Chemical injuries in eye

1. By: Dr. Deeksha K
Assistant Professor
Yenepoya (Deemed to be) University
REVIEWED BY : PPT REVIEW COMITTE, YSAHS
CHEMICAL INJURY

2. Specific Learning Objective
Describe the epidemiology and etiology of
chemical burns
Describe the common alkali and acid
substances
Describe about pathophysiology of alkali and
acid burn
Describe about Classification of chemical
injuries
Describe the management of chemical
injuries

3. Chemical injuries
 One of the true ophthalmic emergencies
 Often result in significant ocular morbidity and
generally strike young adults in the prime of
life
 Alkali injuries are more common and can be
more deleterious

4. Epidemiology
 Chemical injuries between 11.5% to 22.1%
ocular traumas
 About 2/3 of these injuries occurs in young
man
 Majority occur in the workplace as a result of
industrial accidents
 A minority of injuries occur in the home or
secondary to assault

5. Etiology
• Alkaline (pH > 7.0)
• Acidic (pH < 7.0)

6. Alkali

7. Acids

8. Alkali
 Lipophilic penetrate tissues more rapidly than
acids
 They saponify the fatty acids of cell membranes
 Corneal stroma and destroy proteoglycan ground
substance and collagen bundles
 Damaged tissues then
secrete proteolytic enzymes which lead to further
damage.

9. Acids
 Acids are generally less harmful than alkali substances
 Cause damage by denaturing and precipitating proteins
in the tissues they contact
 The coagulated proteins act as a barrier to prevent
further penetration
 Except hydrofluoric acid, where the fluoride ion rapidly
penetrates the thickness of the cornea and causes
significant anterior segment destruction

11. History
Severity of ocular injury depends on four factors
 Toxicity of the chemical
 How long the chemical is in contact
 Depth of penetration
 Area of involvement

12.  Critical to take a careful history to document
these factors
 The patient should be asked when the injury
occurred
 Whether they rinsed their eyes afterwards and
for how long
 Type of chemical that splashed in the eye
 It is helpful to obtain the packaging of the
chemical

13. Physical examination
 PH of both eyes should be checked
 If the pH is not in physiologic range
 Eye must be irrigated to bring the pH to an
appropriate range
 It is recommended to wait at least 5 minutes after
irrigation before checking the pH

14.  The physical exam should be used to assess the
extent and depth of injury
 Specifically
Degree of corneal, conjunctival and limbal
involvement should be documented
 The IOP should also be documented, as alkali
injuries cause an elevation of IOP

15. Classification of Chemical
injuries
 Two major classification schemes for corneal
burns
Roper-Hall / Modified
Hughes classification
Dua classification
Roper-Hall classification is based on
the degree of corneal involvement
and limbal ischemia
Based on an estimate of limbal
involvement (in clock hours) and the
percentage of conjunctival
involvement

18. Symptoms
 Severe pain
 Epiphora
 Blepharospasm
 Reduced visual acuity

19. Management
 Regardless of the chemical involved, common
goals of management includes
 Removing the offending agent
 Promote ocular surface healing
 Control inflammation
 Preventing Infection
 Controlling IOP

20. Management
 Irrigation- Immediate management
 Medical therapy
 Follow up

21. Examination and Emergent
management

22. Irrigation
 The goal of irrigation is to remove the offending
substance
 Restore the physiologic pH
 It may be necessary to irrigate as much as 20 liters
to achieve this
 If clean water is available at the site of injury and a
standard irrigating solution is not, then the eyes

23. Medical management
 Patients with mild to moderate injury have a good
prognosis
 Treated successfully with medical treatment alone
 Enhance recovery of the corneal epithelium and
augment collagen synthesis
 Also minimizing collagen breakdown and
controlling inflammation

24. Medical management
 Patients with mild to moderate injury have a good
prognosis
 Treated successfully with medical treatment alone
 Enhance recovery of the corneal epithelium and
augment collagen synthesis
 Controlling inflammation
 Support repair and minimize ulceration
 Adjuvent therapy – braod spectrum antibiotics

25.  Antibiotics- A topical antibiotic ointment like erythromycin
ointment four times daily can be used to provide ocular
lubrication and prevent superinfection
 Stronger antibiotics (e.g. a topical fluoroquinolone) are
employed for more severe injuries (e.g. Grade II and above).
 Cycloplegic agents such as atropine or cyclopentolate can
help with comfort
 Artificial tears- and other lubricating eye drops, preferably
preservative free, should be used generously for comfort
 Steroid drops- In the first week following injury,
topical steroids can help calm inflammation and prevent
further corneal breakdown

26. Other treatments
 Ascorbic acid- fundamental role in collagen
remodeling, leading to an improvement in
corneal healing
 Doxycycline – Antibiotic- reduce ulceration
 Citrate- Promotes corneal wound healing
 Tear substitutes
 Bandage soft contact lenses

27. Surgical
 Debridement of necrotic epithelium
 Amniotic membrane transplantation (AMT)
 Limbal stem cell transplant
 Cultivated oral mucosal epithelial transplantation
(COMET)
 Boston Keratoprosthesis- artificial cornea

28. Grade 1
 Topical antibiotic ointment
 Prednisolone acetate 1% four times a day
 Preservative free artificial tears as needed
 If there is pain, consider a short acting
cycloplegic like cyclopentolate three times a
day

29. Grade 2
 Topical antibiotic drop like fluoroquinolone four
times daily
 Prednisolone acetate 1% hourly while awake
for the first 7-10 days.
 Long acting cycloplegic like atropine
 Oral Vitamin C, 2 grams four times a day
 Doxycycline, 100 mg twice a day (avoid in
children)
 Preservative free artificial tears as needed

30. Grade3
 As for Grade II
 Consider amniotic membrane transplant
Grade 4
 As for Grade II/III
 Early surgery is usually necessary

31. Follow up
 Once the health of the ocular surface has
been restored, follow up can be spread apart
 Long term monitoring for glaucoma and dry
eye.

32. Glaucoma
 The mechanism of glaucoma is multi factorial
and includes
 contraction of the anterior structures
 Inflammatory debris in the trabecular
meshwork
 Damage to the trabecular meshwork itself

33. Dry eye
 Chemical injury can destroy conjunctival goblet cells
 leading to a reduction or even absence of mucus in
the tear film
 Even in well-healed eyes, chronic dry eye can
Discomfort
Visual disturbance
Potential for damage of the ocular surface

34. Damage to the eyelids or
palpebral conjunctiva
 Direct chemical damage to the conjunctiva can
lead to
Scarring
Forniceal shortening
Symblepharon formation
Entropion or ectropion

35. Protection

36. In the eyes of the law
 Under the terms of the 1992 PPE Work
Regulations
 Eye and face protection must be worn in
hazardous areas and employers are required
to provide suitable eye protection to
employees who could be exposed to risk

37. Chemical Splash Protection
 Where chemical splashes and vapour are a
problem
 Full face visors should also be considered -
with chin guards to protect from upward
splashes

38. Goggles
 Primary protectors intended to shield the eyes
against liquid or chemical splash, irritating
mists, vapors, and fumes.

39. Face shields
 Secondary protectors intended to protect the
entire face against exposure to chemical
hazards

40. Over all protection

41. Summary