Ординатура / Офтальмология / Учебные материалы / Clinical Diagnosis and Management of ocular trauma

56

Clinical Diagnosis and Management of Ocular Trauma

Treatment

Accidental Hypothermia

Treatment of the lid burn:

It occurs on exposures at high altitudes in snow-storm.

• The best emergency measure is to cover the face

Aviators in open aircraft, in a damaged cockpit or while

with sterile dressing or handkerchief.

bailing out from an aircraft in difficulties can also suffer

• In early stage the affected area thoroughly cleansed

from hypothermia.

with saline and surrounding area with soap and

Clinical lesions: Clinical cases are rare because of

water

the protection afforded by the richly vascular lids and

• All the aseptic measures to be taken while treating

the care usually taken of them even in conditions of

this patients

severe stress and even the temperature of cornea is

• Blisters to be fully opened, loose epidermis cut away,

3 to 5 degrees less than the other tissues of the body.

remnants of signed lashes removed

There can be varying degrees of conjunctival

• Antibiotic cream applied over the denuded area.

hyperemia, corneal erosion or opacity which may

•

Sofratulle dressing applied

disappear without any ill effects. Severe bilateral

• For full thickness burns of the lids, the only effective

ulceration of the cornea leading to permanent opacity

treatment is graft

of the cornea.

• Full thickness skin graft should be carried out as

an emergency measure.

Cryosurgery

Treatment of the burns of the eye:

It is used as a therapeutic modality in different cases

with varying indications. The effects of the freezing on

• Local analgesics avoided owing to their deleritious

the various ocular tissues and intraocular fluids depends

effect on epithelialization.

on the temperature used, the area involved, the length

•

Topical cycloplegics – Atropine eye drops

of

application and the type of cell principally

•

Systemic NSAIDs/Sedatives to achieve comfort

concerned.

•

Antibiotics to prevent secondary infection

•

Ocular lubrication for corneal burns

Clinical lesions:

• Glass rod to be passed in the fornices to prevent

•

Conjunctiva: Congestion, edema.

the risk of symblepharon or use of symblepharon

•

Muscles and tendons: Edema and hemorrhage

ring

• Sclera: Swelling and separation of scleral fibers seen

•

Conjunctival transposition flap

microscopically, no clinically evident change

• Corneal leucomatous opacity at later stage can be

• Ciliary body: Freezing of ciliary body resulting in

replaced by corneal graft-PK or LK

reduce aqueous humor formation

• Amniotic membrane graft or Limbal cell transplant

• Lens: Freezing of the lens utilised in cryoextraction

also has a role to play

of the lens

• Topical corticosteroids also can be used judiciously

• Retina and choroid: Adhesive chorioretinal reaction

in case to case basis.

• Vitreous: Vitreous ice balls.

HYPOTHERMAL INJURIES

Ultrasonic Injuries

Surgical Hypothermia

Sound waves (sonic or acoustic energy) which are

It occurs in cardiovascular surgery and in neurosurgery

audible to the human ear produce no recognizable

or by immersing the patient in ice packs and cold baths,

ocular injury. Ultrasonic vibrations above the limits of

hearing may produce characteristic biological reactions.

supplemented by injection of lytic cock-tail.

Besides its diagnostic and therapeutic applications,

Clinical lesions: At temperatures far under the

ultrasonic energy can produce the following injuries

therapeutic range opacities developed in the cornea

to the eye.

and lens associated with widespread cellular and

CLINICAL LESIONS

hemorrhagic changes in the ocular tissues, particularly

in the ciliary body and retina. Retinal arteries and veins

• Eyelids—epilation, ulceration of the skin edema.

become indistinct and show a fine stippling of the blood

• Cornea—slight and transient turbidity and swelling

column and the retina becomes pale and optic disc

in superficial corneal layers, earlier changes are

white, however, within two seconds of restoration of

reversible but the later are irreversible and lead to

the circulation the fundus assumes its normal

necrosis. High intensities of radiation cause necrosis

appearance.

and ulceration of the epithelium, a general

Injuries of the Eye due to Physical Agents (Thermal, Ultrasonic and Electrical Injuries)

57

thickening of the stroma with the formation of dense

•

Corneal lesions—The commonest lesions are

leucomatous opacities.

interstitial opacities which can be punctate, striate

•

Lens—Two types of cataract—Cavitation and

or diffuse. This type of generalised corneal

Thermal. In cavitation cataract a zone of frothy,

cloudiness usually clears up in few days. However,

spume like turbidity of the deeper layers of the

if destructive electrical burn is formed the epithelium

cortex around the nucleus. In thermal cataract there

may become necrotic and exfoliate and sensation

is densely white permanent opacity and it develops

may be impaired or lost so that serious ulceration

after radiation of high frequency and greater

may develop and become recurrent

and

intensity.

permanent scar may form. In some cases there can

• Vitreous—liquefied irreversibly by a few seconds

be purulent infiltration of entire cornea, extensive

exposure.

necrosis, perforation or phthisis of the globe.

