Congenital nasolacrimal duct obstruction
Ophthalmia neonatorum
How to Treat – Paediatric eye – the first 12 months
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GLAUCOMA is an umbrella term that refers to any condition in which elevated intraocular pressure causes damage to the optic nerve fibres, resulting in a progressive optic neuropathy with loss of peripheral vision, colour vision and ultimately, central vision.
Congenital glaucoma affects approximately 1 in 10,000 babies, and is either sporadic or autosomal dominant. 1 It is due to an inborn anomaly of the usual aqueous outflow pathway. Because the aqueous continues to be produced and the wall of a baby’ s eye is quite pliable, the eye progressively enlarges, causing buphthalmos.
This results in a number of clinical
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signs that are visible to the naked eye. These include enlarged corneas(“ what beautiful big eyes”) and corneal clouding due to a split in one of the deep the corneal layers( Descemet’ s membrane |
splits causing Haab’ s striae). Photophobia and watering occur as a result of the corneal clouding( see figure 4). With specialist ophthalmic equipment, it is also possible to identify the other common |
Figure 4. Bilateral corneal enlargement and clouding in congenital glaucoma. Also note the epiphora from the left eye.
clinical signs: elevated intraocular pressures; thickened corneae; progressive myopia; Haab’ s striae; anatomically anomalous drainage angles; and cupping of the optic discs. Congenital glaucoma is a
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bilateral condition, but the signs are frequently asymmetrical.
The management of congenital glaucoma is surgical: the principle of surgery involves correcting( via a goniotomy or trabeculotomy) or creating( via a trabeculectomy or glaucoma drainage device / tube) a pathway to allow the aqueous to drain out of the eye. Eye drops and systemic medications that lower the intraocular pressure, and laser procedures to reduce the amount of aqueous produced, are also used in the treatment of this condition. Concurrent management of any myopia and amblyopia is important, as is genetic counselling for the family.
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Congenital nasolacrimal duct obstruction
TEARS are made in the lacrimal gland, which lies under the temporal half of each upper eyelid. The tears flow across the ocular surface, aided by blinking. They then drain off the ocular surface though the punctum, into the lacrimal sac and then the nasal cavity via the nasolacrimal duct.
It is common for canalisation of the nasolacrimal duct to be incomplete at the time of birth. This condition can be either unilateral or bilateral.
Because the lacrimal gland does not produce many tears in the first few weeks of life, there may be only very mild signs at first. However, as tear production increases, if there is no open drainage pathway into which the tears can drain, tears will pool on the ocular surface( seen as a‘ high tear film’ or‘ high tear lake’) or run over the lid margin causing epiphora. The constant epiphora results in the eyelashes becoming sticky and matted, and the skin around the eye may become excoriated.
It is common for a sticky yellow discharge to accumulate in the medial corner of the eye, especially after a sleep. This alone does not indicate infection— it is just an accumulation of dried tears and ocular secretions.
Topical antibiotics are not routinely required; they are only required if there is associated infection of the conjunctiva, indicated by a red eye with muco-purrulent discharge that reaccumulates quickly after cleaning it away.
More than 90 % of congenital nasolacrimal duct obstructions resolve spontaneously within the first year of life with conservative treatment. 1 This comprises massage of the lacrimal sac( see box 3 and figure 5).
Those obstructions that do not resolve with conservative treatment may warrant probing of the nasolacrimal duct, usually done between 12 and 24 months of life. This short procedure is performed under a general anaesthetic and is successful in opening the obstruction in around 90 % of uncomplicated cases. 5 If the obstruction recurs after one or more‘ successful’ probings, the nasolacrimal duct may require intubation with silicon tubing. The tubes are left
THOSE OBSTRUCTIONS THAT DO NOT RESOLVE WITH CONSERVATIVE TREATMENT MAY WARRANT PROBING OF THE NASOLACRIMAL DUCT.
Box 3. Lacrimal sac massage for congenital nasolacrimal duct obstruction
• Wash your hands.
• The lacrimal sac lies just below the medical canthus. Imagine a line connecting the sac with the opposite ear.
• Place your index finger over the lacrimal sac and apply pressure in five short, firm bursts towards the opposite ear. This increases the pressure in the sac, forcing fluid down the nasolacrimal duct, which can open the obstruction.
• Repeat this process three times per day or prior to each feed.
• It will cause mild discomfort if you are using the correct pressure. Some parents report feeling a small‘ pop’ when the obstruction opens.
in place to help‘ stent’ the system open for several months, at which stage they can be removed.
It is important to consider and assess for other causes of a watery eye in a neonate, particularly congenital glaucoma— in which the cornea may appear large and cloudy, with concurrent photophobia. It is also important to distinguish congenital from acquired epiphora; acquired epiphora can
Figure 5. Lacrimal sac massage for nasolacrimal duct obstruction.
be a sign of nasal cavity pathology such as craniopharyngioma, allergy or infection.
Complications of congenital nasolacrimal duct obstruction are uncommon. They can include conjunctivitis, a dacryocystocele( a collection of sterile fluid in the lacrimal sac seen as a blue-coloured mass overlying the lacrimal sac in newborn babies) or dacryocystitis( infection in the lacrimal sac).
Ophthalmia neonatorum
OPHTHALMIA neonatorum, or conjunctivitis, in the first 28 days of life, is a medical emergency. It must be treated as an infection acquired from the birth canal until proven otherwise.
The infant requires admission to hospital and treatment is started urgently after the collection of conjunctival swabs. Antibiotic therapy is initially empirical and must cover gonococcus( parenteral ceftriaxone), chlamydia( parenteral or oral erythromycin or azithromycin) and herpes simplex virus if there is a maternal history of the same( intravenous acyclovir). The urgency arises from the potential for life-and sight-threatening complication; gonococcal infection can rapidly progress to corneal perforation and the herpes virus can cause encephalitis in newborns.
Once the microbiology results have identified the causative organism, the treatment can be more accurately directed.
The signs of ophthalmia neonatorum include mucopurulent discharge that reaccumulates quickly after cleaning, ocular redness and lid oedema. Referral of both parents for sexual health screening and counselling is an important part of the management.
20 | Australian Doctor | 28 July 2017 www. australiandoctor. com. au