Dacryocystitis

# Overview
Dacryocystitis refers to the inflammation of the lacrimal sac. It is commonly a bacterial infection of the nasolacrimal sac/duct that occurs following partial or complete obstruction within the nasolacrimal duct/sac. It is the most common infection of the lacrimal apparatus, and it is more common in neonates and females above the age of 40 years. Common symptoms of dacryocystitis include epiphora, eye discharge, and the development of a painful lump in the nasolacrimal area. Timely intervention is often required to prevent the spread of infection to adjacent soft tissues which may result in preseptal cellulitis, abscess formation, or even orbital cellulitis in rare cases.

# Anatomy of the Lacrimal System
The lacrimal gland produces tears, and it secretes an approximate volume of 10mL in 24hrs. Tears flow across the eye, draining into the puncta, canaliculi, lacrimal sac, and lacrimal duct into the nasal cavity. The valves within the drainage system are unidirectional, allowing one-way flow of tears only.

# Classification
Dacryocystitis may be classified as:
- Acute- This is an acute inflammation of the lacrimal sac with tenderness and erythema of the overlying tissues
- Subacute
- Chronic- This may be the end stage of acute/subacute dacryocystitis

# Pathophysiology
Dacryocystitis is an inflammation and infection of the lacrimal sac. Dacryocystitis usually occurs following partial/complete obstruction within the nasolacrimal duct or in the lacrimal sac, and it is the most common infection of the lacrimal apparatus. Nasolacrimal duct obstruction can occur in any age group, and it can be congenital or acquired. The lacrimal excretory system drain tears from the eyes into the nasal cavity and its mucous membrane-lined tract are contiguous with the conjunctival and nasal mucosal surfaces which are normally colonized with bacteria. Following the obstruction of the nasolacrimal duct, stasis occurs with the accumulation of tears, desquamated cells, and mucoid secretions, creating an enabling environment for superimposed bacterial infection.
Nasolacrimal duct obstruction
- Congenital obstruction- This occurs in 36% of term infants. The nasal end of the duct is commonly affected, and it can be blocked by epithelial debris or an imperforate mucosal membrane resulting from incomplete canalization of the embryonic duct.
- Acquired obstruction- This can be primary or secondary
- Primary acquired nasolacrimal duct obstruction- seen in idiopathic inflammatory stenosis.
- Secondary acquired nasolacrimal duct obstruction- occurs as a result of trauma, infection, inflammation, neoplasm, or mechanical obstruction.

# Causes
Bacterial Causes- Dacryocystitis is commonly due to a bacterial infection. Bacterial causes include the following:
The most common aerobic organisms
- Staphylococcus species like S. epidermidis, S. aureus
- Streptococcus sp
- Pseudomonas sp
- Pneumococcal species
The most common anaerobic organisms:
- Peptostreptococcus sp
- Propionibacterium sp
- Prevotella sp
- Fusobacterium species
The most common gram-negative bacteria
- Pseudomonas aeruginosa
- Klebsiella sp
- Escherichia coli
- H. influenza
- Enterobacter sp
- Citrobacter sp
Uncommon bacterial causes
- Neisseria sp
- Pantoea sp
- Stenotrophomonas maltophilia
- Proteus mirabilis
Fungal causes- These are rare causes of dacrocystitis.
- Actinomyces sp
- Aspergillus sp
- Candida species
- Sporothrix
- Mucorales fungi
- Fusarium sp
Parasitic causes- Parasites are not a common cause of dacryocystitis. Some parasites that have been documented to cause dacryocystitis include:
- Rhinosporidium seeberi
- Leishmania parasites
Viral causes
- Epstein-Barr virus (EBV)- Viruses such as the EBV are rare causes of dacrocystitis

# Differential Diagnosis
Swellings in the region of the medial epicanthi can occur in the absence of infection. The following conditions can mimic dacryocystitis:
- Dacryocystocele- Blockage of the nasolacrimal duct/sac results in the distension of the lacrimal sac. The distended, uninfected lacrimal sac is often referred to as a dacryocystocele or dacryocele.
- Malignant tumors of the lacrimal sac such as:
- Squamous cell carcinoma
- Adenoid cystic carcinoma
- Oncocytic carcinoma
- Epidermoid carcinoma
- Benign lesions affecting the lacrimal sac such as:
- Papilloma
- Dermoid cysts
- Mucoepidermoid cysts
- Adenoma
- Lymphoproliferative disorders
- Mesenchymal tumors- Mesenchymal tumors of the lacrimal sac is rare, and they include:
- Hemangioma
- Hemangiopericytoma
- Melanoma
- Fibroma
- Fibrous histiocytoma
- Neurilemmoma
- Plexiform neuroma
- Granulomatous diseases affecting the lacrimal sac- e.g Wegener's and sarcoid granulomatosis
- Secondary involvement of the lacrimal sac from cutaneous squamous cell carcinoma and basal cell carcinoma.
- Metastatic disease of the lacrimal sac- This is very rare.

