Paediatrics: Back of the eye problems

Back of the eye problems

Endophthalmitis

Infection within the eye may be endogenous (spread of bacterial or fungal infection from the bloodstream) or exogenous (s to trauma or surgery). Symptoms may vary in severity, but include achy pain, photophobia, float-ers, and loss of vision, the eye is usually red and a pus level within the an-terior chamber (hypopyon) may be seen. Endophthalmitis requires emer-gency ophthalmic referral and management with systemic and intra-vitreal agents to prevent blindness.

Retinopathy of prematurity

This is a fibrovascular proliferative retinal disorder occurring in preterm and low birth weight infants. Its development has been associated with high concentrations of inspired oxygen during the neonatal period. Normal retinal vascularization is not complete until full term. In preterm infants this process is interrupted and, on restart-ing, may proceed abnormally with aberrant and proliferative new vessel formation.

ROP screening 

Infants born <31wks gestation, or weighing <1500g are screened from 6wks of age until the retina has vascularized.

Treatment 

Indirect laser therapy is used in severe cases.

Other medical conditions causing retinopathy

Sickle cell disease

The deformed RBCs in sickle cell disease may cause retinal vascular occlu-sion or ischaemia. A proliferative retinopathy with new vessel formation, or a non-proliferative retinopathy with scarring and fibrosis may develop. Screening is required with laser photocoagulation for new vessel forma-tion.

Diabetes mellitus

Diabetic retinopathy is rarely seen in children with type 1 diabetes and not usually before onset of puberty and teenage years.

Retinitis pigmentosa (RP)

This progressive degenerative disorder of the retina is characterized by typical pigmented retinal appearances. It is an important cause of night blindness, reduced central and peripheral vision, and cataracts. It may occur as an isolated finding or may be part of a systemic disorder.

•   Usher’s syndrome: RP + congenital deafness.

•   Bassen–Kornweig syndrome: RP + abetalipoproteinaemia, ataxia, and malabsorption.

•   Refsum’s disease: RP + polyneuropathy, deafness, and cerebellar dysfunction.

Kearns–Sayre syndrome: RP + ophthalmoplegia, cardiac conduction defect.

Retinal dystrophies

A group of inherited disorders causing rod, cone and/or inner retinal cell dysfunction. Early onset retinal dystrophy may cause blindness in infancy, other forms can cause progressive visual loss during childhood.

Rod dystrophies primarily reduce night and peripheral vision. Cone dystrophies primarily reduce colour vision, central vision, and cause pho-tophobia. Most children are otherwise healthy, but retinal dystrophy can be part of a widespread disorder, e.g. Bardet–Biedl syndrome, Cockayne syndrome, Batten disease, and peroxisomal disorders. Children with early onset SN hearing loss should be referred in order to exclude Usher syn-drome. Supportive help with optical and educational aids has been the mainstay of management in the past, but recent success with gene therapy gives us some optimism for future treatment.

Papilloedema/optic disc swelling

There are many causes of optic disc swelling and the term papilloedema is reserved for optic disc swelling secondary to raised ICP. Visual acuity is usually good initially, but symptoms such as visual obscurations (momen-tary loss of vision when leaning over or coughing) and diplopia secondary to bilateral sixth nerve paresis may occur. If left untreated, the papilloe-dematous nerve will start to become atrophic, initially causing visual field constriction and eventually loss of central and colour vision.

Optic disc drusen are calcific deposits in the optic nerve head that can mimic optic disc swelling. Drusen ‘light up’ on ultrasonography (performed by an ophthalmologist) and this non-invasive test can prevent unnecessary neurological investigation.

Optic neuritis/neuropathy

Inflammation, infiltration, or compression of the optic nerve cause ear-ly loss of central and colour vision. Assessment of optic nerve function should include:

• Visual acuity.

• Visual fields to confrontation (or perimetry if able).

• Colour vision (ask child to compare brightness of red target in one eye to the other).

• Pupil reactions look for a relative afferent papillary defect (Fig. 24.2).

• Visualize the optic disc— it may be swollen or atrophic.