Last week was World Glaucoma Week. Glaucoma is usually a disease with no symptoms, and with no change in outward appearance of the eyes, and for this reason alone attempts to raise awareness are critical so that people at risk can be examined, diagnosed and treated.
Glaucoma in young children and babies is different. The initial signs and symptoms are normally apparent for parents, relatives, health care nurses and doctors to see, but because the disease is so uncommon these symptoms are often not recognized. How uncommon is it? The best Australian figures (MacKinnon et al, 2004) suggest 1 case for every 30,000 babies born, but there are variations between ethnic communities. In the UK amongst those less than 16 years old, 0.28/100,000 white British kids had glaucoma, whilst 2.46/100,000 kids of Pakistani origin had glaucoma. 1 in 2500 Saudi children has glaucoma, and in Slovakia a study showed that 1 in 1250 gypsy children had it whilst only 1 in 22,000 non-gypsy children had it. Some of the variation in groups is traditionally explained by increased consanguinity (close relations between families, such as marriage between cousins) and there are certainly differences in the frequency of important genes.
The most important signs of infantile glaucoma are the “classic triad” of tearing, photophobia (light sensitivity) and blepharospasm (screwing the eyelids closed). Tearing is very common in babies and is frequently caused by a blocked tear duct, but this is rarely if ever accompanied by photophobia and blepharospasm.
Infantile glaucoma can also cause the eyeball to be enlarged, most usually seen as an increase in the corneal diameter, and in most cases of infant glaucoma that I’ve seen this was the presenting sign. A normal newborn has a corneal diameter of around 10 – 10.5mm, and an increase in this, especially over 12mm, is highly suspicious. One of my patients had well-meaning admirers comment on her “beautiful big eyes”.
In almost all cases the treatment for childhood glaucoma is surgery. 70 years ago a San Francisco ophthalmologist, Otto Barkan, developed the first successful operation for infantile glaucoma, the goniotomy, by adapting a technique developed by an Italian surgeon De Vincentiis 50 years earlier. This is still one of the two most common treatments for this rare disease, substantially unchanged from his original description (the other procedure, trabeculotomy, is similar in many ways but doesn’t require a clear cornea). Although some children with recalcitrant glaucoma go on to require more invasive surgery, the majority of children with this disease can be managed very well with one of these techniques.
But only if they’re diagnosed.