1. Mechanical
(a) Penetrating
(i) Direct: lacerations from sharp objects
(ii) Indirect: lacerations from high-impact blunt objects: punch, hard balls and objects, blunt weapons, etc.
(b) Avulsions
2. Thermal
3. Chemical
(a) Vitriolage and domestic or industrial accidents
(b) Chemotherapeutic agents: 5-FU, paclitaxel, docetaxel, etc.
4. Radiation
(a) External beam radiotherapy, IMRT
(b) Beta irradiation (historical)
5. Iatrogenic: multifactorial:
(a) Accidental:
(i) Mechanical (direct (cuts) or indirect (avulsions – aggressive retraction during orbital surgery), false passage, mucosa tear with traumatic probing)
(ii) Thermal (electrocautery, lasers, etc.)
(iii) Chemical (3 b)
(iv) Radiation (4a, b)
(b) Intentional, e.g., punctal or canalicular thermal cautery or surgical closure for dry eye management
Fig. 16.1
Broken glasses in lacrimal trauma
Fig. 16.2
Eyelid and canthal lacerations with underlying NOE fracture
Classification
Lacrimal system trauma may be classified based on anatomical structures involved or the mechanisms of injury. Based on the anatomic structures, it is further classified as bony or soft tissue trauma. Injuries may involve the lacrimal puncta at the eyelid margins; the vertical or more commonly the horizontal component of the canaliculi, usually the lower or the common canaliculus (most frequent); the lacrimal sac; and lastly the bony nasolacrimal canal and nasolacrimal duct (second most frequent). Table 16.1 reflects Wulc and Jordan’s classification of lacrimal drainage system trauma [4, 5].
Clinical Features
As stated above, the frequency of involvement of the lacrimal drainage apparatus structures from most frequent to least frequent is as follows: canaliculus (lower, upper, and bicanalicular), nasolacrimal duct, lacrimal sac, and finally lacrimal puncta.
Most patients are diagnosed based on a high degree of suspicion [8–13]. The general principle of eyelid lacerations is that all eyelid lacerations medial to the puncta involve the canaliculus (canaliculi) until proven otherwise (Fig. 16.3). Thus, the onus is upon the trauma physician or Ophthalmologist to diagnose and plan the management accordingly. Likewise, in all patients with facio-maxillary trauma, an evaluation of the CT scan for evidence of bony nasolacrimal duct disruption (Figs. 16.4, 16.5, and 16.6) should prompt the Ophthalmologist to consider lacrimal irrigation to confirm patency of the drainage system, either immediately before facial fracture repair or after reduction of the NOE fragments but before plating of the involved bones. In the acutely traumatized patient, tearing and fluorescein dye disappearance test are generally unhelpful and unreliable owing to the false-positive results from edema resulting in drainage dysfunction [8–13].
Fig. 16.3
Upper and lower eyelid with medical canthal lacerations
Fig. 16.4
CT scan, axial cut, and bony window, showing a left bony NLD fracture
Fig. 16.5
CT scan and coronal cut showing bony and soft tissue NLD disruption following a blast injury
Fig. 16.6
CT scan, coronal cut, and bony window, showing bilateral bony NLD fracture
After stabilization of the patient to rule out poly trauma, intracranial injury, cervical spine stabilization, and underlying globe injury, a preliminary examination of the medial upper and lower eyelids under magnification/slit lamp and medial canthal region without infiltrative anesthesia is recommended, partly to confirm the diagnosis and also to help identify distal cut end of the canaliculus. Gentle probing under topical anesthesia is usually well tolerated (Fig. 16.7). The classic clinical “calamari ring” sign (Fig. 16.8), a white collagenous ring surrounded by bloodstained soft tissue, is obvious once local hemostasis is secured with ice packs and analgesia prior to examination. This helps counsel patients accordingly and plan treatment. Inexperienced Ophthalmologists may also diagnose a canalicular laceration upon lacrimal irrigation through the puncta (upper and lower separately) when extravasations of the irrigant fluid are visualized, prompting an exploration in the operating room under either local or general anesthesia.
Fig. 16.7
Probing the distal cut end
Fig. 16.8
Calamari sign
Nasolacrimal duct injuries may be either bony duct fractures alone with intact soft tissue duct or obvious disruption of both (Figs. 16.2, 16.5, and 16.6) [3, 14–18]. Following a radiological examination of fine-cut CT from the lacrimal sac fossa down to the inferior turbinate, lacrimal irrigation may be attempted on the operating table after nasal decongestion to confirm the same. Direct visualization of fluorescein either under the inferior meatus or site of disruption is usually aided by a rigid nasal endoscope.
