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