Eye injury

Overview
Physical or chemical injuries of the eye can be a serious threat to vision if not treated appropriately and in a timely fashion. The most obvious presentation of ocular (eye) injuries is redness and pain of the affected eyes. This is not, however, universally true, as tiny metallic projectiles may cause neither symptom. Tiny metallic projectiles should be suspected when a patient reports metal on metal contact, such as with hammering a metal surface. Intraocular foreign bodies do not cause pain because of the lack of nerve endings in the vitreous humour and retina that can transmit pain sensations. As such, general or emergency room doctors should refer cases involving the posterior segment of the eye or intraocular foreign bodies to an ophthalmologist. Ideally, ointment would not be used when referring to an ophthalmologist, since it diminishes the ability to carry out a thorough eye examination.

Causes
Flying pieces of wood, metal, glass, stone and other material are notorious for causing much of the eye trauma. Blunt injury by fist (during a drunken brawl), ball (cricket ball, lawn tennis ball), shuttle cock (from Badminton) and other high speed flying objects can strike the eye. Small children may indulge in bow-and-arrow games and firecrackers (respectively common during Dussehra and Diwali festivals in India) which can lead to eye trauma. Road traffic accidents (RTAs) with head and facial trauma may also have an eye injury - these are usually severe in nature with multiple lacerations, shards of glasses embedded in tissues, orbital fractures, severe hematoma and penetrating open-globe injuries with prolapse of eye contents. Other causes of intraocular trauma may arise from workplace tools or even common household implements. Feist RM, Lim JI, Joondeph BC, Pflugfelder SC, Mieler WF, Ticho BH, Resnick K. "Penetrating ocular injury from contaminated eating utensils." Archives of Ophthalmology. 1991 Jan;109(1):23-30. PMID 1987951.

Effects of eye injury

 * Closed globe injury or Non-penetrating trauma: The eye globe is intact, but the seven rings of the eye have been classically described as affected by blunt trauma.
 * Perforating trauma: The globe integrity is disrupted in one place and may be associated with prolapse of internal contents of the eye.
 * Penetrating trauma: The globe integrity is disrupted in two places (through and through injury). This is a quite severe type of eye injury.
 * Blowout fracture of the orbit is caused by blunt trauma, classically described for fist or ball injury, leading to fracture of the floor or medial wall of the orbit due to sudden increased pressure on the orbital contents.

Epidemiology
A recent study estimated that from 2002-2003 there were 27,152 injuries in the United States related to the wearing of eyeglasses. The same study concluded that sports-related injuries due to eyeglasses wear were more common in those under the age of 18 and that fall-related injuries due to eyeglasses wear were more common in those aged 65 or more. Although eyeglasses-related injuries do occur, prescription eyeglasses and non-prescription sunglasses have been found to "offer measurable protection which results in a lower incidence of severe eye injuries to those wearing [them]".

Investigation
The goal of investigation is the assessment of the severity of the ocular injury with an eye to implementing a management plan as soon as is required. The usual eye examination should be attempted, and may require a topical anesthetic in order to be tolerable.

The first step is to assess the external condition of the eye and orbit, and check for perforations, hyphema, uveal prolapse, or globe penetration. If the pupil is teardrop-shaped, and the anterior chamber is flat, this is almost always a perforating injury of the cornea or limbal area.

Depending on the medical history and preliminary examination, the primary care physician should designate the eye injury as a true emergency, urgent or semi-urgent.

Emergency
An emergency must be treated within minutes. This would include chemical burns of the conjunctiva and cornea.

Urgent
An urgent case must be treated within hours. This includes penetrating globe injuries; corneal abrasions or corneal foreign bodies; hyphema (must be referred)' eyelid lacerations that are deep, involve the lid margin or involve the lacrimal canaliculi; radiant energy burns such as arc eye (welder's burn) or snow blindness; or, rarely, traumatic optic neuropathy.

Semi-urgent
Semi-urgent cases must be managed within 1-2 days. They include orbital fractures and subconjunctival hemorrhages.

Irrigation
The first line of management for chemical injuries is usually copious irrigation of the eye with an isotonic saline or sterile water. In the cases of chemical burns, one should not try to buffer the solution, but instead dilute it with copious flushing.

Patching
Depending on the type of ocular injury, either a pressure patch or shield patch should be applied. In most cases, such as those of corneal abrasion or the like, a pressure patch should be applied that ensures some tension is applied to the eye, and that the patient cannot open her or his eye under the patch. In cases of globe penetration, pressure patches should never be applied, and instead a shield patch should be applied that protects the eye without applying any pressure.

Suturing
In cases of eyelid laceration, sutures may be a part of appropriate management by the primary care physician so long as the laceration does not threaten the canaliculi, is not deep, and does not affect the lid margins.

Complications
Multiple complications are known to occur following eye injury: corneal scarring, hyphema, iridodialysis, post-traumatic glaucoma, uveitis cataract, vitreous hemorrhage and retinal detachment. The complications risk is high with retinal tears, penetrating injuries and severe blunt trauma.