•

Retina and choroid—adhesive chorioretinal

adhesion with less damage to the sclera than caused

•

Lesions of the iris and ciliary body—Iris and ciliary

by diathermy or by ultrasonic energy of megahertz

body show irritative changes in any type of electrical

frequencies, retinal edema within 12-24 hours

injury. There can be mild and transient iritis,

followed by proliferative and pigmentary changes.

sometimes widespread synechiae formation with

heavy aqueous flare and occasionally hyphema.

Electrical Injuries

• Lesions of the pupil—Unilateral or bilateral extreme

miosis with sluggish or absent reactions, spasm of

Electrical injuries are due to passage of an electric

accomodation.

current through the body and the commonest cause

•

Electric cataract—Lenticular opacities form

being direct double contact between two live electric

sometime after the accident and is sometimes the

conductors or a single contact either direct or by short

only finding in cases with electrical injury. Main

circuit, between a conductor and the earth so that the

changes are localized in the capsule itself and in

circuit is completed. The similar effect result on being

the immediate cortex underneath the capsule. It

stuck by lightning. There is a point of entry and often

involves both anterior and posterior surface of lens.

of exit of the elctric current causing an electrical burn,

There is formation of vacuoles underneath the

the passage of current usually produces violent tetanic

capsule. The type of opacification varies from slight

spasms of the muscles, low voltage currents cause

indefinite haze to densely crowded punctate

auricular fibrillation and high voltage currents affects

opacities. There can be evident polychromatic

the central nervous system and lead to loss of

lusture seen on the lens.

consciousness or death from respiratory failure or

• Lesions of the retina and choroid—Retinal edema,

cardiac arrest and shock. The high resistance offered

papilledema, hemorrhages, traumatic chorioretinitis

by the non-nervous tissue accounts for the thermal

in the periphery, detachment of the retina, vitreous

effects of electric injuries, which may result in immediate

opacities. Most dramatic changes are at the posterior

coagulation of the proteins of the cells.

pole which can be combination of the electric

CLINICAL LESIONS

current and radiation resulting in macular edema,

punctate pigmentary degeneration, cystoid changes.

• Lesions of the lids—Typical electrical burn at the

•

Optic nerve—Optic neuritis.

point of entry – imprint as a sharply defined necrotic

•

Functional disabilites—Photophobia, blepharo-

mark without surrounding hyperemia. Lid burns

spasm, transient blindness to permanent bilateral

differs from heat burns in that the former are

visual loss, concentric contraction of the field, ring

painless, dry and aseptic and usually circumscribed,

scotoma, absolute central scotoma, disturbance of

mainly due to the very high temperatures and short

binocular fusion.

duration. Electrical gangrene may supervene in the

subsequent days or weeks due to circulatory

LIGHTNING INJURY

impairment.

•

Even in fatal cases the body may be unmarked,

•

Lesions of the conjunctiva—There can be

substantial damage to the eye in both electrical as

•

In some a deep necrotic burn is formed at the point

well as lightning injuries. Minor degree of

of entry,

conjunctival hyperemia and ciliary injection will

•

In others an arborescent tracery of linear burns

invariably occur in each and every case of electrical

appears (lightning prints).

burn. There can be subconjuctival effusion of blood

•

Mydriasis, partial internal ophthalmoplegia,

which is transient and which disappears in few days

blindness from optic atrophy, deafness, loss of

time.

memory, nervous damage.

58

Clinical Diagnosis and Management of Ocular Trauma

•

Injury to the retina caused by brilliance of flash

• Treatment of ocular lesions is on the general

plays an inconspicuous part in the total damage,

principles: Rest, atropine, local heat.

retinal damage in the macular area, rupture of the

Bibliography

choroid.

1.

Ophthalmology Clinics of North America by Ferenc Kuhn

TREATMENT

et al. volume 15, Non mechanical injuries.

