Ординатура / Офтальмология / Английские материалы / Clinical Ophthalmic Echography_Harrie_2008

TA was a 72-year-old sheepherder who had not received any medical care for a number of years. He presented with complaints of a deep aching pain and double vision. Examination revealed vision in the left eye of 20/40 and 5 mm of proptosis with 4 mm of left globe displacement inferolaterally. His referring ophthalmologist suspected Graves’ disease.

Echography demonstrated a large lesion in the superior nasal left orbit with a prominent bone defect (Figs. 113 and 114). The posterior sinus wall spike was quite deep. Signals from the other paranasal sinuses were detected and the diagnosis of a mucocele and pansinusitis was made. CT scan showed a huge mucocele with erosion intracranially bordered by a thin rim of bone (Fig. 115).

FIG. 113. A-scan of mucocele (arrows)

FIG. 114. B-scan of lesion (arrows)

The nasolacrimal system can also generate A-scan signals if there are abnormalities. When the probe is angled medially and somewhat inferiorly in the direction of the lacrimal sac, it can often be displayed along with the nasolacrimal duct in the normal individual, although the anatomy of this system is better appreciated on immersion B-scan and the course of the duct from the nasolacrimal fossa to the inferior meatus of the nose can sometimes be followed. Multiple A-scan spikes from this area are suggestive of abnormality. Dacriocystitis will result in swelling of the lacrimal sac that can be appreciated on echographic examination. The presence of mucus, stones, polyps, and, rarely, malignant tumors will result in multiple spikes coming from the sac.

CB is a 34-year-old woman who had undergone LASIK refractive surgery 6 years prior to presentation. She experienced symptomatic dry eyes afterwards and punctal plugs were placed in the lower punctae bilaterally with improvement in her symptoms. For the past several months she experienced intermittent tearing and pain in the left eye. There was some tenderness to palpation in the area of the left lacrimal sac. A punctal plug was visible in the right lower punctum but not in the left.

Echography was performed and immersion B- scan using the saline-filled finger of a glove over the probe detected a possible foreign body signal in the area of the nasolacrimal osteum in the inferior outlet of the sac (Fig. 116). This was consistent with migration of the plug with a ball valve obstruction of

the nasolacrimal system. A dacriocystorhinostomy (DCR) was performed and the plug was removed.

Chronic aches and pains around the eyes are quite common with sinus disease as the culprit in many patients, but there are other causes detectable by echography. It is not uncommon for the lacrimal glands to be involved by infectious, inflammatory, or malignant processes.

The probe should be placed in the superotemporal area of the orbit and angled from the orbital rim towards the globe. This procedure should be performed from about the 12:00 position over to 10:30 for the right orbit and 12:00 to 1:30 for the left to encompass the entire lacrimal gland. Normally a medium-to-high reflective structure is seen measuring 9 to 14 mm in the anterior to posterior dimension (Fig. 117).

114

FIG. 117. Normal lacrimal gland (arrows)

Abnormalities should be suspected if the gland is much larger than this, if there is more than 2 to 3 mm asymmetry between the right and left side, or if internal reflectivity is low or low to medium on the A-scan. Also any complaints of tenderness as gentle pressure by the probe is applied supports an abnormality of the lacrimal gland as being causative in the patient’s complaints of orbital pain.

Various inflammatory cells can invade the lacrimal gland as part of an orbital pseudotumor. With modern imaging techniques, the

Case Study 41. Foreign Body in Nasolacrimal Duct

general designation of pseudotumor is usually directed to the specific orbital structure that is involved: myositis with extraocular muscles, dacryoadenitis with the lacrimal gland, optic neuritis with the optic nerve, and posterior scleritis. There may be involvement of one or more of these structures and there are sometimes collections of inflammatory cells in other parts of the orbit giving a masslike effect in the case of an orbital pseudotumor.

The question of lacrimal gland infection versus nonspecific inflammation can only be resolved by biopsy and microscopic study with growth of an organism on culture. It is more practical to document thickening of the gland by echography or CT scan and start the patient on a course of antibiotics. The clinical response then directs further diagnostic and therapeutic efforts.

According to Wright, about 50% of lacrimal infiltrative processes are inflammatory or infiltrative and the other half are due to epithelial tumors, with half of these being malignant epithelial lesions, although other authors25 suggest a higher ratio of nonepithelial processes such as lymphoma. A-scan reflectivity can provide important clues to these entities.

YU is a 65-year-old woman who presented with complaints of chronic pain around her left eye. Examination revealed some tenderness to palpation in the area of the left lacrimal gland. A-scan showed slight enlargement of the gland and the reflectivity was low to medium in the central part (Fig. 118). The diagnosis of probable dacryoadenitis was made and she was given a course of oral antibiotics for a week with resolution of her symptoms and some reduction in size of the lacrimal gland on follow-up echography. She was followed with serial clinical and echographic examinations over a year without recurrence of her symptoms and was demonstrated to have further reduction in the size of the gland.

