Ocular penetrating and perforating injuries

17/11/2016

The eye contains in its interior aqueous humour and vitreous, which are jelly-like fluids, that give the eye shape and allow a correct transmission of light. The wall containing both substances is the sclera, which although thin, has a great resistance.  The anterior chamber of the eye contains the aqueous humour and the posterior chamber the vitreous humour.

The aqueous humour, in addition to nourishing structures, maintains the pressure and consistency of the eye. In general, the eyeball contains three fundamental tissues for vision: the iris, the lens, and the retina. They are extremely delicate and their alteration can seriously compromise visual acuity. In addition, since the inside of the eyeball is sterile, contact with the outside could easily cause an infection.

 Summary anatomy of the eyeball: 1. Cornea. 2. Iris. 3. Crystalline. 4. Zonule. 5. Sclera. 6. Vitreous humour.  

CAUSES

Penetrating injuries by definition penetrate into the eye but not through and through, there is no exit wound. Perforating injuries have both entrance and exit wounds. The most common cause these injuries is trauma, and is the leading cause of severe vision loss in people under 40 years of age. Severe infections or degenerative diseases can also lead to penetrating injuries. Ocular traumatisms are divided into physical or chemical, being the latter of extreme urgency since a quick treatment remarkably improves the visual prognosis. Physical disturbances such as blows or the entrance of material of any kind can have a very varied repercussion: from a slight corneal abrasion that heals in a few hours to the dreaded ocular burst with loss of all structures. When a trauma occurs, you must go as soon as possible to ophthalmological emergency.

HOW ARE THEY TREATED?

When a trauma occurs perforation or penetration must be checked. They are not always evident, especially in small perforations, so a thorough examination and complementary tests such as staining or ultrasound are necessary. It is very important to rule out the presence of foreign bodies by performing imaging tests such as x-rays. While waiting for surgical reconstruction, the eye should be covered with a protector, kept at rest, never put pressure on the eye or eyelids, avoid Valsalva maneuvers (for example, withstand breathing or force it), and do not instil drops or ointments. The performance of the emergency ophthalmologist is a fundamental prognostic factor, both in quickness and in execution ability. In such a situation the surgeon faces an eye where there may be injuries in virtually any ocular tissue, from the cornea to the retina. In the same way there may be strange bodies that are really difficult to extract. The treatment varies greatly depending on the affected structures. In some cases we use biological adhesives or membranes that contain perforation as a patch. In others we make sutures that sometimes are a true filigree, the fruit of hours of work. On the other hand, besides containing the perforation, the complications must be solved: from the replacement of the retina, the removal of hemorrhages, the replacement of the lens or the reconstruction of the iris, among others. Once reconstructive surgery is performed, postoperative complications, especially intraocular pressure that is usually elevated, and other late or progressive complications, which can be treated surgically, such as the appearance of cataracts, should be monitored.

Traumatic cataract.

Once the situation is controlled, the main objective is the recovery of vision, although sometimes it is not easy and requires laser therapy or even corneal transplants.

 Trauma sutures injury repaired with a corneal transplant. 

The main message we give as ophthalmology professionals is prevention. Although most cases are fortuitous, some can be avoided by wearing protective goggles when performing some hazardous work or sports. The second message is that once a trauma happens, it is important to urgently go to an ophthalmological emergency department to perform a rapid diagnosis and treatment, which probably will improve the outcome of this situation.