A late diagnosis of disruption of the lacrimal system is made on an asymptomatic patient based on the clinical history, positive fluorescein dye disappearance test, or lacrimal irrigation and probing under topical anesthesia (Fig. 16.7) to confirm the presence of either a soft stop (canalicular obstruction) or hard stop (nasolacrimal duct obstruction). Symptomatic patients often present with wet, teary eye with or without epiphora (overflow) with the constant need to wipe their tears to clear their vision. A Bowman probe or straight lacrimal cannula usually helps confirm the extent and location of the canalicular obstruction. Regurgitation of either clear fluid or mucus with a hard stop usually helps confirm a nasolacrimal duct obstruction. Occasionally mucocele or acute dacryocystitis may be noted late in the course (Fig. 16.9). Not infrequently an obvious scar involving the eyelid margin medial to the punctum and medial canthal area and lateral displacement of the upper or lower puncta are telltale signs of canalicular obstruction.
Fig. 16.9
Acute dacryocystitis following NOE fracture
Diagnostic Evaluation
Apart from clinical examination either at the bedside or at the slit lamp, the following investigations may be indicated based on the presentation. As mentioned earlier, review of CT scans of the face (fine cuts) for evidence of NOE fracture, disruption of the lacrimal sac fossa, and bony nasolacrimal duct down to the inferior meatus is warranted, emphasizing the need for a CT with three-dimensional reconstruction of the whole face in most orbital fractures [3, 14–18]. MRI is contraindicated in the acutely traumatized patient unless magnetizable foreign bodies have been ruled out, for example, gunshot pellets (Fig. 16.10). A CT scan is also useful in patients presenting late with tearing with or without discharge to diagnose the underlying bony deformities including diastasis, nonhealing fractures, and hyperostosis or not infrequently to confirm the location of the metallic plates and screws (Fig. 16.11) which may confound lacrimal bypass surgery. Rarely, a DCG or a CT dacryocystography (CT-DCG) may also be indicated to confirm the site of obstruction and alternative drainage path as well (Fig. 16.12).
Fig. 16.10
CT scan and coronal cut showing numerous gun pellets and disruption of NLD
Fig. 16.11
CT scan, axial cut, and bony window, showing titanium screws near NLD
Fig. 16.12
DCG showing a right distal NLD obstruction
Management
Canalicular Lacerations
The driving principle behind managing canalicular lacerations is that wound healing by primary intention (early primary repair) is always better than secondary intention or late repair [8–13]. While in the past the indication for intervention of a monocanalicular laceration was controversial, it is now well recognized by most orbito-facial surgeons that all canalicular lacerations warrant primary repair, whether they are upper or lower. Canalicular laceration repairs are not true emergencies and may be optimally performed in a controlled environment within 24–48 h, although on rare occasions a successful repair may be done as late as 4–5 days. Adequate anesthesia, magnification, and illumination are essential. Most patients with bicanalicular injury (Figs. 16.13 and 16.14) or avulsion injuries (Fig. 16.15) require bicanalicular intubation and thus better performed under general anesthesia. Local anesthetic infiltration in the medial canthal area may distort or disrupt surgical anatomy and may interfere with identification and repair. It may be considered only in simple direct canalicular lacerations or when general anesthetic is either contraindicated or unavailable. Magnification may be either with surgical operating loupes or the operating microscope. The author prefers the operating loupes as they are versatile and adaptable to eyelid, lacrimal, orbital, and facial reconstruction with angulated viewing when necessary, especially in the medial canthal area or within the nasal cavity. The ENT or neurosurgical microscope is often more useful than a vertically oriented ophthalmological microscope for the same reason. Illumination may be either in the form of “headlights” or from the operating microscope.
Fig. 16.13
Bicanalicular laceration
Fig. 16.14
Upper and lower canalicular injury being repaired
Fig. 16.15
Avulsion injury. It is important to rule out underlying fractures
Intubation Systems in Lacrimal Trauma
The intubation systems in lacrimal trauma can be broadly divided into bicanalicular and monocanalicular ones. The advantages and disadvantages of each are summarized in Table 16.2.
Table 16.2
Comparison of bicanalicular and monocanalicular stents
Advantages | Disadvantages | |
|---|---|---|
Bicanalicular stent
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