•

First and foremost is saving of life.

2.

System of ophthalmology by Sir Stewart Duke Elder, Vol.

XIV, Injuries, Part 2, Non Mechanical Injuries.

• Local burns of the skin of the lids or in the vicinity

3.

Work and the Eye, 2nd edition of Rachel V North,

is treated as in case of thermal burns.

Woburn MA, Butterworth – Heinemann, 2001;51-74.

60

Clinical Diagnosis and Management of Ocular Trauma

Radiation can damage every tissue in the body.

within three months from vomiting, diarrhea,

The particular manifestation will depend upon the

starvation, and infection. Victims receiving 6-10 Sv all

amount of radiation, the time over which it is

at once usually escape anintestinal death, facing

absorbed,and the susceptibility of the tissue. The fastest

instead bone marrow failure and death within two

growing tissues are the most vulnerable, because

months from loss of blood coagulation factors and the

radiation as much as triples its effects during the growth

protection against infection provided by white blood

cells. Between 2-6 Sv gives a fighting chance for survival

phase. Bone marrow cells that make blood are the

if victims are supported with blood transfusions and

fastest growing cells in the body. A fetus in the womb

antibiotics. One or two Sv produces a brief, non-lethal

is equally sensitive. The germinal cells in the testes and

sickness with vomiting, loss of appetite, and generalized

ovaries are only slightly less sensitive. Both can be

discomfort.It is clearly important to have some idea

rendered useless with very small doses of radiation.

of the dose received as early as possible, so that

More resistant are the lining cells of the body—skin

attention can be directed to those victims in the 2-

and intestines. Most resistant are the brain cells, because

10 Sv range that might survive with treatment. Blood

they grow the slowest.

transfusions, protection from infection in damaged

The relative sensitivity of various tissues gives a good

organs, and possibly the use of newer stimulants to

idea of the wide range that presents itself. The numbers

blood formation can save many victims in this category.

represent the minimum damaging doses; a gray and

Local radiation exposures usually damage the skin and

a sievert represent roughly the same amount of

require careful wound care, removal of dead tissue,

radiation:

and skin grafting if the area is large. Again infection

Fetus

2 grays (Gy).

control is imperative.

Bone marrow

2 Gy.

Ovary

2-3 Gy

Injuries of the Eye due to

Testes

5-15 Gy.

Lens of the eye

5 Gy.

Ionizing Radiation

Child cartilage

10 Gy.

X-rays, beta rays, and other radiation sources in

Adult cartilage

60 Gy.

Child bone

20 Gy.

adequate doses can cause ocular injury.

Adult bone

60 Gy.

LIDS

Kidney

23 Gy.

Child muscle

20-30 Gy.

The eyelid is particularly vulnerable to X-ray damage

Adult muscle

100+ Gy.

because of the thinness of its skin. Loss of lashes and

Intestines

45-55 Gy.

scarring can lead to inversion or eversion (entropion

Brain

50 Gy.

or ectropion) of the lid margins and prevent adequate

Notice that the least of these doses is a thousand

closure.

times greater than the background exposure and nearly

50 times greater than the maximum permissible annual

CONJUNCTIVA

dosage. The length of exposure makes a big difference

Scarring of the conjunctiva can impair the production

in what happens. Over time the accumulating damage,

of mucus and the function of the lacrymal gland ducts,

if not enough to kill cells outright, distorts their growth

thereby causing dryness of the eyes.

and causes scarring and/or cancers. In addition to

leukemias, cancers of the thyroid, brain, bone, breast,

LENS

skin, stomach, and lung all arise after radiation. Damage

depends, too, on the ability of the tissue to repair itself.

X-ray radiation in a dose of 500-800 R. directed toward

Some tissues and some types of damage produce

the lens surface can cause cataract, sometimes with

much greater consequences than others.

a delay of several months to a year before the opacities

Immediately after sudden irradiation, the fate of

appear.

the patient depends mostly on the total dose absorbed.

This information comes mostly from survivors of the

Injuries due to Ultraviolet

atomic bomb blasts over Japan in 1945. Massive doses

incinerate immediately and are not distinguishable

Radiation

from the heat of the source. A sudden whole body

dose over 50 Sv produces such profound neurological,

CORNEA

heart,and circulatory damage that patients die within

the first two days. Doses in the 10-20 Sv range affect

Ultraviolet radiation of wave lengths shorter than 300

the intestines, stripping their lining and leading to death

nm (actinic rays) can damage the corneal epithelium.

