Childhood glaucoma” is a heterogeneous group of severe paediatric conditions often associated with significant visual loss and characterized by elevated intraocular pressure (IOP) and optic-disk cupping. Successful IOP control is crucial but challenging and most often achieved surgically, with medical therapy playing a supportive role.
There are many classifications of childhood glaucoma, but they can simply be divided into primary, in which a developmental abnormality of the anterior chamber angle only exists, and secondary, in which aqueous outflow is reduced due to independent mechanisms that secondarily impair the function of the filtration angle.
The majority of cases do not have an identified genetic mutation and, where the mutation is known, the genes often account for only a small proportion of cases. Several pathogenetic mechanisms are known to contribute to the development of childhood glaucoma.
Whatever the cause, it results in a reduced aqueous outflow at the level of the trabecular meshwork. Age of onset and magnitude of the elevated IOP largely determine the clinical manifestation the high variability of clinical manifestations.
Glaucoma from any cause in a neonate and infant is characterized by the classic triad of epiphora, photophobia, and blepharospasm, and could be associated with eye enlargement (buphthalmos) and Haab striae. The eye examination, usually performed under general anesthesia, includes: tonometry, anterior-segment examination, gonioscopy, corneal diameter and axial length measurement, dilated fundoscopy with optic-nerve-head evaluation.
Medical therapy, considering the high frequency of side effects, is generally used as temporizing IOP-lowering treatment before surgery or as adjuvant treatment postoperatively in case of partially successful procedures for refractory glaucomas.
Surgery is the nodal point of the management of refractory childhood glaucoma, so it is crucial to opt for a forward-looking strategy to reach the target IOP and minimize the visual loss.
A condition of raised intraocular pressure in early childhood with developmental anomaly of the anterior chamber angle region without any associated abnormality of eye or adnexa, which obstructs the drainage of aqueous humour.
It appears between birth and 4 yrs of age.
Both eyes are usually involved, but to varying severity
Boys are more affected than girls.
Affects 1 in 10,000 births. Failure/abnormal development of the anterior chamber angle and trabecular meshwork during intrauterine development.
Maldevelopment of trabeculum including the iridotrabecular junction (trabeculodysgenesis)
Angle develops from mesodermal tissue
either in the form of failure of resorption of mesodermal sheet or abnormal cleavage of AC angle.
This is responsible for impaired aqueous outflow resulting in raised IOP.
Symptoms:
Photophobia
Blepharospasm
Lacrimation/watering
Signs:
Enlargement of the globe (buphthalmos) is a result of elevated intraocular pressure.
Bluish discoloration patches over sclera
[due to thinning of sclera underlying uveal tissue becomes visible]
Corneal signs
Corneal oedema
Corneal enlargement. (corneal diameter > 13mm)
Tears and breaks in Descemet’s membrane
(Haab’s striae).
Anterior chamber becomes deep.
Iris may show iridodonesis and atrophic patches in late stage.
Lens becomes flat due to stretching of zonules and may even subluxate.
IOP is raised which is neither marked nor acute.
Axial myopia may occur because of increase inaxial length which may give rise to anisometropic amblyopia
Optic disc may show cupping.
Diagnosis
Measurement of IOP with Schiotz or preferably hand held Perkin’s applanation tonometer.
Measurement of corneal diameter by callipers.
Ophthalmoscopy to evalute optic disc.
Gonioscopic examination of angle of anterior chamber reveals trabeculodysgenesis with either flat or concave iris insertion as described in pathogenesis.
Treatment
The treatment is primarily surgical (medical treatment is given temporarily- beta blockers,hyper osmotics, acetazolamide) .
Different surgical procedures (according to the degree of the maldevelopment and the clarity of the cornea)
Goniotomy (85% success)
Trabeculotomy
Trabeculotomy + Trabeculectomy (best results)
Supplemental treatment options are
Medical therapy
Implant surgery
Cyclodestructive procedures
Conclusion
The pediatric eye has its own inherent difficulties. This combined with the failure to report the symptoms, makes these children the most challenging scenarios that the ophthalmologist may encounter. One of the best things about paedtric glaucoma is that changes are reversible if intervention is done at an early stage.
The message heregoes is that parents/caretakers should report to ophthalmologist any child with excessive watering of eyes ,without delay.
Careful diagnosis and timely intervention leads to the most promising outcome and gives these children a long morbidity free life. Once considered virtually untreatable paedtric glaucomas have now become reasonably manageable in most cases.
Disclaimer: The views and opinions expressed in this article are the personal opinions of the author.
The facts, analysis, assumptions and perspective appearing in the article do not reflect the views of GK.