# Epidemiology and Demographics

## Age
Dacryocystitis can occur at any age. However, a bimodal age distribution is frequently observed, with greater incidence in neonates and individuals above 40 years of age. The peak incidence for adults is usually between 60-70years.

## Sex
There is no sex predilection in neonatal dacryocystitis. Dacryocystitis affecting adults commonly affect females more than males.

## Race
Dacryocystitis is more prevalent in whites compared to blacks.

## Geographical Distribution
Dacryocystitis is common in tropical countries like India, especially in people of lower socioeconomic  status.

# Risk Factor
Predisposing factors for dacryocystitis are often factors that result in the obstruction of the nasolacrimal duct/sac, and they include:
- Mucoceles
- Dacryolith
- Enlarged turbinates
- Rhinitis
- Sinusitis
- Adenoids
- Foreign bodies
- Nasal septum deviation
- Nasal septum abscess
- Tumors
- Iatrogenic causes
- Trauma

# Natural History, Complications, and Prognosis

## Natural History
Untreated dacryocystitis does not undergo spontaneous resolution. Dacryocystitis may lead to lacrimal abscess formation and other complications if left untreated. Up to 60% of patients who have an initial attack of dacryocystitis have recurrent attacks of dacryocystitis.  Microorganisms such as Staphylococcus aureus are commonly implicated, probably reflecting a spread from the nasal flora. Development of stones (dacryoliths) may also occur, leading to intermittent attacks of dacryocystitis (acute dacryocystitis retention syndrome).

## Complications
Dacryocystitis can result in the following complications:
- Lacrimal abscess
- Acquired fistula of the lacrimal sac
- Chronic conjunctivitis
- Corneal ulcer
- Preseptal cellulitis
- Endophthalmitis and panophthalmitis if an intraocular surgery is performed in the presence of unrecognized Dacryocystitis.
Rare complications:
- Orbital cellulitis
- Cavernous sinus thrombosis
- Orbital thrombophlebitis
- Complete loss of vision

## Prognosis
With prompt medical intervention, dacryocystitis has an excellent prognosis. The success rate in the treatment of dacryocystitis via surgical procedures is about 90-95%. Patients with acute dacryocystitis who do not eventually undergo surgical procedures such as dacryocystorhinostomy(DCR) frequently have repeat episodes of dacryocystitis. Untreated dacryocystitis never undergoes spontaneous resolution.

# Diagnosis

## History and Symptoms
The history and symptoms of dacryocystitis usually include the following:
- Exquisite pain and erythema in the lacrimal sac region- This is very common in acute dacryocystitis.
- Swelling in the tear sac area
- Conjunctival injection and discharge
- Epiphora- This is a very common symptom in chronic dacryocystitis and it causes social embarrassment due to chronic watering from the eyes.

## Physical Examination
Physical examination findings may reveal the following:
- Palpable, erythematous, tender swelling near the nasal corner of the eye.
- Excessive tearing (epiphora) and purulent discharge from the eye.
- Expression of purulent material via the lacrimal punctum on application of pressure to the inflamed tear duct
- Eyelid swelling if the infection spreads to the anterior orbit.
- Orbital cellulitis if the infection spreads posteriorly to the orbital septum. When orbital cellulitis occurs, globe proptosis/displacement, afferent pupillary defect, ophthalmoplegia, optic neuropathy, and visual loss can be seen.

## Laboratory Findings
- The diagnosis of dacryocystitis is clinical.
- Culture: It is important to perform cultures from samples taken from the infected area. This can help identify the etiological agent and the antimicrobial susceptibility pattern. The best technique for sample collection is via transcutaneous aspiration of the lacrimal sac content. Other methods of sample collection such as obtaining secretions by application of pressure to the lacrimal sac at the level of the lacrimal punctum, and collection of the mucopurulent material found at the bottom of the conjunctival sac, entail a high risk of contamination of the sample.
- Investigations such as nasal endoscopy may be required to inspect the opening of the nasolacrimal duct in the inferior meatus and also diagnose diseases within the nose.

# Treatment

## Medical Treatment
The medical management of dacryocystitis consists of:
- Application of warm compresses.
- Medications for pain relief.
- Empiric systemic antibiotics such as ampicillin-sulbactam, cloxacillin, or cephalosporins, are prescribed with pending results of antimicrobial susceptibility testing.
- Application of broad-spectrum topical antibiotic eyedrop every 4-6hrs in the affected eye.

## Surgical Treatment
- Incision and drainage of lacrimal sac abscess if present.
- Endonasal dacryocystorhinostomy- For the treatment of acute dacryocystitis with abscess formation.
- Dacryocystorhinostomy-  Dacryocystorhinostomy is done after the acute dacryocystitis settles (usually within 2-3weeks). It is also the definitive treatment of chronic or recurrent dacryocystitis. A bypass conduit is utilized to drain the lacrimal sac into the nose during this operation. External or endonasal dacryocystorhinostomy may be done. Endonasal dacryocystorhinostomy is often avoided when there is obstruction in the upper drainage system or the canaliculi are anatomically abnormal.