Lid tics and blepharospasm are very common in clinical practice. Inflammation of the lacrimal gland can sometimes be the cause of these symptoms.

FIG. 118. A-scan of lacrimal gland involved by dacryoadenitis (vertical arrows)

CN is an 18-year-old man who was noted by his parents to “blink excessively” on the left side. He stated that he had only a slight vague discomfort on that side and was not certain why he was repetitively blinking. A-scan examination revealed a lacrimal gland enlarged to 15.35 mm on the left versus 13.2 mm on the right (Fig. 119). It had a medium reflective area and was mildly tender to compression by the probe. He was diagnosed with dacryoadenitis and given a course of antibiotics with resolution of his symptoms over several weeks, although repeat echography revealed slight residual thickening of the gland of 14.4 mm. He was instructed to return for followup in 4 months.

Sjögren’s syndrome is relatively common and lacrimal gland dysfunction is correlated to an invasion of the tissue by inflammatory cells. A-scan examination of the lacrimal gland in these patients can be helpful in demonstrating thickening and areas of

low reflectivity within the gland. However, the gland in more mild cases of Sjögren’s syndrome often appears unremarkable on echographic evaluation.

FIG. 119. A-scan of inflamed lacrimal gland (vertical arrow)

DA was a 42-year-old woman with a history of rheumatoid arthritis. She complained of scratchy, red eyes and used artificial tears sporadically. A-scan revealed a borderline thickened lacrimal gland with some irregular reflectivity with a central medium reflective area (Fig. 120). The situation was discussed with her and she increased her use of artificial tears and was started on Restasis with resultant reduction of inflammation in the gland with increased tear production.

Sarcoidosis can involve the lacrimal gland and may be difficult to diagnose because of its varied clinical presentations. It is stated that about 8% of patients with sarcoidosis will have lacrimal gland involvement.25a It affects the eye and orbit in about 20% of cases and can result in episcleritis, scleritis, iritis, vitritis, retinal vasculitis, and optic neuritis. The incidence of paraocular involvement is less well defined as the symptoms can be subtle and orbital imaging studies are not often performed.

FIG. 120. A-scan of lacrimal gland in Sjögren’s syndrome (vertical arrows)

A-scan can supply helpful diagnostic information by demonstrating lacrimal gland enlargement with low-to-medium areas of internal reflectivity.

CS is a 54-year-old woman who had a history of uveitis 8 years previously. She had a mild chronic cough and had a “normal” chest x-ray in the last year. A-scan examination of the lacrimal gland showed bilaterally enlarged lacrimal glands with areas of medium internal reflectivity (Fig. 121). Sarcoidosis was included in the differential diagnosis and she was referred for a chest CT that revealed enlarged perihilar lymph nodes consistent with sarcoidosis. A bronchial endoscopic biopsy confirmed the diagnosis.

Benign mixed cell tumors or pleomorphic adenomas are responsible for about 25% of epithelial tumors of the lacrimal gland. These tumors are not truly benign because of the fact that they can be converted into locally invasive and potentially lethal malignancies by incomplete biopsy. An en bloc excision must be performed with the removal of all the involved part of the lacrimal gland. A-scan is quite helpful in this situation by alerting the surgeon to the possibility of a pleomorphic adenoma and the

FIG. 121. A-scan of lacrimal gland in sacrcoidosis (vertical arrows)

need to plan an appropriate surgical approach. The reflectivity pattern is medium-to-high reflective with a decrease in the average internal spike height from the anterior to the posterior part of the lesion (angle kappa) as described by Ossoinig.

SS noted some prominence of her right eye with mild discomfort over several months. Examination found 2 mm of proptosis on the right side and mild inferior displacement of the globe. A-scan demonstrated a medium-to-high reflective, welloutlined lesion in the superior temporal orbit. A significant angle kappa was demonstrated with the initial part of the lesion noted to be high reflective, which uniformly decreased to medium height in the midto posterior part of the tumor (Fig. 122). It was rather firm and nontender upon compression by the probe. There was some molding of the bone but no bone defect was detected. A diagnosis of probable benign mixed cell tumor of the lacrimal gland was made and an en bloc excision later confirmed this.

These tumors can be confused on A-scan with cavernous hemangiomas of the orbit. The reflectivity pattern is cavernouslike (alternating high and

FIG. 122. A-scan of pleomorphic adenoma (arrows) kappa (arrows)

FIG. 123. Microscopic structure of cavernous hemangioma

low-medium spikes) in both lesions. In cavernous hemangiomas this is due to the cystic spaces filled with stagnant blood with minimal flow (Fig. 123). The sound beam strikes the septae between bloodfilled cavities and becomes high reflective. It starts to decrease in height of reflectivity as it passes through the homogenous blood, but soon hits other septae and becomes high again. This repetitive pattern of high and low spikes as it passes through the tumor gives a characteristic honeycomb or cavernous A-scan pattern (Fig. 124).

A similar pattern is seen in benign mixed cell lacrimal tumors because of the tissue structure of solid homogeneous populations of cells with con-