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Primary Care Ocular Trauma Management

Joseph M. Rappon, OD, MS, FAAO

 

Contents

 

Introduction

Ocular trauma is an unfortunate, yet relatively common condition treated in today’s optometric practice. As primary eye care providers, optometrists must stay up-to-date with current trauma management principles. The content of this course is designed to review common as well as unusual traumatic conditions that may be seen and/or necessarily ruled-out when examining a patient who has sustained trauma. Additionally, the management of each condition will be discussed in detail.

 

After completing this course, if nothing else, it is very important to always keep in mind that patients with seemingly mild ocular traumatic conditions, such as periorbital ecchymosis and subconjunctival hemorrhages, need to be examined very carefully as these events signal to us that the eye and/or orbit has sustained a substantial injury that may have caused more serious problems. Optometrists must be vigilant when examining these patients and remember to document thoroughly and dilate as appropriate. Follow-up is also critical as sequelae from trauma may be more obvious and profound at a later time.

 

1.1 Brief Epidemiology

There are approximately 3 million ocular and orbital injuries in the US per year. Of those injuries, approximately 20,000 to 68,000 are vision-threatening injuries and some 40,000 sustain significant vision loss. In the US, trauma is the leading cause of unilateral blindness and is preceded only by cataract as a cause for vision impairment. Males are much more likely than females to sustain ocular trauma and this is especially true for young males.

In the Beaver Dam Eye Study, 20% of adults reported ocular trauma in their lifetime and these people were 3 times more likely to experience further ocular trauma. In this study, sharp objects caused more than half of all injuries. Surprisingly, the home seems to be more dangerous in terms of traumatic eye injuries than the workplace, but about 23% of all ocular injuries are sports-related. Baseball seems to be the most dangerous sports in terms of these injuries. Interestingly, fishing is the second most dangerous sport with bystanders accounting for 25% of these ocular injuries. Although proven to be effective in saving lives, frontal airbags have caused a two-fold increase in eye injuries related to motor vehicle accidents.

In the US, the frequency of traumatic ocular conditions is as follows:

  • Superficial injury of the eye and adnexa (41.6%)
  • Foreign body on the external eye (25.4%)
  • Contusion of the eye and adnexa (16.0%)
  • Open ocular adnexa and eyeball wounds (10.1%)
  • Orbital floor fracture (1.3%)
  • Nerve injury (0.3%)

 

1.2 Pathophysiology

There are four main mechanisms that cause ocular trauma: coup, contrecoup, equatorial expansion and global repositioning. The coup (pronounced “koo”) is the initial force caused directly by the trauma. The contrecoup is the shockwave that is imparted by the coup and is transmitted throughout the ocular and orbital structures. During blunt trauma, the equator of the globe tends to expand and, therefore, distort the normal ocular architecture. Finally, the globe returns to its normal shape, but this is not always a benign event and can cause damage as well. Keep in mind that this is all occurring to tissues and structures that have varying degrees of elasticity and tensional strength. For example, the sclera is rigid due to collagen fortification and the retina is flexible, but the RPE and Bruch’s membrane are less elastic. These differences in mechanical properties play a major role in ocular trauma pathophysiology.

 

1.3 Classification

In a broad sense, the two main categories that ocular trauma can be divided into are closed and open globe injuries. When examining a patient with trauma, it is imperative to determine which of these categories a patient belongs to as this will direct the immediate management of the patient’s condition. Patients with closed globe injuries have a contusion or a lamellar laceration. Patients with open globe injuries have a rupture or a laceration, with the latter being either a penetrating or perforating injury. While seemingly fairly obvious, differentiating between a closed and open globe injury can be on occasion somewhat difficult.

1.4 Trauma Examination


Of course, the problem-oriented exam is used when examining a patient who may have sustained ocular trauma. The case history should be directed particularly to the details of the trauma, pre-injury vision, previous ocular surgery, medical history, current medications and allergies. If the patient is in significant pain, taking their visual acuity can be difficult. In these cases, instilling a topical anesthetic is often necessary to facilitate this task.

Externals should always include pupillary testing, extra-ocular motilities (EOMs), and confrontational visual field testing. If the patient has sustained blunt ocular trauma, cover test and/or Maddox rod testing should be performed to look for an ocular deviation. Also, the eyelids and orbital margins should be palpated and the forehead and cheeks should be evaluated for sensitivity loss or imbalance.

The slit-lamp examination should include fluorescein staining, which is necessary for Seidel testing and applanation tonometry, but tonometry should always be deferred for any known open globe injuries. A dilated fundus exam, with or without scleral depression when appropriate, is an essential part of the complete examination. Of course, other ancillary tests are sometimes helpful for diagnosing, management and follow-up and include color vision and automated visual field testing, gonioscopy, and imaging studies.