Chemical and Thermal Injuries





Ravija Patel

Ravija Patel did fellowship in Orbit, oculoplasty and reconstructive services from Sankara Nethralaya, Chennai, India, after having finished graduation from Baroda Medical College, Gujarat, India. She was awarded gold medal for the best outgoing fellow. Being interested in academics as well as clinical practice, currently she is working as assistant professor at M & J Institute of Ophthalmology in Ahmedabad, India.


 




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Bipasha Mukherjee

Dr. Bipasha Mukherjee is a fellow in Orbit & Oculoplasty from Aravind Eye Hospitals, India, and ICO fellow from University Hospital of Limoges, France, under Prof. Jean-Paul Adenis. She has undergone clinical observerships with stalwarts like Jack Rootman, Richard Collins, Geoff Rose, Mark Duffy, and Robert Goldberg.

She currently heads the department of Orbit, Oculoplasty, Aesthetic & Reconstructive services in Medical Research Foundation, Chennai. She has numerous presentations in national and international conferences and publications in peer-reviewed journals and text books. Her areas of interest include diseases of the orbit and adnexa including tumors, lacrimal surgery, socket reconstruction, traumatic lid and adnexal injuries, training residents and fellows, and photography.

 




Introduction


The function of the eyelids is protection of the eyes. Burns to the eyelids may be caused by thermal, electrical or chemical sources, or ionizing radiation. Eyelid burns occur in less than 10 % of all thermal injuries, but are very common in patients with burns involving the face [1]. The loss of an eye primarily from a thermal injury is rare. This is due to protective mechanisms such as the reflex closure of the eyes and Bell’s phenomenon. The initial corneal or ocular surface injury can be quite trivial compared to the injury sustained to the eyelids [2]. Chemical injuries on the other hand usually involve both the ocular surface and the eyelids. The most common sequelae of eyelid burns are ectropion or lid retraction and lagophthalmos. These, if not treated adequately and in timely fashion, may result in exposure keratopathy, corneal ulceration, and ultimately permanent visual impairment. Hence the role of an ophthalmologist and oculoplastic surgeon is vital in the management of these patients.

In thermal injuries, the degree of the injury is a function of two factors: temperature and exposure time. There is an inverse relationship between the intensity of a thermal exposure and the amount of time required to produce a burn. The common causes of thermal burns include fires (flame), liquid thermal burns either with hot water or combustible liquids like gasoline, and exposure to hot gas. While in chemical burns, the extent of injury varies according to the agent: acid burns are usually self-limiting, and alkali burns, on the other hand, cause much more extensive tissue destruction. In electrical burn, the damage is caused as a result of heat and electrical current itself. The amount of damage is related to the intensity of the current, to its voltage, and to the resistance of the areas through which it travels. The characteristic feature of electrical burns is that the damage is progressive [3]. In radiation injury, it is not possible to establish an exact dose-response relationship as it depends on multiple factors like age the of patient, the condition of tissue, any concurrent illness, dose, dose rate, medications, etc. [4].


Classification of the Severity of Thermal Burns (Fig. 7.1)




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Fig. 7.1
Classification of severity of thermal burns


First-Degree Burns


Only the epidermis of the skin is involved resulting in mild erythema of the lids. Edema of the lid may impair eye opening but this is only transient. There is no blister formation. These injuries, though painful, heal usually within 7 days without any residual scar formation. Severe sunburns are the most common first-degree burns (Fig. 7.2a).

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Fig. 7.2
(a) First-degree burns – involvement of the epidermis without blister formation. (b) Second-degree burns – involvement of the epidermis and a part of the dermis. (c) Third-degree burns involving the epidermis and deep dermis with superimposed infection


Second-Degree Burns (Partial-Thickness Burns)


The entire depth of the epidermis and a part of the dermis are involved (Fig. 7.2b). These are usually more painful than first-degree burns. Depending on the depth of the penetration it can be further divided as:


  1. 1.


    Superficial partial thickness: involves the epidermis and superficial papillary dermis. There is erythematous appearance of the skin with blister formation and it is usually associated with edema. It heals within 2 weeks with minimal or no scarring unless it becomes infected; in which case the depth of tissue destruction and inflammation will result in a clinical course more similar to deep partial-thickness or third-degree burns.

     

  2. 2.


    Deep partial thickness: characterized by a pale white or mottled base under the blister. The clinical course varies from minimal tissue shrinkage and good skin healing within 1–3 weeks to significant contracture requiring a release and grafting procedure. Epithelialization occurs in about 14–28 days. Contracture can occur even after epithelialization occurs but slows down considerably. Deep second-degree burns may progress to third-degree burns if there is extension of avascularity in the transition zone between the viable and the nonviable tissue.

     


Third-Degree Burns (Full-Thickness Burns) (Fig. 7.2c)


These involve both the epidermis and the dermis as well as all the regenerative elements. There is little or no pain. The skin is dry and leathery and because of heat coagulation of dermal vessel, the affected tissue is avascular and white. Healing only occurs from the edges and is associated with significant contracture. Early excision of the affected tissue and skin grafting is almost always required to prevent secondary corneal complications.


Fourth-Degree Burns


These are full-thickness burns with destruction of the underlying muscle, bone, and vital structures. Such burns require extensive and complex management and invariably result in severe contracture and prolonged disability.


Early Ophthalmic Evaluation


Life-threatening problems like asphyxia, shock, and associated trauma such as head injury and spinal cord injury if present should be taken care of.

In case of facial burns, ophthalmic evaluation should be done early before the ensuing conjunctival and eyelid edema prevents a detailed examination.

A thorough history should be taken, as early treatment depends on the etiological factor. For example, a chemical burn should be treated by continuous copious irrigation, and thermal injury should be treated by application of cold compresses.

Complete and detailed ophthalmic assessment should be done. The visual acuity should be recorded if possible. The extent and severity of eyelid burns is to be documented. Clinical photographs can be taken for documentation. Presence of eyelashes should be noted as it indicates intact lid margin. Injury to the globe should be ruled out. Fluorescent staining should be done to rule out corneal epithelial defects. If epithelial defect is present along with significant lagophthalmos special mention must be made about the Bell’s phenomenon as it plays an important role in deciding the management. Fundus examination should be performed if possible especially in electrical burns where electrical damage can cause optic nerve and retinal injury and late cataract formation. Computerized tomography (CT) scan may be requested if there is suspicion of orbital or intraocular foreign body.


Initial Management





  1. 1.


    Head elevation helps to reduce the eyelid edema.

     

  2. 2.


    Cool compresses should be given in case of thermal burns.

     

  3. 3.


    Copious continuous irrigation with saline has to be done in cases of chemical burns.

     

  4. 4.


    Foreign bodies and debris should be removed if present.

     

  5. 5.


    Prophylactic lubricating eye drops should be started three to four times a day. In case of patients with epithelial defects, more frequent lubrication should be initiated with prophylactic topical antibiotics providing gram-negative bacterial coverage to prevent corneal infection.

     

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Oct 16, 2017 | Posted by in OPHTHALMOLOGY | Comments Off on Chemical and Thermal Injuries
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