opacity , total epithelial defect , limbal ischaemia and conjunctival blanching . These signs
afferent pupillary defect , tonometry , and damage to other intraocular and orbital structures . Investigations
recurrent bleeding and high intraocular pressure may result in permanent vision loss . There is a lifelong
of the incident , the nature of the burn , the involvement of one or both eyes and any immediate action that
Management
It is critical to immediately irrigate
require urgent referral for ophthalmic care in hospital . Less severe burns can be less urgently referred
such as ultrasound scans , CT or MRI
increased risk of traumatic glaucoma
was taken . If possible , ascertain the
the eye ’ s fornices and eyelids before
within 24 hours . Mild chemical and
may be undertaken to exclude globe
in all patients , so an annual eye
chemical name or the ingredients
examination as each second can
thermal burns , like flash burns ,
rupture and orbital fracture .
examination is required .
of the substance . Most acids cause
affect prognosis . With the patient
are managed with supportive care ,
Management includes limiting physical activity , sleeping with the head elevated at at least 30 °, and
CORNEAL BURNS
CORNEAL burns are categorised into
more superficial burns whereas alkalis and hydrofluoric acid can penetrate the cornea and cause
supine , irrigate with saline or water for 20-30 minutes , with the simultaneous application of topical anaes-
with topical antibiotics , topical steroids , lubricants , pupil dilation and oral analgesia . More severe
an eye shield , to encourage resorp-
three types : chemical , thermal and
intraocular damage . Thermal burns
thetics , to ensure full ocular surface
burns also require oral doxycycline
tion of the hyphaema and preven-
flash burns . Chemical burns are fur-
commonly result from flames , explo-
irrigation . Litmus paper may be used
and ascorbate to reduce the risk of
tion of recurrent bleeding . This is
ther classified as either acid or alkali
sions or splashing hot materials .
in chemical burns to ensure the
corneal melting and amniotic mem-
most important for the first three
burns , with alkali burns typically
Flash burns result from excessive
corneal pH is between 7.0 and 7.2 .
brane application .