Radiational Injuries to the Eye

61

This is most commonly the result of exposure to the

welding arc can also damage the the retinal macula.

sun at high altitude and in areas where shorter wave

There may be permanent decrease in visual acuity.

lengths are readily reflected from bright surfaces such

The intensity of light, lenght of exposure, and age

as snow, water, and sand.

are all important factors. The older ones are more

Exposure to radiation generated by a welding arc

sensitive, also those who have had cataract surgery

can cause welding flash burn, a form of keratitis.

because filtration of light by the lens is impaired.

LENS

Injuries due to Infrared Radiation

Wavelengths of 300-400 nm. are transmitted through

the cornea, and 80% are absorbed by the lens, where

Potters may be exposed to this type of radiation.

they can cause cataractous changes.

Wavelengths greater than 750 nm. in the infrared

Epidemiologic studies suggest that exposure to solar

spectrum can produce lens changes.

radiation in these wavelengths near the equator is

La “cataracte des verriers”(glassblower’s cataract)

correlated with a higher incidence of cataracts.

is an example of a heat injury that damages the anterior

They also indicate that workers exposed to bright

lens capsule among unprotected artists. Denser

sunlight in occupations such as farming, truck driving

cataractous changes can occur in unprotected workers

and construction work appear to have a higher

who observe glowing masses of glass or iron for many

incidence of cataract than those who work primarily

hours a day.

indoors.

Another important factor is the distance between

Experimental studies have shown that these wave-

the worker and the source of radiation. In the case

lengths cause changes in the lens protein, which lead

of arc welding, infrared radiation decreases rapidly as

to cataract formation in animals.

a function of distance, so that farther than 3 feet away

from where welding takes place, it does not pose an

Injuries due to Visible Radiation

ocular hazard anymore but, ultraviolet radiation still

does. That is why welders wear tinted glasses and

(Light)

surrounding workers only have to wear clear ones.

When we speak of type of exposure, potters look

Visible light has a spectrum of 400-750 nm. If the

at their cone packs for very short periods of time in

wavelengths of this spectrum penetrate fully to the

a repeated way, more often nearing the end of firing;

retina, they can cause thermal, mechanical, or photic

and also according to the use of other methods for

injuries.

measuring temperature, like the concomitant use of

a thermocouple and a reading device.

THERMAL INJURIES

So, these “short-term” exposures are spaced by

They are produced by light intense enough to increase

quite longer “exposure-free” periods and the sum of

the former does not correlate with the concept of many

the temperature in the retina by 10-20C.

hours a day.

Lasers used in therapy can cause this type of injury.

We have searched the literature pertaining to

The light is absorbed by the retinal pigment epithelium,

Occupational Health and Safety and have not found

where its energy is converted to heat, and the heat

a single case of presumed “ceramicist’s or potter’s

causes photocoagulation of retinal tissue.

cataract”, even if the trade of potter is quite older than

MECHANICAL INJURIES

the one of glassblower.

Therefore, I do not think that any of the above

They can be produced by exposure to laser energy

types of radiation present a threat to potters.

from a Q-switched or mode-locked laser, which

It is a good thing, mainly at high temperature, to

produces sonic shock waves that disrupt retinal tissue.

wear lightly tinted industrial grade safety glasses to

PHOTIC INJURIES

better visualize cones (ocular ergonomics) and also to

reassure those who are more worried.

They are caused by prolonged exposure to intense

These glasses also offer a better protection than

light, which produces varying degrees of cellular

typical sun-glasses in case of projection of hot dust

damage in the retinal macula without a significant

particles from a gas kiln when looking through the

increase in the temperature of the tissue.

peephole in a soft brick door.

Sun gazing is the most common cause of this type

By the way with ageing, most if not all of us, will

of injury, but prolonged unprotected exposure to a

suffer from cataracts of the senile type.

62

Clinical Diagnosis and Management of Ocular Trauma

The progress or change and the related reduction in

returning to work in less than two days and 95 percent

vision is usually quite slow.

in less than seven days, some eye injuries are

Nuclear sclerosis-an increasing density in the central

irreversible and permanent visual impairment occurs.

mass of protein-causes a myopic change than can be

This is especially true with infrared and visible spectrum

corrected by changing glasses for some years-in many

(bright light) radiation. Both can penetrate through

instances restoring vision to near normal.

to the retina and—although this is rare—can cause

permanent retinal damage, including cataracts,

Welding Arc Injuries

diminished visual acuity, and higher sensitivity to light

and glare.

