Glaucoma is an eye disease in which the optic nerve progressively gets damaged, often due to intraocular pressure (raised pressure in the eye).
There are several types of glaucoma and most of them affect adults. Congenital glaucoma, however, as the name suggests, affects children.
It is a genetic condition that may be diagnosed at birth or in early childhood. Increased intraocular pressure leads to damage of the structures of the eye, leading to loss of vision.
Although the disease is relatively rare, the impact on visual development and therefore overall quality of life can be extreme. Early recognition and appropriate therapy of congenital glaucoma can significantly improve a child’s future life and vision.
Congenital glaucoma is estimated to occur in one out of every 10,000 births. In Kenya, statistics available from the Ministry of Health show that in 2009, there were 188 children diagnosed with congenital glaucoma.
It has been observed that this condition occurs much more commonly in children born out of consanguineous parentage. This refers to cases where parents are blood relatives, for instance first cousins.
Unlike in adults, where there are often no obvious early symptoms for glaucoma, in children it is fairly easy for parents and health care providers to recognise it. The signs for congenital glaucoma include:
Cloudy large corneas.
Photophobia, which refers to abnormal sensitivity to light.
These symptoms can be picked out right after birth, or in late childhood. The type that occurs in late childhood (between three to 16 years) is referred to as juvenile glaucoma.
There is a need for careful evaluation under general anaesthesia, (EUA) if you suspect that your child has glaucoma. Critical members of the team include a specialist trained in congenital glaucoma care as well as anaesthetists with competency in paediatric anaesthesia.
Under anaesthesia, intra-ocular pressure is accurately measured to establish the extent of damage to the optic nerve as well as other areas and to confirm the diagnosis and grade the severity.
It is also necessary at that time to determine whether the disorder is isolated to the eye(s) or is part of a multisystem general health disorder. If the latter turns out to be the case, then additional specialists may need to be involved.
If confirmed, treatment is mainly through surgery. This is preferably done at the same time as the EUA to reduce the possibility of subjecting the child to multiple sessions of general anaesthesia. The two surgical options that have the highest rates of success based on good evidence are goniotomy and trabeculotomy.
Ask your doctor to explain in detail what these two procedures involve. Early cases do better with goniotomy while trabeculotomy is preferred in advanced cases. Either of these procedures has been shown to have up to a 70 per cent to 90 per cent success rate when performed properly.
The conventional drainage procedure done in adult trabeculectomy has an extremely low success rate in children. If goniotomy and trabeculetomy fail even after repeat treatment, then glaucoma drainage implants surgery, for instance Ahmed Glaucoma Implant, can be used to lower the pressure. This has an encouraging success rate.
It is, therefore, necessary for parents and health care professionals at all levels to recognise and promptly refer affected children for proper evaluation and management. Close follow-up is also important to spot any possible complications and ensure successful treatment.
Dr Dan Kiage is a glaucoma specialist and head of ophthalmology at Aga Khan University Hospital, Nairobi.