And welders are not the only workers at risk. While

Eye injuries account for one-quarter of all welding

the welding arc is the principal source of UVR, other

injuries, making them by far the most common injury

workers in the area can sustain eye damage from the

for welders, according to research from the Liberty

radiation as far as 50 feet away from UVR reflecting

Mutual Research Institute for Safety. Those most at

off shiny surfaces, concrete, or unpainted metals. To

risk for welding-related eye injuries are workers in

counteract this reflection, you should install shielding

industries that produce industrial and commercial

curtains where practical or require that all workers in

machinery, computer equipment, and fabricated metal

the area wear appropriate eye protection.

products.

Yet, despite the insidious damage radiation can

The best way to control eye injuries is also the most

cause, molten and cold metal particles striking the eye

simple: proper selection and use of eye protection.

are still the most common sources of eye injuries.

Helmets alone do not offer enough protection. Welders

should wear goggles or safety glasses with sideshields.

Eye Protection Goes Beyond

Goggles provide better protection than safety glasses

from impact, dust, and radiation hazards.

the Helmet

Unfortunately, workers don’t always wear goggles

or safety glasses because of low perception of risk,

Helmets and protective clothing shield welders from

poorly maintained lenses, discomfort, having to wear

“sunburn” and “welder’s flash,” but with the majority

prescription lenses underneath, and vanity. It is

of their work performed with the helmet up, welders

important to stress to workers that welding-related eye

also need to wear goggles or safety glasses with

injuries come from a number of sources, including:

sideshields. These will protect them from particles sent

mechanical damage from being struck by flying

flying during pre-job grinding, hammering, and

particles and chipped slag; radiation and

power chipping that make it past the helmet’s

photochemical burns from ultraviolet radiation

protective front.

(UVR), infrared radiation, and intense blue light;

Some guidelines and safety warnings for welding

and irritation and chemical burns from fumes

suggest workers should not wear contact lenses, even

and chemicals.

though there does not appear to be any research that

To help in reducing eye injuries, you should educate

would support such a recommendation. In fact, the

workers about all of the dangers they face and should

National Safety Council, the American Welding Society,

implement an eye protection plan that outlines proper

and the FDA all acknowledge that wearing contact

welding behavior.

lenses while welding is safe and even can provide UV

protection. The only caveat is that contact lenses should

Cumulative Damage Risks

not be used as eye protection in place of safety glasses

or goggles.

All of the most common types of welding (shielded

Once the proper goggles/shields are in hand, you

metal-arc or stick welding, gas metal-arc welding, and

can turn your attention to the type of helmet best suited

oxyacetylene welding) produce potentially harmful

for the job. Published tables are available through the

ultraviolet, infrared, and visible spectrum radiation.

welding helmet vendor or the Internet, which can help

Damage from ultraviolet light can occur very quickly.

you determine the most appropriate lens shade based

Normally absorbed in the cornea and lens of the eye,

on the type of welding and the amperage of the

ultraviolet radiation (UVR) often causes arc eye or arc

welding unit. It is a common misconception that a

flash, a very painful but seldom permanent injury that

darker shade provides more protection against UV.

is characterized by eye swelling, tearing, and pain.

Properly maintained welding helmets, regardless of

While most welding-related eye injuries are

shade, provide 100 percent protection against UV,

reversible, with more than half of injured workers

according to the manufacturers.

Radiational Injuries to the Eye

63

Arc welding helmets can be fixed shade or variable

Now that your workers have the right eye protection

shade. Typically, fixed shade helmets are best for daily

for the job, it is time to implement an ongoing eye

jobs that require the same type of welding at the same

protection plan that ensures they use the equipment

current levels, and variable helmets are best for workers

properly.

with variable welding tasks. Helmet shades come in

Bibliography

a range of darkness levels, rated from 9 to 14 with

1.

Occupational and Environmental Medicine. Joseph

14 being darkest, which adjust manually or

Ladoue and al, last edition.

automatically, depending on the helmet. To determine

2.

Occupational Medicine, Zenz C, 2003.

the best helmet for the job, select a lens shade that

3.

Oshline and Nioshtic database, 2004.

provides comfortable and accurate viewing of the

4.

Precis de Medecine du Travail, Desoille H, Scherrer J,

“puddle” to ensure a quality weld.

Truhaut R, last edition.